VIBRATION ANALYSIS OF FUNCTIONALLY GRADED POROUS CONICAL SHELLS RESTED ON ELASTIC FOUNDATIONS¹⁾

To study the vibration characteristics of porous functionally graded conical shells on elastic foundations, the vibration equations for the functionally graded conical shells with evenly and unevenly distributed pores are derived based on the classical shell theory. The solutions of the free vibrations and the dynamic responses for the shells are obtained by using the Galerkin method. The effects of pores, elastic foundation parameters, semi-vertex angle and other factors on the natural frequencies and the dynamic responses are investigated. The results show that the natural frequencies rise with the increase of the elastic foundation parameters. However, the dynamic responses are significantly reduced. The results also demonstrate that the dynamic responses are increased significantly by increasing semi-vertex angle. Compared with unevenly distributed pores, the effects of evenly distributed pores on the natural frequencies and the dynamic responses are more evident.