变截面双帽箱型横截面点焊薄壁构件的扭转问题

Torsion in Spot-Welded Thin-Walled Box with Varying Section

提出沿构件长度方向截面尺寸发生缓慢变化时双帽箱型横截面点焊薄壁构件扭转特性的分析方法,并利用此方法讨论了变截面等焊点间隔构件和变截面非等焊点间隔构件的翘曲扭转问题并得到如下结论:①变截面构件长度越长,扭转刚度越小,其刚度下降率与等截面构件几乎相等;②采用变截面构件,不仅保持一定刚度,还可以减少焊点数目,降低焊接成本;③若右半部分的焊点间隔p2对左半部分的焊点间隔p1的变化范围小于25%,则其传递剪力变化不大。仿真结果与实验值以及利用cosmos/m而得到的数值解相比较吻合得较好,完全满足工程精度要求。此研究为解决实际车体结构的设计问题,具有有益的参考价值。

A method to analyze torsion performances in a spot-welded thin-walled box is proposed, where the cross-section varies slowly along the longitudinal direction. Warping torsions for two situations, even and uneven pitch of spot-welds, are discussed. It is concluded that torsion rigidity is weakened as the beam length increases, whose decreasing rate is nearly equal to one of uniform section; the beam with varying section keeps a certain rigidity with fewer welding spots and lower cost. If the welded spot pitch p2, in the right, varies within 25% of the pitch p1 in the left, the shearing force transmission nearly unvaries. The simulation results coincide the experimental ones very well.