Numerical characterization of functionally graded active materials under electricaland thermal fields

Abstract

This paper deals with a class of functionally graded materials (FGMs) calledactive FGM that has electro-thermo-elastically graded material phases. The focusis on the characterization of active FGM under electrical and thermal fields.The structure comprises a substrate, an electro-thermo-elastically gradedlayer and an active layer. Using augmented piezoelectric constitutive law,the effect of temperature on the piezoelectric properties is incorporatedin the model. A formulation for exact solutions of the system based onEuler–Bernoulli theory is presented. Polynomial compositional variations of theconstituent phases in the graded layer are considered and their performancefor a range of stiffness and electrical property ratios of the active andsubstrate materials is studied under electrical and thermal fields. Theeffect of temperature dependence of piezoelectric coefficients on the stressdistribution in the active FGM is discussed. It is also observed that thecompositional variation significantly influences the actuation authority of gradedmaterials depending on the modular ratio of the constituent materials.