The inverse approach for the determination of constitutive equations in metal forming

Abstract An inverse identification method for material parameters estimation is proposed in this paper. This method allows an accurate identification by avoiding the usual assumptions made in order to convert experimental measures into constitutive variables. A sensitivity analysis is developed to evaluate the effect of parameters variations on the material response. This analysis is based on a direct differentiation method allowing an accurate sensitivity determination with a low computational cost compared to a finite difference method. This inverse identification procedure is applied to the determination of the viscoplastic behaviour of aluminium alloys in hot working using both the plane strain compression test and the axisymmetric compression test. The results obtained with both tests are the same.