Adjustment of crystal orientations and application to crystal plasticity simulation of cup drawing

To improve the prediction accuracy of the crystal plasticity model, a procedure that adjusts the crystal orientation was proposed. This procedure optimizes crystal orientations such that the predicted R -values for the rolling, diagonal, and transverse directions coincide with the experimental results. The crystal plasticity simulation with the experimental/original texture predicted the experimental trend of R -value variation. However, the predictions deviated slightly from the experimental results. After adjusting the crystal orientations, the predicted R -values agreed well with the experimental results. In contrast, the texture adjustment slightly altered the flow stress anisotropy under uniaxial tension. Furthermore, the texture adjustment had little effect on the strain path and flow stress under biaxial stress states. Thus, texture adjustment improved the R -value prediction, and its influence on other properties was marginal. Subsequently, the deep drawing of the cylindrical cup was simulated using the crystal plasticity finite element method. The crystal plasticity model with the adjusted texture predicted the height and thickness of the cup better than the experimental texture. The R -value is an essential parameter that governs the cup height. Hence, texture adjustment based on the R -value improves the reliability of deep drawing simulations. The present study demonstrated the performance of the proposed texture adjustment procedure on the predictions of plastic anisotropy and sheet metal forming simulations.