Fatigue properties of welded details of steel bridge deck under temperature variation of pavement layer

In order to study the influence of asphalt pavement temperature on the fatigue properties of welded details of an orthotropic steel bridge deck based on linear elastic fracture mechanics, this paper studies the influence of asphalt pavement temperature on the stress of welded details and the stress intensity factor of a fatigue crack tip at the weld toe of the roof. A crack correction coefficient prediction model is established based on the XGBoost algorithm. The results show that the influence of asphalt pavement thickness and temperature effect on the fatigue properties of welded details of steel bridge decks cannot be ignored. Under high temperature conditions, the fatigue crack propagation rate at the weld toe of the roof is faster, and the crack shape ratio has a greater influence on the effective stress intensity factor. Therefore, it is unsafe to evaluate the effect of pavement temperature on the fatigue performance of welded details of steel bridge decks only by stress. The stress at the weld toe of the roof and the effective stress intensity factor at the crack tip are nonlinearly related to the temperature effect of the pavement layer. Combined with the prediction model of the crack correction coefficient established in this paper, the effective stress intensity factor of the fatigue crack tip can be effectively predicted, which is convenient for the rapid evaluation of the fatigue properties of welded details under the influence of temperature in engineering.