Research on critical moment of flexural-torsional buckling for steel beam subjected to combined loads
Liu Zhanke1,2 Zhou Xuhong3
1. Key Laboratory of Mechanics on Disaster and Environment in Western China of the Ministry of Education, Lanzhou University, Lanzhou 730000, China;
2. College of Civil Engineering and Mechanics, Lanzhou University, Lanzhou 730000, China;
3. Chongqing University, Chongqing 400044, China
Abstract：Based on the complete total potential energy of flexural-torsion buckling for steel beam subjected to combined loads, the equilibrium differential equation is obtained. The closed-formed formula of critical moment, considering both the height of load and the monosymmetry section constants, is deduced by employing Galerkin method. The theory of equivalent moment factor is also proposed. Based on the proposed equivalent moment factor theory, theoretical formulas of Cb for seven conventional load conditions and practical formulas of Cb for six special load conditions are derived. The practical Cb formulas are compared, about accuracy, application range and form, with those formulas in current literatures. The theory of equivalent moment factor is verified and the criteria on Cb formula is proposed. Two numerical examples are presented to verify the proposed Mcr formula and the criteria on Cb formulas. The results shown that the closed-formed formula of critical moment, considering both the height of load and the monosymmetry section constants, is of simple form, clear physical significance and easy application. The practical Cb formula is of wide application range and high accuracy. The criteria on Cb formula is reasonable and effective.
刘占科 周绪红 . 复合荷载作用下钢梁弯扭屈曲临界弯矩研究[J]. 土木工程学报, 2018, 51(1): 76-90.
Liu Zhanke Zhou Xuhong. Research on critical moment of flexural-torsional buckling for steel beam subjected to combined loads. 土木工程学报, 2018, 51(1): 76-90.
