Linear elastic iteration with high efficiency for ultimate bearing capacity of square-profile CFST frame with second order effect
Yang Lufeng1,2 Zhao Yufeng1,2 Xie Weiwei1,3
1. School of Civil Engineering and Architecture, Guangxi University, Nanning 530004,China;
2. Key Laboratory of Engineering Disaster Prevention and Structural Safety of the Ministry of Education, Guangxi University, Nanning 530004, China;
3. Guangxi Road & Bridge Engineering Group Co., Ltd., Nanning 530011, China
Abstract：In this work, the elastic modulus reduction method (EMRM) was presented to take into consideration the second order effect on the ultimate bearing capacity of square-profile concrete-filled steel tube (CFST) frames, which is difficult to be dealt with in the conventional elastic modulus adjustment procedures. Firstly, the influence functions for confinement factor and stability factor were developed, respectively, using the quadratic polynomials so that the homogeneous generalized yield function (HGYF) was constructed for the CFST member with second order effect using the first order polynomial with fractional-exponential powers by means of the regression analysis. Secondly, the degradation of structural stiffness was simulated by reducing strategically the elastic modulus of highly-stressed elements, while the ultimate bearing capacity of square-profile CFST frame was evaluated by linear elastic iteration. Finally, it was validated that the proposed elastic modulus reduction method is accurate enough with high computational efficiency for evaluating the ultimate bearing capacity of the square-profile CFST frame with second order effect under in-plane or spatial loadings, when comparing to the results from the incremental nonlinear finite element method and the test data. Results show that the second order effect has significant influences on the medium-long components and the CFST frames.
杨绿峰 赵玉峰 解威威. 方形钢管混凝土框架二阶效应下极限承载力的高效线弹性迭代分析[J]. 土木工程学报, 2022, 55(2): 1-10.
Yang Lufeng Zhao Yufeng Xie Weiwei. Linear elastic iteration with high efficiency for ultimate bearing capacity of square-profile CFST frame with second order effect. 土木工程学报, 2022, 55(2): 1-10.
