Implementation of Uncoupled ductile damage model for damage assessment during edge stretching

Edge cracking is a common failure when stamping dual-phase steel sheet components. The edge cracking behaviour is evaluated using a hole expansion test. The failure during hole expansion by fracture can be modeled using appropriate damage criteria. This study focuses on the analysis of a hole expansion test using an uncoupled damage model, wherein the failure is assumed to occur when the damage variable attains a critical value. A user subroutine is implemented to model the evolution of damage using a field variable. The procedure is generic and can be easily adapted to a range of materials and damage criteria. The user subroutine implemented in a commercial finite element software is validated using the test results of DP600 steel grade.