Modelling impact damage in marine composite panels

In order to establish the survivability of a composite structure under a dynamic load, it is important to be able to predict the damage incurred and the effect of the contact force. The damage caused by low velocity impact is often hidden and for thicker plates the transverse stresses are significant in promoting delamination. In this study, woven vinyl-ester composite plates up to 1.37 m long are numerically modelled with a simple, gradually damaging three-dimensional material model and the results are compared with full-scale tests. The model is based on damage mechanics principles using cyclic test data to obtain modulus reduction with damage. Delamination is modelled with a mixed-mode traction-separation law using cohesive elements. The nonlinear elastic orthotropic material model for the woven plies is written in a VUMAT in Abaqus/Explicit and the effects of varying some of the modelling parameters are briefly discussed through the examination of the contact force.