A Constitutive Model for Glass Fibre Fabric Composites under Impact

Abstract

A new composite constitutive failure model for woven glass fibre fabric reinforced with epoxy/polyester was developed, and implemented into an explicit dynamic non-linear finite element code for both the shell and solid element implementation. The approach uses a novel damage mechanics formulation to predict both matrix cracks and fibre fracture in the warp and weft directions with the woven fabric composite, subject to an impact or other dynamic event. Strain-rate effects are implicitly incorporated into the model using a damage lag methodology. Results are compared with laboratory composite beam and plate impact experiments. The comparisons indicate that the damage model can predict with reasonable accuracy the damage modes observed in the laboratory experiments. Conclusions are presented also on the logical extensions to the damage formulation necessary to improve both the accuracy and the scope of composite materials that may be analysed.