12 results on '"Bourrier, Franck"'
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2. A Novel DEM Approach to Simulate Block Propagation on Forested Slopes
- Author
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Toe, David, Bourrier, Franck, Dorren, Luuk, and Berger, Frédéric
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- 2018
- Full Text
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3. Analysis of the effect of trees on block propagation using a DEM model: implications for rockfall modelling
- Author
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Toe, David, Bourrier, Franck, Olmedo, Ignacio, Monnet, Jean-Matthieu, and Berger, Frédéric
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- 2017
- Full Text
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4. Bayesian interface based calibration of a novel rockfall protection structure modelled in the Non-smooth contact dynamics framework
- Author
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Gupta, Ritesh, Bourrier, Franck, Acary, Vincent, Lambert, Stéphane, Institut des Géosciences de l’Environnement (IGE), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA), Modélisation, simulation et commande des systèmes dynamiques non lisses (TRIPOP), Inria Grenoble - Rhône-Alpes, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Laboratoire Jean Kuntzmann (LJK), Institut National de Recherche en Informatique et en Automatique (Inria)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), and Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )
- Subjects
[STAT]Statistics [stat] ,statistical learning ,[SPI]Engineering Sciences [physics] ,NSCD modeling ,rockfall ,impact ,meta-model ,calibration ,Bayesian interface - Abstract
This article presents the development and calibration of a numerical model simulating the response of large structure to a localized dynamic loading. A novel rockfall protection structure composed of piled up concrete blocks interconnected via metallic components is studied, where the underlying intricacies are revealed by real-scale impact experiments. The numerical model is developed using the SICONOS software based on the Non-Smooth Contact Dynamics (NSCD) method to further investigate the efficiency and performance of this new structure type. All geometrical features and mechanical properties of the real structure components are incorporated via specific developments pertinent to the modeling requirements in SICONOS. Some parameters peculiar to the numerical model are calibrated against the spatial-temporal measurements from two full-scale impact experiments. The Bayesian interface statistical learning method aided by the polynomial chaos expansion based meta-model of the NSCD model is deployed for the calibration. The additional understanding of the model dynamics through the byproducts of meta-model are highlighted. In the end, the NSCD model is successfully calibrated against the spatial-temporal response of the experimental structure for impact energies up to 1 MJ.
- Published
- 2023
5. Physical processes within a 2D granular layer during an impact
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Bourrier, Franck, Nicot, François, and Darve, Félix
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- 2008
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6. Dynamic analysis of wooden rockfall protection structures subjected to impact loading using a discrete element model.
- Author
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Olmedo, Ignacio, Bourrier, Franck, Bertrand, David, Berger, Frédéric, and Limam, Ali
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IMPACT (Mechanics) , *IMPACT loads , *DISCRETE element method , *IMPACT craters , *IMPACT testing - Abstract
Wooden structures made of felled trees are used in forested slopes as protection structures against rockfall. A model based on the Discrete Element Method is developed to analyse their response to normal impacts of blocks. The interaction between the blocks and the stems and the stem response are explicitly integrated. After the model calibration using impact tests, a wide range of impact scenarii representative of real configurations is explored. The influence of three parameters (stem diameter, impact velocity and block diameter) is analysed. Three impact types were identified for different ratios R D between the block and stem diameters. For small R D , the impact is limited to a brief contact. For intermediate R D , successive contacts of similar duration are observed. After the last contact, the block is sent back with a large velocity. For large R D , two contacts are observed. The second contact can be assimilated to a quasi-static loading of the stem. In addition, structure damage increases for increasing R D ranging from almost no damage for the first impact type to rupture of the stem for the third type. The largest R D associated with the first impact type is the target configuration that favours block energy decrease and limits structure damage. [ABSTRACT FROM AUTHOR]
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- 2020
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7. Variational approach for nonsmooth elasto-plastic dynamics with contact and impacts.
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Acary, Vincent, Bourrier, Franck, and Viano, Benoit
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STRAIN hardening , *CONVEX sets , *VARIATIONAL inequalities (Mathematics) , *NONSMOOTH optimization , *COMPUTER simulation - Abstract
The objective of this article is the modeling and the numerical simulation of the response of elastoplastic structures to impacts. To this end, a numerical method is proposed that takes into account one-sided contact (Signorini condition) and impact phenomena together with plasticity in a monolithic solver, while accounting for the non-smooth character of the dynamics. The formulation of the plasticity and the contact laws are based on inclusions into normal cones of convex sets, or equivalently, variational inequalities following the pioneering work of Moreau (1974) and Halphen and Nguyen (1975), who introduced the assumptions of normal dissipation and of generalized standard materials (GSM) in the framework of associated plasticity with strain hardening. The proposed time–stepping method is an extension of the Jean and Moreau (1987) scheme for nonsmooth dynamics. The discrete energy balance shows that spurious numerical damping can be suppressed and that the scheme is in practice unconditionally stable. Furthermore, the finite-dimensional variational inequality at each time–step is well–posed and can be solved by optimization methods for convex quadratic programs, providing an interesting alternative to the return mapping algorithm coupled with a dedicated frictional contact method. The paper is completed by illustrative numerical examples of impacts on steel structures consisting of beams. • Formulation in a single variational inequality of the elastoplastic and contact laws • A Moreau-Jean type time–stepping method consistent with the nonsmooth dynamics • formulation of a convex quadratic program with well-posedness results • A discrete energy balance that ensures that the scheme is practically stable. • Simulation of multi-criteria elasto-plastic flow rules with contact constraints. • Application to impact on structures made of beams. [ABSTRACT FROM AUTHOR]
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- 2023
- Full Text
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8. Comparing numerical and experimental approaches for the stochastic modeling of the bouncing of a boulder on a coarse soil
- Author
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Bourrier, Franck, Nicot, François, Eckert, Nicolas, Darve, F., Érosion torrentielle, neige et avalanches (UR ETGR (ETNA)), Centre national du machinisme agricole, du génie rural, des eaux et forêts (CEMAGREF), Ecosystèmes montagnards (UR EMGR), and Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )
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rockfall hazard ,[SDE]Environmental Sciences ,impact ,stochastic ,trajectory analysis ,discrete element method ,GeneralLiterature_MISCELLANEOUS - Abstract
International audience; This paper proposes numerical investigations for the stochastic modeling of a boulder impacting a coarse granular soil. The soil is considered as a noncohesive granular medium using a discrete element method and the soil model is calibrated compared to results from half-scale experiments. Based on this numerical model, an extensive numerical simulation campaign is carried out. The statistical analysis of the numerical results allows the definition of a stochastic bouncing model that quantifies most of the variability of the numerical results. Comparisons with classical bouncing models in the field of trajectory analysis highlight that this model expands classical approaches. The comparison of results from real-scale experiments to trajectory simulations based on the stochastic model show the relevance of the proposed approach to modeling rockfall trajectories.
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- 2010
9. Définition numérique du rebond d'une particule sur un lit granulaire
- Author
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Bourrier, Franck, Nicot, François, Darve, F., Érosion torrentielle, neige et avalanches (UR ETGR (ETNA)), Centre national du machinisme agricole, du génie rural, des eaux et forêts (CEMAGREF), Ecosystèmes montagnards (UR EMGR), and Centre National de la Recherche Scientifique (CNRS)
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IMPACT ,[SDE]Environmental Sciences ,ONDE DE COMPRESSION ,REBOND - Abstract
International audience; The impact of a block on a coarse granular soil corresponding to rockfall events is investigated using the Discrete Element Method. Different impacting particle and medium characteristics are considered. Based on these numerical results, the impacting particle bouncing occurrence diagram is defined for various impacting particle sizes, incident kinematic parameters and sample heights. The bouncing occurrence diagram brings out three impact regimes. For a small impacting particle, the impact is mainly determined by the first interaction between the impacting particle and the soil, whereas for an intermediate-sized impacting particle, the compression wave propagation through the sample is the leading phenomenon. For large impacting particles, bouncing is associated with the formation of a compact layer below the impacting particle.
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- 2009
10. Modeling the impact of a boulder on a natural soil, application to rockfall trajectory simulations
- Author
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Bourrier, Franck, 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), Institut National Polytechnique de Grenoble - INPG, François Nicot, Félix Darve(francois.nicot@cemagref.fr, felix.darve@inpg.fr), 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), Érosion torrentielle, neige et avalanches (UR ETGR (ETNA)), and Centre national du machinisme agricole, du génie rural, des eaux et forêts (CEMAGREF)
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Rockfall ,Granular materials ,Trajectographie ,Trajectory analysis ,Matériaux granulaires ,Stochastic analysis ,Méthode des Eléments Discrets ,Inférence Bayésienne ,Chute de blocs ,[SPI]Engineering Sciences [physics] ,Impact ,Discrete Element Method ,Bayesian inference ,Analyse stochastique - Abstract
This thesis is dedicated to the study of falling rocks bouncing on natural soils in order to improve the models used for rockfall hazard assessment. The impact of a rock on a scree slope is modelled using the Discrete Element Method. The comparison between numerical results and half-scale experimental results of impacts on a coarse soil shows that the numerical model allows accurately predicting the bouncing of the rock for a reduced number of model parameters to be calibrated. The numerical results also emphasize that the interaction between the impacting particle and the granular soil is composed of three stages : the partial energy exchange from the impacting particle to the soil, the propagation of a shockwave from the impact point and the wave reflection on the substratum. The study of energy exchanges during these three stages allows defining the impacting particle bouncing occurrence diagram as well as three impact regimes. The statistical analysis of numerical results using Bayesian inference leads to the definition of a stochastic impact model. This model is relevant for rock velocity after impact depending on both rock velocity before impact and soil particles layout near the impact point. Finally, the stochastic impact model is integrated into trajectory analysis models which allows defining a global probabilistic approach of rockfall hazard assessment including protective structures design.; Ce travail de thèse porte sur la caractérisation du rebond d'un bloc sur un terrain naturel dans la perspective d'améliorer les modèles de détermination de l'aléa de chute de blocs. L'impact d'un bloc rocheux sur un sol composé d'éboulis est modélisé par la Méthode des Elements Discrets. La comparaison entre les résultats de simulation et les résultats d'essais à échelle réduite d'impact sur un sol granulaire grossier met en évidence que le modèle numérique développé assure une prédiction pertinente du rebond pour un nombre réduit de paramètres de simulation à calibrer. L'analyse de l'impact à l'aide du modèle numérique montre que l'interaction entre l'impactant et le sol peut être décomposée en trois phases : le transfert énergétique initial du bloc vers le sol, la propagation d'une onde de compression du point d'impact vers l'intérieur du sol et la réflexion de l'onde de compression sur le substratum. L'étude des échanges énergétiques lors de ces trois phases conduit à la définition d'un diagramme d'existence du rebond délimitant les domaines d'arrêt et de rebond de l'impactant et à l'identification de trois régimes d'impact. Le traitement statistique des résultats de simulation par des méthodes statistiques basées sur l'inférence Bayésienne permet également de définir une loi d'impact stochastique. Cette loi est représentative de la variabilité des vitesses du bloc après impact en fonction des paramètres cinématiques incidents et de l'arrangement géométrique des particules du sol au voisinage du point d'impact. Enfin, suite à l'intégration de la loi stochastique d'impact dans le contexte de l'analyse trajectographique, une approche probabiliste globale permettant la caractérisation détaillée de l'aléa de chute de bloc ainsi que l'implantation et le dimensionnement d'ouvrages de protection est proposée.
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- 2008
11. Caractérisation numérique d'une loi stochastique d'impact d'un bloc rocheux sur un éboulis
- Author
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Bourrier, Franck, NICOT, François, Darve, Félix, and Association Française de Mécanique
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Milieu granulaire ,Chute de blocs ,Impact ,DEM ,[PHYS.MECA]Physics [physics]/Mechanics [physics] - Abstract
Colloque avec actes et comité de lecture. Internationale.; International audience; Les logiciels de trajectographie constituent un outil indispensable pour la détermination des zones soumises à un risque de chute de bloc en zones montagneuses. Une amélioration fondamentale à apporter à ces codes de calcul est la caractérisation fine du rebond du bloc sur le sol. Dans cette optique, une modélisation numérique de l'interaction entre le bloc et le sol par la Méthode des Elements Discrets est développée de façon à étudier l'impact d'un bloc rocheux sur un éboulis. Le traitement statistique des résultats issus des simulations numériques permet de définir une loi d'impact stochastique valable quels que soient le point d'impact et les conditions cinématiques initiales du bloc.
- Published
- 2007
12. Evolution of the micromechanical properties of impacted granular materials
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Bourrier, Franck, Nicot, François, and Darve, Felix
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MICROMECHANICS , *MECHANICAL behavior of materials , *GRANULAR materials , *FRICTION , *MATHEMATICAL models , *NUMERICAL analysis - Abstract
Abstract: The impact of a projectile on a granular material induces important changes in the micromechanical properties of the impacted material. These changes are studied using a Discrete Element Method model of the impact. The numerical results show that the impact first entails an energy propagation from the impact point to the limit of the sample through the existing force chains. A significant kinetic energy and a total breakage of the existing contact force chains are the main consequences of the energy propagation. During the long recovery balance phase observed after the energy propagation phase, frictional processes cause the kinetic energy dissipation. The motions of the particles and the numerous contact openings first prevent the formation of stable force chains. However, for long durations after the beginning of the impact, contact openings stop. The balance recovery phase therefore finally results in the creation of new stable contact force networks. [Copyright &y& Elsevier]
- Published
- 2010
- Full Text
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