Conical-cylindrical shells are widely used in generous engineering applications such as rockets, turbines, components of missiles and submarine. They are of the most widely engineering structures and various studies have been conducted in the analysis of their behavior. Vibration analysis is one of the most important issues in the field. Nowadays in order to improve the behavior and properties of the shells, functionally graded materials (FGM) are used in the productions. Mechanical properties of them as non-homogeneous materials are changed continuously. Usually, these materials are made from ceramic and metal. The ceramic constituent of the material provides the high temperature resistance due to its low thermal conductivity. The ductile metal constituent prevents fracture caused by stresses due to high temperature gradient.In this research, free vibration of rotating functionally graded truncated conical shells and conical-cylindrical shell is investigated.The left; MARGIN: 0cm 0cm 10pt; unicode-bidi: embed; DIRECTION: ltr" dir=ltr The results show convergence of this method and are compared with other published works. By several numerical solutions, the effects of material property graded index, angular velocity, geometrical parameters and boundary conditions on the natural frequency are investigated. Keywords: Free Vibration, Conical Shells, Conical-Cylindrical Shells, Functionally Graded Materials, GDQ, Classical Theory.
