Dynamic Growth and Coalescence of Drilled Voids in Pure Copper Sheets

Abstract

AbstractA series of tensile tests for pure copper sheets containing drilled holes of multi-configurations are carried out on a tensile split Hopkinson bar (TSHB) at a range of tensile velocities. The dynamic growth and coalescence of drilled voids were recorded by a high-speed camera. The results of scanning electron microscopical (SEM) investigation of microvoid evolution at edges of ruptured zones between drilled voids in recovered sheets show void coalescence mechanisms, which are similar to evolution of visualized drilled voids. The experimentally recovered and high-speed camera recorded evolution of drilled voids in pure copper sheets are compared with the numerical simulations involving different models for void coalescence in order to overcome the difficulty of assessing the validity of available models for void coalescence. The possible application of Thomason model and Brown–Embury model for void coalescence to thermoviscoplastic material was explored under impact tension, and the rapid local straining of intervoid ligament was revealed.