Fatigue Life Prediction of New 160‐Type Multidirectional Displacement Comb‐Plate Expansion Device

ABSTRACT Under the coupling effect of traffic loads and the environment, bridge expansion devices are prone to fatigue failure, which directly affects the safety and service life of bridges. This study developed a fatigue life prediction method based on multibody dynamics, finite elements, and actual vehicle load spectrum. The stress–time history curves of the critical points at different vehicle speeds were calculated, the one‐dimensional stress spectrum of the critical points was derived using the rainflow counting and Goodman methods, and the fatigue life of the critical points was evaluated using nominal stress. The results showed that the fatigue life of the critical points at 100 km/h was 2.57 years, whereas it was 47.06 years at 40 km/h. The simulated critical points were located at the tooth root along the wheel centerline, which is consistent with the results obtained from the nominal stress and fatigue test.