Advanced Search

Journal Navigation

Journal Home

Subscriptions

Archive

Contact Us

Table of Contents

Sign In to gain access to subscriptions and/or personal tools.
Structural Health Monitoring
This Article
Right arrow Full Text (PDF)
Right arrow References
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Alert me to new issues of the journal
Right arrow Add to Saved Citations
Right arrow Download to citation manager
Right arrowRequest Permissions
Right arrow Request Reprints
Right arrow Add to My Marked Citations
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Right arrow Citing Articles via Scopus
Google Scholar
Right arrow Articles by Pai, P. F.
Right arrow Articles by Lee, S.-Y.
Right arrow Search for Related Content
Social Bookmarking
Add to CiteULike   Add to Complore   Add to Connotea   Add to Del.icio.us   Add to Digg   Add to Reddit   Add to Technorati   Add to Twitter  
What's this?

Detection of Defects in Circular Plates using a Scanning Laser Vibrometer

P. Frank Pai

Department of Mechanical and Aerospace Engineering, University of Missouri-Columbia, Columbia, MO 65211, paip{at}missouri.edu

Yunje Oh

Department of Mechanical and Aerospace Engineering, University of Missouri-Columbia, Columbia, MO 65211

Seung-Yoon Lee

Department of Mechanical and Aerospace Engineering, University of Missouri-Columbia, Columbia, MO 65211

This paper investigates dynamic characteristics (mode shapes and natural frequencies) and defect detection of circular plates using a scanning laser vibrometer. Analytical dynamic characteristics of a circular aluminum plate having a clamped inner rim and a free outer rim are obtained using two methods; one uses Bessel functions and the other uses a multiple shooting method. An in-house finite element code GESA is also used to analyze the circular plate using the DKT plate element. Numerical results show that high-frequency Operational Deflection Shapes (ODSs) are needed in order to locate small defects. Detection of two defects in the circular aluminum plate is experimentally studied using the distributions of RMS velocities under broadband periodic chirp excitations, RMS velocities of ODSs, symmetry breaking of ODSs, splitting of natural frequencies and ODSs, and a Boundary Effect Detection (BED) method. The BED method is a dynamics-based non-destructive method; it processes experimental ODSs to reveal extra local boundary effects caused by defects to reveal locations of defects. Experimental results show that small defects in circular plates can be pinpointed by these approaches. Moreover, a new concept of using the balance of elastic and kinetic energies within a mode cell for detecting defects in two-dimensional structures of irregular shapes is proposed.

Key Words: damage detection • circular plates • boundary effects • scanning laser vibrometer

Structural Health Monitoring, Vol. 1, No. 1, 63-88 (2002)
DOI: 10.1177/147592170200100105
Add to CiteULike CiteULike   Add to Complore Complore   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us   Add to Digg Digg   Add to Reddit Reddit   Add to Technorati Technorati   Add to Twitter Twitter    What's this?


This article has been cited by other articles:


Home page
 Journal of Intelligent Material Systems and StructuresHome page
P. F. Pai, B.-S. Kim, and J. H. Chung
Dynamics-based Damage Inspection of an Aircraft Wing Panel
Journal of Intelligent Material Systems and Structures, November 1, 2004; 15(11): 803 - 821.
[Abstract] [PDF]