| An examination of disorder on the dynamics of continuously shrouded bladed-disk assemblies is presented. The system used in this study consists of a nearly periodic assemblage of disordered, composite blade substructures. Each substructure is attached to an assumed rigid, rotating disk, and is ideally represented as a multiple degree-of-freedom oscillator attached to a mass coupled with adjacent ones through linear springs of negligible mass. Here, the dynamical energies of the blade substructures are constructed from elasticity-based Ritz formulations incorporating three-dimensional, geometrically nonlinear, shear-deformable, smear methodologies. The focus is to identify the effects of disorder on the free vibrations of periodic assemblies in terms of various parameters coined to the phenomenon of vibration localization. The disorder of blade assemblies could be formed by structural as well as material imperfection. A key aspect of this study is to provide some basic information from which a structural dynamicist could create deterministic criteria that measure and track the sensitivity of dynamic energies of blade substructures participating in localized modes to identify permissible ranges of blade disorder and interblade coupling with which such modes may be either alleviated or separated and dispersed. The contribution of this work provides a computationally robust analytical tool to increase the predictive and control capabilities of structural dynamicists faced with unwanted localized vibrations in disordered assemblies. |
