Abstract

In this work the different failure mechanisms have been studied on 5HS woven composite laminates subjected to low velocity impacts. A large range of energies (5-75J) has been used to induce different failures: delamination, fiber failure, out-plane shear and perforation. In addition, different configurations of AGP 280-5HS woven coupons have been manufactured to analyze the influence of thickness ((0/90)4S, (0/90)6S and (0/90)8S) and ply sequence ((0/90)8S, (±45)8S, [(±45)/(0/90)]4S, [(±45)2/(0/90)2]2S, and [(±45)4/(0/90)4]S)). Laminates have been subjected to low velocity impact using an INSTRON-CEAST Fractovis 6875 drop weight tower according to ASTM standards (D7136). Each test has been recorded with two high speed video-cameras (Photron SA-Z 2100K) in order to analyze the plate behavior during the impact. In addition, a three dimensional high velocity digital image correlation (HV-DIC) analysis has been performed to measure the out of plane displacement. Once impacted, the damaged area of the composite laminates was evaluated by ultrasonic inspections. The analysis of the influence of the plate thickness and ply sequence have been made according to the Composite Structure Impact Performance Assessment Program (CSIPAP) proposed by Feraboli and Kedward using the peak force and the absorbed energy.