Failure indentation analysis of composite sandwich plates via hierarchical models

In this study, an indentation failure analysis of sandwich composite plates via several higher-order theories is presented. The unified formulation by Carrera is adopted in order to derive displacement based or mixed, refined theories based on an equivalent single layer approach or a layerwise one. In this manner, out-of-plane normal and transverse shear stresses responsible for the indentation failure can be accurately described. A closed form, Navier-type solution is assumed. Simply supported plates made of fibre-reinforced polymeric skins and foam cores are investigated. The side-to-thickness ratio, a/h, and the indenter side dimension are considered as analysis parameters. The effect of skins' lamination and thickness is also investigated. Failure indentation is described in terms of failure loading value and failure position. The variation of displacement and stress fields near the indentation area are also presented. The accuracy of the proposed theories is assessed towards Pagano's three-dimensional exact solution. The obtained results show that higher-order models are required to accurately describe the indentation failure of sandwich plates.