Biaxial Very High Cycle Fatigue Testing and Failure Mechanism of Welded Joints in Structural Steel Q345
Bing Xue,
Yongbo Li,
Wanshuang Yi,
Shoucheng Shi,
Yajun Dai,
Chang Liu,
Maojia Ren,
Chao He
Affiliations
Bing Xue
Science and Technology Research Center, China Yangtze Power Corp. (CYPC), Wuhan 440010, China
Yongbo Li
Science and Technology Research Center, China Yangtze Power Corp. (CYPC), Wuhan 440010, China
Wanshuang Yi
Science and Technology Research Center, China Yangtze Power Corp. (CYPC), Wuhan 440010, China
Shoucheng Shi
Key Laboratory of Deep Earth Science and Engineering, Ministry of Education, College of Architecture and Environment, Sichuan University, Chengdu 610065, China
Yajun Dai
Key Laboratory of Deep Earth Science and Engineering, Ministry of Education, College of Architecture and Environment, Sichuan University, Chengdu 610065, China
Chang Liu
Key Laboratory of Deep Earth Science and Engineering, Ministry of Education, College of Architecture and Environment, Sichuan University, Chengdu 610065, China
Maojia Ren
Key Laboratory of Deep Earth Science and Engineering, Ministry of Education, College of Architecture and Environment, Sichuan University, Chengdu 610065, China
Chao He
Key Laboratory of Deep Earth Science and Engineering, Ministry of Education, College of Architecture and Environment, Sichuan University, Chengdu 610065, China
The very high cycle fatigue (VHCF) strength of welded joints made of high-strength structural materials is generally poor, which poses a serious threat to the long life and reliability of the structural components. This work employs an ultrasonic vibration fatigue testing system to investigate the biaxial fatigue failure mechanism of the welded joints. The results revealed that under uniaxial loading conditions, the propensity for fatigue failure in plate specimens was predominantly observed at the specimen surface. Regardless of whether under uniaxial or biaxial loading, the initiation of fatigue cracks in cruciform joints was consistently traced back to unfused flaws, which were primarily located at the interface between the solder and the base material. Concurrently, it was noted that the fatigue strength of cruciform joints under biaxial loading was merely 44.4% of that under uniaxial loading. The geometric peculiarities of the unfused defects led to severe stress concentrations, which significantly reduced the fatigue life of the material under biaxial loading conditions.
