Explicit FEM analysis of the deep drawing of paperboard

An explicit finite element model of the deep-drawing of paperboard has been developed utilizing a custom yet simple material model which describes the anisotropy and plasticity of paperboard. The model was verified with a variety of tests and was then utilized to compare the punch force that was measured during the deep-drawing experiments to the punch force that was calculated during the deep-drawing simulations. All material parameters were calibrated based on individual experiments; thus, no parameter fitting was utilized to match the experimental deep-drawing results. The model was found to predict the experimental results with reasonable accuracy up to the point when wrinkling began to dominate the material response. Since most failures during paperboard deep-drawing occur before wrinkling begins to play a major role, this model can probably be utilized to study and predict the failure of deep-drawn paperboard cups. The overall trends and the effects of major process parameters are predicted by the model. The process parameters that were varied and compared for both experiments and simulations were: blankholder force, die temperature, and thickness. The model was utilized to discover that friction of the blankholder and die have significant effects on the punch force and thus the stress, implying that low-friction dies and blankholders can considerably reduce the failure probability and thus also improve the quality of deep-drawn paperboard cups.