Capturing Mistuning Within Shrouded Integrally Bladed Disks With the Generalized Model of Mistuning

Abstract

Abstract. Bladed disks and blisks are designed to be cyclic structures that ideally have identical sectors. There will, however, always be mistuning, which is blade-to-blade differences that break the cyclic symmetry of the system and can result in an increase in vibrational amplitudes. Many different methods for producing reduced order models (ROMs) have been developed, with each generally designed to accurately capture a particular form of mistuning that is present. For high-dimensional finite element (FE) models, ROMs are needed to perform many structural dynamic calculations quickly. These ROMs are also required to perform any statistical analysis to characterize random mistuning. Recently, a generalized model of mistuning (GMM) method was developed that enables efficient construction of ROMs that can readily capture multiple forms of mistuning in bladed disks simultaneously. GMM has been demonstrated to be an effective way to model mistuning separately in the blade and disk, where the mistuning can be any combination of damping, small or large stiffness, or geometric mistuning. This work extends GMM to capture systems that contain shrouds and dual flow path (DFP) blisks with multiple sources of mistuning. GMM uses only single-sector models and calculations in the construction of the ROM, allowing realistic industrial models to be analyzed. For each of the systems studied, GMM is validated using a full-stage finite element model.