钢梁稳定分析的单肢解析化方法

A slabs-disassembled stability analysis method of steel beams

钢梁整体稳定分析理论几十年来的发展趋势是板的非线性理论的全面引入,而发展的最初动力则是解决横向荷载Wagner效应的计算问题.根据薄壁杆翘曲和弯曲分析统一性观点,提出单肢解析化的薄壁杆件弯扭屈曲分析方法.该方法立足于简单的杆的稳定理论而无需引入复杂的板的非线性理论,但解决了Timoshenko和Bleich最初的弯扭屈曲理论应用于梁时横向荷载Wagner效应的缺失问题.对于各种典型的梁弯扭屈曲问题,特别是其中目前尚存在广泛争议的单轴对称截面梁弯扭屈曲临界力问题,该方法均取得了良好的对比分析结论.

When Timoshenko and Bleich put forward the original method for calculation of lateral-torsional buckling moment of thin-walled beams, they could not figure out the Wagner term of beams under lateral loads. Some researchers insisted the nonlinear longitudinal normal strain, and then the nonlinear shear strain, and finally the nonlinear transverse normal strain of its middle plain should be taken into account when analyzing a flexural-torsional buckled thin-walled bar. The authors of this paper discovered either bend or warp, together with torsion, of a thin-waUed bar was a sort of results of constituted slabs＇ bends on their middle plain, and then, the fictitious loads of a buckled bar could be carried out slab by slab. The new method was based mainly on the stability theory set up by Timoshenko, but the new results embodied the Wagner term of beams under lateral loads. Furthermore, results of different sorts of beams, especially of those with monosymmetricat sections, were confirmed.