Qualitative health monitoring and incipient damage inspection/evaluation

Simple item page
dc.contributor.authorAyres, John W.en
dc.contributor.committeechairRogers, Craig A.en
dc.contributor.committeememberLalande, Fredericen
dc.contributor.committeememberRobertshaw, Harry H.en
dc.contributor.departmentMechanical Engineeringen
dc.date.accessioned2014-03-14T21:37:48Zen
dc.date.adate2009-06-11en
dc.date.available2014-03-14T21:37:48Zen
dc.date.issued1996-05-01en
dc.date.rdate2009-06-11en
dc.date.sdate2009-06-11en
dc.description.abstractReal-time structural integrity monitoring is a concept that is becoming a reality in the engineering community. It will soon be possible for a structure to warn the user when its own structural integrity has been altered. A qualitative impedance-based health monitoring technique, which can be implemented for real-time damage evaluation of complex structures, is investigated. The basic principle of the technique is to monitor the structure's mechanical impedance which will be changed with the presence of damage. The mechanical impedance variations are monitored by measuring the electrical impedance of a bonded piezoelectric actuator/sensor (PZT). This mechanical-electrical impedance relation is due to the electro-mechanical coupling property of piezoelectric materials. This health monitoring technique can be easily adapted to existing structures, since only a small non-intrusive PZT patch is needed. This impedance-based method operates at high frequencies (generally above 100kHz), which enables it to detect incipient type damage in a localized region. The localized sensing region offers the advantage of not being affected by nonnal operating conditions or by changing boundary conditions. In this thesis, a complete theoretical background on the impedance-based technique is derived. Then, the technique is applied successfully to a variety of case studies; such as composite patch repair, aircraft structures, precision parts, and civil infrastructure. By simplifying the impedance measurement interpretation through a simple scalar damage metric, the real-time implementation of the impedance-based technique has been proven feasible.en
dc.description.degreeMaster of Scienceen
dc.format.extentxi, 75 leavesen
dc.format.mediumBTDen
dc.format.mimetypeapplication/pdfen
dc.identifier.otheretd-06112009-063007en
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-06112009-063007/en
dc.identifier.urihttp://hdl.handle.net/10919/43110en
dc.language.isoenen
dc.publisherVirginia Techen
dc.relation.haspartLD5655.V855_1996.A947.pdfen
dc.relation.isformatofOCLC# 35079103en
dc.rightsIn Copyrighten
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/en
dc.subjectimpedanceen
dc.subjectqualitativeen
dc.subjectsmart structuresen
dc.subjectdamage detectionen
dc.subject.lccLD5655.V855 1996.A947en
dc.titleQualitative health monitoring and incipient damage inspection/evaluationen
dc.typeThesisen
dc.type.dcmitypeTexten
thesis.degree.disciplineMechanical Engineeringen
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen
thesis.degree.levelmastersen
thesis.degree.nameMaster of Scienceen

Files

Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
LD5655.V855_1996.A947.pdf
Size:
14.7 MB
Format:
Adobe Portable Document Format
Download

Collections

Masters Theses