Elastomeric Polymers for Shockwave Mitigation and Extreme Loading Conditions

Abstract

Recent investigations into blast resistant properties of polymers with high rate sensitivity, have shown that they interact with the underlying substrates in quite different manner than any ballistic material known to the shock community. We are going to discuss in this paper that these polymers have a profound effect on the failure (fracture) mechanism of the substrate: suppression or delay of shear localization (or penetration) mechanisms, and delay of necking instability in ductile metals, in addition to dissipating large amounts of energy through wave reflections. The intrinsic property of the polymer under blast/ballistic/ shock, in addition to its high strain rate sensitivity, is a very large increase of its shear properties, both modulus and strength, under very high pressure and loading rate, which exists under extreme loading conditions. In addition, because these elastomeric polymers are multi-phase of hard and soft domains, at the nano scale, they can dissipate broad bands of frequencies such as those encountered in blast events. We will discuss also research in the development of polymers-by-design to divert and dissipate shockwaves from the head and thus prevent Traumatic Brain Injury—TBI, using molecular dynamics, polymer synthesis and high strain rate testing of shock properties for constitutive models, and the continuum analysis of shockwave propagation.