开口截面薄壁杆件畸变效应的分析

对一类较简单的开口截面薄壁杆件讨论在扭转荷载作用下的截面变形问题。采用基于势能变分原理的半离散解法,分析过程中放弃了古典薄壁杆理论的两个基本假设,同时描述剪力滞后和畸变两种现象。杆件横截面的翘曲位移采用转换的Ｂ３样条函数插值,并增加了畸变能项。通过变分原理,可导出控制微分方程和自然边界条件。算例结果表明,对开口截面薄壁杆件,Ｖｌａｓｏｖ的第一个假设精确成立。本文结论对箱梁之类复杂截面薄壁杆件的精确

Analysis of Open Cross Section Thin Walled Bar for Distorsion Effection

The paper talk about a series of open cross section thin-walled bar's twist analysis considering the cross surface geometric defomation. By abandoning the two classic assump- tion of thin-walled bar the effection of shear lag and distorsion pheomenon can be considered under the present theory in the meantime. The new interpolation function, called "transformed splinefunction", is used to simulate the longitudinal wraping displacement along the center line of cross section. The distor- sion energy is also considered. By means of the variational principle, a group ofordinary differential equations (ODES) and boundary condition (Bes) can be obtained. The numerical solution manifestS that Vlasov's first hypothesie is explict. The conclusion has guidance magnificonce to composite cross sec- tion thin walled bar such as box girder.