Effect of weld penetration on low-cycle fatigue strength of load-carrying cruciform joints

Abstract

This study examined the low-cycle fatigue behavior of load-carrying cruciform-welded joints containing incomplete penetration. Five types of specimens with different sizes of weld penetrations and weld leg lengths were tested under cyclic plastic strains. During testing, cracking behavior was observed on the side surface of the specimen. The test results revealed that the fatigue strength and cracking patterns depend on the ratio of the weld penetration to the main plate thickness and the ratio of the weld leg length to the 5main plate thickness, respectively. Elasto-plastic finite element analyses including the effective notch concept were then performed. The results indicate that the fatigue strength and cracking pattern of the specimens can be correlated with the local strain distribution around the effective notch.