Parametric instability of shaft with discs

AEROS Conference 2017

Wahab, A.M. Abdul^1 ; Rasid, Z.A.^1 ; Abu, A.^1 ; Noor Rudin, N.F. Mohd^1

Malaysia-Japan International Institute of Technology, Kuala Lumpur, Malaysia^1

关键词: Bolotin's method;    Finite element formulations;    Finite element method model (FEM);    Parametric instabilities;    Parametric resonance;    Rotating speed;    Timoshenko's beam theory;    Torsional motion;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/270/1/012024/pdf
DOI  :  10.1088/1757-899X/270/1/012024

来源: IOP

【 摘 要 】

The occurrence of resonance is a major criterion to be considered in the design of shaft. While force resonance occurs merely when the natural frequency of the rotor system equals speed of the shaft, parametric resonance or parametric instability can occur at excitation speed that is integral or sub-multiple of the frequency of the rotor. This makes the study on parametric resonance crucial. Parametric instability of a shaft system consisting of a shaft and disks has been investigated in this study. The finite element formulation of the Mathieu-Hill equation that represents the parametric instability problem of the shaft is developed based on Timoshenko's beam theory and Nelson's finite element method (FEM) model that considers the effect of torsional motion on such problem. The Bolotin's method is used to determine the regions of instability and the Strut-Ince diagram. The validation works show that the results of this study are in close agreement to past results. It is found that a larger radius of disk will cause the shaft to become more unstable compared to smaller radius although both weights are similar. Furthermore, the effect of torsional motion on the parametric instability of the shaft is significant at higher rotating speed.