Characterization of mechanical behaviors of advanced thermoplastic composite after impact

Abstract

The objective of this study is to characterize the effect of impact damage on static and fatigue mechanical behaviors of advanced thermoplastic composites Gr/PEEK (AS-4/APC-2 and IM-7/APC-2), and the conventional thermoset composite, Gr/Epoxy (T-300/976) for comparison purpose. The specimens of 16-ply quasi-isotropic stacking sequence were drop-weight impacted, and compression and tension after impact were tested to measure the reduction of the static compressive strength and tensile strength. The results show that the compressive and tensile retention strength after impact for the three materials are both in the order: IM-7/APC-2 > AS-4/APC-2 > T-300/976. To characterize the fatigue mechanical behavior, tension-tension cyclic loading were applied on impact damaged laminates. The results show that the impact damages have no effect on the fatigue characteristics of laminates, but will reduce the fatigue life. The fatigue life of impact damaged laminate can be predicted by the parameters of the S-N curve of un-impacted laminates and the static retention strength of impact damaged laminates.