DUCTILE FRACTURE OF PURE COPPER - AN EXPERIMENTAL AND NUMERICAL STUDY

This paper describes the results of interrupted tensile tests carried out on 99.95% pure copper specimens over a range of stress triaxiality conditions. The tested specimens were sectioned and polished to ident ify the conditions at which voids nucleate and coalesce before the fin al fracture takes place. Results show that void nucleation and coalesc ence both have a very strong dependence on stress triaxiality, but app ear to be less sensitive to strain-rate. Based on the combined experim ental and numerical results, a new criterion for void nucleation is pr oposed as a function of stress triaxiality.