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Proceedings Paper

Monitoring of bolt preload using piezoelectric active devices
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Paper Abstract

It is estimated that 70% of all mechanical failures are related to fastener failure. One important mode of fastener failure is self-loosening of bolted joints. Self-loosening is especially problematic when the bolted joint is in an inaccessible location, a hostile environment, or a part of a machine whose shutdown would be costly. In this study, a piezoelectric (PZT) active-sensing device was used to detect the self-loosening mode in bolted joint connections. PZT enhanced washers were used to continuously monitor the condition of the joint by monitoring its dynamic characteristics. The mechanical impedance matching between the PZT enhanced devices and the joint connections was used as a key feature to monitor the preload changes and prevent further failure. The dynamic response was readily measured using electromechanical coupling property of the PZT patch, in which its electrical impedance is coupled with the mechanical impedance of the structure. This paper summarizes experimental results, the considerations needed in experimental procedures and design and several issues that can be used as a guideline for future investigation.

Paper Details

Date Published: 9 May 2005
PDF: 8 pages
Proc. SPIE 5768, Health Monitoring and Smart Nondestructive Evaluation of Structural and Biological Systems IV, (9 May 2005); doi: 10.1117/12.604512
Show Author Affiliations
David D. L. Mascarenas, Los Alamos National Lab. (United States)
Gyuhae Park, Los Alamos National Lab. (United States)
Charles R. Farrar, Los Alamos National Lab. (United States)


Published in SPIE Proceedings Vol. 5768:
Health Monitoring and Smart Nondestructive Evaluation of Structural and Biological Systems IV
Tribikram Kundu, Editor(s)

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