Metal ductility at low stress triaxiality application to sheet trimming
Abstract
The growth and coalescence of voids nucleated by decohesion or cracking of second phase particles is a common damage process for many metallic alloys. Classical damage models, based on void growth and coalescence, predict a ductility increase if the stress triaxiality is decreased. But experiments show that the material ductility decreases at very low stress triaxialities typical of sheet metal forming operations. At very low stress triaxiality no void growth is observed in metals containing second phase particles. In the present work, a new damage model for metals containing second phase particles submitted to low stress triaxiality loading is proposed