STUDY ON LOW-TEMPERATURE FATIGUE OF STEEL STRUCTURES AND FATIGUE PROPERTIES OF WELDS UNDER SHEARS STRESS
Yuanqing Wang 1*, Haoyang Gu 1, Xiaowei Liao 1, Liang Zong 2, Tianshen Zhang 1
1 Key Laboratory of Civil Engineering Safety and Durability of China Education Ministry, Department of Civil Engineering, Tsinghua University, Beijing, China
2 Department of Civil Engineering, Tianjin University, Tianjin, China
China's new specification GB50017-2017 was revised according to Eurocode3. The fatigue-related provisions were further specified, but whether these provisions are suitable for China's situation is doubted. In addition, there has been controversy regarding the effect of low temperature on the fatigue properties of steel structures. In this paper we present our work on the fatigue performance of steel structure welds at low temperatures and under shear stress. Side welded details were tested under shear stress and the results were found to be in good agreement with curves given by the specification. But the results of front welded details indicated that the specification was conservative. Constant amplitude fatigue tests were performed on Q345qD and Q370qE base metal, welds, and structural details. It was found that the low temperature slightly improved fatigue performance of the base metal and welds. Results of structural details tended to be more discrete, in which case residual stresses may play a controlling role. In addition, studies show that the low temperature will reduce the fatigue crack propagation rate of the base metal but will accelerate that of the welds.
Fatigue under shear stress; Low-temperature fatigue; Crack propagation rate; Weld; Structural detail