Electrothermomechanical behaviors of spherical vessels with different configurations of functionally graded piezoelectric coating

Abstract

Piezoelectric material has widely been used as sensors or actuators in smart structures. In this study, electrothermomechanical behaviors of homogeneous spherical vessels with different configurations of functionally graded piezoelectric material coating are investigated. Homogeneous vessels with inner, outer, and both inner and outer layers of functionally graded piezoelectric material are taken into account. Infinitesimal strain theory and axisymmetric assumption are considered to formulate the problem. Moreover, it is considered that material properties in functionally graded piezoelectric material vary based on the power function of radius. Results show that homogeneous sphere with outer functionally graded piezoelectric material coating has the lowest tensile circumferential stress compared to the other cases in functionally graded piezoelectric material layer. In the second case, effects of grading indices and functionally graded piezoelectric material layer thickness are also studied. It is shown that the grading index variation could have a great effect on the thermomechanical behavior of both functionally graded piezoelectric material and homogeneous layers. It is turned out that lower grading index could lead to the lower circumferential stress and higher induced electric potential. It is shown that significant difference between thermal conductivity of functionally graded piezoelectric material and homogeneous layer can extremely affect the distribution of radial stress and electric potential.