Impact energy absorption composites with shear stiffening gel-filled negative poisson's ratio skeleton by Kirigami method

Abstract

A new type of Negative Poisson's ratio skeleton composites (NPRSC) filled with shear stiffening gels (SSG) is presented in this work. The skeleton is manufactured by Kirigami method for a simplest folding process. Combined with the shear stiffening property of SSG and auxetic effect of Negative Poisson's ratio (NPR) skeleton, the flexible composites show excellent impact energy absorption performance. Static compression experiment displays that compared with Positive Poisson's ratio (PPR) skeleton, the NPR structure composed of re-entrant elements is more flexible with a lower initial compression modulus for its special curvature effect. Dynamic impact experiments and numerical simulation reveals that the auxetic effect of NPR skeleton further facilitates the dynamic shear stiffening property of SSG and helps to dissipate the stress transversely. Specifically, the NPR skeleton contributes to a lower peak load, higher energy absorption ratio (EAR) and specific energy absorption (SEA) cooperated with SSG. The NPRSC exhibits improved energy absorption with the increase of impact velocity due to the strain rate sensitivity of SSG. This method provides an innovative idea for the structural design of shear stiffening materials and may be widely applied in the field of intelligent protection.