FORCED RESPONSE ANALYSIS OF MISTUNED TURBINE BLADINGS

It is well-known that the vibrational behavior of a mistuned bladed disk differs strongly from that of a tuned bladed disk. A large number of publications dealing with the dynamics of a mistuned bladed disk is available in the literature. Nearly all published mechanical models for a mistimed bladed disk consider the mistuning in terms of a perturbation of the mass and/or the stiffness matrix or in terms of a perturbation of the tuned system natural frequencies. Therefore, the possible effect of a damping mistuning is neglected in these models. In this paper a model of a mistuned bladed disk with a combined damping and natural frequency mistiming is presented. This model is based on the well-known Fundamental Model of Mistuning with a novel extension to include the damping mistuning in a straight-forward way.