Elastic-Plastic Finite Element Analysis of Deep Drawing Processes by Membrane and Shell Elements

Abstract

Both cylindrical cup drawing and square cup drawing are analyzed using both membrane analysis and shell analysis by the elastic-plastic finite element method. An incremental formulation incorporating the effect of large deformation and anisotropy is used for the analysis of elastic-plastic non-steady deformation. The corresponding experiments are carried out to show the validity of the analysis. Comparisons are made in punch load and distribution of thickness strain between the membrane analysis and the shell analysis for both cylindrical and square cup drawing processes. In punch load, both methods of analysis show very little difference and also show generally good agreement with the experiment. For the cylindrical cup deep drawing, the computed thickness strain of a membrane analysis, however, shows a wide difference with the experiment. In the shell analysis, the thickness strain shows good agreement with the experiment. For the square cup deep drawing, both membrane and shell analysis show a wide difference with experiment, this may be attributable to the ignorance of the shear deformation. Concludingly, it has been shown that the membrane approach shows a limitation for the deep drawing process in which the effect of bending is not negligible and more exact information on the thickness strain distribution is required.