Compression-after-impact response of woven fiber-reinforced composites

We have conducted an integrated experimental and numerical analysis to study the compression-after-impact (CAI) response of woven fiber-reinforced composites.

The material used is glass fiber reinforced vinyl-ester composites. Rectangular panels of this composite specimen are subjected to impact damage followed by compression until failure. Compression failure of composite structures previously damaged by an impact event is due to the propogation of impact-induced damage mechanisms such as interlaminar debonding, constituent (matrix and fiber) microcracking, sublaminate buckling as well as interactions between these mechanisms. The failure mechanisms within each ply are idealized based on a reduced order multiscale computational model, in which, the damage propagation in the matrix and fibers upon compression is explicitly modeled. Delamination along the ply interfaces is idealized using a cohesive surface model. The numerical investigations suggest extensive propagation of delamination with mode transition preceding sublaminate buckling. Initiation and propogation of matrix and fiber cracking, observed upon sublaminate buckling, is the cause of ultimate shear failure.  Our paper will be published in Composites Science and Technology.