Fatigue characterization and modeling of AZ31B magnesium alloy spot-welds

Cyclic behavior of AZ31B spot-welds was studied using different specimen configurations, and compared with steel and aluminum spot-welds. Fatigue strength of magnesium spot-welds was similar to aluminum and less than steel. Three failure modes were observed in tensile-shear specimens and one mode of failure in cross-tension specimens. Fatigue crack initiation life was 50% and 30% of the total life for tensile-shear and cross-tension specimens, respectively. A number of available fatigue models were assessed by predicting fatigue life of magnesium spot-welds. Although these models do not account for the asymmetric cyclic hardening behavior, some of them performed successfully for magnesium spot-welds.