Numerical modelling of impact damage

A method is described for predicting barely visible impact damage in realistic composite structures. It avoids a three-dimensional finite element analysis by ‘embedding’ coupon tests as a calibrator in the finite element model of the larger actual structure. Predictions are then made for all the dynamic responses including force and strain histories. A theoretical method is devised for predicting threshold fracture loads. This strategy is successfully validated by tests for carbon composite structures, and then extended to glass and Kevlar laminated plates with varying degrees of success.