Fatigue strength and fatigue fracture mechanism for spot welds in U-shape specimens

In this paper, the fatigue behavior of the metallic welded U-shape specimens subjected to cyclic loading have been investigated via experimental and numerical analysis. To do so, two sets of the spot welded specimens with different sizes were prepared and fatigue tests were conducted under the various cyclic loads. The crack propagation is numerically examined by using the stress intensity factor values achieved from FE analyses. The modified Paris and Forman-Newman-De Koning models were used to estimate the fatigue crack growth rate. The results indicate that the fatigue life of specimens decreases with any increase in load level.