A story buckling method for evaluating system buckling load of plane sway frames

作者：Li Kuinian^*

来源：International Journal of Steel Structures, 2014, 14(1): 173-183.

DOI：10.1007/s13296-014-1015-3

• story buckling
• plane frame
• sway
• system buckling load
• stiffness

With the intension of developing a simple method for system buckling analysis for engineering practice, a story buckling method for evaluating the system buckling load of a plane rigid frame is suggested. The method is developed based on the idea that at lower modes a plane sway frame buckles in story and story stiffness is getting to zero as the system getting close to the corresponding mode of buckling at that story. The stiffness of any story of a plane sway frame can be found with the stiffness without loading and then modified by a negative stiffness which represents the effect of vertical loads on the horizontal stiffness. P-Delta effect is first considered independently by letting the modified stiffness equal to zero and the system buckling load by first order analysis is obtained. To take P-delta effect into account, the buckling load from the first order analysis is modified with a modification factor and an estimation of buckling load of the whole system is obtained. Application examples are presented and the results are compared with those from FEA of the whole system. The simplicity and accuracy of the suggested method are demonstrated. The restraints of the method for application are discussed.

• 出版日期2014-3