SEPARATION AND IDENTIFICATION OF TRAVELING-WAVE MODES IN ROTATING-DISK VIA DIRECTIONAL SPECTRAL-ANALYSIS

Abstract

Directional frequency response functions are introduced for isotropic rotating disks, treating pairs of excitations and measurements as the complex input and output, respectively. The directivity information of the modes carried in the directional frequency response functions is used in a modal testing method of rotating disks which is proposed for separation of the forward and backward travelling wave modes and identification. of the diametrical node numbers associated with modes of interest. Numerical examples of a rotating disk are treated to demonstrate the analytical developments. Experiments with a laboratory rotating disk have also been performed to verify the theoretical findings and the practicality of the proposed method. (C) 1995 Academic Press Limited