000022074 001__ 22074
000022074 005__ 20170622145955.0
000022074 04107 $$aeng
000022074 046__ $$k2015-05-25
000022074 100__ $$aPanagiotopoulos, Christos
000022074 24500 $$aTIME REVERSAL IN ELASTODYNAMICS AND APPLICATIONS TO STRUCTURAL HEALTH MONITORING

000022074 24630 $$n5.$$pComputational Methods in Structural Dynamics and Earhquake Engineering
000022074 260__ $$bNational Technical University of Athens, 2015
000022074 506__ $$arestricted
000022074 520__ $$2eng$$aIn structural health monitoring, detection of localized damage can be achieved by exploiting recorded signals at a limited number of sensors within the structure. Here we propose the localization of damage using an array of sensors as a computational time-reversal mirror (TRM). Time reversal (TR) is a physical process that exploits the time reversibility of wave equations and achieves re-focusing of the wave on the source of its origin by sending back, reversed in time, the signals recorded on an array of transducers. TR was originally introduced by Mathias Fink and his group and has several applications ranging from medical imaging to telecommunications [14]. In the present work, we perform time reversal numerically in order to effectively detect and localize defects in a bounded two-dimensional elastic domain. This is a generalization of a respective time-reversal implementation in an acoustic medium [12]. The solid contains a number of Nr sensors which can act as sources as well. Our data is the response matrix of the scattered field, that is, the difference between the total field obtained in the damaged structure and the incident field corresponding to the response in the healthy structure. Numerical solution of the wave propagation problem is performed using a mixed finite element formulation in terms of the velocity and stress fields [6]. In order to dissociate the response caused by Nd different defects, we apply the singular value decomposition (SVD) of the response matrix, while back-propagation of the projection of each singular vector corresponding to a non-zero singular value is performed in order to highlight each defect separately.

000022074 540__ $$aText je chráněný podle autorského zákona č. 121/2000 Sb.
000022074 653__ $$aElastic wave propagation, time reversal, source localization, damage detection, structural health monitoring, finite element method.

000022074 7112_ $$aCOMPDYN 2015 - 5th International Thematic Conference$$cCrete (GR)$$d2015-05-25 / 2015-05-27$$gCOMPDYN2015
000022074 720__ $$aPanagiotopoulos, Christos$$iTsogka, Chrysoula$$iPetromichelakis, Yiannis
000022074 8560_ $$ffischerc@itam.cas.cz
000022074 8564_ $$s779490$$uhttp://invenio.itam.cas.cz/record/22074/files/C1131.pdf$$yOriginal version of the author's contribution as presented on CD, section: 
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000022074 962__ $$r22030
000022074 980__ $$aPAPER