Parametric study of damping characteristics of rotating laminated composite cylindrical shells using Haar wavelets

Abstract

In this paper, the damping characteristics of rotating laminated composite cylindrical shells considering the frequency dependent damping of composite materials are studied. Based on the Love thin shell theory, Hamilton principle is used to obtain the governing equations of the composite cylindrical shell, which are converted into ordinal differential equations by the separation of variables. The dynamical equations and corresponding boundary conditions are discretized by Haar wavelet method and then the standard eigenvalue equation is obtained. The damping with frequency dependence of composite materials is taken into account by the complex modulus method. The eigenvalue equation is solved by iterative calculation to obtain the modal frequency and damping characteristics of rotating composite cylindrical shells. The correctness of present analysis is validated by comparing the predicted results with those given in the literature. The effects of frequency, rotation speed, lamination and geometric parameters on damping properties of the composite shell under four typical boundary conditions are further analyzed. Numerical results show that it is important to consider the frequency dependence of damping of composite materials, especially for the analysis of lower order modes. There are forward and backward damping respectively corresponding to the forward travelling wave and backward travelling wave modes, and the forward wave motion is more stable. The rotating composite cylindrical shell may lose its stability under certain geometric parameters due to the influences of rotation and the inherent material damping.