框架高阶屈曲波形的应用价值分析*
- 摘 要
-
（1 杭州科技职业技术学院， 杭州 311400； 2 浙江大学建筑工程学院， 杭州 310058）
［摘要］对顶层抽柱的四层三跨钢框架进行屈曲分析,采用传统计算长度系数法计算层抗侧刚度，并与SAP2000软件计算的层抗侧刚度比较发现,施加水平荷载求得的各层剪力之比与采用临界荷载方法计算的层抗侧刚度之比相等时，两者结果接近。对钢框架进行整体屈曲分析，指出第1屈曲模态对应的是薄弱层的屈曲，第2及以上屈曲模态因不能正确反映框架梁对框架柱的约束，不能直接加以应用。顶层抽柱导致屋面梁轴力加大，自身临界荷载降低，使得屋面梁对顶层柱的转动约束作用减小或消失，需要在顶层柱计算长度系数计算中予以考虑。［关键词］变截面梁; 计算长度系数法; 矩阵位移法; 屈曲因子; 抗侧刚度; 临界荷载中图分类号：TU391 文献标识码：A 文章编号：1002-848X(2015)21-0047-05
Application value analysis of high order buckling wave of frameJin Bo1, Tong Genshu2, Zheng Junhua1（1 Hangzhou Polytechnic College, Hangzhou 311400, China; 2 School of Architecture & Engineering, Zhejiang University, Hangzhou 310058, China）Abstract: The buckling analysis of a four-layer and three-span steel frame without some columns in top layer was carried out by using the traditional calculation length coefficient method to calculate the lateral resistance stiffness of the layer. The comparison of the lateral resistance stiffness by traditional method and by the SAP2000 software was carried out. Results show that two results are close when the ratio of the shear force of each layer by the horizontal load is equal to that the ratio of the lateral resistance stiffness of the layer by critical load method. The overall buckling analysis of the steel frame was carried out, and the first buckling mode is pointed out to be the buckling of weak layer, and the second and higher buckling modes can not be used because they can not reflect the constraint of frame beam to frame column correctly. Lacking of some columns in top layer leads to increase of axial force in roof beam, decrease of critical load, and the decrease or disappearance of the rotation constraint action of roof beam to frame column, which needs to be considered in calculation of calculation length coefficient of column in top layer.Keywords: beam with variable cross-section; calculation length coefficient method; matrix displacement method; buckling factor; lateral resistance stiffness; critical load
*杭州市科技局重点项目（20100333T25），浙江省教育厅科研项目（Y201122425, Y201223824）。作者简介：金波，硕士，副教授，高级工程师，Email：jb@mail.hzaspt.edu.cn。
