Low velocity impact responses of hollow core sandwich laminate and interply hybrid laminate

Two different fabrics, an integrated hollow pile glass fabric and a nonwoven mat, inlaid into multiaxial warp knit blankets were laminated to form a sandwich structure and a hybrid structure. The impact loads and the energies of the panels corresponding to different damage characteristics under drop-weight tests were calculated. Fracture patterns and damage characteristics were observed and photographed using a camera. The damage characteristics of the penetration process in both laminates are described in this study. Significant delamination was found in both the sandwich laminate and the hybrid laminate, which would be a reason to improve the impact energy absorption. Results showed that the inlaid materials played a very important role in the impact behavior and damage characteristics of the laminates.