空间钢框架二阶弹塑性稳定极限承载力分析

Ultimate Strength Analysis of the Second-order Elastic-plastic Stability for Space Steel Frame

采用非线性连续介质力学的有限变形理论和内力屈服面塑性流动理论，对空间钢框架结构体系进行了二阶弹塑性稳定极限承载力分析，同时分析了主弯曲、非对称水平荷载对空间钢框架极限承载力的影响．经算例分析得知：如果非对称水平荷载比在0．5～2．0之间，则水平荷载的非对称性对结构的极限承载力影响很小；主弯曲对钢框架整体极限承载力的影响随结构层数的增加而减小．

Based on the finite-deformation theory of nonlinear continuum mechanics and stress-resultant yield surface plastic rule, the second - order elastic-plastic ultimate strength analysis of space steel frame structure was carried out. And the ultimate strength analysis was done by considering the effect of the main contortion and asymmetrical level loads. The analytic result showed that, when the ratio of the asymmetrical level loads was in the range of 0.5～2.0, the asymmetrical level loads could only slightly affect the ultimate strength, and that the effect of the main contortion upon the ultimate strength of steel frame decreased with the increase of layers.