Material characterization for the prediction of ductile fracture occurrence: An inverse approach

The most advanced approach to the prediction of ductile fracture occurrence in metal forming processes is represented by a damage mechanics formulation. Such an approach requires a suitable evaluation of the parameters which appear in the yield condition for the damaging material and in the model which governs the evolution of microvoids (nucleation, growth and coalescence), which allow to calibrate the model with respect to the actual state and properties of the material. In the paper this aim is pursued employing an inverse identification approach based on an optimization technique which permits to adjust the material variables so that the numerical response matches the experimental one. In particular the load vs. displacement curve during a tensile test has been used to optimise the comparison between the numerical and the experimental results and to develop a full damage characterisation of the material.