Prediction of Rotating Blade Modes from Measured Nonrotating Modal Parameters

Abstract

The method presented in this paper can predict the modal parameters of a rotating blade accurately via the easily measured modal parameters of the blade in the nonrotating state. The derivation of the eigenvalue problem in nonrotating modal coordinates is based on the continuum model of general linear elastic solids such that it can be applied to complex real structures. Therefore, the modal parameters for different rotating speeds can be found without testing the blade under each different rotating speed. Experiments were conducted to check the proposed method. The results showed that the predicted characteristics were in good agreement with the measured characteristics.