中文摘要：

采用有限元分析软件,对汽车底盘纵梁的弯曲成形、预成形及内高压成形工艺过程进行了数值模拟。研究内容为,在弯曲成形工步中,管坯各个弯曲位置在相同弯曲半径、不同弯曲角度下的壁厚分布;在预成形工步中,管坯压扁过程中弯曲位置的减薄问题;在内高压成形工步中,优化后的压力加载路径对最终成形零件壁厚的影响。基于有限元模拟结果,分别进行了弯曲成形、预成形和内高压成形试验。结果表明,弯曲成形、预成形和内高压成形弯曲叠加处最易破裂;通过改变模具圆角半径可避免破裂缺陷。实际成形试验结果与数值模拟结果基本一致。

英文摘要：

Numerical simulation of bending,preforming and hydroforming of automobile chassis vertical beam was conducted by using finite element analysis software.The wall thickness variation under different bending angles and the same radius for bending was analyzed.Further,the thinning phenomenon of bending position in flattening process was analyzed in details.Finally,the effects of the loading paths on the wall thinning of the hydroformed part were revealed.Subsequently,the bending,preforming and hydroforming experiments were carried out based on the simulation results.The forming results indicated that the bend superposition of bending,performing and hydroforming is the most easy to rupture,and the crack defects could be avoided by changing die fillet radius.In addition,the experimental results are approximately accordant with the simulative ones.