A reduced order model based on sector mistuning for the dynamic analysis of mistuned bladed disks

In this paper, a pre-existing reduction technique suitable for the analysis of mistuned bladed disk dynamics, the Component Mode Mistuning technique (CMM), originally developed exclusively for the use of blade frequency mistuning pattern, is extended in order to allow for the introduction of a sector frequency mistuning pattern. If either mistuning is not confined to the blades (i.e. blades-to-disk interface mistuning), or the blades can not be removed from the bladed disk (i.e. integral bladed disks), sector mistuning rather than blade mistuning is a more suitable choice to perturb the tuned system. As a consequence, the extension of the original technique is referred as Integral Mode Mistuning (IMM). After a theory review of the original technique, the modifications leading to the IMM are described. Finally, the proposed IMM technique is validated in terms of both modal parameters estimation and forced response calculation, by means of a dummy bladed disk developed at Politecnico di Torino.

► FE model reduction technique for the analysis of mistuned bladed disk dynamics.
► Sector frequency mistuning is preferable to model integral bladed disks.
► Sector frequency mistuning is preferable to capture blade-to-disk irregularities.
► Extension of the pre-existing CMM model to the Integral Mode Mistuning (IMM).
► Numerical validation of the IMM model.