Estimation of life-cycle fatigue damage for suspension bridge hangers

Steel structures are subjected to several vibrations due to wind action. Therefore, in order to ensure an adequate safety level for the users, the life-cycle design of this kind of structures must consider the high cycle fatigue effects. In the case of suspension bridges serving railway traffic, an analysis to prevent the failure due to fatigue effects should take into account the vibrations due to both train transit and wind action. In the present paper this problem is investigated with respect of the case study of long span suspension bridge, where the life duration of different structural members is assessed.