Fatigue Life Assessment of a Plate Girder Bridge Using an Uncoupled Iterative Scheme for Bridge-Vehicle Interaction

Most commercial software allows moving-load analysis to be performed on finite-element bridge models. However, the available software does not allow the incorporation of the dynamic load induced by vehicles due to vibration resulting from pavement roughness. The present study, aims to utilize an uncoupled iterative scheme to incorporate road roughness into the numerical model in order to overcome this problem. The vehicle-induced stress history obtained using the uncoupled iterative scheme is then used to determine the fatigue life of a plate girder bridge. A fatigue damage model is proposed, which incorporates the load sequence effects and the segregation of load cycles into crack-initiation and propagation stages. Investigation of various influencing parameters reveals the significance of vehicle speed, vehicle arrival time, pavement category, and the eccentricity of the load and girder design variables on the fatigue life of the bridge.