Analysis of Sensor Installation Methods in Impedance-based SHM Applications

Abstract

In recent years, piezoelectric sensors have been used in many non-destructive methods for detection of structural damage in structural health monitoring (SHM) systems, including the electromechanical impedance (EMI) technique. The classic method to install the sensor in the structure to be monitored is using a high stiffness adhesive. However, many studies have proposed alternative methods of sensor installation. Thus, the purpose of this study is to conduct a comparative experimental analysis of the main installation methods of the sensors in the electromechanical impedance technique, which are the direct installation, the magnetic coupling, and using aluminum foils. Tests with the three installation methods were carried out on aluminum structures and the results were compared using the electrical impedance signatures and damage indices. The experimental results indicate important features of each method relative to the feasibility for detection of structural damage.