## Finite element analysis and measurements of ultrasonic piezoceramic transducers in air and water

Magne Aanes, Espen Storheim, Magne Vestrheim, Per Lunde

University of Bergen, Department of Physics and Technology, Postboks 7803, N-5020 BERGEN, Norway

Christian Michelsen Research AS (CMR), P.O. Box 6031 Postterminalen, N-5892 BERGEN, Norway

Advantages, limitations and problems in applying nite element modeling of ultrasonic piezoceramic trans-

ducers are discussed, with examples from air and water. Finite element simulations of transducers are

compared to measurements and simplied one-dimensional MASON-type models for piezoceramic materials

with emphasis on deviations, even at high D/T (diameter to thickness)-ratios. Electrical properties are then

compared to a frequency [1] thickness (fT) versus D/T type eigenfrequency spectrum derived using modal

analysis. This spectrum together with mode superposition provides information regarding the impact of

dierent eigenmodes, and the eect modes have on electrical and acoustical properties. With the accurate

nite element methods achieved in recent years the standardized methods for determining material data

for simulations do not provide adequate precision. Comparison of nite element simulations with electrical

measurements are used to adjust material data. Finite element modeling is used for both modal and direct

harmonic analysis. Interactions between electrical and acoustical properties, including displacement on the

surfaces of the transducer, are studied using both solution methods. Acoustical properties such as source

sensitivity and directivity are simulated using nite element methods and compared to measurements. Thus,

agreement and disagreement for electrical and acoustical transducer properties are discussed on basis of the

nite element methodology and material data.