Dynamics Characterisation of Cymbal Transducers for Power Ultrasonics Applications

Feeney, A. , Bejarano, F. and Lucas, M. (2012) Dynamics Characterisation of Cymbal Transducers for Power Ultrasonics Applications. In: 41st UIA Symposium, San Francisco, CA, USA, 16-18 Apr 2012,

Full text not currently available from Enlighten.

Abstract

A Class V ‘cymbal’ flextensional transducer is composed of a piezoceramic disc sandwiched between two cymbal-shaped shell end-caps. These end-caps act as mechanical transformers to convert high impedance, low radial displacement into low impedance, large axial motion of the end-cap. In the cymbal transducer there are two parameters which can limit the operational amplitude range of the device and these can restrict their applicability to power ultrasonics applications. Depending on the type of piezoceramic, there exists a maximum voltage that can be reached without depolarization, but also, at higher voltage levels, amplitude saturation can occur. In addition, there is a restriction imposed by the mechanical strength of the bonding agent. The effects of input voltage levels on the non-linear vibration response of two different cymbal transducer designs are studied in this paper. The transducers are fabricated using the commercial Eccobond 45LV epoxy adhesive as the bonding agent. The first cymbal transducer has a standard configuration of bonding the end-caps to the piezoceramic disc, but the second cymbal transducer includes a metal ring bonded to the outer edge of the piezoceramic disc. The reason for this metal ring is to improve the mechanical coupling with the end-caps and to investigate the capability of the device to operate at higher voltages, thereby generating higher output displacements, by removing the problems associated with de-bonding in the epoxy layer. This, therefore, makes this design particularly suitable for power ultrasonics applications. The input voltages applied to the piezoceramic disc are increased incrementally at the cavity resonance frequency of the devices to illustrate the ranges in which dynamic responses are linear and non-linear. Through a combination of numerical modelling and experiments, it is shown how the dynamic characteristics of the cymbal transducer incorporating a metal ring allow higher vibration amplitudes to be reached.

Item Type:Conference Proceedings
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Bejarano, Mr Fernando and Feeney, Dr Andrew and Lucas, Professor Margaret
Authors: Feeney, A., Bejarano, F., and Lucas, M.
College/School:College of Science and Engineering > School of Engineering > Systems Power and Energy
Related URLs:

University Staff: Request a correction | Enlighten Editors: Update this record