Corrosion-Fatigue Strain-Life Model for Steel Bridge Girders under Various Weathering Conditions

Corrosion of existing infrastructure, such as steel bridges, would significantly reduce its anticipated fatigue life. There are very few corrosion-fatigue models that address civil engineering applications. To account for corrosion in the fatigue life prediction of steel bridges, a new fatigue strain-life model based on the Smith-Watson-Topper model is proposed. The proposed model provides the fatigue life predictions in the form of ranges with a minimum and a maximum value. The model takes into account the corrosivity of the environment, the stress level, and the corrosive behavior of the material used. The resulting fatigue life predictions using the proposed model matched well with the experimental results reported in the literature for 24 steel beams that were subjected to various fatigue and weathering conditions. The analytical predictions show that the proposed model is accurate, simple, and practical and can be easily calibrated for different materials.