Multiple damage detection in piezoelectric ceramic sensor using point contact excitation and detection method

TL;DR

This paper presents a novel point contact excitation and detection method combined with Haar DWT for accurate detection and localization of micro-defects in PZT sensors, enhancing structural health monitoring.

Contribution

It introduces a new ultrasonic SHM technique using point contact methods and wavelet analysis to detect micro-defects with improved accuracy.

Findings

Defects up to 100 um diameter can be detected and localized.

Haar DWT improves defect detection accuracy.

Method addresses impedance mismatch issues in ultrasound SHM.

Abstract

Lead Zirconate Titanate [(ZrxTi1-x)O3 ]is used to make ultrasound transducers, sensors, and actuators due to its large piezoelectric coefficient. Several surfaces and subsurface micro defects develop within the Lead Zirconate Titanate (PZT) sensor due to delamination, corrosion, huge temperature fluctuation, etc., causing a decline in its performance. It is thus necessary to identify, locate, and quantify the defects. Non-Destructive Structural Health Monitoring (SHM) is the most optimal and economical method of evaluation. Traditional ultrasound SHM techniques have a huge impedance mismatch between air and any solid material. And most of the popular signal processing methods define time-series signals in only one domain which gives sub-optimal results. Thus to improve the accuracy of detection point contact excitation and detection methods have been implemented to determine the interaction of ultrasonic waves with microscale defects in the PZT. And Haar Discrete Wavelet Transformation (DWT) is applied to the time series data obtained from the Coulomb coupling setup. Using the above process, defect up to 100 um in diameter could be successfully distinguished and localized.