Showing papers on "Sandwich panel published in 2018"
TL;DR: In this paper, the authors compared composite sandwich panels composed of auxetic and conventional honeycomb cores and metal facets and compared for their resistance performances against impulsive loadings, taking into account the rate-dependent effects.
271 citations
TL;DR: In this paper, a semi-analytical methodology is developed for conducting structural and low-velocity impact analyses based on a modified higher-order shear deformation theory, and the standard mechanics homogenization is implemented through finite element modelling to accurately predict the effective mechanical properties of architected cellular cores.
170 citations
TL;DR: In this article, a comparative study on the reliability of re-entrant honeycomb and non-auxetic lattice composites is presented, which shows that the reentrant topology exhibits lower energy absorption capacity but superior robustness and durability.
117 citations
TL;DR: In this paper, the effects of layer and cell numbers on the quasi-static compressive responses of a lattice sandwich panel are systematically investigated through theoretical modeling, experimental testing, and finite element method.
112 citations
TL;DR: In this article, a combined experimental and numerical study on the dynamic response and failure mechanisms of honeycomb sandwich panels subjected to high-velocity impact by a spherical steel projectile is presented.
110 citations
TL;DR: In this article, the authors investigated the structural properties of aluminum sandwich panels with honeycomb core and found that changes in the core parameters have relatively small influences in total energy absorption but sizeable effects on the force-displacement curve and failure modes.
101 citations
TL;DR: In this paper, the impact performance of sandwich panels with homogeneous and stepwise graded aluminium foam cores subjected to impact loadings was investigated via experimentation and finite element simulation in a drop-weight impact facility at four different velocities, the results of which were compared in terms of force displacement response, energy absorption and damage status.
89 citations
TL;DR: A novel sandwich panel with three-dimensional double-V Auxetic (DVA) structure core was proposed for air blast protection purpose and performed much better both in lightweight and protection than solid plate and has an apparent merit in lightweight aspect compared with square honeycomb core sandwich panel.
82 citations
TL;DR: In this paper, the effects of geometric configurations of corrugated cores on the local impact response and planar compression performance of sandwich panels are presented by FEM in the present research.
Abstract: The effects of geometric configurations of corrugated cores on the local impact response and planar compression performance of sandwich panels are presented by FEM in the present research. Five sandwich panels with various corrugated cores of different geometric configurations with the same size, weight, and materials were designed. The next step was to identify the effects of geometric configurations of the cores on the response of the sandwich panels under minor energy impact and high energy impact. Numerical simulation results of low-velocity local impact show that the geometric configuration of the core had a significant influence on energy absorption capability under minor energy impact. Sandwich panels with sinusoidal and arc-shaped cores caused lower energy absorption due to lower out-of-plane stiffness. Significant debonding occurred in the sandwich panels with sinusoidal, arc-shaped and triangular cores due to a small bonding area. Geometric configuration of the cores has no significant influence on energy absorption capability under high energy impact. Afterwards, the influence of the geometric configuration of corrugated cores on the performance of sandwich panels under planar compression was presented. Numerical results of planar compression show that sandwich panels with sinusoidal and arc-shaped cores have lower compression stiffnesses and lower ultimate strengths. A simplified analytical method for calculating ultimate strength of the five sandwich panels under lateral compression was presented, and the results matches well with the numerical results. Altogether, the trapezoidal corrugated sandwich panel has advantage in energy absorption capability under low-velocity impact and has a better performance under lateral compression among the five kinds of sandwich panels.
65 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 article, the application of full-field vibration measurements in the debonding assessment of an aluminium honeycomb sandwich panel is investigated, where four methods to compute damage indices are evaluated: mode shape curvatures, uniform load surface, modal strain energy and gapped smoothing.
TL;DR: In this paper, the bending behavior of an innovative fiber reinforced polymer (FRP) sandwich panel was investigated for application in a multistory building, and the results showed that the bending stiffness and ultimate bending strength could be enhanced by increasing the web thickness, web height, and facesheet thickness, as well as by reducing web spacing.
Abstract: The bending behavior of an innovative fiber reinforced polymer (FRP) sandwich panel was investigated for application in a multistory building. The panels featured a paulownia wood core reinforced by glass fiber reinforced polymer (GFRP) facesheets and web and was manufactured by a vacuum assisted resin infusion process. Specimens with different web thickness, web spacing, height, and facesheet thickness were loaded under four-point bending to validate the effectiveness of the detailed web configuration in improving panel stiffness and capacity. The results showed that the bending stiffness and ultimate bending strength could be enhanced by increasing the web thickness, web height, and facesheet thickness, as well as by reducing web spacing. An theoretical model based on Timoshenko beam theory was proposed to predict the bending stiffness and ultimate strength of the sandwich specimens. Furthermore, finite element analysis was established to verify the influences of web height, thickness, spacing, and facesheets on the GFRP floor panel performance. The theoretical results showed good agreement with the numerical and experimental results in terms of stiffness and ultimate bending strength. This work therefore assists the design of a multistory building completed with the proposed sandwich panel as the floor system.
TL;DR: In this paper, a truss core sandwich panel is filled with polyurethane foam (PUF) to achieve better vibro-acoustic and sound transmission loss characteristics.
TL;DR: In this paper, a hybrid sandwich beam made with PCTPE (Plasticized Co-polyamide Thermoplastic Elastomer) nylon using Fused Filament Fabrication (FFF).
TL;DR: In this article, the effects of foam filling on the dynamic response of metallic corrugated core sandwich panels by conducting air blast testing were investigated by investigating the influences of specific parameters, like the foam filler density, the core configuration and the filling material, on the blast performance from the aspects of permanent deformation, failure modes and associated mechanisms.
TL;DR: In this article, the in-plane crushing behaviors of the over-expanded honeycomb (OH) were revealed by experiments and it was suggested that the incident angle should not be larger than 45°.
TL;DR: In this paper, transient elasto-plastic deformations of two-core sandwich plates with and without a bumper and subjected to blast loads with the objective of ascertaining the energy dissipated due to plastic deformations.
Abstract: We analyze transient elasto-plastic deformations of two-core sandwich plates with and without a bumper and subjected to blast loads with the objective of ascertaining the energy dissipated due to plastic deformations. The facesheets and the core are assumed to be made of a high strength steel modeled as an isotropic material that obeys the von Mises yield criterion with linear strain hardening. It is first shown that considering a material failure criterion and deleting failed elements does not noticeably affect the energy dissipated in a sandwich plate. Subsequent analyses of two-core structures with and without a blast shield ignore the material failure and assume facesheets to be perfectly bonded to the core. The nonlinear transient problems have been numerically analyzed with the commercial finite element software, ABAQUS/ Explicit. Four different two-core sandwich plates obtained by varying locations of the Miura-ori and honeycomb cores are considered. Results without a shield indicate that using a Miura-ori core beneath the topmost facesheet dissipates more energy for moderate blast loads, while a combination of a honeycomb and a Miura-ori core has the least facesheet deflections. The effects of using a blast shield or a bumper, at a fixed standoff distance from a honeycomb-Miura sandwich panel, is studied by ensuring that the shield and the sandwich structure combination has the same areal density as the sandwich panel without the shield. It is found that for a given blast load, using the shield significantly reduces the energy dissipated in the sandwich panel, the bottom facesheet maximum centroidal deflection and the maximum plastic strain in the cores when compared with equal-weight panels without a shield. For the same energy dissipation, the structure with a blast shield has approximately 42% less weight than that without the shield.
TL;DR: In this article, the dynamic compressive strength of the sandwich panels with shear thickening fluid (STF) filled pyramidal lattice truss cores at high strain rates is compared with that of pure STF as well as the sandwich panel with empty and water filled pyramid truss core by modified split Hopkinson pressure bar (SHPB) apparatus.
TL;DR: In this paper, the authors investigated the energy absorption characteristics of two-layered corrugated core sandwich panels with different arrangements under quasi-static compression loading, and compared the experimental results of these two different arrangements twolayered sandwich panels, it was found that the symmetric-arranged corrugaded sandwich panel has better energy absorption characteristic, which is more than 17.17% at 6 mm displacement before densification stage compare to regularly arranged.
Abstract: In this study, the energy absorption characteristic of two-layered corrugated core sandwich panels with different arrangements under quasi-static compression loading were firstly investigated experimentally. Then compared the experimental results of these two different arrangements two-layered sandwich panels, it was found that the symmetric-arranged corrugated sandwich panel has better energy absorption characteristic, which is more than 17.17% at 6 mm displacement before densification stage compare to regularly-arranged. Numerical calculations were carried out and good agreement is achieved between the experimentally results and numerical results. Finally, parameter analysis and optimization study of the symmetric-arranged two-layered corrugated sandwich panel under planar impact was carried out with crashworthiness criteria by using finite element model and response surface method. The selection of parameters in optimization study were determined by parameter analysis. The size of sandwich panel was firstly optimized for maximizing specific energy absorption (SEA). Then the multi-objective optimization of core cell shape with optimal sandwich panel size was optimized by maximizing SEA and minimizing the peak force, a Non-dominated Sorting Genetic Algorithms (NSGA-II) code was used to perform the optimization process in a gradual evolution trend, which led to obtain the Pareto front that consisted of a set of optimal objective function vectors.
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...
TL;DR: In this paper, a corrugated channel-cored sandwich panel (3CSP) was proposed for simultaneous loadbearing and active cooling applications for convective heat transfer rate and superior mechanical performance.
TL;DR: In this article, a comparison of overall and local flow characteristics and heat transfer between two sandwich panels with single-layered Kagome and wire-woven bulk Kagome cores under an identical porosity is presented.
TL;DR: In this paper, the lattice truss structures (LTS) are used for 3D-printing of sandwich panels and the absorption energy and failure mechanisms of lattice cells under low-velocity impact loads are investigated.
Abstract: Sandwich panel structures are widely used in aerospace, marine, and automotive applications because of their high flexural stiffness, strength-to-weight ratio, good vibration damping, and low through-thickness thermal conductivity. These structures consist of solid face sheets and low-density cellular core structures, which are traditionally based upon honeycomb folded-sheet topologies. The recent advances in additive manufacturing (AM) or 3D printing process allow lattice core configurations to be designed with improved mechanical properties. In this work, the sandwich core is comprised of lattice truss structures (LTS). Two different LTS designs are 3D-printed using acrylonitrile butadiene styrene (ABS) and are tested under low-velocity impact loads. The absorption energy and the failure mechanisms of lattice cells under such loads are investigated. The differences in energy-absorption capabilities are captured by integrating the load–displacement curve found from the impact response. It is observed that selective placement of vertical support struts in the unit-cell results in an increase in the absorption energy of the sandwich panels.
TL;DR: In this paper, the authors compared the thermo-fluidic characteristics of sandwich panels with the X-lattice and the Pyramidal lattice at a given porosity and surface area density.
TL;DR: In this article, a new cohesive zone traction-separation law was developed, implemented with a finite element (FE) model, and applied to simulate the delamination between the facesheet and core of a composite honeycomb sandwich panel.
TL;DR: In this article, experimental and simple analytical studies on the structural behavior of Precast Foamed Concrete Sandwich Panel (PFCSP) were reported, and the computed ultimate strength values using American Concrete Institute equation (ACI318) and other empirical formulas developed by pervious researchers which applicable to predict the ultimate strength capacity of sandwich panels were compared with the experimental test results and FEA data obtained.
Abstract: In this paper, experimental and simple analytical studies on the structural behavior of Precast Foamed Concrete Sandwich Panel (PFCSP) were reported. Full-scale tests on six PFCSP panels varying in thickness were performed under axial load applications. Axial load-bearing capacity, load-deflection profiles, load-strain relationships, slenderness ratio, load-displacement, load-deformation, typical modes of failure and cracking patterns under constantly increasing axial loads were discussed. Nonlinear Finite Element Analysis (FEA) using LUSAS software to investigate the structural behavior of PFCSP was contacted. The computed ultimate strength values using American Concrete Institute equation (ACI318) and other empirical formulas developed by pervious researchers which applicable to predict the ultimate strength capacity of sandwich panels were compared with the experimental test results and FEA data obtained; therefore, very conservative values resulted, a significant agreement with the FEA data that presented a high degree of accuracy with experiments and an increase in slenderness function.
TL;DR: In this article, the authors investigate cylindrical bending deformations of two-layered triangular corrugated and webcore linearly elastic sandwich panels by using the mechanics of materials approach and the classical plate theory.
Abstract: We analytically investigate infinitesimal cylindrical bending deformations of two-layered triangular corrugated and webcore linearly elastic sandwich panels by using the mechanics of materials approach and the classical plate theory. The model is validated by comparing its predictions with the solution by the finite element method of the linear elasticity equations for plane strain deformations. The model can accurately capture the secondary bending of the facesheets, manifested as changes in their curvature between the webs and the resulting changes in the axial stresses, from being tensile to possibly compressive, that the commonly-employed homogenization schemes fail to capture. Subsequently, the model is used to analyze several problems with the sandwich panel having a pinned support at the left edge and a roller support at the right edge, and a uniformly distributed load applied on the top facesheet of the panel. It is found that the core plates mostly deform in compression and bending, respectively, for corrugated and web core panels. Furthermore, a significant fraction of the work done by the external load on the structure is absorbed as strain energy of deformations of the core plates near the supports. For four hybrid combinations of corrugated and webcore configurations in two-layered panels, the combination with the upper corrugated core set-up has the least maximum face sheet deflection and axial stress. The analytical technique can be easily extended to multi-layered hybrid configurations and provides quick means of finding efficient strain-energy absorbing hybrid designs.
TL;DR: In this paper, the vibrational and acoustic properties of a clamped rectangular sandwich panel in high temperature environments were investigated using the piecewise shear deformation theory and the mode superposition method.
TL;DR: In this article, a glass/pp-based sandwich panel has been studied experimentally and numerically with the aims of its potential applications in the automotive structures, and the experimental results achieved for the load-carrying capacity of panels using three-point bend tests for its static flexural behaviour.
Abstract: Cost and recyclability are among the primary factors on exploiting the engineering materials for their new applications. In this context, glass/pp-based sandwich panel has been studied experimentally and numerically with the aims of its potential applications in the automotive structures. The first part of this work presents the experimental results achieved for the load-carrying capacity of panels using three-point bend tests for its static flexural behaviour. Static behaviour is studied to compare the top-roller diameter effect on the flexural behaviour of the panels and shows a significant difference in the results. Impact behaviour of the panels is explored using three different types of impactor end-shapes that generate different levels of damage in the material with the same level of impact energy. The second part of this paper deals with the development of numerical models for the three-point bend and impact behaviour of the panels using a commercial finite element code of Abaqus. Strain energy-bas...
TL;DR: In this article, the authors focused on the sound transmission loss (STL) of the sandwich panels constituted of orthotropic materials in thermal environment and derived the natural frequencies and corresponding mode functions with thermal stresses taking into account.
Abstract: Composite sandwich structures are extensively applied in automotive, marine, aircraft because of superior stiffness-to-weight ratios. These structures are invariably exposed to the thermal and noise environment in their service life especially as a component of the hypersonic aircraft. The paper is originally focused on the sound transmission loss (STL) of the sandwich panels constituted of orthotropic materials in thermal environment. Firstly, the governing equations are obtained by applying Hamilton's principle. Both the natural frequencies and corresponding mode functions are derived with thermal stresses taking into account. The formulation of STL is obtained by using the mode superposition method. Then the published experimental result and numerical simulation are demonstrated to validate the accuracy of the analytical solution. Finally, the influences of temperature, elevation angle and azimuth angle of incident sound on the STL of finite sandwich panels are investigated systematically. It is observed that natural frequencies of the panel decrease and peaks of the STL tend to drop and flow to the lower frequencies with the increment of the temperature. The STL decreases with the increment of the elevation angle.