Abstract
In this study, the fatigue growth behavior of the transverse crack, which is the most dangerous damage among the various types of rail defects, was investigated using the notched keyhole specimen under constant amplitude and variable amplitude loads. Fatigue limit of the smooth specimen in rail steel at R=0 was 110MPa. And, in the region of the low stress amplitude (i.e. long life), most portions of the total fatigue life were occupied by the fatigue crack initiation life. The fatigue strength under variable amplitude load was converted to the equivalent fatigue strength based on the Miner's rule, which was estimated about 9% lower than that under constant amplitude load.
