Forming and Crash Induced Damage Evolution and Failure Prediction - Part 1: Extension of the Gurson Model to Forming Simulations

With increasing requirements on the crash safety of automotive components and on virtual prototyping it is important to model the damage and the failure behaviour of structural components in crashworthiness simulations. In the past several continuum models have been developed to simulate the ductile damage behaviour of metals. Among these models the Gurson constitutive model has been applied successfully in crash simulations. Usually ductile damage models assume either initial damage equal to zero or a constant value very close to zero at the beginning of the crash simulation. Generally these models do not take into consideration that damage already evolutes from the metal forming process. Therefore in the present work the damage description of the micromechanically motivated Gurson model has been linked to the Barlat model, which is a widely used material model for sheet metal forming processes. It will be shown that prediction of the damage in metal forming processes and subsequently the use of the results as initial damage values in crash simulations is possible and necessary to predict structural failure in crashworthiness simulations.