Structural damage detection based on the electromechanical impedance technique with high voltage excitation signal

Abstract

Structural health monitoring (SHM) systems are able to detect incipient structural damage, increasing the safety and reducing the maintenance costs. Among the fields of application are the civilian infrastructures and means of transportation, such as bridges, dams, pipelines, ships and aircrafts. Among the various damage detection methods, the electromechanical impedance (EMI) principle has been considered the most promising for the development of SHM systems using low-cost and lightweight piezoelectric transducers, which makes this technique less invasive and allows the installation of multiple transducers for monitoring large areas of the structure without changing its mechanical properties. In the EMI technique, the transducer is excited with a low voltage signal to avoid nonlinearities. However, new studies have reported that a signal with high voltage may be necessary in some applications to ensure adequate sensitivity to detect damage. Therefore, the purpose of this research project is to analyze the effects of the amplitude of the excitation signal in damage detection based on the EMI method. The activities proposed here are related to the research project already approved by FAPESP (2015/02500-6) titled "Monitoring Systems Based on the Electromechanical Impedance Technique: New Trends and Challenges".