Stress release waves in plastic solids

Abstract

Better understanding of damage under high strain rate deformation is critical; whether assessing the impact of new weapon systems, calculating safety issues, or even modeling modern high speed machining. Mott waves, one of the keystones needed to predict bomb debris size, are reexamined. Mott assumed instantaneous through thickness crack propagation and stress relaxation waves unloading the material surrounding the crack. But, following experimental evidence, crack extension velocity actually has limits. A new energy balance based framework, considering damage development during stress release waves propagation is presented. Exact boundaries for the time and wave position at failure are established. Particular wave paths close to these boundaries are analyzed. This work will be the basis to predict more accurately fragment size distributions having industrial as well as military applications.