The thickness effect of hot spot S-N curves for welded aluminum joints

This study aimed to investigate the design S-N curve on the basis of the hot spot stress (HSS) approach considering proper thickness effect for welded aluminum joints. The effect of the main plate thickness is examined by using the results of fatigue tests in this study and references of fatigue data of previous literature. The fatigue tests are performed on 5083-O welded joint specimens with four kinds of main plate thicknesses, namely 12 mm, 16 mm, 20 mm, and 25 mm. The main plate thicknesses of the fatigue data of the references ranged from 2.8 to 25 mm. We clarify the relationship between fatigue strength and main plate thickness, and propose hot spot design S-N curve for welded aluminum joints with thickness of less than 25 mm based on the research of the thickness effect. Fatigue tests of large-scale model are carried out to test the validity of the proposed design S-N curve for welded structures.