Ductile dynamic fracture modeling using embedded strong discontinuities in CGI machining simulations

Paper in proceeding, 2012

In order to model the material behavior in machining simulations it is proposed to use a continuum damage approach on the basis of the Johnson-Cook (JC) plasticity model for the ductile continuous behavior up to the critical stress–strain states where discontinuous bifurcation may occur. Whenever a critical state has been diagnosed, a Cohesive Zone (CZ) is established so that the actual critical stress state is located right at the onset of stress degradation in the CZ. Both pre–peak continuum damage and post–peak CZ damage are considered in the formulation. The localized cohesive zone damage is kinematically realized as an element embedded discontinuity, cf. [2], which is introduced elementwise, thereby facilitating the model developments in standard FE-packages.