Nonlinear Dynamic Finite Element Analysis of Thick Transversly Flexible Sandwich Panel on Elastic Foundation with Account of Damage Progression in Time. Part 1. Three-Dimensional Formulation and Two-Dimensional Plate Theory

摘要

In order to construct a plate theory for a thick transversely compressible sandwich plate with composite laminated face sheets, the author makes simplifying assumptions regarding distribution of transverse strain components in the thickness direction. It is assumed that the transverse strains, i.e., v,, e,..,and e.. do not vary in the thickness direction within the face sheets and the core, but can be different functions of the in-plane coordinates in different sublaminates (the face sheets and the core). An algorithm, which takes account of damage progression in dynamic problems, is incorporated into the computational scheme based on the geometrically nonlinear formulation, and is applied to failure analysis of a sandwich plate under ground impact. The proposed model of the sandwich plate does not require many degrees of freedom in the finite element computations and has a wide range of applicability: it can be applied to the sandwich plates with a wide range of ratios of thickness to the in-plane di-mensions, with both thin and thick face sheets (as compared to the thickness of the core) and to the sandwich plates with both transversely rigid and transversely compressible face sheets and cores.