ABSTRACT
Fracture failure of many ductile materials takes the form of accumulated damage from the growth and coalescence of microviods. The voids often grow due to plastic straining of the surrounding material where flow localization takes place. When the ligaments between the neighbouring voids become sufficiently thin, void coalescence occurs by successive propagation of cracks. In recent decades, some constitutive models have been developed for void-containing materials. Based on a rigid-plastic solution for a spherically symmetric deformation applied around a spherical inclusion, Gurson [1] presented a theory to predict the plastic flow in voided ductile media. Since then some modifications have been made to this model, for example that by Tvergaard and Needleman [2] who introduced more parameters into the approximate yield conditions for a matrix with periodically arranged voids. For void growth and coalescence in materials under dynamic loading, Curran et al [3] have presented a detailed review.
