Shear response behavior of SSE/Kevlar composite fabric before and after shear interlocking effect

Shear stiffening gel (SSG) material was obtained by high-temperature polymerization with boric acid and hydroxyl silicone oil, shear stiffening elastomer (SSE) material was enhanced by vulcanization, and the rheological properties were analyzed. SSG and SSE/Kevlar composite fabric was obtained by “dip–dry” and “hot-pressing” process, and a picture frame test was performed on neat fabric and composite fabrics under three loading rates. The in-plane shear deformation behaviors of the fabrics were characterized by the DIC marker method, and the shear deformation mechanism of braided cells was analyzed theoretically. The results show that the SSG material has superior shear stiffening characteristics, whereas the SSE material has a much higher initial degree of crosslinking and does not have cold-flow characteristics. The fabrics experience typical shear interlocking behavior in shear deformation, and different shear deformation stiffness and energy absorption capacity before and after the shear interlocking was observed, which is caused by the different resistance mechanisms of braided cell to external shear force. The strain rate phase-change characteristics of SSG and SSE materials make the composite fabric have higher shear deformation stiffness and energy absorption at high speed, and SSE material significantly reduces the contact force between adjacent yarns after shear interlocking.