Sleeve bolts, which can provide an interference fit in a cylindrical hole by expanding during assembly, were used on an aerospace structural joint. Ultrasound was used to take measurements during preload application and monitoring. Ultrasonic bolt gages have commonly been used on regular bolts and studs, but not sleeve bolts. Ultrasound preload measurement on a sleeve bolt is different in many ways from that on a regular bolt. The pressure and friction on the sleeve bolt shank are absent or insignificant for regular bolts. Pressure and friction change depending upon initial conditions and applied load. The two factors affect the stress distribution inside the bolt and the ultrasound measurements. No published material was available for ultrasonic measurement of preload in sleeve bolts. The manufacturers of both the SLEEVbolt^R (PB Fasteners, Inc.) and the ultrasonic bolt gage were asked for information about this application. Since they had no experience in this application and were unable to help, the author developed the application descried in this paper.

Date Published: 7 July 1995
PDF: 13 pages
Proc. SPIE 2455, Nondestructive Evaluation of Aging Aircraft, Airports, Aerospace Hardware, and Materials, (7 July 1995); doi: 10.1117/12.213557

Published in SPIE Proceedings Vol. 2455:
Nondestructive Evaluation of Aging Aircraft, Airports, Aerospace Hardware, and Materials
Tobey M. Cordell; Raymond D. Rempt, Editor(s)