Influence of the joint geometry on heat energy, generated during the plunge stage of friction stir welding
The numerical simulation of friction stir welded T-joints made of AA2024 T3is investigated. Analysis of heat generation due to friction and plastic workis performed, as well as of the reaction force in the normal direction duringthe plunge stage of the friction stir welding. The effect of joint geometry isstudied for butt joints and T-joints produced from the same material.Different tool rotation speeds and tool pin lengths were considered forT-joint FSW welding. It was shown that the temperature at the root of theweld below the tool pin is lower in the T-joint than in the butt joint, due tothe efficient conduction of the heat produced through the normal plate. Also,the reaction force was higher for the T-joint than for the butt joint; so, heatproduction by friction was more intense in comparison with the heatproduced by plastic deformation. The reaction force was moderatelyincreased for the tool with a shorter pin, increasing both components of theheat produced. An increase in the tool rotation speed decreased theresistance to the tool plunging into the T-joint, increasing the frictional heatand decreasing the amount of heat generated by plastic deformation.