Quasistatic and dynamic growth of sub-microscale spherical voids

Abstract

This study examines the quasistatic and dynamic growth of sub-microscale spherical voids. A general dynamic model of void growth is first developed by considering conservation of local energy, including external work, surface energy, kinetic energy, elastic strain energy, and plastic dissipation associated with growing void driven by hydrostatic tensile stress. It properly accounts for material compressibility and limited size of elastic deformation in dynamic growth of spherical voids. A closed form of pressure-void size relation is obtained for quasistatic growth of spherical voids embedded in non-strain hardening materials. Critical condition is identified for unbounded growth, which depends strongly on initial void size. For subcritical loading, a void can only grow to a very limited size. An interesting crossover phenomenon is identified pertaining to the influences of yield stress on void growth rate.