Structural Health Monitoring Using Piezoelectric Transducers Excited with High Frequency Signals

Abstract

Monitoring systems capable of providing a reliable diagnosis of the integrity of a given structure remain as a developing science. Such systems are commonly known as structural health monitoring (SHM) systems and are intended to detect structural damage at an early stage, providing a high level of safety and cost reduction through fast and efficient predictive maintenance. Among the various monitoring technologies, piezoelectric transducers are used in the most promising of them and the electromechanical impedance (EMI) technique stands out because, due to the piezoelectric effect, it allows analyzing the mechanical conditions of the monitored structure through measurement and analysis of the electrical impedance of the transducer. In the EMI method, each piezoelectric transducer operates simultaneously as a sensor and an actuator, excited in an appropriate frequency band. The proposed research project aims to analyze the impedance method by exciting the transducer with high frequency signals above 1 MHz. Several characteristics of the EMI method such as transducer performance, damage sensitivity, temperature effects and the performance of alternative measurement systems will be analyzed under excitation with high frequency signals. The research will consist of theoretical analysis and experimental tests on structures such as bars and plates of aluminum and other materials. Due to the relevance of the theme, the expectation is that this research will result in an expressive scientific production related to the supervision of graduate and undergraduate students. (AU)