The review outlines modern trends in theoretical developments, novel designs and modern applications of sandwich structures. The most recent work published at the time of writing of this review is considered, older sources are listed only on as-needed basis. The review begins with the discussion on the analytical models and methods of analysis of sandwich structures as well as representative problems utilizing or comparing these models. Novel designs of sandwich structures is further elucidated concentrating on miscellaneous cores, introduction of nanotubes and smart materials in the elements of a sandwich structure as well as using functionally graded designs. Examples of problems experienced by developers and designers of sandwich structures, including typical damage, response under miscellaneous loads, environmental effects and fire are considered. Sample applications of sandwich structures included in the review concentrate on aerospace, civil and marine engineering, electronics and biomedical areas. Finally, the authors suggest a list of areas where they envision a pressing need in further research.

Review of current trends in research and applications of sandwich structures

On the free vibration analysis of laminated composite and sandwich plates: A review of recent literature with some numerical results

Finite element analysis of dynamic progressive failure of plastic composite laminates under low velocity impact

An overview of layerwise theories for composite laminates and structures: Development, numerical implementation and application

A review on works that investigate the mechanical behaviour of variable stiffness composite laminated panels is carried out in this paper. The review mostly focuses on buckling, failure and vibrati...

A review on the mechanical behaviour of curvilinear fibre composite laminated panels

It is very challenging to accurately analyze the displacement and stress fields in the laminated composite structures due to the transverse anisotropy and higher transverse flexibilities. The equivalent single-layer theory (EST) is first developed to simplify this complex 3D problem to a pure 2D problem based on a displacement assumption in the thickness direction. The EST gives good results for the global responses of the very thin laminates with minimum computation cost, but poor results for the local responses at the interfaces and can not presents the zig-zag distribution of in-plane displacements. The elasticity solutions based on the 3D displacement-based finite element method (FEM) can present the accurate displacement and stress fields, but requires huge computational cost. As a quasi 3D method, the layerwise theories (LWT) is more accurate than most of the ESTs, and its computational cost is less than that of the 3D-based displacement FEMs, so it is attracting more and more attention with the rapid development of computer technology. This paper presents an overall review for the LWTs of the laminated composite structures and their applications. In general, there are two basic schemes employed to establish a LWT according to the construction of the displacements fields in the thickness direction. In the first scheme, the laminated composite structures are described as an assembly of individual layers, and these individual layers are combined by the interlaminar relationships to keep the displacement continuity and stress equilibrium. All of the individual layers are simulated by using the EST. In the second scheme, the displacement and/or stress fields along the thickness direction are constructed by a 1D interpolation functions and the in-plane displacement and/or stress fields are discretized by the 2D finite elements. The review in this paper is organized by the this classification.

Layerwise Theories of Laminated Composite Structures and Their Applications: A Review

For the delamination and matrix crack prediction of composite laminated structures, the methods based on the damage mechanics and fracture mechanics are most commonly used. However, there are very few methods that can accurately simulate the delaminations together with matrix cracks, although the in-plane matrix cracks always exist alongside the delaminations under impact loading. In this work, an extended layerwise method is developed to model the composite laminated beam with multiple delaminations and matrix cracks. In the displacement field, the nodes in the thickness direction are located at the middle surface of each single layer, the top surface and the bottom surface of the composite beams. The displacement field contains the linear Lagrange interpolation functions, the one-dimensional weak discontinuous function and strong discontinuous function. The strong and weak discontinuous function are applied to model the displacement discontinuity induced by delaminations and the strain discontinuity induced by the interface between the layers, respectively. Because the nodes in the thickness direction are located at the middle surface of each single layer, the extended layerwise method can be conveniently employed to deal with the in-plane matrix cracks combined with the extend FEM. Copyright © 2014 John Wiley & Sons, Ltd.

An extended Layerwise method for composite laminated beams with multiple delaminations and matrix cracks

Extended layerwise method of laminated composite shells

A layerwise/solid-element method for the composite stiffened laminated cylindrical shell structures

In the traditional analysis schemes of the composite sandwich structures the core is firstly simplified as an equivalent anisotropic material and then modeled by the plates and shells theories. Its main disadvantage is that the equivalent core will result in large equivalent error especially in the key area and the thick core will further reduce the analysis accuracy of the plates and shells theories. Therefore, a layerwise/solid-element method (LW/SE) is proposed in this paper, in which the layerwise theory is used to model the behavior of the composite laminated facesheets while the eight-noded solid element is employed to discretize the core. Three models, the full model, the local model and the equivalent model, are presented to model the core. Several numerical examples are investigated and the static analysis and free vibration analysis of the composite sandwich plates are tested. The results of proposed method are in good agreement with those of 3D finite element model. A detailed comparative study is conducted to investigate the performance of three modeling schemes for static analysis and free vibration analysis problems.

D.H. Li

Papers

Layerwise Theories of Laminated Composite Structures and Their Applications: A Review

An extended Layerwise method for composite laminated beams with multiple delaminations and matrix cracks

Extended layerwise method of laminated composite shells

A layerwise/solid-element method for the composite stiffened laminated cylindrical shell structures

A layerwise/solid-element method of the linear static and free vibration analysis for the composite sandwich plates