Sheet Metal Forming Limits Under Complex Strain Paths Using Void Growth and Coalescence Model

Abstract

It is well established that ductile fracture occurs by nucleation, growth and coalescence of voids. Several models have been developed to predict limits under constant strain ratio paths considering void inhomogeneity and void growth. In this paper the void growth and coalescence model developed by Rao and Chaturvedi for predicting forming limits under constant strain ratio paths, has been extended for predicting forming limits under two stage strain paths. The predicted results have been compared with experimental results of Ishigaki and analyzed.