Vibration analysis of rotating pre-twisted blades

Equations of motion for the vibration analysis of rotating pre-twisted blad es are derived from a modelling method which employs hybrid deformation var iables. The derived equations are transformed into dimensionless forms in w hich dimensionless parameters are identified. The effects of the dimensionl ess parameters on the modal characteristics of rotating pre-twisted blades are investigated, In particular, eigenvalue loci veering phenomena and asso ciated mode shape variations are observed and discussed in this work. (C) 2 001 Elsevier Science Ltd. All rights reserved.