Influence of delamination on impact damage in composite structures

This paper describes recent progress on materials modelling and numerical simulation of fibre reinforced composite shell structures subjected to high velocity impacts. A continuum damage mechanics (CDM) model for fabric reinforced composites is applied to model both in-ply damage and delamination failure during impact loading. The CDM model has been implemented in a commercial explicit finite element (FE) code in which a laminate is modelled by stacked shell elements with tied interfaces. Delamination failure is modelled by allowing the interfaces to damage and fracture when a delamination failure energy criterion is reached. The code is applied to predict the response of composite shells subjected to gas gun impact tests by a steel impactor under a range of test conditions. A comparison of structural response and failure modes from numerical simulations and impact tests shows good agreement for the prediction of delamination damage and shell penetration at higher impact energies.