An analysis of void distribution effects on the dynamic growth and coalescence of voids in ductile metals

T HEEFFECTS of void distribution on dynamic failure are studied by modeling a discrete set of randomly distributed cylindrical voids and subjecting them to a tension wave. The model problems are solved numerically with an Eulerian finite element program to allow for the generation of new free surfaces during coalescence. Unlike previous work, the growth and coalescence of small clusters of voids are simulated, i.e. the analysis is continued until the ligaments between the voids are broken and a fracture surface is formed. The peak transmitted stress is found to be insensitive to the magnitude of the tension wave and sensitive to the void distribution, but the time for the voids to coalesce into a fracture surface and the path of the fracture surface are found to be functions of the magnitude of the tension wave. For the small number of voids considered, the effects of the void distribution on the failure stresses were equivalent to the effects of doubling the initial void fraction.