Computational fluid dynamics model of AA6061 friction stir welding with considering mechanical anisotropy

The anisotropy of mechanical properties was introduced into the computational fluid dynamics (CFD) model of the AA6061 friction stir welding (FSW) process. According to the calculated results, the distribution of anisotropy and the distribution of the flow stress/yield strength drop degree due to the mechanical anisotropy are analyzed. Considering the anisotropy, the surface heat generation and viscosity dissipation heat source decrease in the shoulder-affected zone (SAZ) near the pin root and the upper part of the pin-affected zone, especially on the advancing side (AS), the anisotropy of the mechanical property affects the strain rate distribution mainly through heat generation, which leads to the shrinkage of the thermo-mechanically affected zone (TMAZ) profile at the root of the tool pin, especially at the AS, which improves the TMAZ profile predicted accuracy of the CFD model.