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Abstract. Ironing can occur in cylindrical cup drawing whenever the thickness of the drawn flange is larger than the gap between the punch and the die. This is particularly relevant for materials that present r-values lower than 1.0, such as the aluminium alloys, since they tend to present more thickening of the flange. The aim of this study is to evaluate numerically the impact of the elastic deformation of the forming tools on the final cup geometry, i.e., the earing profile and the evolution of thickness along the circumferential direction, at different heights. Different contact conditions are also analysed since they strongly affect both the thickness strain and the earing profile. The process conditions considered are the ones from EXACT, the ESAFORM Benchmark 2021, enabling the comparison with experimental results. Considering the deformation of the forming tools mainly impacts the ironing stage, enabling predicting wall thickness values larger than the gap between the punch and the die.

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Abstract. The 1st ESAFORM Benchmark, called EXACT [1], enabled an in-depth study of the factors that contribute to the accuracy of predictions and efficiency of finite element (FE) simulations of deep drawing of a cup from AA 6016-T4 sheet through the joint work of 11 teams. FE analyses were conducted with elasto-plastic models or crystal plasticity approaches using commercial or academic FE codes. This paper reminds the content of EXACT benchmark and gives new results that highlight the importance of the tool stiffness and various contact conditions to predict the ironing forces and the thickness distribution along the cup wall. The use of the Benchmark experimental data and virtual tests performed with DAMASK crystal plasticity code to identify and validate a two-surface kinematic hardening model based on Yoshida and Uemori approach is also discussed.