ABSTRACT
High-cycle fatigue performance of the butt-welded connections for high strength steels HSS (Q460, Q690 and Q960) were studied in this paper. Based on the experimental results and fracture surface comparison, the S-N curves were obtained through regression analysis of fatigue test data, which are used to evaluate the fatigue strength of HSS butt-welded connections, and compared with the current design code. The characteristics of fatigue fracture were also observed and compared in detail. The results show the fatigue strength of Q690 and Q960 are 21.4%, 9.8% higher than the design value in Eurocode 3 (EC3). EC3 curves was relatively conservative to evaluate the fatigue performance of HSS Q690 and Q960 butt-welded connections. While the fatigue strength of Q460 butt-welded connections was conformed to the design value of EC3 S-N curves (3.6% slightly lower).
