محمد واقفی

The influences of thermal environment on the free vibration characteristics of functionally graded (FG) truncated conical panels are investigated based on the first-order shear deformation theory (FSDT). By taking into account both the temperature dependence of material properties, which are assumed to be graded in the thickness direction, and the initial thermal stresses, the equations of motion and the related boundary conditions are derived using Hamilton's principle. The differential quadrature method (DQM) is employed to discretize the equations of motion subjected to any types of classical boundary conditions. After studying the convergence of the method, its accuracy is demonstrated by solving different examples in the limit cases. Then, the effects of the temperature dependence of the material properties and the initial thermal stresses together with the material graded index and the geometrical parameters on the free vibration of the FG truncated conical panels are investigated. It is shown that in addition to the temperature dependence of material properties, the initial thermal stresses have significant effects on the vibrational characteristics of the FG conical shell panels and cannot be ignored.