Strain-Rate Effects in Metals

Abstract

A series of computations has been completed which investigates strain‐rate effects on stress‐wave propagation in metals. The principal difficulty in calculations of this type is the choice of a functional relationship between stress, strain, and strain rate. Experimental results have shown that the stress‐strain relation of a material experimentally determined under quasistatic conditions may not be extended to dynamic conditions, i.e., the rate of loading is important. Therefore, a relation between stress, strain, and strain rate was constructed that is consistent with the experimental observations of plastic wave propagation in high‐purity aluminum rods (one‐dimensional stress) and adapted to the behavior of 6061‐T6 aluminum. This function was then used to calculate the propagation characteristics of a stress pulse propagating in a state of one‐dimensional strain. The calculations compare favorably with the experimentally observed dynamic behavior of 6061‐T6 aluminum impacted at 322 m/sec.