Low-cycle fatigue estimation of welded beam-to-column connection in steel moment resisting frames using equivalent structural stress
Li Wanrun1,2,3,4 Wang Hui3 Liu Yufei1,2,3 Fang Zhao4 Li Aiqun5 Sun Yuping1,2,3 Du Yongfeng1,2,3
1. Earthquake Protection and Disaster Mitigation Institute, Lanzhou University of Technology, Lanzhou 730050, China;
2. Disaster Prevention and Mitigation Engineering Research Center of Western Civil Engineering , Lanzhou University of Technology, Lanzhou 730050, China; 3. School of Civil Engineering, Lanzhou University of Technology, Lanzhou 730050, China;
4. Key Laboratory of C&PC Structures, Ministry of Education, South East University, Nanjing 210096, China;
5. Beijing Advanced Innovation Center for Future Urban Design, Beijing University of Civil Engineering and Architecture, Beijing 100044, China
Abstract：Beam-to-column connection (BCC) in steel moment resisting frames (SMRFs) can be susceptible to low-cycle fatigue (LCF) phenomena adjacent to the joint under seismic excitation, which leads to the damage of the structure. This paper presents a low-cycle fatigue assessment method for high-rise steel frame beam-column welded joints based on equivalent structural stress method. Firstly, a multi-scale model of welded joints of steel frame beam-column with flange butt weld and web fillet weld details was established by using finite element multi-scale simulation method to verify the effectiveness of multi-scale interface connection. Secondly, under the multi scale model of different element size, the insensitive characteristics of the grid stress are verified, and the fatigue life of the welded joints of the steel frame beam column is evaluated by the equivalent structural stress method. The results show that the sensitivity of the grid can be eliminated by the equivalent structural stress method. Under the action of reciprocating load, the stress level of the weld seam near the process hole is higher than that of the welding seam away from the process hole. The life of the flange in the center of the flange is the lowest. The crack is first produced at the center of the flange weld, and the evaluation method based on the equivalent structural stress method provides technical support for the actual engineering.
李万润 王 辉 刘宇飞 方 钊 李爱群 孙玉萍 杜永峰. 基于等效结构应力的钢框架焊接梁柱节点低周疲劳评估[J]. 土木工程学报, 2018, 51(S2): 21-27.
Li Wanrun Wang Hui Liu Yufei Fang Zhao Li Aiqun Sun Yuping Du Yongfeng. Low-cycle fatigue estimation of welded beam-to-column connection in steel moment resisting frames using equivalent structural stress. 土木工程学报, 2018, 51(S2): 21-27.
