Fatigue Stress Analysis of Surface Coating of Steel-Concrete Composite Beam under Living Load Effect

Based on the principle of equivalent stress, the local model of steel-concrete composite beam was established by ANSYS-Workbench with cohesive force model. The damage mechanism of surface coating of steel-concrete composite beam and its fatigue life prediction under live load were analyzed. The results showed that when the dry film thickness of coating was 210 - 300 μm, the tensile stress of each layer of coating was primer coating, intermediate coating and finishing coating in order from large to small, the shear stress of each layer of coating was intermediate coating, finishing coating and primer coating in order from large to small, and with the increase of fatigue cycle times, the thinner the coating system, the faster the finishing coating would fail and the worse the fatigue resistance. When only live load effect was taken into account, the fatigue life of finishing coating was about 20.9 a when dry film thickness was 210 μm. When dry film thickness was 210 μm, the fatigue life of finishing coating could reach 26.6 a.