Numerical Investigation of Damage in Single-step, Two-step, and Reverse Deep Drawing of Rotationally Symmetric Cups from DP800 Dual Phase Steel

摘要

Damage evolution in deep drawing processes has an influence on the service properties of manufactured components. Knowledge and control of the damage state will therefore allow a reduction in safety factors and, consequently, in sheet thickness. To investigate the damage after deep drawing of rotationally symmetric cups, a Lemaitre type damage model calibrated in previous works was used in the Finite Element (FE) simulation of the deep drawing process. Three process variants were investigated: single-step deep drawing, two-step deep drawing, and reverse deep drawing. The single-step deep drawing process was used as a reference to evaluate the damage evolution in two-step and reverse deep drawing. In both two-step and reverse deep drawing, the overall damage values did not decrease when compared to single-step deep drawing. However, in reverse deep drawing specifically, the location of maximum damage in the cup wall was moved from an area near the cup floor towards the edge of the cup. In real-life components, this control over the location of maximum damage will allow a tailoring of the damage state in the component to the expected service loads, thereby increasing service life or allowing a reduction in sheet thickness, respectively.