Experimental approach for thermo-electro-mechanical characterization of piezoelectric transducers

Abstract Piezoelectric transducers are subject to increasingly stringent
performance requirements. High-power, high-temperature and high-precision
applications are becoming more important. Thus, the maximum permissible
temperature of the transducer and the temperature-dependent performance and
behaviour can become relevant in piezoelectric transducer design here, which
is why thermo-electro-mechanical characterization is becoming essential for the
development of piezoelectric systems. In the current state of the art, electromechanical
piezoelectric characterization is common, whereby the influence of
thermals is disregarded. In this context, an experimental setup has been developed
that enables characterization of the combined thermal, electric and mechanical
behaviour of piezoelectric transducers. The focus of the work here is a nondestructive
characterization of piezoelectric transducers at their electric load,
which maps the special requirements of the application with its thermal and
mechanical load cases by using an additional load actuator and additional thermal
elements. The experimental setup has a modular design so that a large number
of different designs and sizes of piezoelectric transducers can be analysed, with
the focus being on prismatic and cylindrical longitudinal piezoelectric stack
actuators. Beyond that, the experimental setup developed in this work is also
suitable for investigating cooling methods, as we observed, that more and more
concepts for cooling piezoelectric transducers are being developed that need to
be analysed experimentally. In summary, this paper describes the development
of the experimental setup with all implementation measurements and an initial
piezoelectric transducer test using a PZT stack actuator, to show the potential.