Today, spot-welding is the typical joining technique for steel sheet in the
motor car industry. A common laboratory specimen geometry used to evaluate the
fatigue resistance of spot-welded steel sheet is the single-lap (or tensile-
shear) configuration. The influence of various parameters on the fatigue
resistance of single-lap spot-welds are reviewed. However, the results of such
tests are difficult to apply quantitatively to design because they are strongly
dependent on the specimen dimensions, details of gripping, and magnitude of the
maximum load relative to the yield (or plastic collapse) load. Analytical
modeling is used herein to attempt to bring into agreement data from many
investigators. Models included the nominal axial stress range, range of stress
intensity factor, nominal axial load plus first-order bending theory, and
nominal axial load plus second-order bending theory. The models are compared
with one another using data from the literature for fatigue tests on single-lap
specimens with one or two spot-welds on the longitudinal axis of the specimen
and for both uncoated and coated steels.
"Modeling of the Fatigue Resistance of Single Lap Spot Welded Steel Sheet,"
IIW Document III-1469-92, May 1992.