Font Size: a A A

Control of noise and vibration of fluid-loaded shells using periodic piezoelectric shunt networks

Posted on:2002-06-18Degree:Ph.DType:Dissertation
University:The Catholic University of AmericaCandidate:Thorp, Owen G., IIIFull Text:PDF
GTID:1462390014950291Subject:Engineering
Abstract/Summary:
Shunted piezoelectric patches periodically distributed along rods, beams and shells are capable of controlling wave propagation in these structures. The resultant periodic structures are capable of filtering the propagation of waves over specified frequency bands called stop bands. The location and the extension of the stop bands can be tuned, using the shunting capabilities of the piezoelectric materials, in response to external excitation and to compensate for structural uncertainties. Additionally, by proper tuning of the shunting circuit, damping can be introduced to cause energy dissipation of propagating waves outside the stop bands.; A mathematical model is developed to predict the response of rods, beams and shells with periodic shunted piezoelectric patches and to identify regions of stop bands in the considered frequency spectrum and to evaluate the amount of damping introduced through the shunting circuits. The mathematical model also accounts for aperiodicity, introduced by proper tuning of the shunting electrical impedance distribution along the structure. The mathematical model is then extended to include the interaction of vibrating shells with a surrounding fluid in order to verify the effectiveness of the proposed treatment for underwater applications. Finally, the model incorporates intensity level predictions based on structural deformations of the underwater shell.; The numerical predictions demonstrate the effectiveness and potentials of the proposed treatment that requires no control energy and combines the damping characteristics of shunted piezoelectric films, the attenuation potentials of periodic structures, and the localization capabilities of aperiodic structures.
Keywords/Search Tags:Piezoelectric, Periodic, Shells, Structures, Stop bands
Related items