Picture of virus under microscope

Research under the microscope...

The Strathprints institutional repository is a digital archive of University of Strathclyde research outputs.

Strathprints serves world leading Open Access research by the University of Strathclyde, including research by the Strathclyde Institute of Pharmacy and Biomedical Sciences (SIPBS), where research centres such as the Industrial Biotechnology Innovation Centre (IBioIC), the Cancer Research UK Formulation Unit, SeaBioTech and the Centre for Biophotonics are based.

Explore SIPBS research

Theoretical modelling of frequency dependent elastic loss in composite piezoelectric Transducers

Orr, L. and Mulholland, A.J. and O'Leary, R.L. and Parr, A.C.S. and Pethrick, R.A. and Hayward, G. (2007) Theoretical modelling of frequency dependent elastic loss in composite piezoelectric Transducers. Ultrasonics, 47 (1). pp. 130-137. ISSN 0041-624X

[img]
Preview
PDF (orr_2007_ultrasonics(theoretical_modelling_of).pdf)
orr_2007_ultrasonics(theoretical_modelling_of).pdf

Download (419kB) | Preview

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.