薄壁曲线箱梁空间分析的梁段单元

SEGMENT ELEMENT OF THIN-WALLED CURVED BOX GIRDER BY SPATIAL ANALYSIS

广义符拉索夫薄壁梁理论耦合有限元技术 ,推导出一种能模拟拉压、弯曲、扭转、扭翘、剪切和剪力滞效应的薄壁曲线箱梁梁段单元。单元为两节点九自由度 ,除了常规梁单元的六个自由度外 ,还有三个分别考虑扭翘、剪切和剪力滞效应的自由度。利用变分原理在曲线坐标系下推导了单元刚度矩阵的显式及其等效结点荷载列阵。并在推导中考虑了曲线箱梁横截面剪心与形心不重合的影响。算例表明了本单元的有效性和准确性。

Element of thin-walled curve beam segment which can simulate tension,compression,flexure,torsion,warping,shear and shear lag effect of shear was derived from combination of generalized Vlasove's theory on thin-wall beam and finite element method.That element possesses two nodes with nine degrees of freedom:Besides six degrees of freedom for common beam element,there are three degrees of freedom for considering torsion warping,shear and shear lag effect separately.Precise expression of element stiffness matrices and equivalent nodal load vector are derived in curvilinear coordinates based on variational principle. The effects of eccentricity between shear center and centroid of cross section is taken into account. Numerical examples are presented to demonstrate accuracy and efficiency of proposed element.