Evaluation of friction coefficient for simulation of stamping

In order to define the friction coefficient the simulator of strip drawn test between flat dies and cup test were applied. To evaluate the friction coefficient between flat dies the modified Coulomb law was used and to define the friction at die drawing edge the modified Ouehler formula was applied. The applied processes can contribute to quality improvement of FEM analyses at steel sheet stamping. For experiments the extra drawable Zn coated and uncoated steel sheets (DX 54D – extra deep drawable Zn coated steel sheet, TRIP – Tranasformation Inducted Plasticity) suitable for cold forming by stretching were applied.