Theoretical modelling of frequency dependent elastic loss in composite piezoelectric transducers

L. Orr, A.J. Mulholland, R.L. O'Leary, A.C.S. Parr, R.A. Pethrick, G. Hayward

Research output: Contribution to journalArticle

10 Citations (Scopus)

Abstract

The large number of degrees of freedom in the design of piezoelectric transducers requires a theoretical model that is computationally efficient so that a large number of iterations can be performed in the design optimisation. The materials used are often lossy, and indeed loss can be used to enhance the operational characteristics of these designs. Motivated by these needs, this paper extends the one-dimensional linear systems model to incorporate frequency dependent elastic loss. The reception sensitivity, electrical impedance and electromechanical coupling coefficient of a 1-3 composite transducer, with frequency dependent loss in the polymer filler, are investigated. By plotting these operating characteristics as a function of the volume fraction of piezoelectric ceramic an optimum design is obtained. A device with a non-standard, high shear attenuation polymer is also simulated and this leads to an increase in the electromechanical coupling coefficient. A comparison with finite element simulations is then performed. This shows that the two methods are in reasonable agreement in their electrical impedance profiles in all the cases considered. The plots are almost identical away from the main resonant peak where the frequency location of the peaks are comparable but there is in some cases a 20% discrepancy in the magnitude of the peak value and in its bandwidth. The finite element model also shows that the use of a high shear attenuation polymer filler damps out the unwanted, low frequency modes whilst maintaining a reasonable impedance magnitude.
LanguageEnglish
Pages130-137
Number of pages8
JournalUltrasonics
Volume47
Issue number1
Early online date29 Sep 2007
DOIs
Publication statusPublished - 31 Dec 2007

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piezoelectric transducers
electrical impedance
coupling coefficients
fillers
composite materials
polymers
attenuation
shear
plotting
piezoelectric ceramics
design optimization
linear systems
iteration
transducers
degrees of freedom
plots
impedance
low frequencies
bandwidth
sensitivity

Keywords

  • Anisotropic composites
  • Ultrasonic transducer
  • Elastic loss

Cite this

Orr, L. ; Mulholland, A.J. ; O'Leary, R.L. ; Parr, A.C.S. ; Pethrick, R.A. ; Hayward, G. / Theoretical modelling of frequency dependent elastic loss in composite piezoelectric transducers. In: Ultrasonics. 2007 ; Vol. 47, No. 1. pp. 130-137.
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Theoretical modelling of frequency dependent elastic loss in composite piezoelectric transducers. / Orr, L.; Mulholland, A.J.; O'Leary, R.L.; Parr, A.C.S.; Pethrick, R.A.; Hayward, G.

In: Ultrasonics, Vol. 47, No. 1, 31.12.2007, p. 130-137.

Research output: Contribution to journalArticle

TY - JOUR

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AU - Orr, L.

AU - Mulholland, A.J.

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