Comparative study on the impact behavior and damage tolerance of woven carbon fiber reinforced thermoplastic– and thermosetting– composites

Abstract

The purpose of this study is to compare the response of TS-based (epoxy) and TP-based (PPS or PEEK) laminates under low velocity impacts. In order to assess the development of internal damage caused by the different impact energies, non-destructive examinations were done. Impact tests created pyramidal-shaped damage at the center of the specimen, extensive delamination and fiber breakages inside laminates, as well as inter laminar and intra-ply damage. CAI tests showed that PEEK-based composites display the best performance, and the compressive residual strengths of C/PPS and C/Epoxy are the lowest for every impact energy. It turns out that the three materials display a rather similar behavior at increasing impact energy as delaminated areas are larger in C/Epoxy and C/PEEK, whereas the PPS matrix toughness contributes to a less extended delaminated area. One reason for the disappointing residual strength of TP-based composites may be the constraint on the development of the plastic deformation zone in the resin rich area between the woven-plies and at the fiber bundles crimp, preventing the matrix toughness to give to the laminates a better damage tolerance.