Damage Model of Bridge Bearing and Its Influence on Train-Track-Bridge Dynamic System

Bridge bearing damage is unavoidable in railway engineering. This work presents an investigation on the damage model of bridge bearing and its influence on the dynamic responses of the high-speed train-track-bridge system. Primarily, the mathematical description of bridge bearing damage model is explained in detail, which is then compared with the traditional linear model. Then a 3D train-track-bridge dynamic model considering bearing damage is established based on the train-track-bridge dynamic interaction theory. Adopting the model, the influences of single-point-damage and multi-point-damage on the dynamic behaviors of the coupled system are deeply investigated. Results show that the calculated obtained by the proposed model and the traditional linear model are different, especially in frequency-domain. Compared to results of traditional linear model, the results obtained by the proposed model are smaller due to the additional damping effect. Bridge bearing damage has almost no influence on the train vibrations, while has great effect on bridge vibrations. The damage in z-direction mainly affects the vertical vibrations, while damage in y-direction mainly influences the lateral vibrations. Among all the damaged bearings in this work, the influence of damage in x-direction has the least influence on the system. The damage in the fixed bearing is larger than that in other bearings, indicating that more attentions should be paid to the health monitoring of fixed bearings in railway engineering.