Analysis of the Local Stresses at Laser-Welded Lap Joints

Theoretical and numerical stress analyses were performed to understand local stress effect due to geometric eccentricity to estimate the fatigue life of laser-welded overlap joints of automotive thin steel sheets. Two thicknesses and a nonzero root opening were used. The two-dimensional problem of the stress function within a laser-welded bead was solved in the form of a generalized crosswise Fourier series. The nondimensional local stress factors with respect to the remote tensile stress for twelve cases were compared at three locations in a bead. The locations were chosen based on where local maximum stresses occur; such paints can cause failure during a fatigue test.