Very high cycle fatigue behavior of bridge steel welded joint

作     者：Chao He Yongjie Liu Donghui Fang Qingyuan Wang 

作者机构：Department of Mechanics and Engineering ScienceSichuan UniversityChengdu 610065China Department of Civil Engineering&ArchitectureCollege of JinchengSichuan UniversityChengdu 610065China 

出 版 物：《Theoretical & Applied Mechanics Letters》 (力学快报（英文版）)

年 卷 期：2012年第2卷第3期

页      面：36-40页

学科分类：080503[工学-材料加工工程] 08[工学] 080502[工学-材料学] 0805[工学-材料科学与工程（可授工学、理学学位）] 0802[工学-机械工程] 080201[工学-机械制造及其自动化] 

基　　金：supported by the China National Funds for Distinguished Young Scientists(10925211) the National Natural Science Foundation of China(50878174) 

主　　题：welded joint S-N curve failure mechanism very high cycle fatigue 

摘      要：Very high cycle fatigue（VHCF） behaviors of bridge steel（Q345） welded joints were investigated using an ultrasonic fatigue test system at room temperature with a stress ratio R = -1. The results show that the fatigue strength of welded joints is dropped by an average of 60% comparing to the base metal and the fatigue failure still occurred beyond 10~7 *** fatigue fracture of welded joints in the low cycle regime generally occurred at the solder while at the heat-affected zone（HAZ） in the very high cycle *** fatigue fracture surface was analyzed with scanning electron microscopy（SEM）,showing welding defects such as pore,micro-crack and inclusion were the main factors on decreasing the fatigue properties of welded *** effect of welding defects on the fatigue behaviors of welded joints was discussed in terms of experimental results and finite element simulations.