Railway bridge damage detection using vehicle-based inertial measurements and apparent profile

The Cross Entropy optimisation method is used in this study to determine the apparent profiles that generate a vehicle dynamic response most similar to that of a measured input. 'Measured' bogie vertical acceleration signals are generated using a 3-dimensional train-bridge interaction model implemented in Abaqus and used as input to a 2-dimensional algorithm implemented in Matlab. Damage is introduced to the bridge structure by applying a localised reduction in the width of the bottom flange of a bridge beam, simulating the effect of a sudden impact from a vehicle strike. Apparent profiles for a number of damage scenarios are inferred and compared over time to detect damage. The algorithm is also tested for resilience to sensor noise and effectiveness in the presence of track irregularities.