Determination of the stress components of an array of piezoelectric sensors: A numerical study

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 film is 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 structure. The concept of using an array of piezo-sensors to obtain information about the normal stress field in an adhesively bonded joint was described by Dillard and co-workers in 1988. This paper seeks to extend the application of using an array of piezoelectric sensors for determining the in-plane stress field in a structure. To achieve this, a numerical scheme will be required to decouple the piezoelectric sensor signals into their individual stress components. The aim of this paper is to discuss the development of a numerical procedure for the determination of stress components in a structure given a set of signals from an array of piezoelectric thin-film sensors. This set of piezoelectric signals is generated numerically by combining the piezoelectric response equation with a known stress field.