Browse Publications Technical Papers 2010-01-0961
2010-04-12

Fatigue Behavior of Dissimilar 5754/7075 and 7075/5754 Spot Friction Welds in Lap-Shear Specimens 2010-01-0961

Fatigue behavior of spot friction welds or friction stir spot welds in lap-shear specimens of dissimilar aluminum 5754-O and 7075-T6 sheets is investigated based on experimental observations and two fatigue life estimation models. Optical micrographs of the 5754/7075 and 7075/5754 welds after failure under cyclic loading conditions are examined to understand the failure mechanisms of the welds. The micrographs show that the 5754/7075 welds mainly fail from the kinked fatigue crack through the lower sheet thickness. Also, the micrographs show that the 7075/5754 welds mainly fail from the kinked fatigue crack through the lower sheet thickness and from the fracture surface through the upper sheet thickness. A kinked fatigue crack growth model based on the stress intensity factor solutions for finite kinked cracks and a structural stress model based on the closed-form structural stress solutions are adopted to estimate the fatigue lives of the 5754/7075 and 7075/5754 welds in lap-shear specimens. The fatigue life estimations based on the kinked fatigue crack growth model and the structural stress model agree well with the experimental results.

SAE MOBILUS

Subscribers can view annotate, and download all of SAE's content. Learn More »

Access SAE MOBILUS »

Members save up to 43% off list price.
Login to see discount.
Special Offer: Purchase more aerospace standards and aerospace material specifications and save! AeroPaks off a customized subscription plan that lets you pay for just the documents that you need, when you need them.
X