Free vibration analysis of FG porous joined truncated conical-cylindrical shell reinforced by graphene platelets

Natural frequency analysis of functionally graded porous joined truncated conical–cylindrical shell reinforced by graphene platelet is investigated in this paper. The structure is consisting of a layered model with five kinds of distribution of graphene platelets in a metallic matrix containing open-cell interior pores. To calculate the effective properties of the porous nanocomposite joined shell, the generalized rule of mixture and the modified Halpin-Tsai equations are employed. Four different porosity distributions are assumed along the shell thickness: two kinds of symmetric functionally graded distributions, non-symmetric functionally graded distributions and uniform distribution of porosity. Graded finite element method (GFEM) based on Rayleigh-Ritz energy formulation has been used to solve 2D- axisymmetric elasticity equations. A parametric study is also conducted to show the effects of different geometric parameters, boundary conditions, weight fraction of graphene platelets, porosity coefficient, distribution of porosity and dispersion pattern of graphene platelets on the natural frequencies and mode shapes of the structure.