密柱网格式钢框柱计算长度系数研究

Research on the Effective Length of Columns in Dense-Column Steel Grid Frame

摘要: 密柱网格式钢框架抗侧移刚度大，在钢结构住宅中有很好的应用前景。该体系中的密柱因横向支撑的约束无法直接套用现行钢结构设计规范中建议的计算长度系数计算方法，这对其稳定设计带来不便。本文采用ABAQUS软件，通过合理选取密柱网格式钢框架稳定分析简化模型，同时考虑密柱的焊接残余应力、初弯曲以及材料非线性等因素的影响，对密柱进行非线性屈曲分析，得出非线性屈曲临界荷载后，反推其在平面内和平面外的计算长度系数。本文结合软件进行分析，具有较高的研究水平和研究应用价值。结果表明：按照现行规范求得的面内计算长度系数较为保守，偏差值为6.76%~27.93%，横撑位置和数量对平面外计算长度系数有一定的影响，横撑在柱中至柱顶位置时可在一定程度上减小框架柱平面外计算长度系数。

Abstract: Dense-column steel grid frame columns have large lateral stiffness and a good application pros-pect in steel structure residence. The column in this system constrained by horizontal support constraints could not directly apply the present code of steel structure design suggested length coefficient calculation method. It is inconvenient to its stable design. This paper, using ABAQUS software, through reasonable selection of multi-columned steel grid frame stability analysis simplified model, considering the influence of welding residual stress, initial bending and material nonlinearity carries out the nonlinear buckling analysis of dense column. After solving the nonlinear buckling critical load, the effective length factor of the steel frame column in the plane and out of the plane is calculated. This paper combining with software to analysis, has higher research level and application value. The results show that the solution according to the current standard of calculated length coefficient is relatively conservative, and deviation is 6.76% to 27.93%. Lateral brace position and quantity have a certain influence on out-of-plane calculated length coefficient, lateral brace position and pillars. The horizontal support in the position of the center of the column to the top of the column can reduce the out-of-plane calculated length coefficient of frame column to some extent.