考虑支座转动约束作用三管梭形钢格构柱的稳定性研究

Research on stability of the 3-pipe shuttle-shaped steel latticed column with end restraints

通过弹性屈曲分析和考虑大变形的弹塑性分析研究了考虑柱底转动约束作用的三管梭形格构柱的稳定性能.分析了柱底转动约束刚度、初始几何缺陷作用方向、分布形式及幅值对梭形格构柱稳定性能的影响.研究表明:考虑柱底转动约束作用时梭形柱的一阶弹性屈曲模态表现为"C"形和"S"形两种形式;考虑柱底转动约束作用后,初始几何缺陷的作用方向对梭形格构柱的稳定承载力影响较大,柱底转动约束刚度较弱的平面为缺陷的最不利作用方向;梭形格构柱对初始几何缺陷的分布形式较为敏感,当分布形式与其一阶弹性屈曲模态一致时,稳定承载力最小.

The stability behavior of the 3-pipe shuttle-shaped steel latticed column subject to axial compressive forces was investigated theoretically through elastic buckling analysis and geometrically and materially nonlinear analysis considering the effect of the end restraint moment at the column footing. The emphasis was on the effects of column footing rotational restraint stiffness, the orientation and distribution pattern of initial geometric imperfections on the stability behavior of shuttle-shaped steel latticed column. It was found that the first elastic buckling mode of shuttle-shaped steel latticed column considering the effect of the restraint moment involved S-shaped mode and C-shaped mode. It was also shown that the orientation of initial geometric imperfection had obvious influence on the stability bearing capacity of the column with the consideration of the restraint moment. The stability bearing capacity was sensitive to the imperfection distribution pattern, which was minimum when it was consistent to the first elastic buckling mode.