汽车后桥缩径-胀形工艺的仿真分析

针对汽车后桥的缩径-胀形工艺，为得到合理的胀形加载路径，在缩径实验的基础上，使用ABAQUS软件对缩径-胀形工艺进行了数值仿真，确定了仿真过程中的边界条件以及加载方式，分析了不同的加载路径对成形过程的影响，考察了液压胀形的主要工艺参数，即液压与轴向进给量对成形过程的影响，得到了合理的加载路径. 仿真结果表明，缩径仿真结果与实验结果较为吻合；第1次胀形取胀形压力为常压47 MPa，第2次胀形取多线性加载路径，所得桥壳外形和尺寸较为理想；在第2次胀形时进行退火处理，胀形桥壳应力分布更为均匀，所需胀形压力也较小. 

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.