Prediction of Impact-Induced Damage Accumulation in a Composite Using a Macromolecular Polymer Model

Polymers and their composites are increasingly sought for applications where impact resistance constitutes an important design specication. One example of practical significance is the use of polymer-based composites in novel designs of fan blade containment cases (BCCs) of jet engines. During a blade-out event, a failed blade may penetrate the BCCs, but damage has to be contained within the composite. Here, we develop the basic ingredients of a multiscale modeling methodology with focus on the scale of the basic structural unit, where polymeric matrix and reinforcements are explicitly modeled. The polymer model accounts for nonlinear behavior, nite strains, intrinsic softening, tensioncompression asymmetry, rate-sensitivity, thermal softening and kinematic-like hardening associated with macomolecular mechanisms of chain reorientations. In addition to the polymer model, models of matrix cracking and b er debonding are used. The material parameters entering the macromolecular model are identied based on tests conducted on an untoughened epoxy resin for a wide range of temperatures and strain rates. Results from unit-cell calculations are presented to discuss damage initiation and progression as well as competition between modes of failure.