Natural frequency and dynamic analyses of functionally graded saturated porous annular sector plate and cylindrical panel based on 3D elasticity

In this paper, natural frequencies and dynamic response of thick annular sector plates and cylindrical panels made of saturated porous materials are investigated for the first time. The structures have been modeled using 3D elasticity theory. Distribution of porosity along the thickness is considered in three different patterns, which are symmetric nonlinear, nonlinear asymmetric and uniform distributions. The relationship between stress and strain is based on the Biot constitutive law instead of simple Hook's law. Finite element method based on Rayleigh–Ritz energy formulation and Newark methods are used to solve the governing equations. The effect of different boundary conditions and various parameters such as porosity and Skempton coefficients, slenderness ratio, sector angle and different distribution of porosity on natural frequencies and transient responses have been studied.