Analysis of the sensitivity of FEM predictions to numerical parameters in deep drawing simulations

In this study, deep drawing finite element (FE) simulations are compared with experimental results. The steel grade, the geometry and the parameters of the experimental deep drawing processes are detailed in this paper. Particular attention is paid to numerical models. The main part of the article is dedicated to a broad sensitivity study. The influence of several numerical parameters on the predicted punch force and earing profile is analysed. A quadratic [Hill, R., 1948. A theory of the yielding and plastic flow of anisotropic metals. Proc. Roy. Soc. London Ser. A 193, 281–297] constitutive law is compared with more sophisticated micro-macro constitutive laws. The sensitivity of these laws to the initial data characterizing material behaviour is presented. A significant influence of the FE type and the number of FE layers is noticed. Finally, it also appears that friction parameters (penalty coefficient and Coulomb friction coefficient) have a significant influence on numerical results. The low anisotropy of the steel sheet increases the influence of several numerical parameters. That influence would not be observed with a highly anisotropic steel.