Numerical study on the free vibration and thermal buckling behavior of moderately thick functionally graded structures in thermal environments

This paper is aimed at studying the free vibration and thermal buckling behavior of moderately thick functionally graded material (FGM) structures including plates, cylindrical panels and shells under thermal environments. A numerical investigation is performed by applying the finite element method (FEM). A formulation based on the first-order shear deformation theory (FSDT) is proposed for the purpose, which considers the effects of the transverse shear strain and rotary inertia. A graded concept is employed to allow the material property to vary gradually inside the elements. The proposed FGM structures are characterized by two constituents (ceramic and metal) whose material properties are dependent on the temperature and vary continuously throughout the thickness according to a power law distribution proportional to the volume fraction of the constituents. Two different sets of power law distribution are used to describe the volume fraction of the constituents, based on a single, or four parameters. Based on a parametric analysis, we demonstrate the potentials of the proposed method through its comparison with results available from the literature and by means of a convergence study. Several numerical examples are further presented to investigate the effects of material compositions, geometrical parameters, specified thermal loading and boundary conditions on the free vibration and thermal buckling behavior of these structures. The effect of initial thermal stresses on the vibration behavior is also investigated for plate and shell structures.