Optimizing piezoelectric ceramic thickness in ultrasonic transducers

The flexural ultrasonic transducer comprises a piezoelectric ceramic disc bonded to a membrane. The vibrations of the piezoelectric ceramic disc induce flexural modes in the membrane, producing ultrasound waves. The transducer is principally utilized for proximity or flow measurement, designed for operation at atmospheric pressure conditions. However, there is rapidly growing industrial demand for the flexural ultrasonic transducer in applications including water metering or in petrochemical plants where the pressure levels of the gas or liquid environment can approach 100 bar. In this study, characterization methods including electrical impedance analysis and pitch-catch ultrasound measurement are employed to demonstrate the dynamic performance of flexural ultrasonic transducers in air at elevated pressures approaching 100 bar. Measurement principles are discussed, in addition to modifications to the transducer design for ensuring resilience at increasing air pressure levels. The results highlight the importance of controlling the parameters of the measurement environment and show that although the conventional design of flexural ultrasonic transducer can exhibit functionality towards 100 bar, its dynamic performance is unsuitable for accurate ultrasound measurement. It is anticipated that this research will initiate new developments in ultrasound measurement systems for fluid environments at elevated pressures.

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A Novel Drive Option for Piezoelectric Ultrasonic Transducers

Modelling and Simulation in Engineering ◽

10.1155/2011/910876 ◽

2011 ◽

Vol 2011 ◽

pp. 1-6 ◽

Cited By ~ 5

Author(s):

Diana Engelke ◽

Bernd Oehme ◽

Jens Strackeljan

Keyword(s):

Finite Element Method ◽

Finite Element ◽

Piezoelectric Ceramic ◽

Ultrasonic Transducers ◽

The Finite Element Method ◽

Vibration Behavior ◽

New Type ◽

Dental Applications ◽

Element Method

This paper concentrates on ultrasonic transducers, which are driven by piezoelectric ceramic rings that are arranged in a stack. A novel drive option, where the stack contains a new type of divided piezoelectric rings, is analyzed using the finite element method, prototyped, and tested. To gain a better sense of the vibration behavior, the studies focus initially on one ring and subsequently on the different possibilities to assemble the transducer. The investigations point out that natural bending frequencies can be excited at the transducer. Thus, multiple vibration directions of the tip can be controlled, what can be advantageous for instance in dental applications.

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