Efficiency and identification procedures of damage models in dynamic

Abstract

To accurately predict the damage and failure evolution occurring in crashworthiness and sheet metal-forming simulations, a realistic material description is required. The parameters needed to describe such damage models are not easy to obtain and there is no direct test to achieve these parameters. An inverse method to identify the Gurson and Lemaître damage model parameters is presented. Quasi-static and high-rate tensile tests have been carried out on thin notched specimen made of high-strength steel (THR800) from ARCELOR. The aim was to study the combined effects of strain rate and stress triaxiality on the damage material behaviour. Macroscopic measured responses are the global forces and the width at the bottom of the notch versus the elongation. An image-processing software has been developed to measure the evolution of the width at the bottom of the notch versus the elongation from the video tests. The damage parameters are identified by correlating experimental and numerical macroscopic measurements.