Identification and measurement of ductile damage parameters

Abstract

The possibility of extending fracture mechanics concepts and design criteria to ductile failure is an issue that has attracted the attention of many researchers. Many models that address this are available nowadays. For these, two kinds of approach are widely used: the porosity-based model proposed by Gurson and the continuum damage mechanics (CDM) approach. Any new user that has to deal with these models for the first time is often hindered by the difficulty of finding in the literature, or measuring, the material parameters necessary. In addition, the use of these models, which are often available already built into commercial finite element codes, requires great experience and attention in order to avoid the danger of ‘numerical traps and tricks’. Here, constitutive models based on the plasticity criterion for porous media given by Gurson, and the CDM framework proposed by Lemaitre are reviewed, giving attention to identification procedures for the damage parameters.