The effect of shock-wave profile on dynamic brittle failure

TL;DR

This study investigates how shock-wave profile affects brittle failure in tungsten heavy alloy, finding that peak stress, not pulse duration, governs damage and failure mechanisms.

Contribution

It demonstrates that in brittle tungsten alloy, shock pulse duration does not influence failure, with damage driven primarily by peak stress, contrasting with ductile materials.

Findings

Spall strength is similar across different pulse durations.

Failure is dominated by brittle cleavage fracture.

Damage kinetics depend mainly on peak stress.

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.