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.