Sensor self-diagnostics for piezoelectric transducers operating in harsh temperature environments

Abstract

In many condition and health monitoring applications, it is necessary to be able to differentiate between response characteristics that result from structural and sensor specific damage types. An investigation is presented in this paper that considers the effectiveness of sensor self-diagnostic techniques for piezoelectric-based transducers that operate in harsh temperature environments. The motivation behind this work is to develop a method for interrogating sensor health when embedded within high-cost research systems. The theoretical basis for this approach is first presented, along with several analytical test cases in which temperature effects are examined within models of the piezoelectric transducer. Following this, a series of experiments are presented in which transducers with varying types and degrees of damage are subject to repeated temperature cycling from cryogenic to room temperature. The results of this study indicate that capacitive-based self-diagnostic techniques are capable of detecting both sensor delamination and cracking at room and liquid nitrogen temperatures.