结构非线性分叉失稳的扰动策略研究

Disturbance Strategy of Nonlinear Bifurcation Buckling for Structures

将四种经典稳定判别准则中的初始缺陷准则应用于非线性有限元分析,提出了研究非线性分叉失稳扰动策略的初始微小缺陷法,分析了初始微小缺陷法的基本思路、分析步骤和优缺点。对单元铰接穹顶结构、Williams肘形刚架和K 6型凯威特单层网壳的非线性分叉失稳现象进行了深入研究,并对Williams肘形刚架进行了稳定性试验。结果表明,初始微小缺陷法是可行的和正确的,同时也揭示了初始微小缺陷是实际结构存在非线性分叉失稳的真正原因。

The initial imperfections criteria is used in the nonlinear finite element analysis, and the initial minute imperfect method is put forward to research the disturbance strategy of nonlinear bifurcation buckling. The basic thought, the step and the merits, and demerits of the method are analyzed. The method is used to research the behaviors of a truss dome, a Williams toggIe frame and a K6 single-layer latticed dome, The model of the Williams toggle frame is experimented. Results indicate that the initial minute imperfect method is feasible and right. And it is disclosed that the reason of nonlinear bifurcation buckling is the initial minute imperfects of the actual structures.