Two experimental set-ups designed for investigation of friction stir spot welding process

The effects of positioning and clamping conditions of a specimen of friction stir spot welding are investigated in this paper in terms of axial force and torque generated during the process. For this purpose, two special designs of experimental set-ups embedding different positioning and clamping conditions are presented. A four-component mechanical sensor is used for the measurements. First, the effects of the rotational speed of the spindle and the plunge depth of the tool on the axial force and torque are studied. Second, the effects of positioning and clamping conditions are investigated through both set-ups designed, varying the spindle rotation speed. It is shown that the axial force and torque exhibit an important dependence with respect to the rotation speed of the tool and that their maxima depend on positioning and clamping conditions of the specimen.