Low-velocity impact and in-plane axial compression after impact(CAI)behaviors of carbon-aramid/epoxy hybrid braided composite laminates were investigated experimentally.The following three different types of carbon-aramid/epoxy hybrid braided composite laminates were produced and tested:(a)inter-hybrid laminates,(b)sandwich-like inter-hybrid laminates,and(c)unsymmetric-hybrid laminates.At the same time,carbon/epoxy braided composite laminates were used for comparisons.Impact properties and impact resistance were studied.Internal damages and damage mechanisms of laminates were detected by ultrasonic C-scan and B-scan methods.The results show that the ductility index(DI)values of three kinds of hybrid laminates aforementioned are 37%,4%and 120%higher than those of carbon/epoxy laminates,respectively.The peak load of inter-hybrid laminates is higher than that of sandwich-like inter-hybrid laminates and unsymmetric-hybrid laminates.The average damage area and dent depths of inter-hybrid laminates are 64%and 69%smaller than those of carbon/epoxy laminates.Those results show that carbon-aramid/epoxy hybrid braided composite laminates could significantly improve the impact properties and toughness of non-hybrid braided composite laminates.
