A Numerical and Experimental Investigation of Void Coalescence Causing Ductile Fracture

by Joel Sterling Griffin

Institution: University of New Brunswick
Year: 2012
Keywords: ductile fracture; void coalescence; digital image; digital image correlation; plastic limit-load; cylindrical holes
Record ID: 1993243
Full text PDF: http://hdl.handle.net/1882/36784


A series of experiments and finite-element simulations were performed in order to assess existing void coalescence criteria and propose a new model for the coalescence of cylindrical holes in a pure metal matrix during uniaxial stretching. The finite-element simulations were performed so that various plastic limit-load models could be evaluated at each strain increment during deformation, rendering predictions concerning the farfield strains required for coalescence. The experiments were performed in order to identify the actual far-field strain at the moment of incipient coalescence for the specimen geometries considered. The cylindrical-void models of Thomason (1990) and McClintock (1966) outperformed all of the other considered models in their original states. A modified form of the Ragab (2004) plastic limit-load model is proposed in the present work and is shown to have good agreement with the experimental results. The present model accounts for ligament work-hardening and ligament orientation.