Impact behavior of laminated composites: Physical basis for finite element analysis

The aim of this paper is to present a method for taking into account, in numerical terms, the physics of damage events occurring during impact of composite structures and considering both the constraints of the explicit 3D finite-element analysis (especially the stability condition which links time and spatial discretisation) and the lack of local observations during impact. An explicit finite-element code is used to model the dynamic characteristic of the impact loading. We present two approaches for the modeling of damage phenomena: (I) averaging models and the contact technique, (2) simple criteria for determining damage initiation and growth. The latter approach is applied here to the impact loading of symmetric 10-ply glass/epoxy 0/90 laminated plates. In this case matrix cracking controls delamination and hence is considered to be of primary importance. (C) 1998 Elsevier Science Ltd. All rights reserved.