双力矩作用下薄壁梁变形的数值分析

采用有限元实体单元，分析了薄壁截面悬臂梁在双力矩作用下的截面内变形。数值分析表明：开口截面在双力矩的作用下，截面以旋转变形为主，截面内的相对变形很小，与符拉索夫薄壁梁理论的“刚周边假定”吻合，符拉索夫的理论结果与实验结果符合很好；闭口截面在双力矩的作用下，以截面内的相对变形为主，截面的旋转较小，薄壁梁理论的“刚周边”假定与数值分析结果有出入。

Numerical Analysis of Deformation for Thin- walled Beams Acted by Bimoments

By using the solid dements of finite element methods, the deformations of the cross - sections for thin - walled cantilever beams are analyzed by the application of bimoments at the free end. The numerical results show that： for the open thin - walled beam acted by bimoment, the deformation of cross- section is the rotation of the cross - section, and the relative deformation of the cross - section is very small, which accords with Vlasov＇s rigid contour assumption, and numerical results agree well with the Vlasov＇ s theoretical results. For closed thin- walled cantilever beam acted by bimoments at the free end, most of the deformation for cross- section is distortion of the cross - section, and the relation of cross - section is small, and the assumption of rigid contour is not true from the numerical results.