Fatigue Life Prediction and Parameter Analysis of Girder New Detail

In order to study the influence of the cope hole radius, shape and fillet weld size of the new detail of Hutong Railway Yangtze River Bridge girder on fatigue performance, the hot spot stress method was used to predict fatigue life, and the calculation results were compared with the experiment results of 9 welded specimens,then parameter analysis based on finite element models was conducted. The results show that:a little difference exists between fatigue life predicted by hot spot stress method and the results of fatigue experiments, which is within 15%; the mesh size of flange plate near the cope hole had little impact for hot spot stress, which is within 1.6%, two-point and three-point extrapolation method are feasible for this new detail; the fillet weld size and the cope hole radius have some influence on the maximum stress of flange plate and hot spot stress, the variation range is within 10%; the ratio of major and minor axes has a significant impact on the maximum stress of flange plate and web and hot spot stress,the variation range of web is 21.6%, however, the others are not beyond 10%. It is suggested that the welded detail with elliptical the cope hole can be used if the condition allowed, and large ratio of major and minor axes should be selected.