Analysis of Piezoelectric Sensor to Detect Flexural Waves

Abstract

In this paper the electro-mechanical transfer characteristics of adhesively bonded piezoelectric sensors are investigated. Using dynamic piezoelectricity theory, Mindlin plate theory for flexural wave propagation and a multiple integral transform method, the frequency response functions of piezoelectric sensors with and without backing materials are developed and the pressure-voltage transduction functions of the sensors calculated. The corresponding simulation results show that the sensitivity of the sensors is not only dependent on the sensors' inherent features such as piezoelectric properties and geometry, but also on local characteristics of the tested structures and the admittance and impedance of the attached electrical circuit. It is also demonstrated that the simplified rigid mass sensor model can be used to successfully analyse the sensitivity of the sensor at low frequencies, but that the dynamic piezoelectric continuum model has to be used for higher frequencies, especially around the resonance frequency of the coupled sensor-structure vibration system.