Identification of structural damage severity and location using piezo-ceramic transducers

Abstract

The use of smart piezoceramics, more commonly Lead Zirconate Titanate (PZT) patches, in structural health monitoring (SHM) has been of much research in recent years; especially in damage detection and structure identification using electro-mechanical impedance (EMI) technique which is based on the coupling relationships between the PZT and the host structure. In SHM, damage severity identification and localization are of great importance and are the main interests. PZT transducer has shown excellent sensitivity in structural damage identification and has been successfully applied in SHM. However, systematic investigation on damage propagation and localization is still in need.

In this study, monitoring of progressive damage using a single PZT transducer is investigated. Experiments are carried out by creating damages progressively along longitudinal and lateral axis on rectangular aluminum plates and extracting the admittance function through an impedance analyzer. The patterns of variations in signatures under different levels of damage are studied. In order to verify the experimental results, finite element analysis is also carried out and a recently developed 3D EMI model (Annamdas and Soh 2007) is adopted. A statistical index, the Root Mean Square Deviation (RMSD), is adopted to analyze both the experimental and numerical results quantitatively.