Application of cohesive zone elements in damage analysis of composites: strength prediction of a single-bolted joint in cfrp laminates

Abstract

Cohesive zone elements are implemented in 3-D finite element models in order to develop a strength prediction method for single-bolted joints in CFRP composite laminates. The motivation for using the CZEs is to avoid experimental correlation factors by directly simulating the subcritical damage mechanisms, which initiate and grow before the catastrophic failure of the joints. The CZEs, placed in the experimentally determined damage locations, receive shear loads and the corresponding shear stresses cause stress concentration relief around the hole boundary. Therefore, a simple maximum stress failure criterion is used to predict the final failure of the joints when the stress level at the 0 degrees layers reaches the ultimate compressive strength. It is shown that the effect of various joint geometries and laminate lay-ups on the joint strength can be accurately accounted for by the method developed.