汽车用铝合金方形薄壁梁的压溃变形行为

Crushing Deformation Behavior of Aluminum Alloy Square Thin-Walled Beam for Automobile

建立了方形薄壁梁轴向压溃有限元模型,基于准静态拉伸试验获得的应力-应变数据,对6061-T6、6063-T6和6082-T6铝合金方形薄壁梁的压溃变形行为进行研究,分析了单排、双排、三排诱导孔对其压溃变形行为的影响。结果表明:模拟得到无诱导孔铝合金方形薄壁梁均出现3个完整的压溃褶皱,与试验结果相符,证明建立的有限元模型较准确;3种无诱导孔铝合金方形薄壁梁的压溃变形模式均为钻石压溃模式,Mises等效应力分布基本相同,在压溃变形过程中其方形截面上端面两组对边分别依次出现内凹和外鼓,然后顺序压溃形成3个褶皱;开设诱导孔对铝合金方形薄壁梁第一压溃褶皱形成后的压溃变形行为的影响较大,缩短了第二、三压溃褶皱形成所需压溃距离,提升了变形后期的承载能力,开设双排诱导孔时距离最小。

The finite element model of axial crushing of a square thin-walled beam was established.Based on the stress-strain data obtained by quasi-static tensile test,the crushing deformation behaviors of 6061-T6,6063-T6 and 6082-T6 aluminum alloy square thin-walled beams were studied,and the effect of induced holes(single row,double row,triple row)on the crushing deformation behavior was analyzed.The results show that the aluminum alloy square thin-walled beam without induced holes had three complete crushing folds.The crushing morphology obtained by simulating was consistent with the test results,proving that the finite element model was accurate.The crushing deformation modes of the three kinds of aluminum alloy square thin-walled beams without induced holes were all diamond crushing modes,and the Mises equivalent stress distribution of those was basically the same.During crushing deformation,the two sets of opposite sides on the square section of the upper end face appeared concave and bulging respectively and in turn,and then crushing in sequence and formed three folds.Opening induced holes had a great effect on the crushing deformation behavior of the aluminum alloy square thin-walled beam after the formation of the first crushing fold,and shortened the crushing distance required for the formation of the second and third crushing folds,the bearing capacity in the later stage of deformation was improved.The crushing distance was smallest with double row induced holes.