Energy Absorption in the Gigapascal Range – Methods to Absorb Energy for Extreme Mechanical Loads

Design of architected structures and materials for energy absorption is straightforward – choose a solution that maximizes specific energy absorption for a given loading amplitude while keeping below some maximum allowable threshold stress. Novel materials and architectures of lattices and foams have increased the specific energy absorption capacity and threshold stresses that can be tolerated, but these structures are generally dominated by the densification phase for loads exceeding hundreds of Megapascals. In this talk we examine the potential for volume-reducing phase transformations to manipulate waves with amplitudes up to tens of Gigapascals. As an example, the ability for the ��→�� transformation to absorb shock waves in Fe and its alloys is studied for monolithic and hierarchically structured materials using both experiments and computer simulations. Methods are presented for designing new metal alloys, both monolithic and graded, that can achieve high specific energy absorption.