Void coalescence in ductile solids containing two populations of voids

Abstract

Many metallic alloys contain a primary and a secondary population of voids, the difference in size reaching up to orders of magnitude. The present study extends Thomason's and Benzerga-Leblond's criteria for the onset of coalescence of primary voids to incorporate the effects of a secondary population. Plastic limit load analysis is performed within a finite element (FE) framework by using three dimensional (3D) cubic unit cells. The macroscopic stress state of the unit cells corresponds to axisymmetric tension with Sigma(22) > Sigma(11) = Sigma(33). The extended versions of both criteria are able to successfully predict the critical stress for the onset of coalescence. (C) 2015 Elsevier Ltd. All rights reserved.