Fatigue Performance Evaluation for Welded Details in Orthotropic Steel Deck Bridges Using Multi-Scale Finite Element Method

In order to study the fatigue properties of rib-to-deck welded connection and rib-to-rib welded connection in orthotropic steel bridge decks, a multi-scale finite element model was set up to analyze the stress distribution characteristics and the load test was conducted on the Taizhou Yangtze River Bridge. Comparing the vehicle test results with the multi-scale finite element model results to verify the accuracy of the finite element simulation for the stress response of two welded details. The results indicated that: The stress at the rib-to-deck welded connection and the rib-to-rib welded connection are the bending stress and the membrane stress, respectively; the stress response of the two welded connection has strong local characteristics; the lateral stress influence line of the two welded connection is relatively short and the length of the lateral stress influence line is greatly affected by the longitudinal ribs; increasing the thickness of the roof and longitudinal ribs can reduce the stress response and improve the stress performance of the heavy lanes. For the two welded details, the fatigue damage increment of the ordinary lane is greater than the heavy lane. The thickened roof and longitudinal ribs at the position of the heavy lane still cannot balance the fatigue damage caused by the heavy truck. Therefore, it is necessary to strictly control the fatigue effect of overloaded vehicles on steel box girders.