INFLUENCE OF TRAIN SPEED ON FATIGUE PERFORMANCE OF RAILWAY STEEL BRIDGES

Abstract

Fatigue is a major cause of failure of railway bridges and its detrimental effects are further enhanced by the dynamic response of the bridge, if amplification occurs. The objective of the present work is that the effect of the train speed on fatigue related parameters and the codal provisions accounting for dynamic effects. In the present study two girder bridges and two truss bridges are considered to perform dynamic and moving load analyses for different type of train loadings. The dynamic analysis is done at train speed 300 km/h and the moving load analysis is performed by taking impact factor. Stress histories are obtained from the moving load analysis and dynamic analysis and then the fatigue assessment is carried out by Palmgren-Miner linear damage hypothesis for finding the damage of the structural members. Finally it is concluded that the structural members are safe from dynamic point of view.