Reversible fastener clamp load monitor with continuous visual or remote readout

Malcolm H. Hodge; Theodore C. Kausel Jr.; Matthew R. Begley

doi:10.1117/12.305054

31 March 1998 Reversible fastener clamp load monitor with continuous visual or remote readout

Malcolm H. Hodge, Theodore C. Kausel Jr., Matthew R. Begley

Proceedings Volume 3397, Nondestructive Evaluation of Aging Aircraft, Airports, and Aerospace Hardware II; (1998) https://doi.org/10.1117/12.305054
Event: Non-Destructive Evaluation Techniques for Aging Infrastructure and Manufacturing, 1998, San Antonio, TX, United States

Abstract

SIMS has developed a simple means for detecting and monitoring both absolute and relative clamp load, or bolt tension, in fastener systems. More than twenty-five percent of automotive failures are known to be due to undetected loss of fastener clamp load. While the equivalent aerospace maintenance statistics are not known, the average automobile has 3,500 fasteners while a Boeing 747 has closer to one million. It is therefore anticipated that the new SensaBolt clamp load tracking system could find wide applications in the aerospace arena. We describe a visually-evident and retrofitted clamp load monitoring design which is based on the differential joint substrate compression at, and immediately adjacent to, the fastener location. This intrinsically-accurate indicator does not necessarily require alteration in either the bolt or nut geometries, thereby facilitating product introduction and retrofit in aging aircraft applications. In addition, SensaBolt's sole reliance on substrate compression renders it more accurate then torque wrench or turn-of-nut techniques. Readout may be accomplished by any of three principal methods: for those applications with ease of access to the sensor, loss of tension can be determined by direct visual inspection. Application of a standard wrench can then be made to restore the fastener's proper tightness, per the SensaBolt indicators. In those instances where line-of-sight is unimpeded and more formal inspection is desired, the SensaBolt may be interrogated by a laser scanner bar code reader. Finally, SensaBolt may be addressed by the SIMS fiber optic harness for those instances where full-time remote interrogation is desired.

Citation Download Citation

Malcolm H. Hodge, Theodore C. Kausel Jr., and Matthew R. Begley "Reversible fastener clamp load monitor with continuous visual or remote readout", Proc. SPIE 3397, Nondestructive Evaluation of Aging Aircraft, Airports, and Aerospace Hardware II, (31 March 1998); https://doi.org/10.1117/12.305054

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available

Members: $17.00

Non-members: $21.00 ADD TO CART

PROCEEDINGS
8 PAGES

DOWNLOAD PAPER SAVE TO MY LIBRARY

GET CITATION

RIGHTS & PERMISSIONS

Get copyright permission Get copyright permission on Copyright Marketplace

KEYWORDS

Head

Visualization

Aerospace engineering

Fiber optics

Signal attenuation

Computer programming

Finite element methods

Show All Keywords

Keywords/Phrases

Search In:

Publication Years