Friction stir blind rivet joining system and method

A friction stir blind rivet (FSBR) joining method comprising:

• providing a FSBR that includes a mandrel that has a tip and a notch;
• extending the mandrel through a shank that has a head with an outermost point and a surface opposite the outermost point;
• determining parameters that include a mandrel rotational speed (ω), a feed rate (V), a mandrel strength, and a distance dnotch from the tip to the notch;
• setting a machine to operate using the parameters;
• operating the machine to apply the FSBR to a workpiece;
• and
• operating the machine to pull back on the mandrel to break a tail section from the mandrel so that the mandrel extends from the tip to the broken end and so that the broken end is disposed within the head.

A friction stir blind rivet (FSBR) joining system for joining first and second workpieces together comprising:

• a mandrel that has a first head forming a tip, with a stem extending from the head, wherein the stem has a narrowed section forming a notch configured so that a tail section of the mandrel breaks-off at the notch when exposed to a tensile load, wherein the mandrel extends from the tip to a broken end following break-off;
• a shank that has a second head and a body extending from the second head, with a through-hole defined through the shank, including through the head and the body, wherein the second head includes a shoulder forming a surface, with the surface contacting the first workpiece, and the head has an outermost point opposite the surface that is a part of the head farthest from the first workpiece, wherein a range is defined between the outermost point of the head and the surface as dhead;
• and
• a wall projecting from the second workpiece and formed around the body, the wall formed when the mandrel and shank penetrate the workpieces;
• wherein the wall has a size formed by interaction with the mandrel and the shank, wherein the size is controlled by a rotational speed at which the mandrel is rotated;
• and
• wherein the size is controlled to enable the body to deform when the first head is forced against the body by pulling on the mandrel.