Strain induced damage of ductile materials under compression

The problem of ductile damage and failure prediction at the upsetting of cylindrical specimens with artificial voids is solved by taking a change in stress triaxiality into account. It is shown that such a more accurate assessment leads to a greater shift of stress triaxialities into a range of negative values as compared to their averaged values. At such values of stress triaxiality the material can be subjected to compression without failure under arbitrarily large deformations due to healing of micro-defects. The constitutive equations of a recently developed tensorial framework for ductile damage [5] are applied to modelling. (© 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)