### Abstract

Language | English |
---|---|

Pages | 130-137 |

Number of pages | 8 |

Journal | Ultrasonics |

Volume | 47 |

Issue number | 1 |

Early online date | 29 Sep 2007 |

DOIs | |

Publication status | Published - 31 Dec 2007 |

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### Keywords

- Anisotropic composites
- Ultrasonic transducer
- Elastic loss

### Cite this

*Ultrasonics*,

*47*(1), 130-137. https://doi.org/10.1016/j.ultras.2007.09.001

}

*Ultrasonics*, vol. 47, no. 1, pp. 130-137. https://doi.org/10.1016/j.ultras.2007.09.001

**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.

Research output: Contribution to journal › Article

TY - JOUR

T1 - Theoretical modelling of frequency dependent elastic loss in composite piezoelectric transducers

AU - Orr, L.

AU - Mulholland, A.J.

AU - O'Leary, R.L.

AU - Parr, A.C.S.

AU - Pethrick, R.A.

AU - Hayward, G.

PY - 2007/12/31

Y1 - 2007/12/31

N2 - 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.

AB - 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.

KW - Anisotropic composites

KW - Ultrasonic transducer

KW - Elastic loss

U2 - 10.1016/j.ultras.2007.09.001

DO - 10.1016/j.ultras.2007.09.001

M3 - Article

VL - 47

SP - 130

EP - 137

JO - Ultrasonics

T2 - Ultrasonics

JF - Ultrasonics

SN - 0041-624X

IS - 1

ER -