Reduction of Multistage Rotor Models Using Cyclic Modeshapes

This study deals with the reduction of models of bladed disks assemblies through the use of mono-harmonic cyclic mode-shapes. The first part of this paper describes how the classical substructuring technique in cyclic symmetry can be extended to rotors in the case of non compatible meshes to compute mono-harmonic eigenvectors. The second part of the paper then presents the method employed by the authors to seek the full modes of the rotor in a subspace generated from a set of such modeshapes. All the concepts developed here are illustrated on a representative sample.Copyright © 2007 by ASME

[1]  D. J. Ewins,et al.  Vibration Characteristics of Bladed Disc Assemblies , 1973 .

[2]  Christophe Pierre,et al.  Component-Mode-Based Reduced Order Modeling Techniques for Mistuned Bladed Disks—Part I: Theoretical Models , 2001 .

[3]  D. J. Ewins,et al.  A new method for dynamic analysis of mistuned bladed disks based on the exact relationship between tuned and mistuned systems , 2002 .

[4]  Torsten Fransson,et al.  A comparison of two finite element reduction techniques for mistuned bladed-disks , 2000 .

[5]  Christophe Pierre,et al.  Effects of Multistage Coupling and Disk Flexibility on Mistuned Bladed Disk Dynamics , 2003 .

[6]  Christophe Pierre,et al.  Dynamic Response Predictions for a Mistuned Industrial Turbomachinery Rotor Using Reduced-Order Modeling , 2002 .

[7]  D. Tran,et al.  Component mode synthesis methods using interface modes. Application to structures with cyclic symmetry , 2001 .

[8]  Jerry H. Griffin,et al.  A Reduced-Order Model of Mistuning Using a Subset of Nominal System Modes , 2001 .

[9]  J. H. Griffin,et al.  A Fundamental Model of Mistuning for a Single Family of Modes , 2002 .

[10]  Etienne Balmès,et al.  O rthogonal Maximum Sequence Sensor Placements Algorithms for modal tests , expansion and visibility , 2004 .

[11]  A. V. Srinivasan,et al.  Flutter and Resonant Vibration Characteristics of Engine Blades , 1997 .

[12]  Christophe Pierre,et al.  Vibration Modeling of Bladed Disks Subject to Geometric Mistuning and Design Changes , 2004 .

[13]  M. Géradin,et al.  Mechanical Vibrations: Theory and Application to Structural Dynamics , 1994 .

[14]  Matthew P. Castanier,et al.  Modeling and Analysis of Mistuned Bladed Disk Vibration: Status and Emerging Directions , 2006 .