FEM Analysis and Experiment Validation on Multi-Pass Forging of Torx Round Flange Bolt

This study aims at exploring the multi-pass forging of Torx Round Flange Bolt (automotive fastener) to simulate each pass forging process using FEM simulation. The software is used to carry out the simulation analysis. Constant shear friction is always assumed at the interface between die and workpiece to explore the effective stress, the effective strain, the velocity filed, and the forging force for each pass. Through the pass schedule plan and design based on FEM analysis, the four-pass forging process is designed to form the Torx Round Flange Bolt compared the five-pass forging. It is noted that the total forging force is 1,204 kN, so the 200 tons machinery in the factory can be chosen to manufacture this automotive fastener. The die stress analysis for each pass has been explored to realize whether the dies are damaged or not. The forming feasibility of Torx Round Flange Bolt can be performed by FEM simulation. All dies designs and forming results can be proposed to the dies manufacture so as to perform the realistic experiments. Comparisons between FEM and experiment for final product dimensions can be carried out. The maximum dimension error is just around 3.32% to show a good agreement with the experiment. The research results can provide to the industries as the references of establishment of multi-pass forging technology.