Void coalescence in a porous solid under dynamic loading conditions

摘要

Void coalescence in ductile voided solids subjected to dynamic loading is investigated numerically. Finite element simulations of an axisymmetric unit cell, taking inertia and finite strain effects into account, are used to describe the coalescence process in a porous material containing a periodic distribution of initially spherical voids. The numerical results suggest that inertia yields a stabilizing effect and slows down the necking of the ligaments between neighbouring voids. Besides, for sufficiently high stress triaxi-ality and loading rate, coalescence is found to occur by direct impingement, instead of ligament necking. This result correlates with experimental observations in spall fracture and dynamic crack propagation.