Frequency analysis of truncated circular spherical shell with high rotating speed around its symmetrical axis

97 p.Although many published books and journal papers are available for understanding of free vibration of spherical shell, most of them have not dealt with the dynamics of the spherical shell rotating around its symmetrical axis. In terms of the free vibration analysis of a spherical shell, the rotating shell is distinct from non-rotating one, due to the presence of Coriolis and centrifugal accelerations. The purpose of present work is to conduct the analysis of free vibration characteristics of a rotating spherical shell. According to Fliigge theory [1], a nonlinear shell problem may be approximated as two linear problems, which is solved by membrane theory. Based on the formulation given by Chen et al [2], the fundamental dynamic equilibrium equations are constructed for the rotating spherical shell. The stress-displacement relations are then substituted into the resultant forces and momentum equations to obtain the governing partial differential equations in terms of three displacements only. The Galerkin method can thus be employed to generate the eigenvalue equations for frequency analysis of free vibration of the rotating thin truncated circular spherical shells with simply-supported boundary condition. An isotropic spherical shell is chosen as a case study. The corresponding eigenvalue equations are solved via Matlab to carry out a frequency analysis of the isotropic spherical shell rotating around its symmetrical axis. It appears that the dynamic characteristics of a rotating spherical shell have so far not been reported in the literature. Therefore, the frequency characteristics simulated by the present method are compared with those published for the non-rotating spherical shells for numerical validation of the present analysis.Master of Science (Mechanical Engineering