Quality Assessment for the EMI-based Inspection of PWAS

Abstract

This paper presents a new procedure to evaluate a method for piezoelectric wafer active sensor (PWAS) inspection, when it is combined with a given structural health monitoring (SHM) system for structural damage detection. A data-driven method is used, applying a damage indicator DIPWAS based on the electro-mechanical impedance spectrum (EMI), to distinguish between faulty and healthy PWAS. To evaluate the quality of this method, the consequences of PWAS damage are investigated. In this case, these are the changes within the generated wave field. We propose that the damage of the PWAS should be detected before it leads to false alarm by the SHM system. Checking this condition results in a novel type of quality assessment for the investigated EMI-based method to detect damaged PWAS. The methodology can also be transferred to other methods of detecting faulty PWAS. It is explained in detail followed by an application, showing excellent feasibility. doi: 10.12783/SHM2015/84