点焊箱型截面薄壁构件的翘曲扭转研究

构成汽车车身结构的点焊薄壁构件,可以看成是开口截面段和闭口截面段相互穿插组合而成的半闭口截面构件。针对这种构件,基于瓦格纳的翘曲扭转理论,并考虑到点焊薄壁构件焊点处的弹性特性,用一条完整的具有剪切变形特性的“剪切弹簧”来取代构件上的点焊带。通过对这种具有“假想弹簧”的半闭口截面构件的研究,提出了一种分析点焊箱型截面薄壁构件的翘曲扭转的新方法。通过理论值与实验值之间的比较,验证了该方法的精度及合理性,并阐明了扭转刚度对点焊薄壁梁翘曲的影响。此研究同时为今后研究解决实际车体结构的多种约束翘曲问题,打下了良好的理论基础。

RESEARCH ON WARPING TORSION OF SPOT-WELDED THIN-WALLED BOX SECTION BEAM

The spot-welded thin-walled beam, a component of automobile body structure, can be supposed as a half-closed-section beam composed of interval series (closed-section parts and opened-section parts). It is proposed to apply general theory of torsion based on the warping torsion theory (solution of H. Wagner) to this kind of thin-walled box beams with spot-welded joints. Considering the elastic character of weld spots on the thin-walled spot-welded beam, a continuous shear-spring with character of shearing deformation is used for replacing the weld spots on the beam. After a study on this hypothesized spring beam, a method for analyzing warping torsion on spot-welded thin-walled box section beam has been presented. The accuracy and rationality of the method are proved by comparing theoretical analysis and experimental testing results. This method can be applied to solve for torsional rigidity of the double-hat beams, and the effects of binding warping of double-hat beams on the torsional rigidity was also clarified. The research lay the theoretical foundation for later studies on solving real warping problems with multiple restraints.