FORECASTING FATIGUE LIFE OF HORIZONTALLY CURVED THIN-WALLED BOX- GIRDER RAILWAY BRIDGE EXPOSED TO CYCLIC HIGH-SPEED TRAIN LOADS

Damage accumulated through various fatigue processes has a significant impact on the estimated life of a railway bridge exposed to stochastic and variableamplitude railway vehicle repetitions. There is a critical requirement for monitoring the amount of fatigue damage incurred by bridge superstructures in a timely and precise manner, whether through direct or analytical methods. This study uses the rainflow cycle counting approach to determine the rates of fatigue damage build-up on a horizontally curving, thin -walled box-girder bridge under high-speed train-induced dynamic stress. The thin-walled box-beam finite elements which are computationally effective and consider crucial structural actions like torsional warping, distortion, and dis-tortional warping in addition to the usual displacement and rotational degrees of freedom, have been used to numerically model the curved box-girder bridge. The high-speed train is mathematically simulated using a 38-degree-of-freedom system. The findings indicate the variation of bending stresses for varied bridge lengths, vehicle velocities, and rail surface irregularities. Also, a parametric study has been per-formed to examine the impact of some critical parameters on the damage index as well as the fatigue life of the curved bridge.