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38 results on '"Mécanique des Matériaux et des Structures (M2S)"'

1. Failure analysis of masonry wall panels subjected to in-plane and out-of-plane loading using the discrete element method

Author: Sarhosis, T-T Bui, Ali Limam, Mécanique des Matériaux et des Structures (M2S), Géomécanique, Matériaux et Structures (GEOMAS), Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA), Département Génie Civil et Urbanisme (GCU), School of Engineering [Newcastle], and Newcastle University [Newcastle]
Subjects: Environmental Engineering, [SDE.IE]Environmental Sciences/Environmental Engineering, business.industry, in-plane loading, 0211 other engineering and technologies, 02 engineering and technology, Structural engineering, Masonry, Discrete element method, Out of plane, In plane, Block (telecommunications), 021105 building & construction, wall, discrete element method, out-of-plane loading, business, Brickwork, Geology, 021101 geological & geomatics engineering, Civil and Structural Engineering
Abstract: International audience; This paper aims to evaluate the ability of the Discrete Element Method (DEM) to accurately predict the mechanical behavior of modern brickwork and concrete block masonry wall panels subjected to in-plane and out-of-plane loading. The efficiency of the DEM is based on the suitability of the DEM models to predict the development and propagation of cracks up to collapse, the associated stress distributions and the ultimate load carrying capacity of masonry wall panels subjected to external loading. Numerical results are compared with experimental ones obtained from large-scale tests carried out in the laboratory. A good agreement between the numerical and the experimental results were obtained, which confirms the efficiency and robustness of the DEM to simulate the in-plane and out-of-plane non-linear behavior of modern masonry wall panels. Moreover, a collection of verified material parameters is provided to be used by other researchers and engineers to develop reliable computational models and understand the mechanical behavior of masonry structures. Finally, computational results from this study can help prevent engineering failures and provide reference for stakeholders devising strategies for improving risk management and disaster prevention in masonry structures.
Published: 2019
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2. Nonlinear dynamic simulation of cable based structures interacting with sliding objects using the concept of macro element

Author: Franck Bourrier, David Bertrand, Stéphane Grange, Thomas Langlade, Mécanique des Matériaux et des Structures (M2S), Géomécanique, Matériaux et Structures (GEOMAS), Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA), Erosion torrentielle neige et avalanches (UR ETGR (ETNA)), Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), INSA Lyon, European Commission, and Region Auvergne-Rhone-Alpes
Subjects: Mechanical equilibrium, Computer science, Truss, 02 engineering and technology, law.invention, FEM and DEM, 0203 mechanical engineering, law, General Materials Science, Macro, business.industry, Applied Mathematics, Mechanical Engineering, Structural engineering, Macro finite element, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Discrete element method, Finite element method, Mechanical system, Dynamic simulation, 020303 mechanical engineering & transports, Mechanics of Materials, [SPI.MECA.STRU]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Structural mechanics [physics.class-ph], Modeling and Simulation, Bending stiffness, Structural dynamics, [SPI.GCIV.DV]Engineering Sciences [physics]/Civil Engineering/Dynamique, vibrations, [SPI.GCIV.STRUCT]Engineering Sciences [physics]/Civil Engineering/Structures, 0210 nano-technology, business, Cable
Abstract: International audience; This paper presents the formulation of a finite element enclosing a specific internal mechanical equilibrium in order to model cable-based structures in dynamics conditions. It is based on the concept of macro finite element which allows embedding complex mechanical systems solved inside the element boundaries. A significant advantage is to allow an easy implementation within classical commercial codes. The proposed macro finite element describes a cable interacting with a sliding object assimilated to a punctual mass where friction can be accounted for. The dynamic response is described by a model developed within the framework of the DEM (Discrete Element Method) where geometrical nonlinearity (large displacements) is considered. A model combining the proposed macro finite element and a classical linear truss finite element is presented in order to validate its implementation. Finally, illustrative examples are presented. First, a cable yarning system is considered. The effect of friction and of the bending stiffness of the posts on the overall kinematics and force within the system are explored. Then the vulnerability of a cable-stayed bridge to earthquake is explored accounting for guy ropes failure.
Published: 2021
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3. Dynamic discrete element modelling for seismic assessment of rammed earth walls

Author: T.T. Bui, Quoc-Bao Bui, Ali Limam, Laboratoire Optimisation de la Conception et Ingénierie de l'Environnement (LOCIE), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Ton Duc Thang University [Hô-Chi-Minh-City], Département Génie Civil et Urbanisme (GCU), Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA), Mécanique des Matériaux et des Structures (M2S), Géomécanique, Matériaux et Structures (GEOMAS), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), and This research is funded by Vietnam National Foundation for Science and Technology Development (NAFOSTED) under grant number 107.01-2017.22.
Subjects: Seismic behaviour, [SDE.IE]Environmental Sciences/Environmental Engineering, business.industry, Rammed earth, 0211 other engineering and technologies, Discrete element modelling, 020101 civil engineering, 02 engineering and technology, Structural engineering, Physics::Geophysics, 0201 civil engineering, Time history analysis, Seismic assessment, 021105 building & construction, 11. Sustainability, Formwork, Lack of knowledge, Element (category theory), business, Embodied energy, Geology, Civil and Structural Engineering
Abstract: International audience; Rammed earth (RE) is a construction material which is manufactured by compacting the soil within a formwork, in superimposed layers. RE is attracting scientific studies because of its sustainable properties : a very low embodied energy and an advantageous living comfort due to a particular benefic hygro-thermal behaviour. Numerous studies have been conducted to investigate RE material and RE structures, however, a lack of knowledge on the seismic performance of RE buildings is noticed. This paper presents an advanced numerical study to investigate the in-plane seismic behaviour of RE walls. First, a numerical model of an in-situ RE wall was constructed by using discrete element modelling (DEM). The relevancy of the numerical model was verified by comparing dynamic properties of the model with that measured on the in-situ wall. Then, a real earthquake excitation was applied to the model, in order to evaluate the seismic performance of the RE wall studied. This is the first time, to our knowledge, that a dynamic discrete explicite analysis was performed for a RE wall. The excitation was scaled at different amplitudes to assess the damages following different earthquake intensities. The results showed that for seismic excitations lower than 2.3 m/s2, RE walls studied had satisfying in-plane earthquake performance.
Published: 2018
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4. Tightening Torque Influence on Pullout Behavior of Post-installed Expansion Anchors

Author: Fabien Delhomme, Nicolas Rouane, Bertrand Pallud, Mécanique des Matériaux et des Structures (M2S), Géomécanique, Matériaux et Structures (GEOMAS), Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA), and Hilti France
Subjects: pullout test, Load capacity, anchor, business.industry, 0211 other engineering and technologies, 020101 civil engineering, 02 engineering and technology, Structural engineering, Reinforced concrete, creep, 0201 civil engineering, [SPI.GCIV]Engineering Sciences [physics]/Civil Engineering, Tension response, 021105 building & construction, concrete, Torque, prestress, [SPI.GCIV.STRUCT]Engineering Sciences [physics]/Civil Engineering/Structures, business, Slipping, Geology, Civil and Structural Engineering
Abstract: International audience; Post-installed anchors in reinforced concrete structures are increasingly important in current constructions especially in repair or upgrading works. A research program was completed to determine the influence of the tightening torque and the anchorage depth on the pullout performances of torque-controlled expansion anchors. The diameter d of the tested anchors was 10 mm. Six configurations were tested on 18 concrete blocks. Three pre-tension loads and two anchorage depths were considered. The results show that the fastening torque has no influence on the load-bearing capacity far away from the edges. However, an increase of the torque leads to a decrease of the anchor’s slipping during pullout tests. Nevertheless, applying an excessive fastening torque may lead to a steel-rupture of the anchor during the fastening phase. An increase of the anchorage depth leads to a better load capacity of the anchor and reduces the risk of concrete cone rupture. Finally, a simplified model of the tension response of the anchor with a bilinear load-displacement relationship has been suggested.
Published: 2018
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5. Effects of fungal decay on elasticity and damping of small-diameter silver fir logs assessed by the transverse vibration resonant method

Author: Freddy Rey, Jean Baptiste Barré, Franck Bourrier, David Bertrand, Loïc Brancheriau, Ecosystèmes montagnards (UR EMGR), Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), BioWooEB (Cirad-Persyst-UPR 114 BioWooEB), Département Performances des systèmes de production et de transformation tropicaux (Cirad-PERSYST), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad), Mécanique des Matériaux et des Structures (M2S), Géomécanique, Matériaux et Structures (GEOMAS), Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA), BioWooEB (UPR BioWooEB), and Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)
Subjects: K50 - Technologie des produits forestiers, Small diameter, 0211 other engineering and technologies, Larix, Young's modulus, 02 engineering and technology, Plant Science, Industrial and Manufacturing Engineering, 021105 building & construction, Quantitative assessment, General Materials Science, Mathematics, Élasticité, Altitude, Mathematical analysis, Forestry, 04 agricultural and veterinary sciences, Structural engineering, Propriété acoustique, Pseudotsuga menziesii, Transverse plane, symbols, [SPI.GCIV.STRUCT]Engineering Sciences [physics]/Civil Engineering/Structures, Damping ratio, Vibration, Bois, Carie du bois, symbols.namesake, [SPI.GCIV.RISQ]Engineering Sciences [physics]/Civil Engineering/Risques, J12 - Manutention, transport, stockage et conservation des produits forestiers, Elasticity (economics), Propriété physicochimique, 040101 forestry, business.industry, Grume de sciage, Montagne, Pinus, Champignon pathogène, Abies alba, Transverse vibration, Propriété mécanique, 0401 agriculture, forestry, and fisheries, [SPI.GCIV.DV]Engineering Sciences [physics]/Civil Engineering/Dynamique, vibrations, business
Abstract: A number of studies have shown the ability of the vibration resonant method (VRM) to measure the modulus of elasticity (MOE) and the damping ratio ( $$\xi$$ ) of calibrated wooden samples of various dimensions. This method based on free transverse vibrations was also studied to assess the decay extent in small stakes. Nevertheless, a need for investigations was identified in order to apply the method to decayed logs. Both decay and geometrical singularities brought heterogeneity not taken into account by the VRM. The aim of this study was to examine the effects of fungal decay on these two mechanical properties of small-diameter silver fir logs using the VRM. Fifty-five small-diameter logs were monitored over a decay process taking place in a greenhouse located near Grenoble (France). The MOE and $$\xi$$ were measured in intact and decayed states. The results showed the reliability of the measurements of both properties. $$\xi$$ was found to be independent of moisture content for wood above the fibre saturation point. The results validated the loss in MOE and the gain in $$\xi$$ due to fungal activity. Thus, indicators based on the MOE and $$\xi$$ were proposed and compared to quantify the decay extent. Indicators calculated from the first mode of vibration appeared to be relevant for that purpose. Future work is needed to validate indicators on structural size logs and to compare this quantitative assessment to those obtained by the standard EN 152 that currently serves as a benchmark.
Published: 2017
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6. Influence of uniaxial tension and compression on shear strength of concrete slabs without shear reinforcement under concentrated loads

Author: S. Abouri, T. Roure, B. Tedoldi, W.S.A. Nana, T.T. Bui, Ali Limam, Mécanique des Matériaux et des Structures (M2S), Sols - Matériaux - Structures, Intégrité et Durabilité (SMS-ID), Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA), EDF-DIN-SEPTEN, Division GS - Groupe Enceintes de confinement, parent, and Département Génie Civil et Urbanisme (GCU)
Subjects: Axial forces, Materials science, 0211 other engineering and technologies, Uniaxial tension, 020101 civil engineering, 02 engineering and technology, 0201 civil engineering, Concentrated load, 021105 building & construction, Ultimate tensile strength, General Materials Science, Geotechnical engineering, Slab, Civil and Structural Engineering, Shrinkage, T-beam, business.industry, Shear, Building and Construction, Shear reinforcement, Structural engineering, Compression (physics), Experiments Tension, [SPI.GCIV]Engineering Sciences [physics]/Civil Engineering, Tension, Shear (geology), business, Concrete
Abstract: Under the shear load, reinforced concrete structures may be simultaneously subjected to the axial tensile or compressive forces due to shrinkage in restrained members, earthquake, tornado, and so on. Until now, no experiment addressing the effect of the uniaxial load on the shear resistance of reinforced concrete slab has been reported in the literature. All the experimental tests found in the literature were conducted on panel and beam (or wide beam) specimens. The current shear design provisions with axial load (ACI 318 and Eurocode 2) were developed based solely on panel and beam tests and not slab tests. Therefore, the current shear design codes applied to slab structures under the effect of axial forces urgently need revision. The present research studies the shear strength tests of slabs under the concentrated load simply supported on four sides. The effect of the tension/compression forces on the shear capacity was studied on full-scale slabs without shear reinforcement, a design similar to the slabs used in nuclear buildings, under a concentrated load near support. Experimental tests were conducted to quantify the shear capacity and the associated failure modes with the influence of axial forces. In this study, a series of seven tests on seven full-scale slabs measuring 4 m × 2.6 m × 0.3 m is presented. The experiments were used to evaluate the pertinence of Eurocode 2 in terms of shear in reinforced concrete slabs with axial load, to compare these results to the AFCEN ETC-C code used for nuclear buildings, and to compare them to the ACI 318 code. The results showed that the axial tension forces equal to 0.28 f ctm (average concrete tensile capacity) reduced the shear capacity up to 30% in the concrete slab experiments conducted.
Published: 2017
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7. Effective inelastic scattering cross-sections for background analysis in HAXPES of deeply buried layers

Author: Risterucci, Paul, Renault, O., Zborowski, Charlotte, Bertrand, D., Torres, A., Rueff, J., Ceolin, D., Grenet, Geneviève, Schneider, C., Tougaard, S., Commissariat à l'énergie atomique et aux énergies alternatives - Laboratoire d'Electronique et de Technologie de l'Information (CEA-LETI), Direction de Recherche Technologique (CEA) (DRT (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), INL - Hétéroepitaxie et Nanostructures (INL - H&N), Institut des Nanotechnologies de Lyon (INL), École Centrale de Lyon (ECL), Université de Lyon-Université de Lyon-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-École Supérieure de Chimie Physique Électronique de Lyon (CPE)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-École Centrale de Lyon (ECL), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), University of Southern Denmark (SDU), Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), Laboratoire de Chimie Physique - Matière et Rayonnement (LCPMR), Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Mécanique des Matériaux et des Structures (M2S), Sols - Matériaux - Structures, Intégrité et Durabilité (SMS-ID), Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA), Technische Physik, Julius-Maximilians-Universität Würzburg (JMU), Université de Lyon-École supérieure de Chimie Physique Electronique de Lyon (CPE)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Campusvej 55, 5230 Odense, Denmark, Julius-Maximilians-Universität Würzburg [Wurtzbourg, Allemagne] (JMU), Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-École Centrale de Lyon (ECL), Université de Lyon-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-École supérieure de Chimie Physique Electronique de Lyon (CPE)-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-École supérieure de Chimie Physique Electronique de Lyon (CPE), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), and Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon
Subjects: Materials science, Hard X-ray photoemission, Annealing (metallurgy), General Physics and Astronomy, Inelastic scattering cross-section, 02 engineering and technology, Inelastic scattering, 01 natural sciences, Spectral line, [SPI.MAT]Engineering Sciences [physics]/Materials, Overlayer, Optics, 0103 physical sciences, Power semiconductor device, [SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics, [PHYS]Physics [physics], 010302 applied physics, Buried interface, [PHYS.PHYS.PHYS-OPTICS]Physics [physics]/Physics [physics]/Optics [physics.optics], business.industry, Scattering, Bilayer, Surfaces and Interfaces, General Chemistry, Photoelectric effect, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Surfaces, Coatings and Films, [SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic, Optoelectronics, 0210 nano-technology, business, Background analysis
Abstract: International audience; Inelastic background analysis of HAXPES spectra was recently introduced as a powerful method to get access to the elemental distribution in deeply buried layers or interfaces, at depth up to 60 nm below the surface. However the accuracy of the analysis highly relies on suitable scattering cross-sections able to describe effectively the transport of photoelectrons through overlayer structures consisting of individual layers with potentially very different scattering properties. Here, we show that within Tougaard’s practical framework as implemented in the Quases-Analyze software, the photoelectron transport through thick (25–40 nm) multi-layer structures with widely different cross-sections can be reliably described with an effective cross-section in the form of a weighted sum of the individual cross-section of each layer. The high-resolution core-level analysis partly provides a guide for determining the nature of the individual cross-sections to be used. We illustrate this novel approach with the practical case of a top Al/Ti bilayer structure in an AlGaN/GaN power transistor device stack before and after sucessive annealing treatments. The analysis provides reliable insights on the Ti and Ga depth distributions up to nearly 50 nm below the surface.
Published: 2017
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8. Pneumonia in acute ischemic stroke patients requiring invasive ventilation: Impact on short and long-term outcomes

Author: Sybille Merceron, Mouhamed Djahoum Moussa, Yves Cohen, Hatem Kallel, P. Enguerrand, N. Brule, S. Guessens, C. Ouisse, Elie Azoulay, Elisabeth Coupez, J. Bohe, A. Mouaci, Maité Garrouste-Orgeas, Eric Mariotte, Martin Cour, V. Deiler, L. Ferrand, M. Simon, Shidasp Siami, Jean-Ralph Zahar, M. Nouacer, M. Lugosi, Jean-Pierre Quenot, I. Theodose, Gilles Troché, Christophe Adrie, Aguila Radjou, Guillaume Lacave, Antoine Gros, D. Maugars, S. Bekkhouche, Steven Grangé, O. Zambon, T. Hissem, Romain Sonneville, C. Cheval, J. Carvelli, A. Haouache, F. Lecorre, Romain Hernu, Benoit Misset, C. Ara-Somohano, A. Vesin, J. Fournier, Benjamin Sztrymf, K. Mellouk, C. Bretonniere, L. Dopeux, Marie Thuong, V. H. T. Ha, M. Lebrazic, Corinne Alberti, V. Gobert, S. Letrou, Roland Smonig, Claire Dupuis, Marc Gainnier, Sébastien Bailly, J. F. Timsit, Fabrice Bruneel, H. Merle, Michael Darmon, Mélanie Adda, Marion Venot, C. Tournegros, S. Salle, Bernard Allaouchiche, D. Boyer, Jean-Marie Forel, Bruno Mourvillier, Alexandre Lautrette, N. Kaddour, P. Andreu, Daniel da Silva, Olivier Andremont, G. Thierry, Jordane Lebut, T. Baudry, V. Vindrieux, J. Reignier, L. Nicolet, A. Francais, Anne-Sylvie Dumenil, G. van der Meersch, D. Nakache, Mathilde Neuville, Benjamin Planquette, François Philippart, C. Aparicio, S. Bagur, Laurent Papazian, Bertrand Souweine, François Barbier, Virginie Lemiale, J. Bedel, C. Garret, Guillaume Marcotte, Johanna Oziel, C. Agasse, Sebastien Jochmans, Dany Toledano, Mathilde Lermuzeaux, J. B. Joffredo, N. Viguier, Jean Pierre Bedos, J. Bourenne, A. Van-Nieuwenhuyze, Carole Schwebel, Lila Bouadma, Outcomerea Study Grp, F. Lamara, Etienne de Montmollin, B. Berthe, Stéphane Ruckly, Christophe Clec’h, Eric Magalhaes, Laurent Argaud, Cardiovasculaire, métabolisme, diabétologie et nutrition (CarMeN), Institut National de la Recherche Agronomique (INRA)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Hospices Civils de Lyon (HCL)-Institut National de la Santé et de la Recherche Médicale (INSERM), Department of Geology and Applied Geology, University of Mons [Belgium] (UMONS), Mécanique des Matériaux et des Structures (M2S), Géomécanique, Matériaux et Structures (GEOMAS), Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA), Université de Lyon-Institut National des Sciences Appliquées (INSA), Centre Hospitalier Andrée Rosemon [Cayenne, Guyane Française], CHU Gabriel Montpied [Clermont-Ferrand], CHU Clermont-Ferrand, Medical Intensive Care Unit, APHP, Hôpital St-Louis, Paris, France., Infection, Anti-microbiens, Modélisation, Evolution (IAME (UMR_S_1137 / U1137)), Université Paris 13 (UP13)-Université Paris Diderot - Paris 7 (UPD7)-Université Sorbonne Paris Cité (USPC)-Institut National de la Santé et de la Recherche Médicale (INSERM), AP-HP - Hôpital Bichat - Claude Bernard [Paris], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP), Service d'Hépato-Gastro-Entérologie et Nutrition [CHU Limoges], CHU Limoges, Observatoire astronomique de Strasbourg (ObAS), Université de Strasbourg (UNISTRA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), CHU Avicenne, Aix Marseille Université (AMU), Equipe LIPNESS (LNC - U1231) (LIPNESS), Lipides - Nutrition - Cancer [Dijon - U1231] (LNC), Université de Bourgogne (UB)-Institut National de la Santé et de la Recherche Médicale (INSERM)-AgroSup Dijon - Institut National Supérieur des Sciences Agronomiques, de l'Alimentation et de l'Environnement-Université de Bourgogne (UB)-Institut National de la Santé et de la Recherche Médicale (INSERM)-AgroSup Dijon - Institut National Supérieur des Sciences Agronomiques, de l'Alimentation et de l'Environnement, Service de Réanimation Médicale (CHU de Dijon), Centre Hospitalier Universitaire de Dijon - Hôpital François Mitterrand (CHU Dijon), Laboratoire de Chimie Physique - Matière et Rayonnement (LCPMR), Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Centre hospitalier universitaire de Nantes (CHU Nantes), Laboratoire Microorganismes : Génome et Environnement (LMGE), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Université d'Auvergne - Clermont-Ferrand I (UdA)-Centre National de la Recherche Scientifique (CNRS), ESI S.A., Service de Conditionnement des Déchets et Vitrification (SCDV), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), CMI Green Line, Laboratoire Ecologie Fonctionnelle et Environnement (LEFE), Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT), Université Paris Diderot - Paris 7 (UPD7), Centre Hospitalier de Versailles André Mignot (CHV), CHU Pitié-Salpêtrière [AP-HP], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU), Département de Biostatistiques [Paris], Hôpital Edouard Herriot, Service Anesthésie Réanimation, Hopital Civil, Hôpital Edouard Herriot [CHU - HCL], Hospices Civils de Lyon (HCL)-Hospices Civils de Lyon (HCL), Institut de Chimie de Clermont-Ferrand (ICCF), SIGMA Clermont (SIGMA Clermont)-Institut de Chimie du CNRS (INC)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS), Centre Hospitalier Lyon Sud [CHU - HCL] (CHLS), Hospices Civils de Lyon (HCL), CIC - CHU Bichat, Institut National de la Santé et de la Recherche Médicale (INSERM), Hospices Civils de Lyon (HCL)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Institut National de la Recherche Agronomique (INRA), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Université de Bourgogne (UB)-AgroSup Dijon - Institut National Supérieur des Sciences Agronomiques, de l'Alimentation et de l'Environnement-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Bourgogne (UB)-AgroSup Dijon - Institut National Supérieur des Sciences Agronomiques, de l'Alimentation et de l'Environnement-Institut National de la Santé et de la Recherche Médicale (INSERM), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Centre National de la Recherche Scientifique (CNRS)-Université d'Auvergne - Clermont-Ferrand I (UdA), Laboratoire Ecologie Fonctionnelle et Environnement (ECOLAB), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique du Globe de Paris (IPGP), Centre National de la Recherche Scientifique (CNRS)-Université de La Réunion (UR)-Université Paris Diderot - Paris 7 (UPD7)-IPG PARIS-Institut national des sciences de l'Univers (INSU - CNRS), Neuropsychopharmacologie, Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Pierre et Marie Curie - Paris 6 (UPMC), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Hospices Civils de Lyon (HCL), Hopital central Cayenne, CHU Gabriel Montpied (CHU), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Paris 13 (UP13)-Université Paris Diderot - Paris 7 (UPD7)-Université Sorbonne Paris Cité (USPC), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées, Institut national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS), Centre Hospitalier de Versailles (CHV), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de la Santé et de la Recherche Médicale (INSERM), Assistance publique - Hôpitaux de Paris (AP-HP) (APHP), Institut de Chimie de Clermont-Ferrand - Clermont Auvergne (ICCF), and Sigma CLERMONT (Sigma CLERMONT)-Université Clermont Auvergne (UCA)-Centre National de la Recherche Scientifique (CNRS)
Subjects: 0301 basic medicine, Male, Epidemiology, medicine.medical_treatment, consequences, [SDV]Life Sciences [q-bio], multicenter, law.invention, sepsis, 0302 clinical medicine, Mechanical ventilation, onset pneumonia, law, icu, 030212 general & internal medicine, Hospital Mortality, risk-factors, Stroke, withdrawal, Middle Aged, Prognosis, Intensive care unit, 3. Good health, Intensive Care Units, Infectious Diseases, Treatment Outcome, Female, France, Cohort study, Microbiology (medical), medicine.medical_specialty, 030106 microbiology, Sepsis, 03 medical and health sciences, medicine, Humans, Mortality, intensive-care-unit, Aged, business.industry, Proportional hazards model, Glasgow Coma Scale, Pneumonia, Length of Stay, medicine.disease, Respiration, Artificial, Critical care, Emergency medicine, business
Abstract: International audience; Objectives: To describe the epidemiology and prognostic impact of pneumonia in acute ischemic stroke patients requiring invasive mechanical ventilation. Methods: Retrospective analysis from a prospective multicenter cohort study of critically ill patients with acute ischemic stroke requiring invasive mechanical ventilation at admission. Impact of pneumonia was investigated using Cox regression for 1-year mortality, and competing risk survival models for ICU mortality censored at 30-days. Results: We included 195 patients. Stroke was supratentorial in 62% and 64% of patients had a Glasgow coma scale score \textless8 on admission. Mortality at day-30 and 1 year were 56%, and 70%, respectively. Post-stroke pneumonia was identified in 78 (40%) patients, of which 46/78 (59%) episodes were present at ICU admission. Post-stroke pneumonia was associated with an increase in 1-year mortality (adjusted HR 1.49, 95% CI [1.01-2.20]). Post-stroke pneumonia was not associated with ICU mortality but was associated with a 1.6-fold increase in ICU length of stay (CSHR 0.62 [0.39-0.99], p = 0.06). Conclusions: In ischemic stroke patients requiring invasive ventilation, pneumonia occurred in 40% of cases and was associated with a 49% increase in 1-year mortality. Post-stroke pneumonia did not impact day-30 mortality but increased ICU length of stay. (C) 2019 The British Infection Association. Published by Elsevier Ltd. All rights reserved.
Published: 2019
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9. Assessing the Seismic Behavior of Rammed Earth Walls with an L-Form Cross-Section

Author: Thi-Loan Bui, Hoang-An Le, Mai-Phuong Tran, T.T. Bui, Quoc-Bao Bui, Ton Duc Thang University [Hô-Chi-Minh-City], Mécanique des Matériaux et des Structures (M2S), Géomécanique, Matériaux et Structures (GEOMAS), Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA), University of Transport and Communications [Hanoi] (UTC), Ho Chi Minh City University of Transport, Department of Civil and Environmental Engineering [Singapore], National University of Singapore (NUS), and This research is funded by the Vietnam National Foundation for Science and Technology Development(NAFOSTED) under grant number 107.01-2017.22.
Subjects: seismic performance, Geography, Planning and Development, 0211 other engineering and technologies, TJ807-830, 020101 civil engineering, 02 engineering and technology, Management, Monitoring, Policy and Law, Plasticity, TD194-195, Renewable energy sources, 0201 civil engineering, Rammed earth, Cross section (physics), 021105 building & construction, GE1-350, Environmental effects of industries and plants, Renewable Energy, Sustainability and the Environment, business.industry, [SDE.IE]Environmental Sciences/Environmental Engineering, finite element modeling, Structural engineering, Finite element method, Environmental sciences, dynamic behavior, Formwork, business, rammed earth, Geology
Abstract: International audience; Rammed earth (RE) is a construction material which is made by compacting the soil in a formwork. This material is attracting the attention of the scientific community due to its sustainable characteristics. Among different aspects to be investigated, the seismic performance remains an important topic which needs advanced investigations. The existing studies in the literature have mainly adopted simplified approaches to investigate the seismic performance of RE structures. The present paper adopts a numerical approach to investigate the seismic behavior of RE walls with an L-form cross-section. The 3D FEM model used can take into account the plasticity and damage of RE layers and the interfaces. The model was first validated by an experimental test presented in the literature. Then, the model was employed to assess the seismic performance of a L-form wall of a RE house at different amplitudes of earthquake excitations. Influences of the cross-section form on the earthquake performance of RE walls were also investigated. The results show that the L-form cross-section wall has a better seismic performance than a simple rectangular cross-section wall with similar dimensions. For the L-form cross-section wall, the damage observed concentrates essentially on the connection between two flanges of the wall.
Published: 2019
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10. A novel identification method for obtaining bending moment–curvature relations of wood stems based on digital image correlation and SDOF analysis

Author: Nicolas Tardif, Franck Bourrier, David Bertrand, Jean-Baptiste Barré, Stéphane Grange, Mécanique des Matériaux et des Structures (M2S), Géomécanique, Matériaux et Structures (GEOMAS), Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA), Laboratoire de Mécanique des Contacts et des Structures [Villeurbanne] (LaMCoS), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), and Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)
Subjects: Digital image correlation, Environmental Engineering, identification method, SDOF model, Scale (ratio), fresh wood, 0211 other engineering and technologies, Young's modulus, 02 engineering and technology, Bending, Curvature, symbols.namesake, bending behavior, 021105 building & construction, [SPI.MECA.MEMA]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Mechanics of materials [physics.class-ph], digital image correlation, 021101 geological & geomatics engineering, Civil and Structural Engineering, Mathematics, business.industry, Structural engineering, Finite element method, symbols, Bending moment, [SPI.GCIV.STRUCT]Engineering Sciences [physics]/Civil Engineering/Structures, business, Beam (structure)
Abstract: International audience; Bending moment–curvature relations (M-χ) are useful in many beam modelling approaches. It allows describing in a simple way the mechanical behaviour at the cross-section scale and can be used to model continuous beams as single degree of freedom systems dedicated to perform stochastic analysis. This paper focused on tree mechanical charaterisation and presents an identification method for obtaining bending moment–curvature relationships up to failure from Digital Image Correlation (DIC) and experimental three points bending tests. Due to wood intrinsic variability, the proposed identification method has been validated from a Finite Element (FE) model which aims at simulating precisely the bending response of a cylindrical stem. The refined FE model has been developed based on the geometry and the boundary conditions of the experimentally tested stems. M-χ curves are derived from the FE model and used within a Single Degree Of Freedom (SDOF) approach. At the stem scale, the prediction of the SDOF model (Force-Displacement) is compared to the FE model and lead to a good agreement. Then the approach is used to characterise fresh European beech samples allowing deriving their mechanical properties (longitudinal Young modulus, modulus of elasticity and modulus of rupture).
Published: 2019
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11. CAPS criteria fail to identify most severely-ill thrombotic antiphospholipid syndrome patients requiring intensive care unit admission

Author: Nicolas de Prost, Romaric Larcher, Damien Contou, Rémi Coudroy, Alain Combes, Zahir Amoura, Laurent Argaud, Pierre Trouiller, François-Michel Beloncle, Jean-Herlé Raphalen, Elie Azoulay, Stanislas Ledochowski, Marc Pineton de Chambrun, Yacine Tandjaoui-Lambiotte, Alexis Mathian, Charles-Edouard Luyt, Auguste Dargent, Alexandre Demoule, Amélie Couteau-Chardon, Steven Grangé, Matthieu Jamme, Aude Gibelin, Vincent Degos, Samuel Gaugain, Frédéric Pène, Stanislas Faguer, Jérôme Devaquet, Jérémie Lemarié, Centre Hospitalier Régional Universitaire [Montpellier] (CHRU Montpellier), Service de Réanimation Médicale, Hôpital Edouard Herriot, Hospices Civils de Lyon, Lyon, France, parent, Cardiovasculaire, métabolisme, diabétologie et nutrition (CarMeN), Institut National de la Recherche Agronomique (INRA)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Hospices Civils de Lyon (HCL), Service de Pneumologie et Réanimation Médicale [CHU Pitié-Salpêtrière] (Département ' R3S '), Assistance publique - Hôpitaux de Paris (AP-HP) (APHP)-CHU Pitié-Salpêtrière [APHP], Neurophysiologie Respiratoire Expérimentale et Clinique, Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Pierre et Marie Curie - Paris 6 (UPMC), Centre hospitalier universitaire de Poitiers (CHU Poitiers), CIC - Poitiers, Université de Poitiers-Centre hospitalier universitaire de Poitiers (CHU Poitiers)-Direction Générale de l'Organisation des Soins (DGOS)-Institut National de la Santé et de la Recherche Médicale (INSERM), Centre National de Référence du Lupus Systémique, Syndrome des Anticorps Anti-phospholipides et Maladies Auto-immunes Systémiques Rares[CHU Pitié Salpêtrière], Service de médecine interne [CHU Pitié-Salpétrière], Institut E3M [CHU Pitié-Salpêtrière], CHU Pitié-Salpêtrière [APHP], Sorbonne Université - Faculté de Médecine (SU FM), Sorbonne Université (SU), Université Paris Diderot - Paris 7 (UPD7), Service de Réanimation Médicale (CHU de Dijon), Centre Hospitalier Universitaire de Dijon - Hôpital François Mitterrand (CHU Dijon), Lipides - Nutrition - Cancer [Dijon - U1231] (LNC), Université de Bourgogne (UB)-Institut National de la Santé et de la Recherche Médicale (INSERM)-AgroSup Dijon - Institut National Supérieur des Sciences Agronomiques, de l'Alimentation et de l'Environnement, Equipe LIPNESS (LNC - U1231) (LIPNESS), Université de Bourgogne (UB)-Institut National de la Santé et de la Recherche Médicale (INSERM)-AgroSup Dijon - Institut National Supérieur des Sciences Agronomiques, de l'Alimentation et de l'Environnement-Université de Bourgogne (UB)-Institut National de la Santé et de la Recherche Médicale (INSERM)-AgroSup Dijon - Institut National Supérieur des Sciences Agronomiques, de l'Alimentation et de l'Environnement, Laboratoire d'Excellence : Lipoprotéines et Santé : prévention et Traitement des maladies Inflammatoires et du Cancer (LabEx LipSTIC), Institut National de la Recherche Agronomique (INRA)-Université Montpellier 2 - Sciences et Techniques (UM2)-Université Paris-Sud - Paris 11 (UP11)-École pratique des hautes études (EPHE)-Institut Gustave Roussy (IGR)-Centre Hospitalier Régional Universitaire de Nancy (CHRU Nancy)-Université de Bourgogne (UB)-Centre Hospitalier Universitaire de Dijon - Hôpital François Mitterrand (CHU Dijon)-Centre Régional de Lutte contre le cancer - Centre Georges-François Leclerc (CRLCC - CGFL)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Fédération Francophone de la Cancérologie Digestive, FFCD-AgroSup Dijon - Institut National Supérieur des Sciences Agronomiques, de l'Alimentation et de l'Environnement-Etablissement français du sang [Bourgogne-France-Comté] (EFS [Bourgogne-France-Comté])-Centre National de la Recherche Scientifique (CNRS)-Centre Hospitalier Régional Universitaire [Besançon] (CHRU Besançon)-Université de Franche-Comté (UFC)-Université de Montpellier (UM), Mécanique des Matériaux et des Structures (M2S), Géomécanique, Matériaux et Structures (GEOMAS), Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA), Université de Lyon-Institut National des Sciences Appliquées (INSA), Laboratoire Sciences Analytiques, Bioanalytiques, et Miniaturisation (LSABM), ESPCI ParisTech-Centre National de la Recherche Scientifique (CNRS), Service de médecine physique et de réadaptation [CHU Pitié-Salpêtrière], Université Pierre et Marie Curie - Paris 6 (UPMC)-Assistance publique - Hôpitaux de Paris (AP-HP) (APHP)-CHU Pitié-Salpêtrière [APHP], Université Pierre et Marie Curie - Paris 6 (UPMC), Physiologie & médecine expérimentale du Cœur et des Muscles [U 1046] (PhyMedExp), Université de Montpellier (UM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Hospices Civils de Lyon (HCL)-Institut National de la Santé et de la Recherche Médicale (INSERM), CHU Pitié-Salpêtrière [AP-HP], Sorbonne Université (SU)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de la Santé et de la Recherche Médicale (INSERM), Centre National de Référence du Lupus Systémique, Syndrome des Anticorps Anti-phospholipides et Maladies Auto-immunes Systémiques Rares [CHU Pitié Salpêtrière], Service de Médecine Interne 2, maladies auto-immunes et systémiques [CHU Pitié-Salpêtrière], Sorbonne Université (SU)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-CHU Pitié-Salpêtrière [AP-HP], Sorbonne Université (SU)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Institut E3M [CHU Pitié-Salpêtrière], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-CHU Pitié-Salpêtrière [AP-HP], Sorbonne Université (SU)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU), Institut National de la Recherche Agronomique (INRA)-Université Montpellier 2 - Sciences et Techniques (UM2)-Université Paris-Sud - Paris 11 (UP11)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut Gustave Roussy (IGR)-Centre Hospitalier Régional Universitaire de Nancy (CHRU Nancy)-Université de Bourgogne (UB)-Centre Hospitalier Universitaire de Dijon - Hôpital François Mitterrand (CHU Dijon)-Centre Régional de Lutte contre le cancer Georges-François Leclerc [Dijon] (UNICANCER/CRLCC-CGFL), UNICANCER-UNICANCER-Institut National de la Santé et de la Recherche Médicale (INSERM)-Fédération Francophone de la Cancérologie Digestive, FFCD-AgroSup Dijon - Institut National Supérieur des Sciences Agronomiques, de l'Alimentation et de l'Environnement-Etablissement français du sang [Bourgogne-Franche-Comté] (EFS [Bourgogne-Franche-Comté])-Centre National de la Recherche Scientifique (CNRS)-Centre Hospitalier Régional Universitaire de Besançon (CHRU Besançon)-Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université de Montpellier (UM), Chimie-Biologie-Innovation (UMR 8231) (CBI), Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-CHU Pitié-Salpêtrière [AP-HP], Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP), Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-CHU Pitié-Salpêtrière [AP-HP], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Institut E3M [CHU Pitié-Salpêtrière], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut Gustave Roussy (IGR)-Centre Hospitalier Régional Universitaire de Nancy (CHRU Nancy)-Centre Hospitalier Régional Universitaire de Besançon (CHRU Besançon)-Université de Bourgogne (UB)-Centre Hospitalier Universitaire de Dijon - Hôpital François Mitterrand (CHU Dijon)-Centre Régional de Lutte contre le cancer Georges-François Leclerc [Dijon] (UNICANCER/CRLCC-CGFL), UNICANCER-UNICANCER-Institut National de la Santé et de la Recherche Médicale (INSERM)-Fédération Francophone de la Cancérologie Digestive, FFCD-Université de Montpellier (UM)-AgroSup Dijon - Institut National Supérieur des Sciences Agronomiques, de l'Alimentation et de l'Environnement-Etablissement français du sang [Bourgogne-Franche-Comté] (EFS [Bourgogne-Franche-Comté])-Centre National de la Recherche Scientifique (CNRS)-Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC), Hospices Civils de Lyon (HCL)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Institut National de la Recherche Agronomique (INRA), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon, and Institut National des Sciences Appliquées (INSA)-Université de Lyon
Subjects: 0301 basic medicine, Adult, Pediatrics, medicine.medical_specialty, [SDV]Life Sciences [q-bio], Immunology, Catastrophic antiphospholipid syndrome, law.invention, 03 medical and health sciences, 0302 clinical medicine, Systemic lupus erythematosus, law, Antiphospholipid syndrome, medicine, Prevalence, Immunology and Allergy, Humans, Intensive care unit, Diagnostic Errors, Catastrophic Illness, Retrospective Studies, 030203 arthritis & rheumatology, business.industry, Microvascular thrombosis, Retrospective cohort study, Mean age, Thrombosis, Middle Aged, medicine.disease, Prognosis, Survival Analysis, 3. Good health, Icu admission, Intensive Care Units, 030104 developmental biology, Antibodies, Antiphospholipid, Female, France, Probability of survival, business
Abstract: International audience; PURPOSE : Catastrophic antiphospholipid syndrome (CAPS), the most severe manifestation of antiphospholipid syndrome (APS), is characterised by simultaneous thromboses in multiple organs. Diagnosing CAPS can be challenging but its early recognition and management is crucial for a favourable outcome. This study was undertaken to evaluate the frequencies, distributions and ability to predict mortality of "definite/probable" or "no-CAPS" categories of thrombotic APS patients requiring admission to the intensive care unit (ICU).METHOD : This French national multicentre retrospective study, conducted from January 2000 to September 2018, included all APS patients with any new thrombotic manifestation(s) admitted to 24 ICUs. RESULTS : One hundred and thirty-four patients (male/female ratio: 0.4; mean age at admission: 45.4+/-15.0 years), who experienced 152 CAPS episodes, required ICU admission. The numbers of definite, probable or no-CAPS episodes, respectively, were: 11 (7.2%), 60 (39.5%) and 81 (53.3%). No histopathological proof of microvascular thrombosis was the most frequent reason for not being classified as definite CAPS. Overall, 35/152 (23.0%) episodes were fatal, with comparable rates for definite/probable CAPS and no CAPS (23% vs. 28.8% respectively, p=0.4). The Kaplan-Meier curve of estimated probability of survival showed no between-group survival difference (log-rank test p=0.5). CONCLUSIONS : In this study, CAPS criteria were not associated with mortality of thrombotic APS patients requiring ICU admission. Further studies are need evaluate the adequacy of CAPS criteria for critically-ill APS patients.
Published: 2019
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12. Enhancement of a two-dimensional multifibre beam element in the case of reinforced concrete structures for taking into account the lateral confinement of concrete due to stirrups

Author: Stéphane Grange, Natalia Khoder, Yannick Sieffert, Mécanique des Matériaux et des Structures (M2S), Géomécanique, Matériaux et Structures (GEOMAS), Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA), Laboratoire sols, solides, structures - risques [Grenoble] (3SR ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Risques, Vulnérabilité des structures et comportement mécanique des matériaux (RV ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), ANR-11-RSNR-0022,SINAPS@,Séisme et Installation Nucléaire -Améliorer et Pérenniser la Sûreté(2011), Laboratoire sols, solides, structures - risques [Grenoble] (3SR), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Risques, Vulnérabilité des structures et comportement mécanique des matériaux (RV), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), and SINAPS@ ANR-11-RSNR-0022,SINAPS@,SINAPS@: Séisme & Installations Nucléaires: Assurer et Pérenniser la Sûreté
Subjects: Environmental Engineering, Materials science, éléments finis, 020101 civil engineering, 02 engineering and technology, stirrups, 0201 civil engineering, 0203 mechanical engineering, Cyclic loading, Civil and Structural Engineering, business.industry, multifibre beam elements, béton armé, Structural engineering, Reinforced concrete, reinforced concrete, Finite element method, Transverse reinforcement, Transverse plane, [SPI.GCIV]Engineering Sciences [physics]/Civil Engineering, 020303 mechanical engineering & transports, aciers transversaux, finite elements, [SPI.GCIV.STRUCT]Engineering Sciences [physics]/Civil Engineering/Structures, business, élément poutre multifibre, Confinement
Abstract: International audience; To assess the seismic vulnerability of existing reinforced concrete structures, a large number of degrees of freedom is involved. Consequently, efficient numerical tools are required. In the case of slender elements, enhanced beam elements have been developed to try to introduce shear effects, but in these models, the transverse steel is sometimes taken into consideration with approximated manner or often not at all. However, as shown by some experimental tests, the amount of transverse reinforcement triggers significantly the behaviour of beam elements, especially under cyclic loading. Thus, the main goal of this work is to investigate solutions for an enhanced multifibre beam element accounting for vertical stretching of the cross section, occurring due to the presence of transverse reinforcement. The efficiency of the proposed modelling strategies is tested with results obtained from tension and flexure tests conducted on an elastic linear material. Moreover, the implementation of stirrups is verified by comparison with analytical analysis.; Pour déterminer la vulnérabilité sismique des structures existantes en béton armé, des méthodes de calcul numérique à l’échelle structurelle efficaces et suffisamment précises sont nécessaires. Dans le cas d’éléments poutres, les recherches actuelles concernent le développement de cinématiques enrichies pour mieux tenir compte de la déformation des sections. A cette échelle, des formulations permettent déjà de reproduire les déformations générées par le cisaillement. En revanche, concernant les cadres d’armatures, soit ils ne sont pas du tout considérés, soit ils ne permettent pas d’établir un véritable équilibre global de la section transversale permettant de calculer le confinement du béton. Cependant, comme le montrent certains essais expérimentaux, la quantité d’armatures transversales pilote d’une manière significative le comportement de ces poutres. Le travail présenté dans cet article propose un modèle poutre multifibre enrichi pour la prise en compte de l’effet de confinement du béton par les armatures transversales. Des déplacements transversaux additionnels permettent d’enrichir la cinématique de la section transversale pour calculer l’équilibre. Le modèle est dans un premier temps validé avec des tests simples et une loi de comportement élastique linéaire pour le matériau composant la section. De plus, l’implémentation des aciers transversaux est validée par une comparaison faite avec une analyse analytique.
Published: 2019
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13. Full-field measurement with a digital image correlation analysis of a shake table test on a timber-framed structure filled with stones and earth

Author: Stéphane Grange, Philippe Garnier, Yannick Sieffert, F. Vieux-Champagne, Laurent Daudeville, Jean-Charles Duccini, Laboratoire sols, solides, structures - risques [Grenoble] ( 3S-R ), Université Joseph Fourier - Grenoble 1 ( UJF ) -Institut National Polytechnique de Grenoble ( INPG ) -Centre National de la Recherche Scientifique ( CNRS ) -Université Grenoble Alpes ( UGA ), CRAterre ( CRAterre ), École nationale supérieure d'architecture de Grenoble ( ENSAG ) -Ministère de la Culture et de la Communication ( MCC ), Mécanique des Matériaux et des Structures ( M2S ), Géomécanique, Matériaux et Structures ( GEOMAS ), Institut National des Sciences Appliquées de Lyon ( INSA Lyon ), Université de Lyon-Institut National des Sciences Appliquées ( INSA ) -Université de Lyon-Institut National des Sciences Appliquées ( INSA ) -Institut National des Sciences Appliquées de Lyon ( INSA Lyon ), Université de Lyon-Institut National des Sciences Appliquées ( INSA ) -Université de Lyon-Institut National des Sciences Appliquées ( INSA ), Université de Lyon-Institut National des Sciences Appliquées ( INSA ), Institut de recherche en astrophysique et planétologie ( IRAP ), Université Paul Sabatier - Toulouse 3 ( UPS ) -Observatoire Midi-Pyrénées ( OMP ) -Centre National de la Recherche Scientifique ( CNRS ), Institut Technologique Forêt Cellulose Bois-construction Ameublement ( FCBA ), Laboratoire Sols, Solides, Structures ( 3S ), Université Joseph Fourier - Grenoble 1 ( UJF ), Laboratoire sols, solides, structures - risques [Grenoble] (3SR ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Risques, Vulnérabilité des structures et comportement mécanique des matériaux (RV ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), CRAterre (CRAterre), École nationale supérieure d'architecture de Grenoble (ENSAG)-Ministère de la Culture et de la Communication (MCC), Architecture, Environnement & Cultures Constructives (AE&CC), Ministère de la Culture et de la Communication (MCC)-École nationale supérieure d'architecture de Grenoble (ENSAG), École nationale supérieure d'architecture de Grenoble (ENSAG), and Institut Technologique Forêt Cellulose Bois-construction Ameublement (FCBA)
Subjects: 021110 strategic, defence & security studies, Engineering, Digital image correlation, business.industry, 0211 other engineering and technologies, Full scale, [ SPI.GCIV.DV ] Engineering Sciences [physics]/Civil Engineering/Dynamique, vibrations, 020101 civil engineering, 02 engineering and technology, Structural engineering, Displacement (vector), Bracing, [SPI.MECA.GEME]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Mechanical engineering [physics.class-ph], 0201 civil engineering, Infill, Shear wall, Earthquake shaking table, [SPI.GCIV.DV]Engineering Sciences [physics]/Civil Engineering/Dynamique, vibrations, [SPI.GCIV.STRUCT]Engineering Sciences [physics]/Civil Engineering/Structures, [ SPI.GCIV.STRUCT ] Engineering Sciences [physics]/Civil Engineering/Structures, Mortar, business, ComputingMilieux_MISCELLANEOUS, Civil and Structural Engineering
Abstract: International audience; This paper aims at presenting a digital correlation technique to capture the full-field displacement thanks to a high-speed camera of a full scale structure tested on a shaking table. The challenges are both the measurements at a full scale to visualize damages versus the resolution of pictures and the dynamical loading that requires a large number of pictures. The final goal is a better understanding of the seismic behavior of timber-framed structures with infill to help at modeling such structures and predicting their seismic vulnerability. For this purpose, results of shake table tests carried out on a full-scale one-story timber-framed house filled with stones bonded by an earth based mortar are presented and discussed. DIC full-field measurements allow deriving displacements and accelerations on shear walls as well as lateral forces applied on them. The experimental results presented herein allow analyzing the influence of bracing and might be used to propose optimized aseismic constructions based on cheap technological solutions. These results demonstrate the seismic-resistant behavior of timber-framed structures with infill and constitute a key issue for the promotion of such constructions in developing countries.
Published: 2016
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14. Assessing fragility of a reinforced concrete element to snow avalanches using a non-linear dynamic mass-spring model

Author: P. Favier, D. Bertrand, N. Eckert, I. Ousset, M. Naaim, Erosion torrentielle neige et avalanches (UR ETGR (ETNA)), Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), Centro de Investigación para la Gestión Integrada del Riesgo de Desastres (CIGIDEN ), Pontificia Universidad Católica de Chile (UC), Mécanique des Matériaux et des Structures (M2S), Géomécanique, Matériaux et Structures (GEOMAS), Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA), The authors are grateful to the ANR research program MOPERA (MOdélisation Probabiliste pour l'Etude du Risque d'Avalanche), the MAP3 ALCOTRA INTERREG program, the Chilean National Commission for Scientific and Technological Research (CONICYT) under grant Redes 150119 and grant Fondecyt Postdoc 3160483, the Chilean National Research Center for Integrated Natural Disaster Management CONICYT/FONDAP/15110017 (CIGIDEN), and the ECOS-CONICYT Scientific cooperation program under project 'Multi-risk assessment in Chile and France: application to seismic engineering and mountain hazards ECOS170044 and ECOS action C17U02' for financially supporting this work., ANR-09-RISK-0007,MOPERA,MOdélisation Probabiliste pour l'Evaluation du Risque Avalanche(2009), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), and Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon
Subjects: Engineering, 010504 meteorology & atmospheric sciences, 0211 other engineering and technologies, 02 engineering and technology, Bending, 01 natural sciences, lcsh:TD1-1066, Fragility, Sensitivity (control systems), lcsh:Environmental technology. Sanitary engineering, lcsh:Environmental sciences, Reliability (statistics), 0105 earth and related environmental sciences, lcsh:GE1-350, 021110 strategic, defence & security studies, business.industry, [SDE.IE]Environmental Sciences/Environmental Engineering, lcsh:QE1-996.5, lcsh:Geography. Anthropology. Recreation, Structural engineering, Finite element method, lcsh:Geology, lcsh:G, Dynamic loading, General Earth and Planetary Sciences, Dynamic pressure, Material properties, business
Abstract: This paper presents an assessment of the fragility of a reinforced concrete (RC) element subjected to avalanche loads, and more generally to dynamic pressure fields applied orthogonally to a wall, within a reliability framework. In order to obtain accurate numerical results with supportable computation times, a light and efficient Single-Degree-of-Freedom (SDOF) model describing the mechanical response of the RC element is proposed. The model represents its dynamic mechanical response up to failure. Material non-linearity is taken into account by a moment–curvature approach, which describes the overall bending response. The SDOF model is validated under quasi-static and dynamic loading conditions by comparing its results to alternative approaches based on finite element analysis and the yield line theory. Following this, the deterministic SDOF model is embedded within a reliability framework to evaluate the failure probability as a function of the maximal avalanche pressure reached during the loading. Several reliability methods are implemented and compared, suggesting that non-parametric methods provide significant results at a moderate level of computational burden. The sensitivity to material properties, such as tensile and compressive strengths, steel reinforcement ratio, and wall geometry is investigated. The effect of the avalanche loading rate is also underlined and discussed. Finally, the obtained fragility curves are compared with respect to the few proposals available in the snow avalanche engineering field. This approach is systematic and will prove useful in refining formal and practical risk assessments. It could be applied to other similar natural hazards, which induce dynamic pressure fields onto the element at risk (e.g., mudflows, floods) and where potential inertial effects are expected and for which fragility curves are also lacking.
Published: 2018
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15. Co-simulation coupling spectral/finite elements for 3D soil/structure interaction problems

Author: Michael Brun, Florent De Martin, Loïc Zuchowski, Sols - Matériaux - Structures, Intégrité et Durabilité (SMS-ID), Institut National des Sciences Appliquées de Lyon (INSA Lyon), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon, Mécanique des Matériaux et des Structures (M2S), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), and Bureau de Recherches Géologiques et Minières (BRGM) (BRGM)
Subjects: Strategy and Management, 0211 other engineering and technologies, 02 engineering and technology, Co-simulation, 01 natural sciences, Transient analysis, Software, Soil structure interaction, Media Technology, General Materials Science, Domain decomposition, 0101 mathematics, 021106 design practice & management, Marketing, Physics, business.industry, Hybrid Asynchronous, Mathematical analysis, Domain decomposition methods, Time Integrator, [PHYS.MECA]Physics [physics]/Mechanics [physics], Finite element method, Elastic wave, 010101 applied mathematics, Asynchronous communication, Integrator, FEM/SEM co-simulation, Soil/structure interaction, business, Elastic wave propagation
Abstract: International audience; The coupling between an implicit finite elements (FE) code and an explicit spectral elements (SE) code has been explored for solving the elastic wave propagation in the case of soil/structure interaction problem. The coupling approach is based on domain decomposition methods in transient dynamics. The spatial coupling at the interface is managed by a standard coupling mortar approach, whereas the time integration is dealt with an hybrid asynchronous time integrator. An external coupling software, handling the interface problem, has been set up in order to couple the FE software Code_Aster with the SE software EFISPEC3D.
Published: 2018
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16. A new concept of precast concrete retaining wall: from laboratory model to the in-situ tests

Author: Quoc-Bao Bui, T.T. Bui, Marion Bost, Philippe Robit, Ali Limam, H. V. Tran, Mécanique des Matériaux et des Structures (M2S), Sols - Matériaux - Structures, Intégrité et Durabilité (SMS-ID), Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA), Département Génie Civil et Urbanisme (GCU), Risques Rocheux et Ouvrages géotechniques (IFSTTAR/GERS/RRO), Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Université de Lyon, Ton Duc Thang University [Hô-Chi-Minh-City], GTS : travaux publics (GTS), and This work was funded by contract from GTS Group NGE Lyon in France.
Subjects: Computer simulation, business.industry, Computer science, [SDE.IE]Environmental Sciences/Environmental Engineering, Soil nailing, 020101 civil engineering, 02 engineering and technology, Structural engineering, Retaining wall, Shotcrete, 0201 civil engineering, 020303 mechanical engineering & transports, 0203 mechanical engineering, Dynamic loading, Precast concrete, Slab, Bearing capacity, business
Abstract: International audience; A new concept for the soil nail walls is here proposed and validated through experimental and numerical approaches. This process, based on the use of precast elements that are easier to install, is cheaper and more aesthetic than the classical methods, but the main advantage is reducing the cement consumption which conducts to divided carbon footprint by three. In order to characterize the structural capacity of this new process, this article present an investigation on two in-situ representative walls, one in shotcrete which is the old way of construction, and the other, consisting the precast reinforced concrete slabs, which is the new process. We thus have a demonstrator on a real scale, and perfectly representative, since the constructive modes, as well as the mechanical, thermal, and hydric loadings are the real ones associated with the environment in situ. Substantial instrumentation has been realized over a long period (nearly 2 years), enabling to follow the evolution of the displacements of each wall and the efforts in the anchor nails. To determine the bearing capacity of the constituent element of the precast nail wall, an experimental study coupled with a numerical simulation has been conducted in the laboratory on a single precast slab. This study allows the evaluation of the load associated to crack initiation and the bearing capacity associated to the ultimate state, at the scale of the constituent elements. Finally, in order to evaluate the behaviour of the two concepts of nail walls in the case of extreme solicitation, a dynamic loading induced by an explosion has been conducted on the site.
Published: 2018
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17. Simplified Modeling Strategy for the Thermomechanical Analysis of Massive Reinforced Concrete Structures at an Early Age

Author: Jacky Mazars, Matthieu Briffaut, Stéphane Grange, Risques, Vulnérabilité des structures et comportement mécanique des matériaux (RV), Laboratoire sols, solides, structures - risques [Grenoble] (3SR), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Mécanique des Matériaux et des Structures (M2S), Géomécanique, Matériaux et Structures (GEOMAS), Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA), Risques, Vulnérabilité des structures et comportement mécanique des matériaux (RV ), Laboratoire sols, solides, structures - risques [Grenoble] (3SR ), and Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])
Subjects: Work (thermodynamics), Discretization, Computer science, 0211 other engineering and technologies, 020101 civil engineering, early age, 02 engineering and technology, Residual, reinforced concrete, THM modeling, damage modeling, scale effect, lcsh:Technology, 0201 civil engineering, lcsh:Chemistry, 021105 building & construction, General Materials Science, Instrumentation, lcsh:QH301-705.5, Shrinkage, Weibull distribution, Fluid Flow and Transfer Processes, business.industry, lcsh:T, Process Chemistry and Technology, General Engineering, Structural engineering, Reinforced concrete, lcsh:QC1-999, Computer Science Applications, [SPI.MECA.STRU]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Mechanics of the structures [physics.class-ph], lcsh:Biology (General), lcsh:QD1-999, [SPI.MECA.STRU]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Structural mechanics [physics.class-ph], lcsh:TA1-2040, Thermomechanical analysis, [SPI.GCIV.DV]Engineering Sciences [physics]/Civil Engineering/Dynamique, vibrations, business, lcsh:Engineering (General). Civil engineering (General), Beam (structure), lcsh:Physics
Abstract: International audience; The objective of this work is to propose a comprehensive and efficient modeling approach to simulate the entire loading program of the RG8 test (both the restrained shrinkage and mechanical parts) performed within the framework of the French national program CEOS.fr. This effort was made possible by introducing a multi-fiber beam discretization that included a thermomechanical model coupled with a unilateral concrete damage model. Due to the massiveness of the test structure, the scale effect needed to be taken into account. This step could be accomplished through use of a Weibull law. Extensive results were obtained during the experiment, some of which focused on deformations and forces developed in the structure by restrained shrinkage, the times of crack appearance and opening, and the consequences of damage sustained on the residual mechanical performance of the beam. A comparison with calculation output has demonstrated the ability of our modeling approach to simulate phenomena at both global and local levels, thus confirming the relevance of model choices made.
Published: 2018
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18. Introduction of shear warping in fibre beam elements for the computation of the nonlinear behaviour of concrete beams

Author: Sophie Capdevielle, Frédéric Dufour, Cédric Desprez, Stéphane Grange, Laboratoire de Mécanique et Technologie (LMT), École normale supérieure - Cachan (ENS Cachan)-Centre National de la Recherche Scientifique (CNRS), Mécanique des Matériaux et des Structures (M2S), Géomécanique, Matériaux et Structures (GEOMAS), Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA), Laboratoire sols, solides, structures - risques [Grenoble] (3SR), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Risques, Vulnérabilité des structures et comportement mécanique des matériaux (RV), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Sécurité et Durabilité des Ouvrages d'Art (IFSTTAR/MAST/SDOA), Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Communauté Université Paris-Est, Capdevielle, Sophie, Laboratoire sols, solides, structures - risques [Grenoble] (3SR ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Risques, Vulnérabilité des structures et comportement mécanique des matériaux (RV ), and Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])
Subjects: Materials science, Concrete beams, business.industry, Computation, Linear elasticity, [SPI.GCIV.STRUCT] Engineering Sciences [physics]/Civil Engineering/Structures, Torsion (mechanics), 02 engineering and technology, Structural engineering, 01 natural sciences, [SPI.MECA.STRU]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Mechanics of the structures [physics.class-ph], 010101 applied mathematics, Nonlinear system, [SPI.GCIV]Engineering Sciences [physics]/Civil Engineering, 020303 mechanical engineering & transports, 0203 mechanical engineering, [SPI.MECA.STRU]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Structural mechanics [physics.class-ph], Transverse shear, [SPI.GCIV] Engineering Sciences [physics]/Civil Engineering, [SPI.MECA.STRU] Engineering Sciences [physics]/Mechanics [physics.med-ph]/Structural mechanics [physics.class-ph], [SPI.GCIV.STRUCT]Engineering Sciences [physics]/Civil Engineering/Structures, 0101 mathematics, Image warping, business
Abstract: International audience; The present paper deals with modelling the nonlinear behaviour of concrete using the fibre element method. Proved to be efficient for slender structural elements mainly subject to normal stresses, the method lacks in accuracy when modelling the effect of shear. The present contribution proposes to enhanced a Timoshenko fibre beam element by adding shear warping deformations in the formulation. Transverse shear as well as torsion warping is taken into account, enabling the computation of the response to a complex loading. Warping degrees of freedom are computed simultaneously with the beam degrees of freedom by a fully implicit solution procedure. Concrete is modelled using a 3D damage model. Due to the coupling of warping and global beam degrees of freedom, the warping displacements in the beam element can evolve with the evolution of concrete damage. The beam element enhancement is validated at the cross-section scale considering a linear elastic behaviour. Enhanced beam elements are then used to model experimentally-tested structural elements. Both the linear and non-linear parts of the structural response are investigated.
Published: 2018

19. Enhancement of multifiber beam elements in the case of reinforced concrete structures for taking into account the lateral confinement of concrete due to stirrup

Author: Natalia Khoder, Stéphane Grange, Yannick Sieffert, Mécanique des Matériaux et des Structures (M2S), Géomécanique, Matériaux et Structures (GEOMAS), Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA), Université de Lyon-Institut National des Sciences Appliquées (INSA), Laboratoire sols, solides, structures - risques [Grenoble] (3SR ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Risques, Vulnérabilité des structures et comportement mécanique des matériaux (RV ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Sieffert, Yannick, Laboratoire sols, solides, structures - risques [Grenoble] (3SR), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Risques, Vulnérabilité des structures et comportement mécanique des matériaux (RV), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), ECN/UN, and Grange, Stéphane
Subjects: Materials science, [SPI.GCIV.STRUCT] Engineering Sciences [physics]/Civil Engineering/Structures, 0211 other engineering and technologies, 02 engineering and technology, Finite Elements, 010502 geochemistry & geophysics, 01 natural sciences, Multifiber Beam Elements, Stirrups, Cyclic loading, 0101 mathematics, ComputingMilieux_MISCELLANEOUS, 021101 geological & geomatics engineering, 0105 earth and related environmental sciences, business.industry, Structural engineering, Reinforced concrete, Stirrup, Transverse reinforcement, 010101 applied mathematics, Transverse plane, [SPI.GCIV]Engineering Sciences [physics]/Civil Engineering, Shear (geology), [SPI.GCIV] Engineering Sciences [physics]/Civil Engineering, [SPI.GCIV.STRUCT]Engineering Sciences [physics]/Civil Engineering/Structures, business, Reinforced Concrete, Confinement
Abstract: Pour déterminer la vulnérabilité sismique des structures existantes en béton armé, des méthodes de calcul numérique à l’échelle structurelle efficaces et suffisamment précises sont nécessaires. Dans le cas d’éléments poutres, les recherches actuelles concernent le développement de cinématiques enrichies pour mieux tenir compte de la déformée des sections. A cette échelle, des formulations permettent déjà de reproduire les déformations de cisaillement. En revanche, concernant les cadres d’armatures, soit ils ne sont pas du tout considérés, soit ils ne permettent pas d’établir un véritable équilibre global de la section transversale permettant de calculer le confinement du béton. Cependant, comme le montrent certains essais expérimentaux, la quantité d’armatures transversales pilote d’une manière significative le comportement de ces poutres. Le travail présenté dans cet article propose un modèle poutre multifibre enrichi pour la prise en compte de l’effet de confinement du béton par les armatures transversales. Des déplacements transversaux additionnels d’enrichissement permettent d’enrichir la cinématique de la section transversale pour y calculer l’équilibre. Le modèle est dans un premier temps validé avec des tests simples et une loi de comportement élastique linéaire pour le matériau composant la section., Academic Journal of Civil Engineering, Vol 35 No 1 (2017): Special Issue - RUGC 2017 Nantes
Published: 2018

20. Numerical analysis on seismic resistance of a two-story timber-framed structure with stone and earth infill

Author: Stéphane Grange, Laurent Daudeville, Philippe Garnier, E. Fritsch, H. Algusab, Yannick Sieffert, Laboratoire sols, solides, structures - risques [Grenoble] (3SR), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Technische Universität Dresden (TUD), Risques, Vulnérabilité des structures et comportement mécanique des matériaux (RV), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Mécanique des Matériaux et des Structures (M2S), Sols - Matériaux - Structures, Intégrité et Durabilité (SMS-ID), Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA), Architecture, Environnement & Cultures constructives (AE&CC), École nationale supérieure d'architecture de Grenoble (ENSAG)-Ministère de la Culture et de la Communication (MCC), CRAterre (CRAterre), ANR-10-HAIT-0003,REparH(2010), ANR-15-IDEX-02,CYBER@ALPS,Grenoble Alpes Cybersecurity Institute(2017), Laboratoire sols, solides, structures - risques [Grenoble] (3SR ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Technische Universität Dresden = Dresden University of Technology (TU Dresden), Risques, Vulnérabilité des structures et comportement mécanique des matériaux (RV ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Architecture, Environnement & Cultures Constructives (AE&CC), and ANR-15-IDEX-0002,UGA,IDEX UGA(2015)
Subjects: Visual Arts and Performing Arts, 0211 other engineering and technologies, 020101 civil engineering, 02 engineering and technology, Conservation, seismic resistance, 0201 civil engineering, 021105 building & construction, Architecture, traditional house, Infill, Geotechnical engineering, Seismic resistance, hysteresis behavior, [SPI.GCIV.CD]Engineering Sciences [physics]/Civil Engineering/Construction durable, business.industry, Numerical analysis, multi-stories timber-framed, numercial analysis, Masonry, earth mortar, Haiti, [SPI.GCIV.DV]Engineering Sciences [physics]/Civil Engineering/Dynamique, vibrations, nonlinear elements, business, Geology
Abstract: International audience; Due to their seismic resistance, traditional timber-framed structures with masonry infill suffered little damage during recent earthquakes. Moreover, timber-framed structures can be built with reduced costs thanks to the use of locally available materials such as wood, stone, and earth. Based on an experimentally validated numerical simulation for a one-story house, the seismic resistance of a similar two-story house is investigated. A simplified Finite Element Model with linear and nonlinear truss elements is proposed to analyze the seismic resistance of a two-story building. Nonlinear hysteresis constitutive laws are defined only for two majorcomponents of the structure which are assumed to be representative of the global structure behavior: diagonal X-crosses (concentrating the interaction with the infill material) and steel strip connections. These kinds of structures have been overlooked due to a lack of knowledge of their potential behavior in seismic prone area and a lack of building codes and standards for their own design. To promote them, a failure criterion, that might easily be used in engineering studies, is required. This article proposes a simple criterion based on Eurocode 8 to quantify the seismic resistance of one- and two-story houses. The simulation shows that, even in case of high intensity ground motion, the two-story building should not be collapsed. This study may help at designing two-story timber-framed structures in seismic prone areas for (re)construction projects.
Published: 2018
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21. Predicting mechanical degradation indicators of silver fir wooden strips using near infrared spectroscopy

Author: Jean-Baptiste Barré, Loïc Brancheriau, Marie-France Thévenon, Franck Bourrier, Lauric Cécillon, David Bertrand, Freddy Rey, Ecosystèmes montagnards (UR EMGR), Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), Université Grenoble Alpes (UGA), BioWooEB (Cirad-Persyst-UPR 114 BioWooEB), Département Performances des systèmes de production et de transformation tropicaux (Cirad-PERSYST), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad), Botanique et Modélisation de l'Architecture des Plantes et des Végétations (UMR AMAP), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud]), Université Grenoble Alpes - Faculté d'Économie de Grenoble (UGA UFR FEG), Mécanique des Matériaux et des Structures (M2S), Géomécanique, Matériaux et Structures (GEOMAS), Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA), Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), BioWooEB (UPR BioWooEB), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Université de Montpellier (UM), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad), and Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut National de la Recherche Agronomique (INRA)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut de Recherche pour le Développement (IRD [France-Sud])
Subjects: 0106 biological sciences, K50 - Technologie des produits forestiers, Coefficient of determination, Materials science, Mean squared error, Analytical chemistry, Spectroscopie infrarouge, Young's modulus, Biodégradation, 01 natural sciences, symbols.namesake, Bois, [SDV.EE.ECO]Life Sciences [q-bio]/Ecology, environment/Ecosystems, Flexural strength, 010608 biotechnology, Partial least squares regression, J12 - Manutention, transport, stockage et conservation des produits forestiers, General Materials Science, Analyse de régression, Elasticity (economics), Spectroscopy, 040101 forestry, biology, Méthode statistique, business.industry, Élasticité, Forestry, 04 agricultural and veterinary sciences, Structural engineering, biology.organism_classification, Abies alba, Propriété mécanique, Propriété technologique, symbols, 0401 agriculture, forestry, and fisheries, [SDE.BE]Environmental Sciences/Biodiversity and Ecology, business
Abstract: The management of ecological engineering structures making up a timber structure requires periodical evaluations, including the level of decay of the constituent parts of the timber structure. Methods exist to measure the level of decay in the laboratory or in the field. However, they are rarely suitable for the conditions of ecological engineering structures, or give partial information. The aim of this study was to predict two mechanical degradation indicators ( $$Dw_{MOE}$$ and $$Dw_{MOR}$$ ) of silver fir (Abies alba) wooden strips during microbial decomposition using near-infrared spectroscopy (NIRS). For 1.5 years, the degradation of 180 squared wooden strips, 30 mm wide and 500 mm long, buried in a greenhouse near Grenoble, France (Altitude: 200 m) was monitored. $$Dw_{MOE}$$ and $$Dw_{MOR}$$ were set from the normalized losses in modulus of elasticity (MOE) and modulus of rupture (MOR), two mechanical properties classically used for timber-structure design. A calibration set of 109 samples was selected to build two separate predictive models of $$Dw_{MOE}$$ and $$Dw_{MOR}$$ using partial least square regression. The NIR-based models applied to a validation set of 47 samples indicated good prediction performance. The model has a root mean square error of prediction (RMSEP) of 0.15 and a coefficient of determination ( $$r^2_p$$ ) of 0.79. The $$Dw_{MOR}$$ model has a RMSEP of 0.13 and a $$r^{2}$$ -value of 0.91. These results highlight the considerable potential of NIRS in assessing the extension of decay in wooden logs.
Published: 2018
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22. Relaxed micromorphic modeling of the interface between a homogeneous solid and a band-gap metamaterial : new perspectives towards metastructural design

Author: Patrizio Neff, Angela Madeo, Marco Valerio d'Agostino, Marco Miniaci, Gabriele Barbagallo, Manuel Collet, Mécanique des Matériaux et des Structures (M2S), Géomécanique, Matériaux et Structures (GEOMAS), Institut National des Sciences Appliquées de Lyon (INSA Lyon), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon, Institut Universitaire de France (IUF), Ministère de l'Education nationale, de l’Enseignement supérieur et de la Recherche (M.E.N.E.S.R.), Laboratoire de Mécanique des Contacts et des Structures [Villeurbanne] (LaMCoS), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Tribologie et Dynamique des Systèmes (LTDS), École Centrale de Lyon (ECL), Université de Lyon-Université de Lyon-École Nationale des Travaux Publics de l'État (ENTPE)-Ecole Nationale d'Ingénieurs de Saint Etienne-Centre National de la Recherche Scientifique (CNRS), Laboratoire Ondes et Milieux Complexes (LOMC), Centre National de la Recherche Scientifique (CNRS)-Université Le Havre Normandie (ULH), Normandie Université (NU)-Normandie Université (NU), and Universität Duisburg-Essen [Essen]
Subjects: Materials science, AMS 2010: 74A10, 74A30, 74A60, 74E15, 74M25, 74Q15, Band gap, General Mathematics, complete band-gaps, FOS: Physical sciences, 02 engineering and technology, free micro-inertia, 01 natural sciences, gradient micro-inertia, Optics, 0203 mechanical engineering, [PHYS.MECA.SOLID]Physics [physics]/Mechanics [physics]/Solid mechanics [physics.class-ph], non-local, General Materials Science, effects, 0101 mathematics, Condensed Matter - Materials Science, business.industry, Isotropy, transmission, Materials Science (cond-mat.mtrl-sci), Metamaterial, generalized continuum models, Non local, 74A10, 74A30, 74A60, 74E15, 74M25, 74Q15, 010101 applied mathematics, 020303 mechanical engineering & transports, Mechanics of Materials, Homogeneous, relaxed micromorphic model, Mathematik, meta-structures, business, reflection
Abstract: In the present paper, the material parameters of the isotropic relaxed micromorphic model derived for a specific metamaterial in a previous contribution are used to model its transmission properties. Specifically, the reflection and transmission coefficients at an interface between a homogeneous solid and the chosen metamaterial are analyzed by using both the relaxed micromorphic model and a direct FEM implementation of the detailed microstructure. The obtained results show an excellent agreement between the transmission spectra derived via our enriched continuum model and those issued by the direct FEM simulation. Such excellent agreement validates the indirect measure of the material parameters and opens the way towards an efficient meta-structural design., Comment: The paper has been already accepted in Mathematics and Mechanics of Solids as it is
Published: 2018
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23. Evaluation of one-way shear behaviour of reinforced concrete slabs: experimental and numerical analysis

Author: Ali Limam, Wendpanga-Serge-Auguste Nana, Emmanuel Ferrier, Marion Bost, T.T. Bui, Quoc-Bao Bui, Mécanique des Matériaux et des Structures (M2S), Sols - Matériaux - Structures, Intégrité et Durabilité (SMS-ID), Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA), Département Génie Civil et Urbanisme (GCU), Laboratoire des Matériaux Composites pour la Construction (LMC2), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon, Risques Rocheux et Ouvrages géotechniques (IFSTTAR/GERS/RRO), Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Université de Lyon, Ton Duc Thang University [Hô-Chi-Minh-City], Faculty of Civil Engineering, Ton Duc Thang University, Ho Chi Minh CityHo Chi Minh City, and parent
Subjects: Environmental Engineering, Materials science, 0211 other engineering and technologies, 02 engineering and technology, Eurocode, shear, [SPI.MAT]Engineering Sciences [physics]/Materials, CISAILLEMENT, 021105 building & construction, CHARGE LOCALISEE, Geotechnical engineering, EXPERIMENTATION, Boundary value problem, Concrete slab, 021101 geological & geomatics engineering, Civil and Structural Engineering, experiment, business.industry, Numerical analysis, BETON ARME, Structural engineering, Shear reinforcement, [SPI.MECA]Engineering Sciences [physics]/Mechanics [physics.med-ph], Reinforced concrete, concentrated load, Finite element method, [SPI.GCIV]Engineering Sciences [physics]/Civil Engineering, Shear (geology), DALLE, METHODE DES ELEMENTS FINIS, finite element, business, CHARGE
Abstract: The shear design of concrete slabs is still an unsolved problem. The following study presents experimental and numerical investigations on the shear behaviour of reinforced concrete slabs (without shear reinforcement) under concentrated loads. The small thick slabs of 10 cm were tested in this study. Experimental tests were conducted to quantify the shear strength and the associated failure modes. The influence of several variables was addressed such as the influence of boundary conditions, four supported side slabs instead of two supported side slabs, the influence of loading plate length. A series of eight tests on six slabs were presented. The experiments are firstly used to evaluate the pertinence of Eurocode 2 and Model Code 2010 formulations using the levels of approximation LoA I and LoA II for the shear design of reinforced concrete slabs without shear reinforcement in comparison with the French approach, and secondly validated numerical modelling using the non-linear finite element method. The proposed numerical model showed good agreement with the experimental results in terms of slab behaviour.; La conception au cisaillement de dalles en béton reste encore un problème irrésolu. L'étude suivante présente des investigations numérique et expérimentale sur le comportement au cisaillement de dalles en béton armé (sans renforcement au cisaillement) sous charge localisée. Des dalles de faible épaisseur (10cm) ont été testées dans cette étude. Les essais ont permis de quantifier la résistance au cisaillement et les modes de rupture associés. L'influence de plusieurs paramètres a été étudiée telles que les conditions-limites ou les dimensions du plateau de chargement. Une série de 8 essais sur 6 dalles est présentée. Les expériences ont été dans un premier temps, utilisées pour évaluer la pertinence des formules de l'Eurocode 2 et du ModelCode 2010 en utilisant les niveaux d'approximation LoAI et LoAII pour le dimensionnement au cisaillement de dalles en béton armé sans renforcement au cisaillement en comparaison de l'approche française. Dans un second temps, les résultats ont été validés numériquement par une méthode aux éléments finis non-linaires. Le modèle numérique proposé a montré une bonne adéquation avec les résultats expérimentaux en termes de de comportement de dalle.
Published: 2017
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24. Approaches to determine the ultimate strength and failure mechanisms of RC short columns retrofitted by FRP

Author: Emmanuel Ferrier, Michael Brun, Ali Limam, K. Le Nguyen, University of Transport Technology, 54 Trieu Khuc, Thanh Xuan, Hanoi, Vietnam, Mécanique des Matériaux et des Structures (M2S), Sols - Matériaux - Structures, Intégrité et Durabilité (SMS-ID), Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA), Laboratoire de Génie Civil et d'Ingénierie Environnementale (LGCIE), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), and Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)
Subjects: Engineering, Environmental Engineering, business.industry, 0211 other engineering and technologies, 020101 civil engineering, Context (language use), 02 engineering and technology, Structural engineering, Fibre-reinforced plastic, Finite element method, 0201 civil engineering, [SPI.GCIV]Engineering Sciences [physics]/Civil Engineering, Plating, 021105 building & construction, Ultimate tensile strength, short columns, finite-element analysis, Seismic retrofit, CFRP, business, Civil and Structural Engineering, seismic retrofit
Abstract: International audience; In the context of building protection against earthquakes, the strengthening technique by FRP (Fibre-Reinforced Polymers) plating and wrapping provides a relevant solution. The objective of this research is to evaluate the ultimate strength and failure mechanisms of externally FRP retrofitting on RC short columns. The analytical approach employs design equations proposed in construction guidelines for reproducing the concrete confinement provided by FRP wraps with fibres predominantly in the hoop direction. The strength and failure modes provided by the analytical approach are consistent with the experimental data. Then, a pushover analysis using a finite-element method is performed to investigate the efficiency for the FRP-retrofitted configurations of the short RC columns. The numerical assessment of the shear strength turns out to be more accurate than the one issued from analytical approach. In addition, the observed failure modes are well retrieved and are clearly illustrated through the display of consistent bending or shear cracking patterns. Finally, the ultimate displacements are assessed by the numerical procedure, highlighting the advantages of the partially FRP-strengthened configuration in comparison to the fully strengthened case in terms of ductility.
Published: 2017
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25. Experimental Analysis of a Shake Table Test of Timber-Framed Structures with Stone and Earth Infill

Author: Yannick Sieffert, Stéphane Grange, C. Belinga Nko'ol, E. Bertrand, Laurent Daudeville, Jean-Charles Duccini, F. Vieux-Champagne, Carole Faye, CRAterre ( CRAterre ), École nationale supérieure d'architecture de Grenoble ( ENSAG ) -Ministère de la Culture et de la Communication ( MCC ), Laboratoire sols, solides, structures - risques [Grenoble] ( 3S-R ), Université Joseph Fourier - Grenoble 1 ( UJF ) -Institut National Polytechnique de Grenoble ( INPG ) -Centre National de la Recherche Scientifique ( CNRS ) -Université Grenoble Alpes ( UGA ), Mécanique des Matériaux et des Structures ( M2S ), Géomécanique, Matériaux et Structures ( GEOMAS ), Institut National des Sciences Appliquées de Lyon ( INSA Lyon ), Université de Lyon-Institut National des Sciences Appliquées ( INSA ) -Université de Lyon-Institut National des Sciences Appliquées ( INSA ) -Institut National des Sciences Appliquées de Lyon ( INSA Lyon ), Université de Lyon-Institut National des Sciences Appliquées ( INSA ) -Université de Lyon-Institut National des Sciences Appliquées ( INSA ), Université de Lyon-Institut National des Sciences Appliquées ( INSA ), Equipes Traitement de l'Information et Systèmes ( ETIS ), Ecole Nationale Supérieure de l'Electronique et de ses Applications ( ENSEA ) -Université de Cergy Pontoise ( UCP ), Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique ( CNRS ), Laboratoire Sols, Solides, Structures ( 3S ), Université Joseph Fourier - Grenoble 1 ( UJF ), Laboratoire sols, solides, structures - risques [Grenoble] (3SR ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Risques, Vulnérabilité des structures et comportement mécanique des matériaux (RV ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), CRAterre (CRAterre), École nationale supérieure d'architecture de Grenoble (ENSAG)-Ministère de la Culture et de la Communication (MCC), Architecture, Environnement & Cultures Constructives (AE&CC), Ministère de la Culture et de la Communication (MCC)-École nationale supérieure d'architecture de Grenoble (ENSAG), Centre d'Etudes et d'Expertise sur les Risques, l'Environnement, la Mobilité et l'Aménagement - Direction Méditerranée (Cerema Direction Méditerranée), Centre d'Etudes et d'Expertise sur les Risques, l'Environnement, la Mobilité et l'Aménagement (Cerema), and Institut Technologique Forêt Cellulose Bois-construction Ameublement (FCBA)
Subjects: 021110 strategic, defence & security studies, Engineering, [SPI.GCIV.CD]Engineering Sciences [physics]/Civil Engineering/Construction durable, business.industry, 0211 other engineering and technologies, 020101 civil engineering, [ SPI.GCIV.DV ] Engineering Sciences [physics]/Civil Engineering/Dynamique, vibrations, 02 engineering and technology, Structural engineering, Geotechnical Engineering and Engineering Geology, 0201 civil engineering, Geophysics, Infill, [ SPI.GCIV ] Engineering Sciences [physics]/Civil Engineering, Earthquake shaking table, [SPI.GCIV.DV]Engineering Sciences [physics]/Civil Engineering/Dynamique, vibrations, Geotechnical engineering, [SPI.GCIV.STRUCT]Engineering Sciences [physics]/Civil Engineering/Structures, [ SPI.GCIV.STRUCT ] Engineering Sciences [physics]/Civil Engineering/Structures, Mortar, business, Earth (classical element), ComputingMilieux_MISCELLANEOUS
Abstract: International audience; The seismic performance of timber-framed structures filled with stones and earth mortar has been analyzed by introducing the structural subscales (cell, wall, house) at which monotonic and cyclic loadings were considered. This article aims to present the dynamic behavior of a house as determined through shaking table tests. Based on this experimental multiscale analysis, this paper confirms that timbered masonry structures offer effective seismic resistance; moreover, such a comprehensive analysis helps enhance understanding of the seismic-resistant behavior of timber-framed structures with infill. This paper also aids ongoing development of a numerical tool intended to predict the seismic-resistant behavior of this type of structure.
Published: 2017
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26. Experimental and Numerical Modelling of Shear Behaviour of Full-scale RC Slabs Under Concentrated Loads

Author: Ali Limam, W.S.A. Nana, S. Abouri, T.T. Bui, Sols - Matériaux - Structures, Intégrité et Durabilité (SMS-ID), Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA), Mécanique des Matériaux et des Structures (M2S), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Département Génie Civil et Urbanisme (GCU), EDF-DIN-SEPTEN, Division GS - Groupe Enceintes de confinement, and parent
Subjects: Materials science, 0211 other engineering and technologies, Full scale, 020101 civil engineering, 02 engineering and technology, Plasticity, 0201 civil engineering, Concrete damaged plasticity, 021105 building & construction, Architecture, Geotechnical engineering, Safety, Risk, Reliability and Quality, Reinforcement, Concrete slab, Civil and Structural Engineering, business.industry, Shear, Building and Construction, Structural engineering, Finite element method, Constructability, [SPI.GCIV]Engineering Sciences [physics]/Civil Engineering, Compressive strength, Shear (geology), Slab, business, Experiments, Finite element model
Abstract: International audience; In nuclear buildings, situations such as localized heavy loads from equipment, slabs loaded by walls or columns are commonly found. For constructability and cost-effectiveness reasons, shear reinforcement of concrete is an important issue in a new nuclear plant project. This study presents an experimental and numerical investigation of the shear behaviour of full-scale reinforced concrete (RC) slabs without shear reinforcement under a concentrated load near a linear support in nuclear buildings. The main aim was to evaluate experimentally and numerically the influence of several variables: bottom longitudinal reinforcement, bottom transverse reinforcement, compressive strength, concrete aggregate size, slab depth and loading plate length on the shear behaviour of RC slabs under a concentrated load. First, an experimental campaign was performed: a series of ten tests on nine full-scale slabs (one slab measuring 3.2 m × 2.9 m × 0.3 m; six slabs measuring 4 m × 2.6 m × 0.3 m; one slab 4 m × 2.6 m × 0.35 m and one slab 4 m × 2.6 m × 0.4 m) already presented in Bui et al. (2016). The originality of this study is that three new tests added three full-scale slabs measuring 4 m × 2.6 m × 0.3 m to analyse the influence of the compressive strength and the loading plate length on the slabs' shear strength, which had not been tested in the 2016 study. Then concrete damaged plasticity (CDP) in Abaqus software was used for three-dimensional (3D) modelling and calibration. The proposed numerical model showed that the RC slabs' behaviour was in good agreement with the experimental results.
Published: 2017
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27. Decay extent assessment of small-diameter silver fir logs degraded in natural conditions in the French Northern Alps using NIRS and vibration resonance methods

Author: David Bertrand, Franck Bourrier, Marie-France Thévenon, Jean-Baptiste Barré, Freddy Rey, Ecosystèmes montagnards (UR EMGR), Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), Erosion torrentielle neige et avalanches (UR ETGR (ETNA)), Géomécanique, Matériaux et Structures (GEOMAS), Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA), Mécanique des Matériaux et des Structures (M2S), Sols - Matériaux - Structures, Intégrité et Durabilité (SMS-ID), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), BioWooEB (UPR BioWooEB), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad), Département Performances des systèmes de production et de transformation tropicaux (Cirad-PERSYST), BioWooEB (Cirad-Persyst-UPR 114 BioWooEB), and Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)
Subjects: K50 - Technologie des produits forestiers, Engineering, Small diameter, 010501 environmental sciences, 01 natural sciences, Degradation process, biology, [SDE.IE]Environmental Sciences/Environmental Engineering, Élasticité, 04 agricultural and veterinary sciences, Vegetation, Structural engineering, Abies alba, [SPI.GCIV.STRUCT]Engineering Sciences [physics]/Civil Engineering/Structures, Near infra red spectroscopy, Environmental Engineering, Spectroscopie infrarouge, Soil science, Bioengineering, Management, Monitoring, Policy and Law, Vibration, Natural (archaeology), Bois, Microbial community, [SPI.GCIV.RISQ]Engineering Sciences [physics]/Civil Engineering/Risques, J12 - Manutention, transport, stockage et conservation des produits forestiers, 0105 earth and related environmental sciences, Nature and Landscape Conservation, Vibration resonance method, business.industry, Resonance, Near infra-red spectroscopy, Grume de sciage, Modulus of elasticity, 15. Life on land, Champignon pathogène, biology.organism_classification, Biodétérioration, 040103 agronomy & agriculture, 0401 agriculture, forestry, and fisheries, [SPI.GCIV.DV]Engineering Sciences [physics]/Civil Engineering/Dynamique, vibrations, U30 - Méthodes de recherche, business
Abstract: International audience; Bioengineering structures devoted to natural hazard mitigation often require the implementation of vegetation and inert materials, mainly timber logs. The latter are intended to ensure the protective function of the structure until the crop development of the plants is sufficient. The structural use of raw wood, i.e. without wood preservative treatment, in severe decay conditions is specific to the bioengineering structures. It raises practical and scientific issues regarding wood-decay assessment for structure management as well as for studies related to design improvements. In this study, two methods assessing the level of decay – the near infra-red spectroscopy (NIRS) method and the vibration resonance method (VRM) – developed on logs degraded in semi-controlled conditions were applied and compared. These methods are based on a mechanical definition of the level of decay by means of the normalized loss in the modulus of elasticity between intact and decayed states. The level of decay of 60 small-diameter silver fir logs degraded in natural conditions in the French Northern Alps was assessed using both methods. The samples had been put on the ground in four different sites near alpine torrents. The degradation process was assumed to take place in aerobic conditions. Prior to assessment of the level of decay, the applicability of the methods was verified. The level of decay was based on a classification varying from class 1 for the least decayed logs to class 4. Both methods allowed assessing the effects of the microbial activity on the logs. The levels of decay found were mainly classes 1 and 2 in both cases but to various extents depending on the method. Finally, the NIRS method was found to be less reliable than VRM. VRM can be used to assess the level of decay of logs decayed in natural conditions.
Published: 2017
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28. Experimental investigation of shear strength of full-scale concrete slabs subjected to concentrated loads in nuclear buildings

Author: W.S.A. Nana, T. Roure, S. Abouri, B. Tedoldi, T.T. Bui, Ali Limam, Mécanique des Matériaux et des Structures (M2S), Sols - Matériaux - Structures, Intégrité et Durabilité (SMS-ID), Institut National des Sciences Appliquées de Lyon (INSA Lyon), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon, EDF-DIN-SEPTEN, Division GS - Groupe Enceintes de confinement, parent, and Département Génie Civil et Urbanisme (GCU)
Subjects: business.industry, 0211 other engineering and technologies, Full scale, Shear, 020101 civil engineering, 02 engineering and technology, Eurocode, Structural engineering, 0201 civil engineering, Transverse reinforcement, Reinforcement, Concentrated load, [SPI.GCIV]Engineering Sciences [physics]/Civil Engineering, Compressive strength, Shear (geology), 021105 building & construction, Slab, Geotechnical engineering, Boundary value problem, business, Experiments, Geology, Civil and Structural Engineering
Abstract: International audience; The following study analyzes the shear behavior of full-scale slabs without shear reinforcement (the design of slabs used in nuclear buildings) under a concentrated load near a linear support. Experimental tests were conducted to quantify the shear strength and the associated failure modes. We addressed the influence of several variables, such as bottom longitudinal reinforcement, bottom transverse reinforcement, compressive strength, concrete aggregate size, and influence of the slab depth. A series of ten tests on nine full-scale slabs (one slab of 3.2 m × 2.9 m × 0.3 m; six slabs of 4 m × 2.6 m × 0.3 m; one slab of 4 m × 2.6 m × 0.35 m; one slab of 4 m × 2.6 m × 0.4 m) are presented. Realistic boundary conditions with the slabs supported on all four sides were used. The experiments are firstly used to evaluate the pertinence of Eurocode 2 for the shear design of reinforced concrete slabs without shear reinforcement in comparison with the French approach, and then to make comparisons with the ACI 318-14 code. We also studied the verification of a new proposal for the extension of Eurocode 2 proposed by Lantsoght et al. (2015).
Published: 2017
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29. Experimental analysis of the response of fresh wood stems subjected to localized impact loading

Author: F. Bourrier, Ali Limam, David Bertrand, David Toe, Frédéric Berger, Ignacio Olmedo, Ecosystèmes montagnards (UR EMGR), Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), Mécanique des Matériaux et des Structures (M2S), Sols - Matériaux - Structures, Intégrité et Durabilité (SMS-ID), Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA), Laboratoire de Génie Civil et d'Ingénierie Environnementale (LGCIE), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), and Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)
Subjects: Plant Science, Permanent Deformation, Industrial and Manufacturing Engineering, Displacement (vector), Longitudinal Modulus, Rockfall, [SPI.GCIV.RISQ]Engineering Sciences [physics]/Civil Engineering/Risques, General Materials Science, Geotechnical engineering, Fresh Wood, Stem Diamete, Physics, geography, Impact Force, geography.geographical_feature_category, business.industry, Pendulum, Forestry, Structural engineering, 15. Life on land, Dissipation, Partial rupture, Impact loading, [SPI.GCIV.DV]Engineering Sciences [physics]/Civil Engineering/Dynamique, vibrations, [SPI.GCIV.STRUCT]Engineering Sciences [physics]/Civil Engineering/Structures, Impact, business
Abstract: International audience; The forest is a well known and efficient natural protection solution against rockfall. To compensate for a loss of the forest’s protective function after windstorms or maintenance tasks, some of the felled trees can be left in an oblique position on the slope as wooden protection structures. No studies have been conducted on the efficacy of these devices and particularly their resistance to rock impacts and their energy dissipation capacity. The dynamic response of fresh stems to impact was analyzed by laboratory impact experiments with a Mouton-Charpy pendulum. The experimental results allowed the definition of different impact types related to the occurrence of nonlinear processes associated with partial rupture of wood fibers. The physics controlling the stem loading force and displacement were shown to be mainly associated with inertial effects during the early stages of the impact. Second, when the stem displacements become larger, the stem response becomes quasi-static. Based on these results, a practical approach for assessing the capacity of wooden structures made of fallen trees to resist rock impact was proposed and evaluated.
Published: 2015
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30. Simplified method strategies based on damage mechanics for engineering issues

Author: Stéphane Grange, Jacky Mazars, Laboratoire sols, solides, structures - risques [Grenoble] (3SR), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Université Joseph Fourier - Grenoble 1 (UJF)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS), Risques, Vulnérabilité des structures et comportement mécanique des matériaux (RV), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Université Joseph Fourier - Grenoble 1 (UJF)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Université Joseph Fourier - Grenoble 1 (UJF)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS), Mécanique des Matériaux et des Structures (M2S), Géomécanique, Matériaux et Structures (GEOMAS), Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA), Université de Lyon-Institut National des Sciences Appliquées (INSA), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), and Grange, Stéphane
Subjects: Engineering, business.industry, Damage mechanics, 021105 building & construction, 0211 other engineering and technologies, Systems engineering, [SPI.GCIV.DV] Engineering Sciences [physics]/Civil Engineering/Dynamique, vibrations, [SPI.GCIV.DV]Engineering Sciences [physics]/Civil Engineering/Dynamique, vibrations, 02 engineering and technology, business, ComputingMilieux_MISCELLANEOUS
Abstract: International audience
Published: 2014

31. Experimental and numerical dynamic analysis of a live tree stem impacted by a Charpy pendulum

Author: M. Brun, Ali Limam, Frédéric Berger, David Bertrand, I. Olmedo, Franck Bourrier, Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA), Géomécanique, Matériaux et Structures (GEOMAS), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA), Mécanique des Matériaux et des Structures (M2S), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Ecosystèmes montagnards (UR EMGR), Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), Laboratoire de Génie Civil et d'Ingénierie Environnementale (LGCIE), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), and Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)
Subjects: Engineering, 0211 other engineering and technologies, Charpy impact test, 02 engineering and technology, Rockfall, 0203 mechanical engineering, medicine, [SPI.GCIV.RISQ]Engineering Sciences [physics]/Civil Engineering/Risques, General Materials Science, ROCKFALL, ComputingMilieux_MISCELLANEOUS, 021101 geological & geomatics engineering, CALIBRATION, geography, FEM NON LINEAR COMPUTATIONS, geography.geographical_feature_category, business.industry, Applied Mathematics, Mechanical Engineering, Pendulum, Stiffness, Structural engineering, 15. Life on land, Condensed Matter Physics, Finite element method, EXPERIMENTAL IMPACT TEST, NATURAL HAZARDS, LIVE TREE STEM, 020303 mechanical engineering & transports, Mechanics of Materials, Dynamic loading, Modeling and Simulation, Displacement field, Trajectory, IMPACT DYNAMICS, [SPI.GCIV.DV]Engineering Sciences [physics]/Civil Engineering/Dynamique, vibrations, [SPI.GCIV.STRUCT]Engineering Sciences [physics]/Civil Engineering/Structures, medicine.symptom, business
Abstract: International audience; In recent years, the forest has been used as a protective structure to reduce rockfall propagation. When a rock propagates down a forested slope, it hits trees and these interactions modify its trajectory. This paper focuses on the dynamic behavior of small-diameter live trees impacted by a rock To better understand the protective effect of forests against rockfalls, a finite element (FE) model of a live stem subjected to a local dynamic loading is proposed. Large displacements and material nonlinearities are taken into account. The numerical simulations are calibrated based on laboratory tests (free oscillation tests and impact tests). The displacement field measured by a high-speed camera is correctly reproduced by the FE model for both kinds of tests. For impact tests, the analysis of the impactor-stem interaction identified three main regimes of the stem's response (quasi-static/intermediate/impulsive). These depend on the impactor's and stem's mechanical and geometrical features (relative mass and stiffness). Finally, we attempt to predict the regime response of the stem as a function of its diameter and the impactor mass.
Published: 2013
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32. Full-Scale Dynamic Analysis of an Innovative Rockfall Fence Under Impact Using the Discrete Element Method: from the Local Scale to the Structure Scale

Author: David Bertrand, Ayman Trad, C. Silvani, A. Limam, Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA), Géomécanique, Matériaux et Structures (GEOMAS), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA), Mécanique des Matériaux et des Structures (M2S), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Laboratoire de Génie Civil et d'Ingénierie Environnementale (LGCIE), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA), and Groupe de Recherche en Géomécanique (GRG)
Subjects: Fence (finance), Structure (mathematical logic), 021110 strategic, defence & security studies, geography, Engineering, geography.geographical_feature_category, Scale (ratio), Underline, business.industry, 0211 other engineering and technologies, Full scale, Geology, 02 engineering and technology, Structural engineering, Geotechnical Engineering and Engineering Geology, Discrete element method, Rockfall, [SPI.GCIV.RISQ]Engineering Sciences [physics]/Civil Engineering/Risques, Calibration, [SPI.GCIV.DV]Engineering Sciences [physics]/Civil Engineering/Dynamique, vibrations, [SPI.GCIV.STRUCT]Engineering Sciences [physics]/Civil Engineering/Structures, business, ComputingMilieux_MISCELLANEOUS, 021101 geological & geomatics engineering, Civil and Structural Engineering
Abstract: In order to protect infrastructures against rockfalls, civil-engineered mitigation measures are widely used. Flexible metallic fences are particularly well suited to stop the propagation of blocks of rock whose kinetic energy can reach 5000 kJ before impact. This paper focuses on the design of highly flexible rockfall fences under the new European guideline ETAG027. The experimental testing and the numerical modeling using the discrete element method (DEM) of a new metallic rockfall fence are presented. Several scales of study were considered; the mesh, the net and the entire structure. The calibration of the DEM models is described and a parametrical study is proposed. The latter aims to underline the type of information that can be obtained from numerical simulations of such a system to enhance its design.
Published: 2012
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33. Modélisation numérique de cellules géocomposites pour la protection contre les éboulements rocheux

Author: David Bertrand, Mécanique des Matériaux et des Structures (M2S), Géomécanique, Matériaux et Structures (GEOMAS), Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA), Érosion torrentielle, neige et avalanches (UR ETGR (ETNA)), and Centre national du machinisme agricole, du génie rural, des eaux et forêts (CEMAGREF)
Subjects: Engineering, Environmental Engineering, Scale (ratio), 0211 other engineering and technologies, 02 engineering and technology, Granular material, Dynamic load testing, Rockfall, 0203 mechanical engineering, [SPI.GCIV.RISQ]Engineering Sciences [physics]/Civil Engineering/Risques, Simulation, ComputingMilieux_MISCELLANEOUS, General Environmental Science, 021101 geological & geomatics engineering, Civil and Structural Engineering, geography, geography.geographical_feature_category, Computer simulation, business.industry, Geocomposite, Experimental data, Structural engineering, Discrete element method, 020303 mechanical engineering & transports, [SDE]Environmental Sciences, General Earth and Planetary Sciences, [SPI.GCIV.DV]Engineering Sciences [physics]/Civil Engineering/Dynamique, vibrations, [SPI.GCIV.STRUCT]Engineering Sciences [physics]/Civil Engineering/Structures, business
Abstract: International audience; This study investigated rockfall protection barriers built with cell assembly. This structure was modelled using a multiscale approach where the cell scale and the barrier scale were distinguished. This paper focuses on the cell modelling. Cells are composed of a granular media surrounded by a wire mesh. The medium is described using the discrete element method, which is well suited to simulating its granular nature. The numerical model was calibrated and validated by comparing the simulation results to experimental data from mechanical tests on 500-mm cube-like cells. These tests were conducted in quasi-static condition and dynamic condition. The numerical results were in agreement with the experimental results.; L'étude porte sur des structures de protection contre les chutes de bloc à technologie cellulaire. Ce type d'ouvrage fait l'objet d'une modélisation multiéchelle où on distingue l'échelle de la cellule de celle de l'ouvrage. Cet article présente la modélisation numérique de cellules remplies de pierres entourées par un grillage métallique à maille hexagonale. La description du matériau granulaire est réalisée à partir d'une approche numérique discrète adaptée pour simuler sa granularité. Le calage et la validation du modèle numérique sont effectués en comparant les résultats des simulations numériques à des essais expérimentaux réalisés sur des cellules cubiques de 500mm de côté dans des conditions quasi-statique et dynamique d'impact. Les résultats numériques sont en accord avec les expérimentations.
Published: 2011
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34. Pseudo-dynamic tests on low-rise shear walls and simplified model based on the structural frequency drift

Author: Alexis Courtois, M. Brun, David Bertrand, P. Labbe, EDF Division Production Nucléaire/Division Ingénierie Nucléaire (EDF DPN/DIN), EDF (EDF), Laboratoire de Génie Civil et d'Ingénierie Environnementale (LGCIE), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA), Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA), Géomécanique, Matériaux et Structures (GEOMAS), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA), Mécanique des Matériaux et des Structures (M2S), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), and Division Production Ingéniérie Hydraulique (EDF DPIH)
Subjects: Engineering, Normal force, business.industry, Frequency drift, 0211 other engineering and technologies, System identification, Stiffness, 020101 civil engineering, 02 engineering and technology, Structural engineering, Finite element method, 0201 civil engineering, Consistency (statistics), 021105 building & construction, medicine, [SPI.GCIV.RISQ]Engineering Sciences [physics]/Civil Engineering/Risques, Shear wall, [SPI.GCIV.DV]Engineering Sciences [physics]/Civil Engineering/Dynamique, vibrations, [SPI.GCIV.STRUCT]Engineering Sciences [physics]/Civil Engineering/Structures, medicine.symptom, business, ComputingMilieux_MISCELLANEOUS, Civil and Structural Engineering, Dynamic testing
Abstract: Twelve low-rise shear walls, with the same aspect ratio of 0.4 but with different structural parameters including the design frequency, reinforcement ratio and normal force, have been submitted to pseudo-dynamic (PSD) tests conducted at the ELSA laboratory of the Joint Research Centre. The focus of this testing campaign was to study the engineering margin for shear walls depending on the relative position of their structural frequency with respect to the excitation peak. After presenting the parameters of the PSD tests, three methods for identifying the structural frequency drift observed as damage occurs have been used in this paper: a numerical identification from a nonlinear pushover analysis, and two methods from experimental data, a system identification method based on an error output model and a more direct identification method based on the secant stiffness of force–displacement cycles. For each shear wall, a relationship f ( X ) between the structural frequency and the maximum of the top-displacement is derived from the previous methods and the consistency between the three approaches has been checked. Finally, these f ( X ) curves have been employed in a single degree of freedom model for predicting time–history top-displacements. The predictions turn out to be quite satisfactory, in particular when f ( X ) relationship is identified by the error output model.
Published: 2011
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35. Modélisation numérique par la méthode aux éléments discrets (DEM) de grillage double torsade à maille hexagonale

Author: Philippe Gotteland, Stéphane Lambert, David Bertrand, François Nicot, Érosion torrentielle, neige et avalanches (UR ETGR (ETNA)), Centre national du machinisme agricole, du génie rural, des eaux et forêts (CEMAGREF), Centre National de la Recherche Scientifique (CNRS), Ministry of Research, France, European Commission, Pole Grenoblois des Risques Naturels (PGRN), Mécanique des Matériaux et des Structures (M2S), Géomécanique, Matériaux et Structures (GEOMAS), Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA), Erosion torrentielle neige et avalanches (UR ETGR (ETNA)), Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), Laboratoire sols, solides, structures - risques [Grenoble] (3SR), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), and Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique de Grenoble (INPG)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )
Subjects: Engineering, 0211 other engineering and technologies, Numerical modeling, 02 engineering and technology, double-twisted hexagonal mesh, protection contre les chutes de blocs, rockfall pro-tection, 0203 mechanical engineering, Ultimate tensile strength, Gabion, discrete element method, méthode aux éléments discrets, 021101 geological & geomatics engineering, Civil and Structural Engineering, work hardening, grillage à maille hexagonale double torsion, comportement élastoplastique, Hexagonal crystal system, business.industry, Wire mesh, écrouissage, Structural engineering, Geotechnical Engineering and Engineering Geology, Discrete element method, Mechanical system, [SPI.GCIV]Engineering Sciences [physics]/Civil Engineering, 020303 mechanical engineering & transports, Hardening (metallurgy), elastoplastic behavior, business
Abstract: International audience; Rockfall protection embankments are ground lev-ees designed to stop falling boulders. This paper investigates the behaviour of geocells to be used as components of these structures. Geocells, or cellular confinement systems, are composite structures associating a manufactured envelope with a granular geomaterial. Single cubic geocells were subjected to the impact resulting from dropping a spherical boulder. The geocells were filled with fine or coarse materials and different boundary conditions were applied on the lateral faces. The response is analysed in terms of the impact force and the force transmitted by the geocell to its rigid base. The influence on the geocell response of both the fill material and the cell boundary conditions is analysed. The aim was to identify the conditions resulting in greatest reduction of the transmitted force and also to provide data for the validation of a specific numerical model.; Les grillages à mailles hexagonales double torsion sont employés dans de nombreux domaines du génie civil (structures construites à partir de gabions, filets plaqués de protection contre des éboulements rocheux, etc.). Cet article présente une approche basée sur la méthode aux éléments discrets (« DEM ») pour modéliser ce système mécanique particulier. Le comportement mécanique du métal constitutif du grillage est modélisé dans le cadre usuel de l'élasto-plasticité en déformations finies où l'écrouissage du matériau et sa rupture sont traités. Les paramètres du modèle sont calibrés d'un point de vue macroscopique en comparant les résultats des simulations à des essais de traction expérimentaux effectués à l'échelle d'une nappe de grillage. Des essais expérimentaux complémentaires, effectués avec différentes tailles de mailles et diamètres de fil, sont simulés et apportent des éléments permettant de valider l'approche numérique. Pour finir, les possibilités de la modélisation sont explorées. La simulation d'une structure de protection contre les éboulement rocheux soumise à un impact de projectile est présentée et les résultats obtenus sont discutés dans une perspective d'ingéniérie.
Published: 2008
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36. Multiscale approach to geo-composite cellular structures subjected to rock impacts

Author: Stéphane Lambert, David Bertrand, Philippe Gotteland, François Nicot, Érosion torrentielle, neige et avalanches (UR ETGR (ETNA)), Centre national du machinisme agricole, du génie rural, des eaux et forêts (CEMAGREF), Laboratoire sols, solides, structures - risques [Grenoble] (3SR), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Université Joseph Fourier - Grenoble 1 (UJF)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS), Géomécanique, Matériaux et Structures (GEOMAS), Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA), Mécanique des Matériaux et des Structures (M2S), Sols - Matériaux - Structures, Intégrité et Durabilité (SMS-ID), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Erosion torrentielle neige et avalanches (UR ETGR (ETNA)), Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), and Université Grenoble Alpes [2016-2019] (UGA [2016-2019])
Subjects: Engineering, elasto-plastic behaviour, granular materials, Composite number, ELASTO PLASTIC, 0211 other engineering and technologies, Computational Mechanics, Structure (category theory), 02 engineering and technology, multi-scale approach, Granular material, 0203 mechanical engineering, [SPI.GCIV.RISQ]Engineering Sciences [physics]/Civil Engineering/Risques, General Materials Science, discrete element method, ComputingMilieux_MISCELLANEOUS, 021101 geological & geomatics engineering, protective-reinforced structure, business.industry, mechanical interaction, wire structure, Structural engineering, Geotechnical Engineering and Engineering Geology, Discrete element method, Cellular material, 020303 mechanical engineering & transports, Mechanics of Materials, [SDE]Environmental Sciences, Regular array, [SPI.GCIV.DV]Engineering Sciences [physics]/Civil Engineering/Dynamique, vibrations, [SPI.GCIV.STRUCT]Engineering Sciences [physics]/Civil Engineering/Structures, business, Discrete modelling
Abstract: International audience; Geo-composite cellular structures are an efficient technological solution for various applications in civil engineering. This type of structure is particularly well adapted to resisting rockfalls and can act as a defensive structure. However, the design of such structures is for the most part empirically based; this lack of research-based design stagnates optimization and advanced development. In this paper, the mechanical behaviour of a geo-composite cellular structure is investigated using a multi-scale approach, from the individual cell made up of an assembly of rocky particles contained in a wire netting cage to the entire structure composed of a regular array of cells. Based on discrete modelling of both the cell and structure scales, a computational tool has been developed for design purposes.
Published: 2007
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37. Modelling a geo-composite cell using discrete analysis

Author: Stéphane Lambert, François Nicot, David Bertrand, Philippe Gotteland, Érosion torrentielle, neige et avalanches (UR ETGR (ETNA)), Centre national du machinisme agricole, du génie rural, des eaux et forêts (CEMAGREF), LIRIGM UJF GRENOBLE I, Partenaires IRSTEA, Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), Erosion torrentielle neige et avalanches (UR ETGR (ETNA)), Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), Laboratoire sols, solides, structures - risques [Grenoble] (3SR), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Mécanique des Matériaux et des Structures (M2S), Géomécanique, Matériaux et Structures (GEOMAS), Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA), and Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique de Grenoble (INPG)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )
Subjects: Engineering, elasto-plastic behaviour, Scale (ratio), granular materials, Discrete analysis, Constitutive equation, Composite number, 0211 other engineering and technologies, 02 engineering and technology, 0203 mechanical engineering, [SPI.GCIV.RISQ]Engineering Sciences [physics]/Civil Engineering/Risques, discrete element method, ComputingMilieux_MISCELLANEOUS, 021101 geological & geomatics engineering, business.industry, mechanical interaction, Unconfined compression, wire structure, Structural engineering, Geotechnical Engineering and Engineering Geology, Discrete element method, Computer Science Applications, 020303 mechanical engineering & transports, [SPI.GCIV.DV]Engineering Sciences [physics]/Civil Engineering/Dynamique, vibrations, [SPI.GCIV.STRUCT]Engineering Sciences [physics]/Civil Engineering/Structures, business, Confined compression
Abstract: International audience; Reinforced soil structures can be used to protect infrastructures against rockfalls. An innovative way to implement such protection is to construct the front face using a cellular assembly. This paper focuses on the cellular scale, with the cell a complex heterogeneous material, composed of a wire netting box filled with rocky particles. The behaviour of a single cell was modelled using the discrete element method, thus accounting for the interaction between the rocky particles and the interaction between the box and the rocky particles. A constitutive model was developed and calibrated along confined compression loading paths, then preliminary elements of validation were obtained from the simulation of unconfined compression tests.
Published: 2005
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38. Multi-scale modelling of cellular geo-composite structure under localized impact

Author: François Nicot, David Bertrand, Philippe Gotteland, Stéphane Lambert, Francis Derache, Mécanique des Matériaux et des Structures (M2S), Géomécanique, Matériaux et Structures (GEOMAS), Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA), Laboratoire sols, solides, structures - risques [Grenoble] (3SR), Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique de Grenoble (INPG)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Érosion torrentielle, neige et avalanches (UR ETGR (ETNA)), Centre national du machinisme agricole, du génie rural, des eaux et forêts (CEMAGREF), Irstea Publications, Migration, Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Erosion torrentielle neige et avalanches (UR ETGR (ETNA)), Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), FRANCE MACCAFERRI VALENCE, Partenaires IRSTEA, and Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)
Subjects: [SDE] Environmental Sciences, Engineering, Scale (ratio), IMPACT, Constitutive equation, 0211 other engineering and technologies, Structure (category theory), 02 engineering and technology, Cell assembly, Single node, Composite structure, Rockfall, 0502 economics and business, ComputingMilieux_MISCELLANEOUS, 021101 geological & geomatics engineering, General Environmental Science, 050210 logistics & transportation, geography, DEM MODEL, geography.geographical_feature_category, business.industry, 05 social sciences, Structural engineering, [SPI.GCIV]Engineering Sciences [physics]/Civil Engineering, [SDE]Environmental Sciences, General Earth and Planetary Sciences, business
Abstract: This paper focuses on the modelling of an innovative rockfall protection barrier built with cell assembly. The mechanical response of geocomposite structures subjected to an impact is analyzed. The modelling of the structure is based on a multi-scale approach. First the constitutive behaviour of a single cell is investigated. Different kinds of loading paths are considered (quasi-static and dynamical loading conditions). Then, the entire structure is considered. For this purpose each cell is described by a single node and the interaction between adjoining nodes is described by means of the constitutive model developed for each single cell. Preliminary structure impact simulations are commented., L'étude présentée porte sur l'analyse de la réponse mécanique d'une structure de protection contre les éboulements rocheux soumise à un impact. Un développement innovant est de concevoir ce type de structure sur la base d'un assemblage cellulaire. Les cellules sont des éléments géocomposites (géomatériau entouré de grillage). L'approche se fonde sur plusieurs échelles. A l'échelle locale, la cellule est modélisée en trois dimensions grâce à la méthode numérique aux éléments discrets. La réponse mécanique à différentes sollicitations quasi-statiques et dynamique permet de déterminer un modèle constitutif de la cellule. Ensuite, les résultats obtenus à l'échelle de la cellule sont utilisés pour la modélisation de l'ouvrage. La structure est discrétisée et l'interaction entre les éléments est décrite à l'aide du modèle constitutif déterminé à l'échelle locale. Il est alors possible de simuler la réponse de la structure à un impact.

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