Nonlinear Transient Vibration Analysis of Closed Circular Cylindrical Shells

In this paper, non-linear transient vibration of closed shallow-shell circular cylindrical shells is investigated by both expanding a 8-DOF radial mode equation and finite element analysis using Ansys12.0 software. The Donell’ s shallow-shell non-linear theory is used for radial movement ofthin, circular cylindrical shell. Eight ordinary differential equations are obtained for eight variables by means of Galerkin method. Numerical calculations are done by MATLAB R2011a software andits ode45 tool which is based on the Runge-Kutta routine. For finite element analysis, three differenttypes of shell including SHELL 93, SHELL 181 and SHELL 281 are considered. To reduce the cost and time of calculations only the eighth part of cylindrical shell is considered which has symmetryconditions at the ends of shell. By changing the size of meshes, the convergence of results are analyzed.Particularly, two simply-supported models are presented for boundary conditions in which one of them has two cylindrical constraints and the other one has three cylindrical constraints at the ends of shell. The nonlinear response of cylindrical shells are studied under sine shape of loading. The radial movement results obtained by two above mentioned methods are compared with each other.

Keywords:

non-linear vibration , Donell’s theory , closed cylindrical shell , finite element