Stress analysis of cold forging dies

The demand for fasteners which has a great importance in the developing and changing automotive sector is enpanding day by day. It is possible to fulfill the increasing demand by continuing mass production without any stoppage. Therefore, it is necessary to predict problems that may breakdown of mass production and to find solutions to them. The biggest problem that breakdowns of mass production is the fracture in cold forming dies. Estimation of die fracture with finite element methods and studies to increase die life are critical to ensure the continuity of mass production. In this study, the behavior of a cold forming die, which is used for forming a stepped rivet produced by cold forming method and which fracture earlier than the estimated life, against stresses has been investigated. The reasons of fracture in the die were investigated and new die designs were developed to improve the life of the die. he enhanced die designs and the stressese of the mold used in the current situation were examined by the finite element method (FEM). The designed dies were produced as prototypes and life tests were carried out in mass production. The results of the FEM models and the results obtained from the life tests carried out in mass production were compared. It has been observed that the life of the enhanced design molds is increased compared to the existing die that fracture at low cycle.