Research on effect of rings on coupling vibration in a rigid-disk rotor

Abstract

This paper uses new deductions of the equation of motion and obtains new modes of change that differ from the authors’ previous research. The blade-bending, shaft-torsion and ring-bending coupled vibration influence of a single-disk rotor whose blade subsystem was coated with a ring is investigated. In the last two years, the authors adopted two methods, the assumed mode method and finite element method, and compared both parties results. This article continues that work. In this paper, the phenomena of ring joint coupling vibrations are different and interesting. The authors defined two new types, the shaft-blade-ring (SBR) and blade-ring (BR) modes. These two coupling modes can be mutually affected by the shaft, blade, and ring, and no single subsystem predominates. The new change rules of natural frequencies of rotors with two to 15 blades and those of mode shapes are discussed. The influence of the ring thickness and rotational speed are also studied in this paper.