On probabilistic aspects in the dynamic degradation of ductile materials

TL;DR

This paper investigates how high stress waves during dynamic loading cause spallation in ductile materials, using a probabilistic model to explain the influence of stress rate on cavity nucleation and material failure.

Contribution

It introduces a probabilistic framework to analyze the strain-rate dependence of spall strength, explaining experimental observations on tantalum and other ductile metals.

Findings

Spall strength increases with stress rate.

Nucleation inhibition affects cavity growth.

Model aligns with experimental data on tantalum.

Abstract

Dynamic loadings produce high stress waves leading to the spallation of ductile materials such as aluminum, copper, magnesium or tantalum. The main mechanism used herein to explain the change of the number of cavities with the stress rate is nucleation inhibition, as induced by the growth of already nucleated cavities. The dependence of the spall strength and critical time with the loading rate is investigated in the framework of a probabilistic model. The present approach, which explains previous experimental findings on the strain-rate dependence of the spall strength, is applied to analyze experimental data on tantalum.