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During a fire load, a charred layer forms on the timber elements, which is a natural protection against fire, so that a certain level of fire resistance could be achieved by using elements with a larger cross-section. However, this modus of fire protection is not always suitable. One of the most commonly used fire protection systems are fire protection boards. In this work, a large-scale fire test was carried out on a protected load-bearing wall made of hollow elements under the effect of sustained mechanical loads and fire exposure. Different stages of charring were observed. The test was aborted at the 91st minute due to a decrease in the load-bearing capacity and integrity criteria. The allowable average temperature rise on the non-exposed side of the specimen (140 K) was not exceeded until the 91st minute of the test, and the allowable maximum temperature rise on the non-exposed side of the specimen (180 K) was not exceeded until the 90th minute of the test. The loss of specimen integrity occurred at the 90th minute of the test. For surfaces protected by fire-resistant panels, it should be considered that the onset of charring is delayed until a certain time. According to EN 1995-1-2, charring can start before the fire protection is removed, but at a lower charring rate than the rates up to the time of failure of the fire protection. The expression proposed in EN 1995-1-2 shows relatively accurate results for certain systems and thicknesses of fire protection linings. However, it does not consider the presence of more than one lining layer or the full range of lining thicknesses themselves. For the wall described in this paper, the predicted failure time of the fire boards would therefore be 41.5 min, which is not consistent with the results of the experiment (51 min). The results of the calculation model according to EN 1995-1-2 did not fully agree with the results of the fire test on the protected load-bearing wall. [ABSTRACT FROM AUTHOR]

Hydroxyapatite (HAP) displays a high degree of similarity to the inorganic components that make up roughly 70% of human hard tissue, and it possesses exceptional biological activity and biocompatibility. It is currently internationally recognized as the most biologically active hard tissue implant material. However, its substandard mechanical properties have significantly limited the application of HAP in areas requiring load bearing or in the repair of large bone defects. In this study, HAP/45S5 bioglass laminated ceramic composites were consolidated using the spark plasma sintering (SPS) technique. The grain growth and phase transformation of HAP and 45S5 bioglass were examined at various sintering temperatures. The mechanical properties of the laminated composites were investigated. At 950 °C, the flexural strength and fracture work of the sintered body were (153.22 ± 7.7) MPa and (2049 ± 34) J·m−2, respectively. These results corresponded to the load–displacement curves and showed that the composites met the mechanical performance requirements of the support material. [ABSTRACT FROM AUTHOR]

The bamboo structure has received more and more attention as a green, renewable construction with an increasing focus on environmental issues. Cracking at joints or openings and brittle fracture of bamboo are urgent problems in bamboo structures, leading to reduced rigidity, decreased load capacity, and even endangering structural safety. This research aims to explore the mechanism of self-tapping screw reinforcement in improving the brittle fracture characteristic of bamboo laminate. To achieve an optimal effect of reinforcement, fracture tests of bamboo laminated with different numbers of self-tapping screws and screw positions were conducted to study their impact on fracture behaviors. Through the analysis of the ultimate load, the deformation capacity, the initial energy release rate, and the energy release rate caused by the self-tapping screws reinforcement, a model for calculating the energy release rate of bamboo laminate with self-tapping screws is established. Based on the model, the load-bearing capacity of steel-bamboo connections with self-tapping screws can be reasonably estimated.

Stitched filaments are known to modify the mechanical properties of glass-fiber-reinforced polymers 2D (GFRPs 2D), so studying the effect on mechanical properties is underway to determine the critical variables involved. This research focuses on the study of the tensile strength effect of stitched low-density Barkley FBA BGQS15-15 nylon monofilament on biaxial E-Glass Saertex 830 g/m2 (+/−45°) cured with Polyester Sypol Resin 8086 CCP using a vacuum infusion process. Four specimens were made with longitudinal distances between the stitched reinforcements of 0.5, 1.0, 1.5, and 2.0 cm, respectively. Tensile strength tests based on standard ASTM D3039 were performed to study how stitching can affect toughness, Young's modulus, deformation, ultimate strength, and yield strength. The results indicated that the stitching increases Young's modulus up to 99.2%, UTS is increased by up to +3.14%, deformation decreases by up to −41.66%, and toughness decreases by up to −36.89%. Although the stitching's main function is to increase interlaminar resistance, it also induces the formation of stress concentrations by the new threads, and premature failure in the matrix was shown. [ABSTRACT FROM AUTHOR]

Bamboo is suitable to be a material for the production of new products that can be used indoors and outdoors. Five-, seven- and nine-ply laminated woven bamboo mat boards from semantan bamboo, Gigantochloa scortechinii, were fabricated in this study. G. scortechinii has been used commercially in a structural application and is easily available in Malaysia. The present work investigated the physico-mechanical properties and flammability of the laminated bamboo mat boards as a function of the number of ply. Phenol-formaldehyde resin was used as a binder. The panels' density, physical, mechanical properties, formaldehyde emission and flammability were evaluated. As the number of ply increased, the density of the laminated boards decreased. Similarly, the highest modulus of elasticity was found in 5-ply laminated boards. However, the lowest modulus of rupture was also measured in 5-ply laminated boards. Regarding shear strength, 5-ply and 7-ply laminated boards outperformed 9-ply laminated boards. Meanwhile, 7-ply laminated boards exhibited the highest dimensional stability, as evidenced by the lowest water absorption and thickness swelling. In terms of flammability, all composites are classified as V-0 because the burning stops within 10 s and no flaming drips are observed. [ABSTRACT FROM AUTHOR]

This study aims to analyze the performance of laminated glass against ballistic loading and investigates its residual load-bearing capacity. Two groups of specimens were used in quasi-static four-point bending experiments, first without prior ballistic damage and then with it. The main objective was to compare the load-bearing capacity of these two groups to see the effect of ballistic damage. Three different layer compositions were used. The ballistic loading was conducted using an in-service 9 mm bullet fired from a semiautomatic carbine with the glass specimens hanging on steel ropes in a free boundary setup. Numerical simulation and analytical methods were used and validated against the measured response of the undamaged specimens. The simulations were in good agreement with the experimental results. All of the glass specimens were able to withstand the ballistic loading, and the subsequent performance during the quasi-static bending loading was similar to that of the undamaged specimens. The quality of the glass edges seemed to be more important than ballistic damage. The front-plate damage played a negligible role, and the back-plate damage needed to be extensive to influence subsequent performance. Provided that ballistic damage is mainly localized only to the centers of the plates, it did not affect the post-impact loading capacity. [ABSTRACT FROM AUTHOR]

Stitched filaments are known to modify the mechanical properties of glass-fiber-reinforced polymers 2D (GFRPs 2D), so studying the effect on mechanical properties is underway to determine the critical variables involved. This research focuses on the study of the tensile strength effect of stitched low-density Barkley FBA BGQS15-15 nylon monofilament on biaxial E-Glass Saertex 830 g/m2 (+/−45°) cured with Polyester Sypol Resin 8086 CCP using a vacuum infusion process. Four specimens were made with longitudinal distances between the stitched reinforcements of 0.5, 1.0, 1.5, and 2.0 cm, respectively. Tensile strength tests based on standard ASTM D3039 were performed to study how stitching can affect toughness, Young’s modulus, deformation, ultimate strength, and yield strength. The results indicated that the stitching increases Young’s modulus up to 99.2%, UTS is increased by up to +3.14%, deformation decreases by up to −41.66%, and toughness decreases by up to −36.89%. Although the stitching’s main function is to increase interlaminar resistance, it also induces the formation of stress concentrations by the new threads, and premature failure in the matrix was shown.

Fire safety greatly contributes to feeling safe, and it is a key parameter for the selection of building materials. The combustibility of timber is one of the main reasons to have the strict restriction on timber for use as a building material, especially for multistory buildings. Therefore, the main prerequisite for the use of timber in buildings is to ensure adequate fire resistance, using passive and active fire protection measures. This article contains the results of mechanical and fire experimental tests of both normal and innovative hollow glued laminated timber beams. A total of 10 timber beams were tested at ambient temperature, and 3 timber beams in fire conditions, which differed in cross-section type but also in the applied fire protection. The first beam was a normal GL beam without fire protection, the second a hollow beam covered by intumescent paint, while the third was also hollow, additionally protected by mineral wool infill inside the holes. The load-carrying capacity of the hollow beam in ambient conditions was estimated at 65% of the load-carrying capacity of a normal GL beam. Fire tests indicated that hollow timber beams with both intumescent paint and mineral wool infill failed at a similar time as a normal GL beam without fire protection. One-dimensional β0 and notional charring rates βn were obtained. Time to the protective material failure was 17 min. The main cause of failure of hollow beams was the appearance of delamination due to the reduction of the lamella bonding surface. [ABSTRACT FROM AUTHOR]

In this research article, thermal and hygrothermal stress analysis of composite layered and sandwich plate having one dimension infinitely long and simply supported on the edges is presented using a new fifth-order theory. The proposed theory considers, the effect of thickness stretching. The present theory uses a polynomial shape function to account for transverse shear deformation using the expansion of thickness up to the fifth-order while to consider the effect of thickness stretching the derivative of shape function is used in the transverse displacement. In this theory, the shear strain variation is assumed to be parabolic across the thickness. The present displacement field satisfies zero shear stress condition both at the top and bottom surfaces and avoids the use of a shear correction factor. The governing equations are derived using the virtual work principle. For solution of problem, Navier’s solution technique is used. The results generated using the present theory are compared with the existing elasticity solution wherever it is available. However, many results for the cylindrical flexural analysis of laminated and sandwich plates subjected to environmental loading are presented for the first time in this paper.

Mermi gibi hızlı parçacıkların, karşısında ki bir yapıyı delip geçmesini önlemeye yönelik çalışmalar, ilk çağlardan beri insanlık için süregelen uğraşı olmuştur. Mermi ve delici parçalara karşı zırh tasarımı çalışmaları ilgi odağı olmaya devam etmektedir. Bu amaçla yüzlerce çalışmada onlarca malzeme denenmiştir. Çeşitli yapılar, birçok geometrik varyasyonlar ve formlarda tasarlanmakta, test ortamlarında balistik davranışları ölçülmektedir. Levhalı tasarımlar ağırlıklı olarak alüminyum, seramik ve zırh çeliği levhalarla oluşturulmuşlardır. Ön ve arka destek katmanları olarak bu malzemeler kullanılmıştır. Bazı çalışmalarda, polietilen, fiber, kevlar kumaş gibi malzemelerle bileşik ve kompozit yapılar meydana getirilmiştir. Kompozit yapıların bazılarında, mermi ve delici parçacık yönünü değiştirebilecek farklı geometrik yapılar tasarlanmıştır. Bu sert metal malzemeli yapı, kumaş içine alınarak kolay hareket ve taşınabilirlik ihtiyacı karşılanmaya çalışılmıştır. Bazı çalışmalarda seçilen metal levha malzeme, çeşitli kalınlık ve sıralamalarla test edilmiş, balistik performansları ve darbe etkisine karşı dayanım özellikleri tespit edilmiştir. Bu derleme çalışmasında son yıllarda yapılan çalışmaların bir kısmının özetleri sunulmakta, gelecekte yapılabilecek çalışmalara bir hedef ve perspektif oluşturulmak istenmektedir.

Bamboo is suitable to be a material for the production of new products that can be used indoors and outdoors. Five-, seven- and nine-ply laminated woven bamboo mat boards from semantan bamboo, Gigantochloa scortechinii, were fabricated in this study. G. scortechinii has been used commercially in a structural application and is easily available in Malaysia. The present work investigated the physico-mechanical properties and flammability of the laminated bamboo mat boards as a function of the number of ply. Phenol-formaldehyde resin was used as a binder. The panels’ density, physical, mechanical properties, formaldehyde emission and flammability were evaluated. As the number of ply increased, the density of the laminated boards decreased. Similarly, the highest modulus of elasticity was found in 5-ply laminated boards. However, the lowest modulus of rupture was also measured in 5-ply laminated boards. Regarding shear strength, 5-ply and 7-ply laminated boards outperformed 9-ply laminated boards. Meanwhile, 7-ply laminated boards exhibited the highest dimensional stability, as evidenced by the lowest water absorption and thickness swelling. In terms of flammability, all composites are classified as V-0 because the burning stops within 10 s and no flaming drips are observed.

Based on the finite element model, laminated graphene ceramic tool materials were designed, and the effects of the number of layers and thickness ratio on the residual stress were investigated. According to the simulation design results, laminated Al 2 O 3 –TiB 2 –graphene/Al 2 O 3 –TiN (ATBGN) ceramic tool materials with various structures were prepared using the spark plasma sintering process, and their mechanical properties and microstructures were studied and analyzed. The fracture toughness and flexural strength of ATBGN were 8.65 ± 0.18 MPa m1/2 and 755 ± 25 MPa, respectively, which increased by 66.7% and 21.6%, respectively, compared to those of monolithic Al 2 O 3 –TiB 2 ceramic. Under the synergistic action of graphene and residual compressive stress, the multiscale deflection of cracks and the change in fracture mode occurred, which made the substantial contribution to the improvement in mechanical properties. [ABSTRACT FROM AUTHOR]

Laminated ZrB 2 –SiC ceramics with graphite and BN as the interface layers were fabricated by tape casting and consequent hot pressing. The influences of interface materials on the thermal shock resistance of the laminated ceramics were studied by both experimental and theoretical analyses. Experimental results show that the critical temperature differences of G/LZS (laminated ZrB 2 –SiC/G) and BN/LZS (laminated ZrB 2 –SiC/BN) were 237 and 99 °C, respectively. The stress gradients of G/LZS and BN/LZS calculated via finite element analysis were 709 and 809 MPa/mm, respectively. Thus, the thermal shock resistance of G/LZS was higher than that of BN/LZS. Such merits of G/LZS can be explained by the following two reasons: one is the thermal conductivity of the graphite interface layer was higher than that of the BN interface layer; the other is the difference of the thermal expansion coefficient for the graphite interface layer and the matrix layer was lower than that for the BN interface layer and the matrix layer. [ABSTRACT FROM AUTHOR]

The Messeturm (“Trade Fair Tower”) in Frankfurt/Main is currently adjusted to the requirements of a modern office building. The lobby area has been enlarged by a highly transparent façade consisting of oversized insulating glass (IG) units. The IG units are curved and have a size of up to 17 m x 2.8 m. To obtain a perfectly curved façade, the IG units were fabricated with laminated cold-bended glass panes. Horizontally the IG units are supported by tapered stainless steel fins. Inclined steel beams connect the top of the façade fins with the tower structure creating a rounded roof. The vertical façade with its glass roof allows maximum transparency for people inside the lobby as well as for people passing by outside to the nearby trade fair grounds. The glass was fabricated by sedak. The façade was installed by seele on behalf of the owner OFFICEFIRST, the asset-management of Blackstone.

The current work presents a hygrothermal analysis of laminated composite rhombic hyperbolic paraboloids. The cubic variation in displacement field together with cross curvature effects of the shell were used to solve the hygrothermal problem. Because of the parabolic variation of the transverse shear deformation, the shear correction factor was not necessary in this paper. In the mathematical model, the zero conditions of the transverse shear stress at the bottom and top of the shell were applied. The nine-noded curved isoparametric element with seven unknowns in each node was used to implement the present realistic mathematical model. The implementation of the finite element C0 (FE) of the present mathematical model was coded and performed in FORTRAN. The skew hyperbolic paraboloid on which the hygrothermal analysis was conducted had various temperatures, ply orientation, curvatures, moisture concentration, boundary conditions and thickness ratio. The paper shows that with the increase of the skew angle, the non-dimensional deflection decreases, and with the increase of moisture concentration, hygrothermal load and curvature ratio, the deflection increases. The results of the model presented in the paper were compared with other results published in the literature and were found to be consistent with them.

In this study, effects of gelcoat thickness on the mechanical properties and interfacial bonding of woven glass/polyester laminated composite are investigated by using three point flexural test and tensile test. The composites had been applied at variance thickness of gelcoat layers (0.25, 0.3, 0.35, 0.4, 0.45, and 0.5mm) using hand lay-up method. Samples were measured in two techniques for the flexural test, i.e., coated surface facing the loads (concave) and bare surface facing the loads (convex). Since the coated surface was concavely bent, greatest increase of flexural strength that acquired 5- fold of increase was shown by composite with 0.3 mm of gelcoat thickness for both measurements. The increasing of thickness to 0.35 mm and above deflated the rising percentage in flexural strength. This event was happened because of the gelcoat thickness ratio was greater than the matrix/reinforcement ratio. For tensile test, composite applied with gelcoat of 0.4 mm thickness exhibited the highest increase in strength. An increase of almost 38 % in tensile strength was recorded compared to the uncoated composite. Similarly, the increase in tensile strength reduced slightly when the gelcoat thickness was increased above 0.4 mm. The results demonstrate that the mechanical properties of the composite improve as the gelcoat thickness increases. However, the mechanical properties show no further improvement as the thickness is further increased above the optimum thickness.

The lifetime of ceramic tool is decreased because of the extension of cracks, and it will be prolonged if the cracks can be self healed. The healing ability of laminated Al 2 O 3 cutting tool composites (Al 2 O 3 -(WC-Co)-MgO/Al 2 O 3 –TiC–MgO) were assessed. For determining which laminated structure and the healing condition was the best for the composite, the flexural strength and recovery rates were measured and different healing condition were used. XRD, EDS and SEM technology were carried out to identify their compositions and microstructures after the healing. The number of cracks filled with TiO 2 , crack size and the oxide content effect were utilized to explain why the flexural strength and recovery rates of laminated Al 2 O 3 cutting tool composite after the healing were different. A single particle model was utilized to identify the relation between the threshold time, grain size and the self healing temperature of the composites. [ABSTRACT FROM AUTHOR]

The laminated Al 2 O 3 –ZrB 2 –MgO/Al 2 O 3 –TiN–MgO (AZTM) ceramic composites were fabricated by hot-press sintering technology. The mechanical properties, microstructures and fracture behaviors of the laminated AZTM ceramic composites, were investigated comprehensively from the micro and macro scale perspectives. The residual stresses, R -curve behaviors and displacement in the laminated AZTM ceramic composites were calculated and analyzed. Compared to the monolithic Al 2 O 3 –TiN ceramic composite, the remarkable improvement in the fracture toughness of the laminated AZTM ceramic composite was obtained. Micro and macro crack deflection, crack bifurcation, bridging toughening and serrated propagation were helpful to the enhancement of the fracture toughness. An intracrystalline/intergranular mixed microstructure, as well as the combination of intergranular failure and transgranular failure contributed to the improvement of the flexural strength for the laminated AZTM ceramic composite. [ABSTRACT FROM AUTHOR]

The current work presents a hygrothermal analysis of laminated composite rhombic hyperbolic paraboloids. The cubic variation in displacement field together with cross curvature effects of the shell were used to solve the hygrothermal problem. Because of the parabolic variation of the transverse shear deformation, the shear correction factor was not necessary in this paper. In the mathematical model, the zero conditions of the transverse shear stress at the bottom and top of the shell were applied. The nine-noded curved isoparametric element with seven unknowns in each node was used to implement the present realistic mathematical model. The implementation of the finite element C0 (FE) of the present mathematical model was coded and performed in FORTRAN. The skew hyperbolic paraboloid on which the hygrothermal analysis was conducted had various temperatures, ply orientation, curvatures, moisture concentration, boundary conditions and thickness ratio. The paper shows that with the increase of the skew angle, the non-dimensional deflection decreases, and with the increase of moisture concentration, hygrothermal load and curvature ratio, the deflection increases. The results of the model presented in the paper were compared with other results published in the literature and were found to be consistent with them. [ABSTRACT FROM AUTHOR]

Abstract In this article, higher-order closed-form solutions are obtained for static bending and free vibration analysis of laminated composite and sandwich spherical shells using a generalized higher-order shell theory. A theory is independent of the choice of shearing stress function (polynomial/non-polynomial) which eventually results in a theoretical unification of most of the classical and higher-order shear deformation theories. The present theory yields an accurate distribution of transverse shear stresses through the shell thickness; therefore, it does not require problem dependent shear correction factor. Governing equations and associated boundary conditions of the theory are derived by employing Hamilton's principle. Navier type higher-order closed-form solutions are obtained for simply supported boundary conditions. Displacements, stresses and natural frequencies are presented for laminated composite and sandwich plates as well as shallow and deep spherical shells. The results of parabolic, trigonometric, hyperbolic, and exponential models are compared with each other and previously published results to verify the accuracy and efficiency of the present generalized shell theory. [ABSTRACT FROM AUTHOR]

The comprehensive effect of the mechanical properties, laminated structure and healing conditions on the self-healing behaviors of laminated Al 2 O 3 -MgO ceramic composites was researched. The flexural strengths before and after healing at the temperatures of 715, 815 and 915 °C for 30 min, 60 min and 90 min were measured. According to recovering rate the best healing condition was 900 °C for 60 min. The crack-healing ability of the laminated Al 2 O 3 -MgO ceramic composites was improved due to the enhancement of the original flexural residual effect and the oxide content effect by the elimination of pores and the filling of cracks. In addition, the factors influencing the original flexural residual effect and the oxide content effect were analyzed. Meanwhile, the effects of the particle size and the healing temperature on the healing ability were analyzed qualitatively based on the healing of a single particle model. [ABSTRACT FROM AUTHOR]

Abstract Laminated structure is an effective design to improve the fracture and ablation behaviors of ceramics in the high temperature fields. To investigate the effect of interface layer on the fracture manner of laminated ceramics, two laminated ZrB 2 -SiC/SiC w (LZS w) and ZrB 2 -SiC/SiC p (LZS p) ceramics were prepared by hot pressing with SiC whiskers and SiC powders as strong interface layers, respectively. The flexural strength and fracture toughness of LZS w ceramic reached 471 MPa and 15.9 MPa m1/2, respectively. This improved fracture toughness of the LZS w ceramic was mainly attributed to the introduction of SiC whiskers as the strong interface layer, which significantly prompted crack deflection and branching, increased crack propagation path and consumed more fracture energy during fracture process. [ABSTRACT FROM AUTHOR]

The owner of a 1970s, 24-story commercial office tower in Ottawa, Canada sought to rejuvenate their main lobby with a new glass entry wall. The wall’s purpose is to provide a notable, grand entryway for the re-development of a commercial podium on a main thoroughfare. The final design featured a 12 m tall by 35 m long curving glass fin wall. The height of the wall is broken up into two sections. The first is a 9 m tall section between the ground floor and a third-floor terrace that provides the main building with a new front entrance, including a double-height space. The second is a cantilevered 3 m tall balustrade that creates a new third floor terrace. The glass fins between the ground floor and third floor terrace are continuous, triple-laminated panels free of splices. The curved panels have a 30 m curvature radius and feature a ceramic frit to prevent bird strikes and promote environmental sensitivity. In addition, the panels are insulated glass units (IGUs) with a low-emissivity coating (low-e) to meet the City of Ottawa’s energy standards and the expected interior comfort of top tier retail and office space within the city. Furthermore, the glass panels are supported at discrete points, so the team used a composite resin as the laminate for the interior and exterior lites to maintain the cold bent curvature radius.

The aim of this paper is to explain how the design intent of a bespoke glazed façade develops from the point of view of the façade consultant BIFF SA. The explanation of this concept development is not only interesting because of the different phases of the process, but also because of the unusual specifications and demands established by the architects and the Client, and for the project evolution trough several technical solutions up to final project state. During the concept development materials like stone, steel, aluminum or fabric are normally combined with glass. This challenging glazed façade has been developed for a luxury villa in Switzerland where a triple laminated glass cladding has been selected as the final most suitable solution for creating a building envelope with glass panes of 3000mm W x 7000mm H bonded to a back frame with structural silicone. These units have obviously aesthetic requirements and also different functional applications and the solution should fulfill all demands and do not the technical aspects of building up a façade with such a big glass units.

Due to the recent terrorist attacks, the market demand for security glazing has rapidly grown and turned from a “bank counters” market to a facade market. In this context, it appears to be legitimate to ask the question of the applicability of current standards to this changing environment: Are they still adapted to fulfil the security requirements of the market ? If not, which adaptations could be performed ? In the present talk, the current European standards dedicated to the security glazing resistance against explosion pressure - EN 13541 - is reviewed and compared to its ISO standard pendant - ISO 16934 - and alternative - ISO 16933 -. Moreover, based on numerical simulations, the current extension rules applicable to the specific case of the explosion resistance of insulating glazing units - EN 1279-5 - are discussed as well.

Laminated ZrC-SiC ceramic was prepared through tape casting and hot pressing. The green tapes of ZrC and SiC were prepared at room temperature. In order to improve the density of composite, the binder of green tapes were removed at 550 °C for 1 h. The laminated structure and the cracks propagation path, which is not a straight line, are observed by optical metalloscope. The compact laminated ZrC-SiC composite sintered by vacuum hot-pressing at 1650 °C for 90 min under pressure of 20 MPa was researched by X-ray diffraction and scanning electron microscopy (SEM) equipped with energy dispersive X-ray analysis. The results showed that interlayer bonding is tight, and no disordered phase has formed in the interlayers of ZrC or SiC, and the combination mode is physical mechanism.

Abstract This article reports the fabrication of fiber cloth-reinforced mullite composite via an optimized layer-by-layer (LbL) assembly method involving the infiltration and pyrolysis of fiber cloth with mullite precursor (PIP) followed by brushing matrix onto the treated fiber cloth and hot pressing. The influence of fiber content on the microstructure and mechanical properties of composite are investigated and the crack propagation is discussed to explain the toughening mechanisms. The composite with 30 vol% fiber content exhibited a high density 2.89 g/cm3, flexural strength 135.5 MPa and fracture toughness 4.13 MPa m1/2. After PIP pretreatment, the gaps existed in the fiber bundle are filled with mullite matrix which transform from mullite precursor, improving the density from 2.89 g/cm3 to 2.94 g/cm3, flexural strength from 135.5 MPa to 163.2 MPa and fracture toughness from 4.13 MPa m1/2 to 4.55 MPa m1/2. The optimized LbL assembly method realizes the creation of fiber cloth-reinforced mullite composites with high density and excellent mechanical properties. [ABSTRACT FROM AUTHOR]

In the present paper, a new fifth-order shear and normal deformation theory (FOSNDT) is developed for the bi-directional bending analysis of laminated composite and sandwich plates subjected to transverse loads. This theory considered the effects of both transverse shear and normal deformations. In-plane displacements use a polynomial shape function expanded up to fifth-order in terms of the thickness coordinate to properly account the effect of transverse shear deformation. Transverse displacement is the function of x, y and z-coordinates to account the effect of transverse normal deformations i.e. thickness stretching. Hence, the present theory involves nine unknowns in the displacement field. The present theory does not require a problem dependent shear correction factor as it satisfies traction free boundary conditions at top and bottom surfaces of the plate. The governing differential equations and associated boundary conditions are obtained using the principle of virtual work. The plate is analysed for simply supported boundary conditions using Navier's solution technique. To prove the efficiency of the present theory, the nondimensional displacements and stresses obtained for laminated composite and sandwich plates are compared with existing exact elasticity solutions and other theories. It is observed from the comparision that the displacements and stresses obtained by the present theory are in excellent agreement with the results obtained by exact elasticity solutions compared to other higher-order plate theories available in the literature. [ABSTRACT FROM AUTHOR]

Laminated G/ZrB 2 –SiC ceramics were prepared by tap-casting and hot-pressing sintering. The effect of adding ZrB 2 and SiC particles into graphite interface layer on the mechanical properties, oxidation resistance and the residual strength after oxidation was investigated. The results showed that the laminated G/ZrB 2 –SiC ceramics, with 40 vol% ZrB 2 and 10 vol% SiC in the graphite interface layer, had a bending strength of 670 MPa at room temperature and fracture toughness of 13.7 MPa m 1/2 . After oxidation at 1500 °C for 10 h, its bending strength still reached 576 MPa and fracture toughness reached 12.7 MPa m 1/2 . The high retention rate of mechanical properties after oxidation was attributed to the dense SiO 2 layer formed on the surface which healed the surface defects and protected effectively the graphite interface layer from oxidation. [ABSTRACT FROM AUTHOR]

This study focuses on one of the resistivity imaging tools owned by Schlumberger; Full-bore Formation Micro Imager (FMI). The objective of this paper is to analyze quantitative analysis that is carried out focusing on calculating the volume on clay volume and net-to-gross measurement. Clay volume in a thinly bedded interval was estimated based on the gamma ray log and one FMI trace (out of 192 traces). The gamma ray log data resolution is considerably lower than the FMI log to reflect accurate lithology changes in thinly bedded reservoirs. It has been found afterthought some calibrations and corrections on the FMI resistivity log, the new processed log is used for clay volume and net to gross calculation of the reservoir, indicating the potential of this log for analysis of thin beds. A comparison between VNG-NERGE, NORTH SEA WELL, NERWING and LAGIA-8, LAGIA, EGYPT indicates the calculation for shale volume at different intervals using FMI tools. [ABSTRACT FROM AUTHOR]

Laminated composite and sandwich structures are lightweight structures that can be found in many diverse applications especially civil, mechanical and aerospace engineering. The rapid increase in the industrial use of these structures has necessitated the development of new theories that suitable for the bending, buckling and vibration analysis of composite structures. Many review articles are reported in the literature on laminated composite plates and shells in the last few decades. But, in the whole variety of literature very few review articles are available exclusively on laminated composite and sandwich beams. In this article, a critical review of literature on bending, buckling and free vibration analysis of shear deformable isotropic, laminated composite and sandwich beams based on equivalent single layer theories, layerwise theories, zig-zag theories and exact elasticity solution is presented. In addition to this, literature on finite element modeling of laminated and sandwich beams based on classical and refined theories is also reviewed. Finally, displacement fields of various equivalent single layer and layerwise theories are summarized in the present study for the reference of researchers in this area. This article cites 515 references and highlights, the possible scope for the future research on laminated composite and sandwich beams. [ABSTRACT FROM AUTHOR]

An experimental study has taken place to quantify the strength of single sided structural silicone glazing joints under blast loading. The structural silicone specimens in this experiment were tested using a high-speed servo-hydraulic test machine at varying rates, representative of that experienced in a blast. Tests were conducted at displacement rates of 1m/s, 2m/s and 4m/s. The load was applied at two different angles of 30° and 45°. The tests were carried out on samples with different bite depths. The load was measured and the strength of the silicone joint was calculated at different testing rates. For a given testing rate and loading angle, the strength was found to be constant for different bite depths. The strength also showed an escalation at higher displacement rates. For the loading angles tested, there was no correlation found between the angle of loading and the strength. Through the measurement of displacement during the test, the work done on the silicone joint was also calculated.

Enclosed envelopes without any visible supporting structure or stairs which seem to float on air are the dreams of many architects and designers. Glass is one of the few materials that can allow this dream to become a reality. For this reason full glass structures can appear to be practically invisible and the observer experiences the wonderful sensation of seeing a floating, weightless and totally transparent structure, as if it's almost not there. To fulfill these demands but also to enable the integrity of the whole glass structure, the connections between the elements represent one of the most critical aspects for this type of glass design. These connecting elements represent the “remaining visible” parts and therefore these details become the central focus of interest when looking at an all glass structure. Simple borehole connections often do not satisfy the architect’s demands these days. In this article we will show a few of our recent all glass structures with a keen focus on the all important "connecting parts". There will be shown a solution with special glass treatment for a customized structure as well as applications for transparent glued connection elements which can be used by the industry in general product applications. The generalization of connecting details in the use of load carrying full glass structures could open new fields of application for full glass structures apart from the typical and well known façade industry.

The increasing demand for use of laminated glass in building facades is the driving force for new interlayers testing and their implementation. Architects’ and engineers’ requests require searching for new solutions and processes of lamination. Intelligent facades, electrochromic windows, integrated photovoltaics, integrated lighting, enhanced solar control, acoustic pollution reduction, wires incorporation, use of special sealants and glues are some of the design drivers of new laminated structures. Laminated safety glass is composed of two or more glass panes bonded by one or more interlayers. The interlayers are typically soft polymers like polyvinyl butyral (PVB), ethylene vinyl acetate (EVA), polyurethane (PU) or ionomer. Today, there are many interlayers on the market with a large variation in their properties. For some projects, it is a challenging task to choose the optimal interlayer.

The dispersion of thermoelastic waves propagation in an arbitrary direction in laminated composites plates is studied in the framework of generalized thermoelasticity in this article. Three dimensional field equations of thermoelasticity with relaxation times are considered. Characteristic equation is obtained on employing the continuity of displacements, temperature, stresses and thermal gradient at the layers’ interfaces. Some important particular cases such as of free waves on reducing plates to single layer and the surface waves when thickness tends to infinity are also discussed. Uncoupled and coupled thermoelasticity are the particular cases of the obtained results. Numerical results are also obtained and represented graphically.

The fabrication of stratified pieces (LOM) is a fabrication method where a 3D model is constructed by adding, pasting and cutting the sections in a cycle that repeated starting with the first layer at the bottom of the piece and ending by the last layer at the top of the piece.

Este artículo presenta los resultados de un estudio experimental, desarrollado en la Universidad de los Andes en Bogotá D.C., Colombia, acerca del potencial de los laminados de guadua (Guadua angustifolia Kunt) como material estructural. La influencia de la dirección de las fibras y de la ubicación de las láminas de guadua en las propiedades mecánicas es discutida en detalle. Los esfuerzos de diseño a compresión, tracción, corte y flexión de los laminados de guadua son comparados con los respectivos esfuerzos de las maderas estructurales Andinas. Además, el efecto en la resistencia al corte del adhesivo cuando el laminado de guadua es sometido a diferentes temperaturas de ensayo es estudiado. Basado en los resultados obtenidos del programa experimental desarrollado en este estudio y desde el punto de vista de sus propiedades mecánicas, se puede concluir que los laminados de guadua se proyectan como un material alternativo para la construcción de estructuras.An exploratory study, conducted at Universidad de los Andes in Bogotá, Colombia, of the potential use of glued laminated bamboo guadua (Guadua angustifolia Kunt) as a structural material is presented in this paper. The influence of the direction of the fiber and the location of the laminae in the mechanical properties is discussed. The compression, tension, shear and flexural design stresses of glued laminated guadua are compared to those of Andean structural woods (lumber). Additionally, the effect on the mechanical properties of the bond strength of the adhesive at different test temperatures is investigated. Based on the mechanical properties obtained in this research, glued laminated guadua bamboo can be a suitable construction material for structures.

A trigonometric beam theory (TBT) is developed for the bending analysis of laminated composite and sandwich beams considering the effect of transverse shear deformation. The axial displacement field uses trigonometric function in terms of thickness coordinate to include the effect of transverse shear deformation. The transverse displacement is considered as a sum of two partial displacements, the displacement due to bending and the displacement due to transverse shearing. Governing equations and boundary conditions are obtained by using the principle of virtual work. To demonstrate the validity of present theory it is applied to the bending analysis of laminated composite and sandwich beams. The numerical results of displacements and stresses obtained by using present theory are presented and compared with those of other trigonometric theories available in literature along with elasticity solution wherever possible.

Magneto-dielectric laminated ceramic composites of x Ba(Fe 0.5 Nb 0.5 )O 3 -(1- x )Bi 0.2 Y 2.8 Fe 5 O 12 (BFN-BYIG) with high volume fractions of the giant dielectric constant material BFN ( x =10, 30, 50, 70 wt%) were fabricated by the solid-state sintering method. Microstructure, dielectric and magnetic properties of the composites were investigated. The composites possess stable dielectric properties in the frequency range from 100 Hz to 1 MHz with high dielectric constant and low dielectric loss. The maximum permeability of the magneto-dielectric laminated composites reaches up to about 25. And the magnetic behaviors are strongly dependent on the mass ratio of BYIG. The results indicate that such multilayer structures of BFN/BYIG can enhance the permeability and decrease the dielectric and magnetic loss efficiently. [ABSTRACT FROM AUTHOR]

In this paper, a displacement-based unified shear deformation theory is developed for the analysis of shear deformable advanced composite beams and plates. The theory is developed with the inclusion of parabolic (PSDT), trigonometric (TSDT), hyperbolic (HSDT) and exponential (ESDT) shape functions in terms of thickness coordinate to account for the effect of transverse shear deformation. The in-plane displacements consider the combined effect of bending rotation and shear rotation. The use of parabolic shape function in the present theory leads to the Reddy's theory, but trigonometric, hyperbolic and exponential functions are first time used in the present displacement field. The present theory is accounted for an accurate distribution of transverse shear stresses through the thickness of plate, therefore, it does not require problem dependent shear correction factor. Governing equations and associated boundary conditions of the theory are derived from the principle of virtual work. Navier type closed-form solutions are obtained for simply supported boundary conditions. To verify the global response of the present theory it is applied for the bending of both one-dimensional (beams) and two-dimensional (plates) functionally graded, laminated composite and sandwich structures. The present results are compared with exact elasticity solution and other higher order shear deformation theories to verify the accuracy and efficiency of the present theory. [ABSTRACT FROM AUTHOR]

A geometrically nonlinear theory is developed for shells of generic shape allowing for third-order shear deformation and rotary inertia by using five parameters: in-plane and transverse displacements and the two rotations of the normal; geometric imperfections are also taken into account. The novelty is that geometrically nonlinear strain–displacement relationships are derived retaining full nonlinear terms in all the five parameters. These relationships are presented in curvilinear coordinates, ready to be implemented in computer codes. Higher order terms in the transverse coordinate are retained in the derivation so that the theory is suitable also for thick laminated shells. The theory is applied to laminated composite circular cylindrical shells complete around the circumference and simply supported at both ends. Initially static finite deformation and buckling due to lateral pressure is studied. Finally, large-amplitude forced vibrations under radial harmonic excitation are investigated by using the new theory and results are compared to another third-order shear deformation theory that neglects nonlinear terms in rotations of the normal. [ABSTRACT FROM AUTHOR]

A geometrically non-linear theory is developed for shells of generic shape allowing for third-order thickness and shear deformation and rotary inertia by using eight parameters; geometric imperfections are also taken into account. The geometrically non-linear strain–displacement relationships are derived retaining full non-linear terms in all the 8 parameters, i.e. in-plane and transverse displacements, rotations of the normal and thickness deformation parameters; these relationships are presented in curvilinear coordinates, ready to be implemented in computer codes. Higher order terms in the transverse coordinate are retained in the derivation so that the theory is suitable also for thick laminated shells. Three-dimensional constitutive equations are used for linear elasticity. The theory is applied to circular cylindrical shells complete around the circumference and simply supported at both ends to study initially static finite deformation. Both radially distributed forces and displacement-dependent pressure are used as load and results for different shell theories are compared. Results show that a 6 parameter non-linear shell theory is quite accurate for isotropic shells. Finally, large-amplitude forced vibrations under harmonic excitation are investigated by using the new theory and results are compared to other available theories. The new theory with non-linearity in all the 8 parameters is the only one to predict correctly the thickness deformation; it works accurately for both static and dynamics loads. [ABSTRACT FROM AUTHOR]

Laminated ZrC-SiC ceramic was prepared through tape casting and hot pressing. The green tapes of ZrC and SiC were prepared at room temperature. In order to improve the density of composite, the binder of green tapes were removed at 550 °C for 1 h. The laminated structure and the cracks propagation path, which is not a straight line, are observed by optical metalloscope. The compact laminated ZrC-SiC composite sintered by vacuum hot-pressing at 1650 °C for 90 min under pressure of 20 MPa was researched by X-ray diffraction and scanning electron microscopy (SEM) equipped with energy dispersive X-ray analysis. The results showed that interlayer bonding is tight, and no disordered phase has formed in the interlayers of ZrC or SiC, and the combination mode is physical mechanism. [ABSTRACT FROM AUTHOR]