OICC Press Journal of Solid Mechanics 2008-7683 12 2 2020 06 30 Free Vibration and Transient Response of Heterogeneous Piezoelectric Sandwich Annular Plate Using Third-Order Shear Deformation Assumption 315 333 EN P Roodgar Saffari Department of Mechanical Engineering, Lahijan Branch, Islamic Azad University, Lahijan, Iran M Fakhraie Department of Mechanical Engineering, Lahijan Branch, Islamic Azad University, Lahijan, Iran M.A Roudbari Department of Mechanical Engineering, University of Guilan, Rasht, Iran--- Department of Civil Engineering, Zhejiang University, Hangzhou 310058, People’s Republic of China, China Journal Article 2020 06 30 Based on the third-order shear deformation theory (TSDT), this paper numerically investigates the natural frequencies and time response of three-layered annular plate with functionally graded materials (FGMs) sheet core and piezoelectric face sheets, under initial external electric voltage. The impressive material specifications of FGM core are assumed to vary continuously across the plate thickness utilizing a power law distribution. The equilibriumequations are obtained employing Hamilton’s method and then solved applying differential quadrature method (DQM) in conjunction with Newmark-β. Numerical studies are carried out to express the influences of the external electric voltage, aspect ratio, and material gradient on the variations of the natural frequencies and time response curves of FGM piezoelectric sandwich annular plate. It is precisely shown that these parameters have considerable effects on the free vibration and transient response.