分析高层钢刚架弹塑性稳定的改进PΔ法

An Improved P-Δ Method for Analysing Elasto-plastic Stability of Tall Steel Frames

本文对PΔ法加以改进,保留了只用弹性刚度矩阵,引入虚拟水平力以及迭代计算等特点,抛弃了计算虚拟水平力的经验放大系数,改进了虚拟水平力算式,并引进了虚拟的竖向力和弯矩,提出了改进的PΔ法。经与试验结果和采用二阶协调分析法计算结果比较,本法具有良好的精度。采用本法计算不必繁冗地确定塑铰分布情况,计算过程单调重复,内存少,计算速度快,一般在微机上就可计算,易于使用。

An Improved P-△ method for analysing elasto-plastic stability of tall steel frames is presented in this paper, in which only elastic stiffness matrix is needed and imaginary forces and processes of successive approximation are introduced to approach the accurate result. Comparing the load carrying capacity and the locations of plastic hinges of the steel frames calculated by the improved P-△ method with that of experiments and that obtained from the second order compatibility analysis, the authors are convinced that this method gives good precision, can get rid of cumbersome work for determining the locations of plastic hinges, and requires small storage volume from computer. The computation process of this method is simple and time-saving. In general cases a personal computer is enough.