中文摘要：

采用LS-DYNA软件对Ω形薄壁圆管的四道弯曲工序的绕弯成形及回弹进行了仿真。测量分析了实验得到的各弯曲角壁厚变化规律及最终回弹,并与仿真结果进行了比较;分析了塑性成形过程中弹性模量的变化对回弹的影响。结果表明,Ω形薄壁管多次绕弯成形过程中后续弯曲角成形可影响前道已成形弯曲角的回弹,造成零件最终几何不对称;由于弹性模量随塑性应变发生变化,弯管卸载后的应变回复包括弹性部分和非弹性部分,非弹性回复增加了整体的回弹,变形较大的弯曲角非弹性回复所占比例最大达到24%。

英文摘要：

The four rotary bending and springback of Ω-shaped thin-wall tube were simulated by LS-DYNA software. The changing rule of wall thickness and the final springback were measured and analyzed. Then the simulation results were compared with the experimental ones. The influence of elastic modulus changed on springbaek during plastic deformation was analyzed. Results show that the latter bending angle affects the springback of the formed bending angle in the multi-bending process of Ω-shaped thin-wall tube, which results in the geometry asymmetric of the final part. The total recovery is composed by elastic recovery and inelastic recovery due to the variation of elastic modulus with plastic strain. Inelastic recovery increases springback, and the percentage of inelastic recovery is up to 24% for the bigger angle.