RETRACTED ARTICLE: Rate-dependent behavior and failure characteristics of carbon/Kevlar hybrid woven composites

Abstract

Rate-dependent behavior together with failure characteristics of carbon/Kevlar hybrid woven composite under high-strain-rate impact loading were examined. High levels of strain rate, 1008/s∼1922/s, tests were conducted on the cylindrical carbon/Kevlar hybrid composite specimen by means of a Split Hopkinson pressure bar (SHPB) and a high pressure gas gun system. The dependence of flow stress on the strain rate was determined firstly. In order to investigate the micro-structural failure mechanisms on the dynamic characteristics of carbon/Kevlar hybrid woven composite, then the fractured zones in the SHPB tests were analyzed by an optical and a scanning electron microscope. According to the high-strain-rate compressive test results, the flow stress at the level of strain 0.01 and peak stress of the materials increased by as much as 52% and 80 % with increasing strain rate over the range of 1008/s to 1922/s. The failure strain, however decreased by approximately 16%. Microscopic examination of the carbon/Kevlar hybrid woven composite showed complicated and multiple growth of various failure mechanisms, such as matrix fracture, fiber/matrix interfacial debonding, yarn-to-yarn friction and wear, fiber breakages including fiber pull-out and fibrillation at the broken fiber tip. Particularly, extensive delamination induced the final fracture of the materials.