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

Bending, buckling and free vibration of laminated composite and sandwich beams: A critical review of literature

https://northumbria-test.eprints-hosting.org/id/document/265204

A review of continuum mechanics models for size-dependent analysis of beams and plates

A first gradient nonlocal model of bending for Timoshenko functionally graded nanobeams based on the Eringen model is proposed. The material properties vary in the thickness direction. A thermodynamic approach is used to provide the variational formulation of the nonlocal model. The governing equations for nanobeam bending with the relevant higher order boundary conditions are then consistently derived. Analytical solutions of the proposed nonlocal functionally graded nanobeam model are provided for a simply supported beam in terms of rotations and transverse displacements. Current results are then compared with existing ones to establish the validity of the present formulation.

Functionally graded Timoshenko nanobeams: A novel nonlocal gradient formulation

A novel three-variable shear deformation plate formulation: Theory and Isogeometric implementation

In this paper, the bending and buckling analyses of shear deformable laminated composite curved beams with arbitrary lay-up and curvature are presented based on the NURBS-based isogeometric approach. The equivalent modulus of elasticity is utilized to account for all the material couplings in laminated composite curved beams and the deepness term is exactly integrated into laminate stiffness parameters. The displacement field, geometry and curvature are all together modelled by NURBS. Results of the non-dimensional maximum deflection and the non-dimensional critical buckling load are compared with other available results in order to demonstrate the validity of the proposed isogeometric analysis framework. The buckling response of laminated circular beams under uniform compression and parabolic curved beams subjected to a vertical load uniformly distributed along the span is investigated. The buckling mode transition phenomenon is exhibited for both types of curved beams.

Bending and buckling of general laminated curved beams using NURBS-based isogeometric analysis

NURBS-based isogeometric vibration analysis of generally laminated deep curved beams with variable curvature

In this paper, the finite free-form curved beam element is formulated by the isogeometric approach based on the Timoshenko Rcurved beam theory to investigate the free vibration behavior of the curved beams with arbitrary curvature. The non-uniform rational B-splines (NURBS) functions which define the geometry of the curved beam are used as the basis functions for the finite element analysis. In order to enrich the basis functions and to increase the accuracy of the solution fields, the h-, p-, and k-refinement techniques are implemented. The geometry and curvature of free-form curved beams are modelled in a unique way based on NURBS. The gap between the free vibration analysis of the curved beams with constant curvature and those with variable curvature is eliminated. All the effects of the axis extensibility, the shear deformation, and the rotary inertia are taken into consideration by the present isogeometric model. Results of the parabolic and elliptic curved beams for non-dimensional frequencies are compared with other available results in order to show the accuracy and efficiency of the present isogeometric approach. Furthermore, the free vibration analysis of the elliptic thick rings is presented. Particularly, the Tschirnhausen’s cubic curved beam is considered to study the dynamic behavior as an example of free-form curved beams.

Nam-Il Kim

Papers

Bending and buckling of general laminated curved beams using NURBS-based isogeometric analysis

NURBS-based isogeometric vibration analysis of generally laminated deep curved beams with variable curvature

Isogeometric vibration analysis of free-form Timoshenko curved beams

Analysis of thin-walled open-section beams with functionally graded materials

Mixed finite element analysis of nonlocal Euler-Bernoulli nanobeams