Vibration Analysis of Mistuned Bladed Disc of Steam Turbine

Cyclic symmetry in bladed disc is often destroyed by difference in blade structural properties and this results in mistuning. The effect of centrifugal force on the mistuning of bladed disc was investigated by three dimensional finite element analyses. Vibration characteristics of mistuned bladed disc caused by random Young's moduli in all blades were also investigated by probability method. The results indicate that the centrifugal force reduces the localization. As Young's moduli of blades are in the tolerance of 5%, the bladed disc can be treated as a cyclic symmetry structure.