Attractive properties of Functionally Graded (FG) porous materials (porous materials with functionally graded porosity) are of special interest to engineers and researchers to design and develop improved mechanical properties in a wide range of aerospace, biomedical, civil, mechanical and vehicle engineering applications. This paper aims to use First-order Shear Deformation Theory (FSDT) and investigate free vibration of tapered circular porous plates with graded open-cell porosity as a new lightweight and basic structural element. Plates with both constant and linear symmetric thickness variations about the mid-plane of the circular plate are studied. FGInternal- Solid, FG-External-Solid and Uniform porosities are also introduced as three types of porosity distributions through the radial direction of the circular plate. The equations of motion are derived using Newton's second law with simply supported and clamped end conditions. A pseudospectral method is used to numerically solve the equations of motions. The influences of thickness variation profiles, boundary conditions and types of porosity on the vibrational properties of tapered circular plates are also investigated in detail.
