Vibration analysis of rotating pre-twisted blades

Equations of motion for the vibration analysis of rotating pre-twisted blades are derived from a modelling method which employs hybrid deformation variables. The derived equations are transformed into dimensionless forms in which dimensionless parameters are identified. The effects of the dimensionless parameters on the modal characteristics of rotating pre-twisted blades are investigated. In particular, eigenvalue loci veering phenomena and associated mode shape variations are observed and discussed in this work.