Approaching steady cavitation: The time scale in hypervelocity cavity expansion in work hardening and transformation hardening solids

• Theoretical and numerical analysis of dynamic spherical cavity expansion.
• Evaluation of the time required to approach the steady-state limit.
• Appearance of plastic shock waves at hypervelocities.
• Strain hardening does not play a role in dynamic cavitation instabilities.

The extreme phenomena of dynamic cavitation is studied both theoretically and numerically for two families of strain hardening materials. Though analytical results are limited to the steady, self-similar expansion state, the numerical approach facilitates investigation of the transient response, including evaluation of the time required to approach the steady-state limit. While recent studies show that shock waves may appear in hypervelocity cavity expansion fields, the present study suggests a numerical model which can capture the appearance and evolution of these shock waves. That model is validated by comparison with theoretical results at the steady-state limit, thus facilitating future investigation of the dynamic response for materials with more complicated constitutive behavior, for which theoretical results are limited. The constitutive sensitivities are also examined, showing that the specific hardening response of the material has little effect on the cavitation response.