Dynamic crushing of composite coupons: An experimental and numerical study

Abstract

Dynamic crushing of composites is studied proposing an optimised experimental design: flat, millimetre-scale specimens reduce geometrical influences and facilitate detailed numerical studies. Crushing behaviour is investigated on a universal testing machine and a drop-tower at varying loading rates using two different force measurement techniques. The results show a decrease in the maximum stress and absorbed energy at elevated rates due to a higher extent of delamination, caused by strain-rate-induced increase of intralaminar damage property values. The experiments are simulated in an explicit finite element solver with different through-thickness discretisation, showing that a stacked-laminate model is incapable of reproducing the crushing response at high velocities. However, a discrete-ply model is capable of describing the main failure mechanisms and energy absorption for all loading rates. Further improvement of the model’s predictive capability could be achieved by adding a plasticity formulation in the ply material model.