Investigation of Mode I Delamination Resistance in Inter-ply and Intra-ply Hybrid Composites Reinforced with Basalt/Nylon Woven Fabrics

Due to their sensitivity to impact-induced delamination, woven fabric reinforced polymer composites have limited practical applications. Hybridization of polymer composites has been proposed as a solution to this problem. In this study, the effects of fiber reinforcement type, hybridization method, plies stacking sequence and loading rate on mode I delamination behavior of pure basalt, pure nylon, inter-ply and intra-ply hybrid (basalt/nylon) composites were investigated. Composites were length during its propagation in composite samples was measured by mode I delamination test. The inter-laminar fracture toughness of composite specimens was calculated using modified double-cantilever beam theory and the results were compared by statistical methods. A 30 to 80% improvement in the critical fracture toughness of intra-ply hybrid composite compared to pure ones was recorded. Moreover, the delamination initiation load decreased significantly by increasing the loading rate.