the effects of proportional loading, plane stress, and constant thickness assumptions on hydro-mechanical deep drawing process

the goal of this study is to evaluate the effects of proportional loading, plane stress, and constant thickness assumptions on hydro-mechanical deep drawing (hdd) by developing analytical models. the main model includes no simplifying assumption, and then each of the mentioned assumptions is considered in a specific model. the interrelationships between geometrical and mechanical variables are obtained in the finite difference form based on the incremental strain theory, thereby being solved by broyden algorithm. published experimental and fe results are used for evaluation of the results obtained in the present work. the results of models under proportional loading, plane stress, and constant thickness conditions show more differences with the experimental data in strain distributions than the results of the main model. thus, the analyses will be more accurate and the results more reliable without considering such assumptions.