ABSTRACT
In order to investigate the long-term fatigue performance of the flange-web welded details of the guideway under eccentric loads, the digital fatigue tests of the flange-web welded details are carried out by using the extended finite element method (XFEM) and fracture mechanic theory. The results show a large welding residual tensile stress approaching to the yield stress of Q345 steel at the flange-web weld toes. Out-of-plane distortion will increase the local stress of steel structure under live load. The fatigue crack at the web is a mixed Mode I-II-III composite crack dominated by Mode I crack. This research determines the effect of residual tensile stress on distortion-induced fatigue behavior of this detail and the fatigue crack type under coupling actions. The design and construction of the guideway should avoid eccentric setting web, and the welding residual stress of fatigue-sensitive detail parts should be reduced by ultrasonic impact treatment.
