考虑约束扭转的薄壁梁单元刚度矩阵

推导了薄壁空间梁单元刚度矩阵 ,考虑了双向弯曲及截面约束扭转对杆件轴向变形的影响 ;计算了截面的翘曲变形 ,以及二次剪应力对翘曲变形的影响 ,可适用于任意截面 (包括开口、闭口和混合剖面 )的薄壁杆件。计算结果表明 ,考虑约束扭转的薄壁梁单元刚度矩阵有相当好的精确度 ,可以用于薄壁杆件的静动力分析。

Element stiffness matrix of thin-walled beam considering restrained torsion

On basis of an improved deformation pattern, a kind of element stiffness matrix of thin-walled beam is deduced, which consider the effect of two way bend and warping on the axial deformation of beam, the effect of warping deformation of beam and the effect of quadratic shear stress on the warping deformation. The stiffness matrix can be used to static or dynamic analysis of the thin walled beam with arbitrary cross section (including open section, closed section and combinative section). The corresponding program is worked out, and the numerical examples indicate the effectiveness and precision of the element stiffness matrix.