|
Abstract The vibration of a ring-stiffened cylindrical shell is an important technical issue in engineering applications, such as pressure vessels, rockets and submerged marine structures. The presence of structural discontinuities and arbitrary boundary conditions does not permit an analytical solution, so we have to resort to numerical approaches to address the problem. Two approaches have been developed to determine the dynamic behavior of ring-stiffened cylindrical shell. One approach, called the smeared approach, assumes that the stiffeners are close together with equal spacing and are evaluated by averaging their properties over the surface of the shell. For a more general model, the ring stiffeners have to be treated as discrete elements, and many methods have been proposed by researchers. The existing literature was restricted to the calculation of vibration characteristics of ring-stiffened cylindrical shell with only a few classical boundary conditions, such as the free, simply supported and clamped boundary conditions. With the changes of boundary conditions, the displacement functions and boundary parameters should be changed, which means more functions and programs should be built. The main objective of this paper was to develop an alternative and unified solution for the vibration analysis of ring-stiffened cylindrical shell with arbitrary elastic boundary conditions. In this paper, an improved Fourier series was introduced as an admissible displacement function. Based on the energy method, the dynamic model of ring-stiffened cylindrical shell with arbitrary boundary conditions was constructed while the stiffeners were treated as discrete elements. The Rayleigh-Ritz technique was used to solve the Lagrange’s function of the structure, and the vibration modes and frequency response characteristics were obtained. The accuracy of the present method was validated by comparing the results with those from the modal experiment and calculated using the finite element method (FEM). In addition, the effects of the parameters of stiffener eccentricity, cross section dimension, position distribution and spring stiffness on the vibration characteristics of ring-stiffened cylindrical shell were studied. The present method for the ring-stiffened cylindrical shell should not only be useful in solving the arbitrary boundary conditions, but also serve as a reference source for future researchers.
|
|
Received: 04 July 2016
Published: 15 June 2017
|
|
|
|
2017, Vol. 38 
