Damage Monitoring in Metallic Structures Using Piezoelectric Thin Film Sensors

Abstract

The increasing emphasis on intelligent material systems and structures has resulted in a significant research effort in the areas of embedded and bonded sensors and actuators. Piezoelectric thin film sensors are one of the many sensing materials available. The piezoelectric sensor output is proportional to changes in surface displacement and can be used to interpret variations in structural and material properties, e.g., the compliance of the material. The aim of this paper is to demonstrate the potential of using piezoelectric thin film sensors for structural integrity monitoring and assessment. To illustrate this potential, piezoelectric film sensors will be used for monitoring crack growth in an aluminium alloy specimen. Structural integrity assessment traditionally requires a detailed knowledge of the stress field in the critical region. In this respect, a numerical/analytical scheme will also be presented to show that data from an array of piezoelectric thin film sensors can be used to predict the stress field in a given region.