管材内高压成形多步法数值模拟

利用动态显式有限元程序LS-DYNA,采用多步法和单步法两种方式,以某型号副车架为例,对曲线空心构件的内高压成形过程进行了数值模拟研究,给出了两种方式下副车架内高压成形后的壁厚分布.在模拟的基础上进行弯曲、预成形和内高压成形试验,获得了副车架内高压成形件,给出了典型截面的壁厚分布,并与两种模拟结果进行了比较.结果表明,采用多步法数值模拟技术模拟曲线空心构件的内高压成形过程,考虑了弯曲和预成形对后续的内高压成形过程的影响,模拟结果与试验结果基本吻合,能够更加准确地反映曲线空心构件的内高压成形过程.

Multistep method in numerical simulation of tube hydroforming

Taking an engine cradle as a typical example, a numerical simulation investigation of hydroforming for curved hollow components, is conducted by using a dynamic explicit FEM code, IS - DYNA. During the simulation, multistep and single-step methods are used respectively and the thickness distribution of hydroforming of the engine cradle is given. On basis of the simulation, experiments of tube bending, preforming and hydroforming are carried out and the hydroformed engine cradle is obtained. The thickness distribution of typical section is measured and compared with the simulation results. It shows that the simulation results of the multistep method agree well with the experimentals in which the influences of bending and preforming on the subsequent hydroforming process are taken into account. The multistep method is more reasonable than single step method to simulate the process of hydroforming for a curved hollow component.