Cold formability prediction by the modified maximum force criterion with a non-associated Hill48 model accounting for anisotropic hardening

10th International Conference and Workshop on Numerical Simulation of 3D Sheet Metal Forming Processes

Lian, J.^1 ; Ahn, D.C.^2 ; Chae, D.C.^3 ; Münstermann, S.^1 ; Bleck, W.^1

Steel Institute, RWTH Aachen University, Intzestraße 1, Aachen

52072, Germany^1

Metal Forming Group, Global RandD Centre, POSCO, 180-1 Songdo-dong, Yeonsu-gu, Incheon

406-840, Korea, Republic of^2

Stainless Steel Products Research Group, Technical Research Laboratories, POSCO, 1 Goedong-dong, Nam-gu, Gyeongbuk, Pohang

790-300, Korea, Republic of^3

关键词: Anisotropic hardenings;    Cold formability;    Forming limit diagrams;    Non-associated flow rule;    Numerical investigations;    Numerical predictions;    Plasticity model;    Predictive capabilities;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/734/3/032112/pdf
DOI  :  10.1088/1742-6596/734/3/032112

来源: IOP

【 摘 要 】

Experimental and numerical investigations on the characterisation and prediction of cold formability of a ferritic steel sheet are performed in this study. Tensile tests and Nakajima tests were performed for the plasticity characterisation and the forming limit diagram determination. In the numerical prediction, the modified maximum force criterion is selected as the localisation criterion. For the plasticity model, a non-associated formulation of the Hill48 model is employed. With the non-associated flow rule, the model can result in a similar predictive capability of stress and r-value directionality to the advanced non-quadratic associated models. To accurately characterise the anisotropy evolution during hardening, the anisotropic hardening is also calibrated and implemented into the model for the prediction of the formability.