芯棒伸出量对薄壁矩形管弯曲失稳起皱影响的数值模拟

基于动态显式有限元平台ABAQUS/Explicit,建立了3A21铝合金薄壁矩形管绕弯成形过程的三维有限元模型,模拟分析了芯棒伸出量对薄壁矩形管绕弯成形过程中失稳起皱的影响规律。结果表明:随着芯棒伸出量的增大,起皱波纹高度逐渐减小,切向压应力极大值波动的峰值减小,等效应力逐渐减小,并且变化趋于平缓;当芯棒伸出量达到一定值后,随着芯棒伸出量的增大,起皱波纹高度极大值变化不明显。该研究对薄壁矩形管绕弯成形工艺参数的确定具有重要的参考价值。

Numerical Simulation of Influence of Mandrel on Wrinkling in Bending of Thin-walled Rectangular Tube

A three-dimensional FEM model of rotary draw bending of thin-walled rectangular tube is built under the ABAQUS/Explicit environment. Based on the model, a simulation and analysis of rotary draw bending for aluminum alloy 3A21 thin-walled rectangular tube have been carried out. The results show that the maximum height of wrinkling wave decreases obviously with the increase of the initial lead of the mandrel, the maximum tangential compress stress and the equivalent stress decreases gradually, and the variation become steadier.The maximum height of wrinkling wave does not almost alter with the increase of the initial lead of the mandrel when the initial lead reached a fixed value. The achievements of this study provide a guideline for determining the process parameters for thin-walled rectangular tube in rotary draw bending process.