Showing papers in "Journal of Sandwich Structures and Materials in 2018"
TL;DR: Auxetic cellular solids in the forms of honeycombs under blast load have great potential in a diverse range of applications, including core material in sandwich plates composite components.
Abstract: Auxetic cellular solids in the forms of honeycombs under blast load have great potential in a diverse range of applications, including core material in sandwich plates composite components. Based o...
125 citations
TL;DR: In this article, the nonlinear dynamic response of higher order shear deformable sandwich functionally graded circular cylindrical shells with outer surface-bonded piezoelectric actuator was studied.
Abstract: In this paper, we study the nonlinear dynamic response of higher order shear deformable sandwich functionally graded circular cylindrical shells with outer surface-bonded piezoelectric actuator on ...
92 citations
TL;DR: In this paper, a novel computationally efficient damage identification methodology for web core fiber-reinforced polymer composite bridges has been developed based on multivariate adaptive regress (MAR) for detecting bridge damage.
Abstract: A novel computationally efficient damage identification methodology for web core fiber-reinforced polymer composite bridges has been developed in this article based on multivariate adaptive regress...
54 citations
TL;DR: In this article, the effect of foam core density on the behaviour of sandwich panels with novel bio-composite unidirectional flax fibre-reinforced polymer skins, along with a comparison to p...
Abstract: This study investigates the effect of foam core density on the behaviour of sandwich panels with novel bio-composite unidirectional flax fibre-reinforced polymer skins, along with a comparison to p...
52 citations
TL;DR: In this paper, the flexural behavior of sandwich composite beams made of fiber-reinforced polymer (FRP) skins and light-weight cores is studied and the focus is on the comparison of natural and synthetic materials.
Abstract: In this study, the flexural behavior of sandwich composite beams made of fiber-reinforced polymer (FRP) skins and light-weight cores are studied The focus is on the comparison of natural and synth
51 citations
TL;DR: In this article, a variable-kinematic model is implemented in the framework of the Carrera unified formulation, which is a hierarchical approach allowing for the straightforward implementation of the theories of structures.
Abstract: In this paper, classical as well as various refined plate finite elements for the analysis of laminates and sandwich structures are discussed. The attention is particularly focussed on a new variable-kinematic plate element. According to the proposed modelling approach, the plate kinematics can vary through the thickness within the same finite element. Therefore, refined approximations and layer-wise descriptions of the primary mechanical variables can be adopted in selected portions of the structures that require a more accurate analysis. The variable-kinematic model is implemented in the framework of the Carrera unified formulation, which is a hierarchical approach allowing for the straightforward implementation of the theories of structures. In particular, Legendre-like polynomial expansions are adopted to approximate the through-the-thickness unknowns and develop equivalent single layer, layer-wise, as well as variable-kinematic theories. In this paper, the principle of virtual displacements is used t...
43 citations
TL;DR: In this paper, the nonlinear dynamic analysis and vibration of imperfect functionally graded sandwich plates in thermal environment with piezoelectric actuators (PFGM) on elastic foundations subjected to a combination of electrical, damping loadings and temperature are investigated.
Abstract: Used the Reddy's higher-order shear deformation plate theory, the nonlinear dynamic analysis and vibration of imperfect functionally graded sandwich plates in thermal environment with piezoelectric actuators (PFGM) on elastic foundations subjected to a combination of electrical, damping loadings and temperature are investigated in this article. One of the salient features of this work is the consideration of temperature on the piezoelectric layer, and the material properties of the PFGM sandwich plates are assumed to be temperature-dependent. The governing equations are established based on the stress function, the Galerkin method, and the Runge–Kutta method. In the numerical results, the effects of geometrical parameters; material properties; imperfections; elastic foundations; electrical, thermal, and damping loads on the vibration and nonlinear dynamic response of the PFGM sandwich plates are discussed. The obtained natural frequencies are verified with the known results in the literature.
41 citations
TL;DR: Honeycomb sandwich structures are increasingly used in the automotive, aerospace and shipbuilding industries where fuel savings, increase in load carrying capacity, vehicle safety and decrease in g... as mentioned in this paper.
Abstract: Honeycomb sandwich structures are increasingly used in the automotive, aerospace and shipbuilding industries where fuel savings, increase in load carrying capacity, vehicle safety and decrease in g...
37 citations
TL;DR: In this paper, the studies carried out on bending and free vibration behavior of truss core sandwich panel filled with foam typically used in aerospace applications were carried out, and the results of the studies were presented.
Abstract: This paper presents the studies carried out on bending and free vibration behavior of truss core sandwich panel filled with foam typically used in aerospace applications. Equivalent stiffness prope...
36 citations
TL;DR: In this paper, the dynamic performance of the partially treated magnetorheological elastomer tapered composite sandwich plates was investigated by dropping off the plies longitudinally in top and bottom composite face layers to yield tapered plates as the face layers.
Abstract: This study investigates the dynamic performance of the partially treated magnetorheological elastomer tapered composite sandwich plates. Various partially treated tapered magnetorheological elastomer laminated composite sandwich plate models are formulated by dropping-off the plies longitudinally in top and bottom composite face layers to yield tapered plates as the face layers. The uniform rubber and magnetorheological elastomer materials are considered as the core layer. The governing differential equations of motion of the various partially treated magnetorheological elastomer tapered composite sandwich plate configurations are derived using classical laminated plate theory and solved numerically. Further, silicon-based magnetorheological elastomer and natural rubber are being fabricated and tested to identify the various mechanical properties. The effectiveness of the developed finite element formulation is demonstrated by comparing the results obtained with experimental tests and available literature...
30 citations
TL;DR: In this paper, the protection property of aluminum alloy sandwich panels with honeycomb cores under the attack of bullets or debris, quasi-static perforation, and ballistic impact tests were conducted.
Abstract: To study the protection property of aluminum alloy sandwich panels with honeycomb cores under the attack of bullets or debris, quasi-static perforation, and ballistic impact tests were conducted, i...
TL;DR: In this article, nonlinear free and forced vibration analysis of an embedded functionally graded sandwich micro-beam with a moving mass is investigated, where the velocity of moving mass was assumed constan...
Abstract: In this study, nonlinear free and forced vibration analysis of an embedded functionally graded sandwich micro-beam with a moving mass is investigated. The velocity of moving mass is assumed constan...
TL;DR: In this paper, a free vibration analysis of a sandwich beam with soft core and carbon nanotube reinforced composite face sheets is presented, which is based on extended high-order sandwich panel theory.
Abstract: Free vibration analysis of a sandwich beam with soft core and carbon nanotube reinforced composite face sheets, hitherto not reported in the literature, based on extended high-order sandwich panel theory is presented. Distribution of fibers through the thickness of the face sheets could be uniform or functionally graded. In this theory, the face sheets follow the first-order shear deformation theory. Besides, the two-dimensional elasticity is used for the core. The field equations are derived via the Ritz-based solution which is suitable for any essential boundary conditions. Chebyshev polynomials multiplying boundary R-functions are used as admissible functions and evidence of their good performance is given. A detailed parametric study is conducted to study the effects of nanotube volume fraction and their distribution pattern, core-to-face sheet thickness ratio, and boundary conditions on the natural frequencies and mode shapes of sandwich beams with functionally graded carbon nanotube reinforced compo...
TL;DR: In this paper, low-velocity impact tests on the titanium honeycomb sandwich structures were carried out in newly developed aircrafts in China, and the results showed that the impact test results were negative.
Abstract: Titanium honeycomb sandwich structures are gradually used in newly developed aircrafts in China. In this study, low-velocity impact tests on the titanium honeycomb sandwich structures were carried ...
TL;DR: In this paper, the impact resistance of the Nomex honeycomb sandwich structures skinned with thin fibre reinforced woven fabric composites was investigated in both drop-weight experimental work and meso-mechanical finite element modelling.
Abstract: In order to investigate the impact resistance of the Nomex honeycomb sandwich structures skinned with thin fibre reinforced woven fabric composites, both drop-weight experimental work and meso-mechanical finite element modelling were conducted and the corresponding output was compared. Drop-weight impact tests with different impact parameters, including impact energy, impactor mass and facesheets, were carried out on Nomex honeycomb-cored sandwich structures. It was found that the impact resistance and the penetration depth of the Nomex honeycomb sandwich structures were significantly influenced by the impact energy. However, for impact energies that cause full perforation, the impact resistance is characterized with almost the same initial stiffness and peak force. The impactor mass has little influence on the impact response and the perforation force is primarily dependent on the thickness of the facesheet, which generally varies linearly with it. In the numerical simulation, a comprehensive finite elem...
TL;DR: In this article, free vibration of laminated composite and soft core sandwich plates resting on Winkler-Pasternak foundations using four-variable refined plate theory is presented. The theory accounts for the hype.
Abstract: Free vibration of laminated composite and soft core sandwich plates resting on Winkler–Pasternak foundations using four-variable refined plate theory are presented. The theory accounts for the hype...
TL;DR: In this article, the nonlinear response of doubly curved functionally graded material sandwich panels resting on elastic foundations, exposed to thermal environments and subjected to uniform thermal conditions was investigated. But the response was not shown to be linear.
Abstract: This paper investigates the nonlinear response of doubly curved functionally graded material sandwich panels resting on elastic foundations, exposed to thermal environments and subjected to uniform...
TL;DR: In this article, shock tube experiments were performed to investigate the blast response of corrugated steel cellular core sandwich panels filled with a silicone-based syntactic foam at room and high temperatures.
Abstract: Shock tube experiments were performed to investigate the blast response of corrugated steel cellular core sandwich panels filled with a silicone based syntactic foam at room and high temperatures. ...
TL;DR: In this article, the flexural behavior of the 3D integrated woven spacer composites with carbon fiber-reinforced polymer face sheets are performed with epoxy and polyester matrix in the warp direction.
Abstract: The flexural behavior of the 3D integrated woven spacer composites with carbon fiber-reinforced polymer face sheets are performed with epoxy and polyester matrix in the warp direction. The static loading of foam core carbon/epoxy and carbon/polyester composite sandwich panels in three-point flexural test was characterized at room temperature (23℃) and at liquid nitrogen temperature (−40℃). Macro-fracture morphology and progress have been examined to understand the deformation and failure mechanism. Significant increases in the flexural strength with brittle type core shear failure were observed at low temperatures as compared with the corresponding room temperature behavior. The performance of the epoxy-based composite is compared to the polyester one. Significant changes in the flexural properties of the composites have been found, first related to the temperature and then to the resin type. The flexural properties of the epoxy-based composites were affected greatly by temperature and exhibited higher fl...
TL;DR: In this article, a novel technique to improve the Mode I and Mode II interlaminar fracture toughness of woven carbon-fiber polymer matrix composite face sheets using zinc oxide nanowires is proposed.
Abstract: A novel technique to improve the Mode I and Mode II interlaminar fracture toughness of woven carbon-fiber polymer matrix composite face sheets using zinc oxide nanowires is proposed. Zinc oxide nanowires are directionally synthesized on dry carbon fabrics that are used to manufacture the laminate. The influence of zinc oxide nanowires on interlaminar fracture toughness is compared against regular interfaces using double cantilever beam and end-notched flexure tests to provide fracture toughness values. A significant improvement in the Mode I and Mode II interlaminar fracture toughness values is observed with zinc oxide nanowires. Therefore, zinc oxide nanowire interlaminar reinforcement has been proven to enhance the interlaminar fracture toughness of textile composites.
TL;DR: In this article, experimental and analytical investigations about the elastic and viscoelastic (creep) behaviour of sandwich panels made of glass-fibre reinforced polymer faces and a polyethylen...
Abstract: This paper presents experimental and analytical investigations about the elastic and viscoelastic (creep) behaviour of sandwich panels made of glass-fibre reinforced polymer faces and a polyethylen...
TL;DR: In this article, the experimental and numerical studies of sandwich panels with a hybrid core are presented, which consists of external steel facings and a core made of polyurethane foam or mineral wool or a combination of those two materials.
Abstract: The paper presents the experimental and numerical studies of sandwich panels with a hybrid core The sandwich panel consists of external steel facings and a core, which is made of polyurethane foam or mineral wool or a combination of those two materials The polyurethane foam material has a low weight and high thermal insulation properties, while the mineral wool material can provide high acoustic insulation and excellent fire resistance Various proportions of the core materials are taken into account It is assumed that a proper combination can provide the benefits of both materials The structural behavior of a sandwich structure with a hybrid core is observed during laboratory tests The failure mechanism is investigated in a four-point bending test The material parameters of the core and facings are determined in standardized tests The obtained parameters are used for FE simulations of the four-point bending tests The criteria of damage initiation and propagation are defined in the interface layer
TL;DR: In this paper, the accuracy of the Refined Zigzag Theory in reproducing the static bending response of sandwich beams is experimentally assessed, and an analytical solution of the equilibrium equations is presented for the boundary and loading conditions under investigation.
Abstract: In the present work, for the first time, the accuracy of the Refined Zigzag Theory in reproducing the static bending response of sandwich beams is experimentally assessed. The theory is briefly reviewed and an analytical solution of the equilibrium equations is presented for the boundary and loading conditions under investigation (four-point bending). The experimental campaign is described, including the material characterization and the bending tests. The experimentally measured deflections and axial strains are compared with those provided by Refined Zigzag Theory and by the Timoshenko Beam Theory with an ad hoc shear correction factor. The Refined Zigzag Theory is shown to be more accurate than the Timoshenko Beam Theory, in particular for beams with higher face-to-core thickness and stiffness ratios and with a reduced slenderness.
TL;DR: Titanium honeycomb sandwich structures are gradually used in several newly developed aircrafts in China as mentioned in this paper, during the manufacturing process and aircraft service life, low-velocity impacts from foreg...
Abstract: Titanium honeycomb sandwich structures are gradually used in several newly developed aircrafts in China. During the manufacturing process and aircraft service life, low-velocity impacts from foreig...
TL;DR: In this article, failure modes of foam core sandwich composites are investigated by using embedded Fiber Bragg Grating sensors, embedded inside the face sheet, are manufactured using vacuum infusion process and then subjected to a static and a cyclic loading under the three-point bending mode.
Abstract: In this study, failure modes of foam core sandwich composites are investigated by using embedded Fiber Bragg Grating sensors. Sandwich specimens with Fiber Bragg Grating sensors, embedded inside the face sheet, are manufactured using vacuum infusion process and then subjected to a static and a cyclic loading under the three-point bending mode. Different failure modes are monitored utilizing the wavelength shift and the spectrum of Fiber Bragg Grating sensors. It is shown that the responses of the Fiber Bragg Grating sensor differ depending on damage modes thereby making structural health monitoring of sandwich structures possible.
TL;DR: In this article, the behavior of a simple and innovative multi-layer sandwich panels having a polypropylene honeycomb core has been investigated carefully, theoretically and experimentally, and a four-point bending test was performed to detect the mechanical characteristics of the multilayer core.
Abstract: The behavior of a simple and innovative multi-layer sandwich panels having a polypropylene honeycomb core has been investigated carefully, theoretically and experimentally. A four-point bending test was performed to detect the mechanical characteristics of the multi-layer core. The experimental results emphasize a better rigidity of the multi-layer structure compared to the weakness displayed by the single-layer configuration. In fact, a small increase in the final weight of the component leads to a significant increase of the mechanical properties. In the second part of this study, analytical and numerical homogenization approaches were developed to compute the effective properties of the single polypropylene honeycomb core. The numerical model complies with the experimental protocol, and the simulation conducted is aiming to reproduce a typical four-point bending test on a polypropylene honeycomb multi-layer sandwich panel. Both numerical and experimental results are presented in details and a good corr...
TL;DR: In this paper, the boundary layer hygrothermal stresses in the thick sandwich cylinder with laminated face were investigated, and uniform and through the thickness steady-state distribution for temperature and moisturization was obtained.
Abstract: The boundary layer hygrothermal stresses in the thick sandwich cylinder with laminated face are investigated. Uniform and through the thickness steady-state distribution for temperature and moistur...
TL;DR: An experimental investigation on sandwich composite materials composed of glass-fiber face sheet and polyvinyl-chloride foam core has been carried out in this article, which demonstrates improvement in mixedmode delamination fracture toughness values of samples under mixed-mode bending condition.
Abstract: An experimental investigation on sandwich composite materials composed of glass-fiber face sheet and polyvinyl-chloride foam core has been carried out. The research demonstrates improvement in mixed-mode delamination fracture toughness values of samples under mixed-mode bending condition. The improvement is recorded with addition of a certain percentage by weight of multiwalled carbon nanotubes in comparison to conventional samples. An easy and cost-effective methodology of multiwalled carbon nanotube insertion through sonication of epoxy resin followed by mixing with hardener and vacuum resin infusion technology for manufacturing of sandwich composites has been utilized in this study. The study also identifies the optimum weight percentage of multiwalled carbon nanotube addition in the resin system for maximum performance gain in mixed-mode fracture toughness. The results of observations in this study have been supported by field emission scanning electron microscope studies as well as high-resolution tr...
TL;DR: In this article, the authors investigated the potential of sandwich structures in the novel application of road freight trailer decking, and developed a lightweight replacement to conventional bimodal panels.
Abstract: This paper investigates the potential of sandwich structures in the novel application of road freight trailer decking. Sandwich panels are developed to be lightweight replacements to conventional b...
TL;DR: In this article, the influence of 3D fabric on the flexural behavior of cementitious composites has been investigated, and the maximum spacer yarn stress derived by finite element analysis was used to calculate the efficiency reinforcement factor for all the textile reinforced concrete samples.
Abstract: In this study, the influence of 3D fabric on the flexural behavior of cementitious composites has been investigated. Three 3D fabric samples were produced with different spacer yarn orientation angles of 65°, 55°, and 47°. The cementitious matrix was fabricated by cement and waste stone powder. After casting of all samples, flexural test was carried out on all specimens. Results showed that cementitious sample reinforced by 3D fabric with less spacer yarn orientation angle proposed the highest flexural strength among all samples (reinforced and unreinforced samples). Moreover, finite element method was used to predict the flexural behavior of textile reinforced concrete. Finite element method results showed good agreement with the experimental data. Consequently, the maximum spacer yarn stress derived by finite element analysis was used to calculate the efficiency reinforcement factor for all the textile reinforced concrete samples.