Numerical Simulation Of Hydroforming Process For Automobile Rear Axle Housing

Hydroforming is a young process in automobile industry. So the lack of experience and experimental findings makes technological design difficult. It will be very time-consuming and expensive using trial and error method to determine the process parameters. Through numerical simulation, valuable information regarding the forming process can be obtained, which can dramatically improve the potential of the hydroforming process. In order to provide reliable data for productive practice, an FEM (Finite Element Method) program, ANSYS, is used to analyze the sinking and the hydro-bulging in the hydroforming process for automobile axle housing based on early experiments.To analyses the sinking process, a one-side sinking process using general hydropress is designed to realize that the lengths of the two sink-formed parts are equal. Then the test of this process and its numerical simulation are done. The simulation results are in good agreement with the experimental data, which approves the reliability of the numerical simulation. Based on the simulation, linear relation between the tube's initial and deformed length is given.For the analysis of the hydro-bulging process, different load paths are applied in order to find proper combination of the internal pressure and the axial feeding. The numerical simulation places emphasis on the characteristic failure modes in the hydro-bulging process and provides a simple criterion of bursting. The paper also does an exploratory study on tangential corners' formation and gets a reasonable loading path range in which a sound final product can be obtained. At last, the distribution of stress and strain in the successful bulged tube is given.