The effect of shock-wave profile on dynamic brittle failure

Abstract

The influence of shock-wave-loading profile on the failure processes in a brittle material has been investigated. Tungsten heavy alloy (WHA) specimens have been subjected to two shock-wave loading profiles with a similar peak stress of 15.4 GPa but different pulse durations. Contrary to the strong dependence of strength on wave profile observed in ductile metals, for WHA, specimens subjected to different loading profiles exhibited similar spall strength and damage evolution morphology. Post-mortem examination of recovered samples revealed that dynamic failure for both loading profiles is dominated by brittle cleavage fracture, with additional energy dissipation through crack branching in the more brittle tungsten particles. Overall, in this brittle material all relevant damage kinetics and the spall strength are shown to be dominated by the shock peak stress, independent of pulse duration.