A PIEZOTHERMOELASTIC THIN SHELL THEORY APPLIED TO ACTIVE STRUCTURES

''Smart '' structures with integrated sensors, actuators, and control electronics are of importance to the next-generation high-performance structural systems. Piezoelectric materials possess unique electromech anical properties, the direct and converse effects, which, respectivel y, can be used in sensor and actuator applications. In this study, pie zothermoelastic characteristics of piezoelectric shell continua are st udied and applications of the theory to active structures in sensing a nd control are discussed. A generic piezothermoelastic shell theory fo r thin piezoelectric shells is derived, using the linear piezoelectric theory and Kirchhoff-Love assumptions. It shows that the piezothermoe lastic equations, in three principal directions, include thermal induc ed loads, as well as conventional electric and mechanical loads. The e lectric membrane forces and moments induced by the con verse effect ca n be used to control the thermal and mechanical loads. A simplificatio n procedure, based on the Lame parameters and radii of curvatures, is proposed and applications of the theory to (1) a piezoelectric cylindr ical shell, (2) a piezoelectric ring, and (3) a piezoelectric beam are demonstrated.