Prediction of fatigue life of welding tool in friction stir welding of AA6061-T6

Computational fluid dynamics model is proposed for the calculation of tool forces in friction stir welding of AA6061-T6. Then, a finite element model is established to calculate the fatigue stress of the welding tool. Damage accumulation method and KBM multiaxial fatigue formulation are used to predict the fatigue life of the welding tool. Results indicate that the fatigue stresses on the tool pin are in tension at the front side and in compression at the rear side. Fatigue life of the welding tool can be increased with the increase of the rotation speed and can be decreased with the increase of the transverse speed. Both the increase of the shoulder diameter and the pin diameter can lead to the increase of the fatigue life of the welding tool.