簿壁杆件在纯弯下屈曲的样条有限杆元法

Spline Finite Member Element Method for Analysing the Buckling of Thin-Walled Member under Pure Bending

根据位移变分原理，用一个称为样条有限杆元法的综合方法对任意截面形状的薄壁杆件在纯弯下进行屈曲分析，并提出用一个经过变换的三次Ｂ样条函数来模拟薄壁杆件横截面的纵向翘曲位移场．屈曲分析考虑了反映剪力滞后现象的杆壁中面上剪应变的影响，与经典理论及有限元软件包ＣＯＳＭＯＳ／Ｍ的结果比较，本文方法能够灵活、精确和有效地进行薄壁杆的屈由分析．数值算例的快速收敛说明了文中数值结果的可靠性．

Based on displacement variational principle,a comprehensive method known as spline finite member element method is used for analysing the buckling of thin-walled member with arbitrary section.A transformed B3-spline function is presented for simulating the longitudinal warping displacement field along the cross-section of thin-walled member.The effect of shearing strain of the middle surface,which reflect shearing lag,has been taken into account during buckling analysis.As compared with the results from classical theory and finite element software package COSMOS/M,this is a flexible,accurate,and effective method for the buckling analysis of thin-walled member.The fast convergence of numerical examples account for the reliability of its numerical results.