ABSTRACT
In this study, the long term fatigue behaviour of steel highway bridges is investigated through variable amplitude fatigue tests using steel girder specimens with web gusset welded joints and flange attachment welded joints under computer-simulated variable amplitude loading with the number of loading cycles more than 10–100 million cycles. The principal results obtained through this study are as follows: (1)Fatigue failure life of web gusset joints and patch plate joints plotted against the equivalent nominal principal and bending stress range satisfies the one rank higher fatigue class recommended by JSSC. (2) Fatigue failure life of longitudinal hanger piece joints plotted against the equivalent nominal bending stress range satisfies the one rank lower fatigue class recommended by JSSC.
