Browse Publications Technical Papers 2011-01-0470
2011-04-12

Fatigue Behavior of Spot Friction Welds in Cross-Tension Specimens of Aluminum 6061-T6 Sheets 2011-01-0470

Failure modes of spot friction welds in cross-tension specimens of aluminum 6061-T6 sheets are first investigated based on experimental observations. Optical and scanning electron micrographs of the welds before and after failure under quasi-static and cyclic loading conditions are examined. Experimental results show that the failure modes of the welds under quasi-static and cyclic loading conditions are quite different. Under quasi-static loading conditions, the failure mainly starts from the necking of the upper sheet outside the weld. Under low-cycle loading conditions, the dominant fatigue cracks are the kinked cracks growing into the upper sheet from the crack tips; hence, the upper nugget pullout failure mode can be seen. Under high-cycle loading conditions, the dominant fatigue cracks are kinked cracks growing into the lower sheet from the crack tips; subsequently, the lower nugget pullout failure mode can be seen. A fatigue crack growth model based on the paths of the dominant kinked fatigue cracks is then adopted to estimate the fatigue lives of the spot friction welds. The accurate global and local stress intensity factors for finite kinked cracks based on the three-dimensional finite element computations and the Paris law for fatigue crack propagation are utilized in the fatigue crack growth model. The fatigue life estimations based on the fatigue crack growth model correlate 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 18% off list price.
Login to see discount.
We also recommend:
JOURNAL ARTICLE

Failure Mode and Fatigue Behavior of Ultrasonic Spot Welds with Adhesive in Lap-Shear Specimens of Magnesium and Steel Sheets

2013-01-1020

View Details

JOURNAL ARTICLE

Investigation of Failure Mode and Fatigue Behavior of Flow Drill Screw Joints in Lap-Shear Specimens of Aluminum 6082-T6 Sheets

2016-01-0501

View Details

JOURNAL ARTICLE

Impact of Rivet Head Height on the Tensile and Fatigue Properties of Lap Shear Self-Pierced Riveted CFRP to Aluminum

2017-01-0477

View Details

X