A non-iterative parameter identification procedure for the non-local Gurson-Tvergaard-Needleman model based on standardized experiments

Abstract

Damage mechanics models exhibit favorable properties such as the intrinsic influence of stress triaxiality on damage evolution and the prediction of crack initiation as well as propagation leading to structural failure. However, their application requires advanced expertise hindering the transfer of these models into industrial practice. Especially the parameter calibration can be identified as a key obstacle. In this paper, a simplified procedure is proposed for a non-local extension of the Gurson-Tvergaard-Needleman model (GTN), which is a highly accepted model for ductile failure of metals. The procedure is iteration free and finally requires experimental input data from only two standardized tests. The parameters are determined using look-up diagrams created on the basis of systematic simulations and made available for different material behavior covering the majority of ductile metals. Benchmark tests for three different steels are conducted to evaluate the robustness of the proposed procedure. The reliability of the GTN model is validated for all investigated materials.