In the deep drawing, the low blank holder force (BHF) will cause the wrinkle, while the high BHF will result in the tearing. Therefore it is important to determine the appropriate BHF in the forming. In this paper, the variable blank holder force (VBHF) approach for the deep drawing is employed. The simple closed-type algorithm is developed to obtain the VBHF trajectory. The proposed algorithm is roughly divided into two phases. The objective of first phase is to check the wrinkle and the tearing. In this phase, the low BHF, which causes the wrinkle, is used as the initial BHF. The BHF is increased in order to avoid the wrinkle. The algorithm will be terminated when the tearing occurs. The distance between the die and the blank holder is used to measure the wrinkle. Then, the second phase is considered. The main objective of second phase is to examine the thickness deviations. It is expected that the BHF will be decreased by considering the thickness deviation. The wrinkle is also checked in the second phase. By iterating above two phases, the VBHF trajectory can be obtained. One of the advantages by the VBHF is to reduce the forming energy. The validity is examined through the numerical simulation and experiment.
