Structural fatigue performance of L-shaped support in continuous welded stainless steel roof system

The fatigue life of the L-shaped support in a continuous metal roof system was determined under various cyclic loads with different amplitudes using tensile fatigue tests. The performance of the SUS304 stainless steel used in the support was examined, the safe range of cyclic loads for the support was determined using on the stress-time curves, and a calculation model was subsequently developed based on the relationship between the cyclic load magnitude and fatigue life. The results indicate that there are two types of fatigue failure modes for the L-shaped supports: failure at the screw hole and failure at the corner. Furthermore, the stresses experienced by the support under cyclic loads smaller than 60% of the tensile bearing capacity remained within the yield strength except near failure, demonstrating structural safety and reliability. Finally, the proposed calculation model effectively reflected the observed relationship between cyclic load magnitude and L-shaped support fatigue life, providing valuable technical guidance for determining the service life of L-shaped supports in practical engineering applications.