Numerical simulation research on the necking and the hydraulic bulging process of automobile rear axle

In order to get a reasonable bulging loading path, a numerical simulation method was developed in ABAQUS to simulate the necking-hydraulic bulging process of automobile rear axle. Its numerical information was got from the necking experiment mainly. The impact of different loading paths on the forming process was analyzed after determining the boundary conditions and load method in the simulation. And a reasonable load path was got with investigating the hydraulic bulging process parameters, which were the internal pressure and axial feed rate on the forming process. The simulation results show that: simulated results of necking are more consistent with experimental results; the common pressure for first bulging should be of 47 MPa and the second bulging with multiple linear loading path would produce the shape and size of the automobile rear axle ideally. An annealing treatment in the second bulging can make the stress distribution of the automobile axle housing more uniform and the bulging pressure lesser.