Effects of Specimen Width and Overlap Length on Stress Intensity Factors of Spot Welds in Lap-Shear Specimens

In this paper, the stress intensity factor solutions at the critical locations of spot welds in lap-shear specimens are investigated by finite element analyses. Three-dimensional finite element models are developed for lap-shear specimens to obtain accurate stress intensity factor solutions. Various ratios of the half specimen width to the nugget radius and the overlap length of the upper and lower sheets to the nugget radius are considered in this investigation. The computational results provide geometric functions in terms of the normalized specimen width and the normalized overlap length to the stress intensity factor solutions of Zhang [1,2] for lap-shear specimens. The computational results also indicate that when the spacing between spot welds decreases, the mode I stress intensity factor solution at the critical locations increases and the mode mixture of the stress intensity factors changes consequently.