Abstract

In this dissertation, we used the smoothed particle hydrodynamics method for the two-dimensional study of the effect of three different triangular, square, and circular pins on the material flow in friction stir welding. A statistical study was performed to investigate the number of migration particles by each pin, and it was found that the triangular pin, due to its unique nature and geometry, causes more mixing of particles 1.34 times than the square pin and 2.80 times the circular pin. In addition, the square pin has 2.08 times more influence on the material flow than the circular pin. This effect was also evident in the early moments of pin rotation, and the velocity field results in triangular, square, and circular pins also prove this. Finally, the locas of particles were plotted for particles that had crossed the junction line of the two plates at least once. The triangular pin was found to cause more turbulence than the other two pins. The simulation results were in good agreement with the existing results and studies.

Keywords: Material flow, Friction Stir Welding, Smoothed Particle Hydrodynamics, Pin shape, Optimization