Some improvements on the unfolding inverse finite element method for simulation of deep drawing process

The linear unfolding inverse finite element method (IFEM) has been modified and enhanced by implementing large deformation relations. The method is helpful to predict forming severity of the part that should be deep drawn as well as its blank shape and strain distribution in preliminary design stage. The approach deals with minimization of potential energy and large deformation relations with membrane elements. To reduce the computation time, the part is unfolded properly on the flat sheet and treated as 2D problem. Moreover, the nonlinear stress-strain relationship of plastic material properties has been considered to increase the accuracy of the results. An experiment set up has been prepared to form a rectangular cup. Then, the obtained cup has been analyzed by linear unfolding IFEM and the proposed method. Comparisons of the measured thickness strains and the blank shape show that the proposed method predicts the strain distribution more accurately than the linear method.