Mode Localization of a Cracked Blade Disk

Abstract

In this paper, the effect of blade crack on the mode localization of a rotating blade disk is studied. Pretwisted taper beams are used to simulate blades of a blade disk. The crack on the blade can be regarded as a local disorder of this periodically coupled blades system. An application of Hamilton’s principle and Galerkin’s method is used to formulate the equations of motion of the mistuned system. Effects of pretwisted angle, rotating speed, and crack depth of the blade on the in-plane and off-plane mode localizations of a rotating system are investigated. Numerical results indicate that the increase of rotating speed, pretwisted angle, and crack depth could enhance the localization phenomenon significantly.