Hole expanding rivet with a shaded tail

摘要

The invention is a tapered tail rivet for joining two or more structural elements together which, during driving, provides a controlled expansion of the hole and, after driving, leaves residul hoop compression stresses around the hole. The tapered tail rivet has a shank having a nominal diameter (the diameter in the middle of the tolerance range). The head diameter may be of the type critically dimensioned based on the shank diameter or other design parameter. The tapered tail length is between 1.30 times the minimum shank diameter and 1.10 times the maximum shank diameter. The distal end of the tapered tail has a diameter of between 0.80 times the minimum shank diameter and 0.68 times the maximum shank diameter. The tapered tail portion should extend to the face of one of the structural elements to just inside the face of that structural element prior to driving. The minimum upset tail diameter should be 1.45 times the nominal shank diameter and the minimum upset tail height should be 0.30 times the nominal shank diameter.