Performance assessment of piezoelectric transducers excited with high frequency signals for structural damage detection based on electromechanical impedance

Abstract

Piezoelectric transducers are used in a wide variety of applications. One of the most reported applications in the literature has been the development of non-destructive techniques for the detection of structural damage in monitoring systems. The electromechanical (E/M) impedance is one of the most known non-destructive techniques, which has as principle the relationship between the electrical impedance of the transducer and the mechanical impedance of the monitored structure, thus allowing structural damages to be detected by means of the measurement and analysis of the electrical impedance of the transducer. Typically, the piezoelectric transducer is excited with low frequency signals up to about 500 kHz. However, recent studies have indicated the use of higher frequencies, usually above 1 MHz, for the detection of some types of damage and the monitoring of some characteristics of the structure that are not possible with low frequencies. Therefore, this scientific initiation research aims to investigate the performance of piezoelectric transducers excited with high frequency signals. The sensitivity to structural damage of commonly used transducers in the electromechanical impedance technique will be evaluated by means of basic damage indices, exciting the transducer with both low and high frequency signals. At the end of this research, it is expected to obtain a comparative analysis of the performance of piezoelectric transducers excited with high frequency signals for the detection of structural damage.