Tensile post-impact behaviour of thin carbon/epoxy and glass/epoxy hybrid woven laminates – Part I: Experimental study

Abstract

This article concerns the study of post-impact damage propagation in two thin hybrid woven composite laminates loaded in tension. Low velocity normal drop weight impact tests are first performed. Post-impact quasi-static tensile tests are then carried out and monitored by Digital Image Correlation. The influence of the impact energy variation on the fracture surfaces and the residual strength is studied. In order o have a better understanding of the mechanisms involved into the hybrid laminates, four monomaterial sample configurations are also tested. When the damage after impact is barely visible, the sample behaves as a non-impacted sample. When the damage is visible, it propagates whatever the impact energy. The damage grows in the direction perpendicular to the loading for all the monomaterial laminates while two different damage scenarios are observed for the hybrid laminates. The residual strength evolves in three steps depending on the impact energy: first a very low decrease, then an important drop and finally a plateau.