Assessment of the Refined Zigzag Theory for bending, vibration, and buckling of sandwich plates: a comparative study of different theories

A nonlinear theory for doubly curved anisotropic sandwich shells with transversely compressible core

The area of sandwich construction has been an active field of research for more than five decades. During this period, a large number of mathematical models for structural sandwich panels has been provided, ranging from the early sandwich membrane models to more sophisticated recent approaches. Especially during the past decade, the increasing demand for high-performance, lightweight structures has stimulated a strong trend toward the develoment of refined models for sandwich plates and shells. The main focus of the present paper is a survey of recent developments and contemporary trends in the modeling of the deformation and buckling behavior of sandwich shells. The development of refined sandwich models is illustrated by an approach recently proposed by the authors. The basic ideas and features of this model are outlined and compared to alternative recent approaches presented by other authors.

Advances in the Structural Modeling of Elastic Sandwich Panels

In the present paper, a new improved high-order theory is presented for biaxial buckling analysis of sandwich plates with soft orthotropic core. Third-order plate theory is used for face sheets and quadratic and cubic functions are assumed for transverse and in-plane displacements of the core, respectively. Continuity conditions for transverse shear stresses at the interfaces as well as the conditions of zero transverse shear stresses on the upper and lower surfaces of plate are satisfied. The nonlinear Von-Karman type relations are used to obtain strains. Also, transverse flexibility and transverse normal strain and stress of the orthotropic core are considered. The equations of motion and boundary conditions are derived by principle of minimum potential energy. Analytical solution for static analysis of simply supported sandwich plates under biaxial in-plane compressive loads is presented using Navier’s solution. Effect of geometrical parameters of face sheets and core and biaxial loads ratio are studied on the overall buckling of sandwich plates. Comparison of the present results with those of the three-dimensional theory of elasticity and some plate theories confirms the accuracy of the proposed theory.

Biaxial buckling analysis of soft-core composite sandwich plates using improved high-order theory

An improved higher order zigzag theory is presented and it is applied to study the buckling of laminated sandwich plates The present theory satisfies the conditions of transverse shear stress continuity at all the layer interfaces including transverse shear stress free conditions at the top and bottom surfaces of the plate The variation of in-plane displacements through thickness direction is assumed to be cubic for both the face sheets and the core, while transverse displacement is assumed to vary quadratically within the core but it remains constant over the face sheets The core is modeled as a three-dimensional elastic continuum An efficient C 0 finite element is proposed for the implementation of the improved plate theory The accuracy and range of applicability of the present formulation are established by comparing the present results with 3D elasticity solutions and other results available in literature

W.X Yuan

Papers

Overall and local buckling of sandwich plates with laminated faceplates, part II: Applications