Nonlinear dynamics of a spinning shaft with non-constant rotating speed

Georgiades, Fotios (2018) Nonlinear dynamics of a spinning shaft with non-constant rotating speed. Nonlinear Dynamics, 93 (1). pp. 89-118. ISSN 0924-090X

Full content URL:

Nonlinear dynamics of a spinning shaft with non-constant rotating speed
Open Access under CC BY 4.0
[img] PDF
Georgiades2018_Article_NonlinearDynamicsOfASpinningSh.pdf - Whole Document
Available under License Creative Commons Attribution 4.0 International.

Item Type:Article
Item Status:Live Archive


Research on spinning shafts is mostly restricted to cases of constant rotating speed without examining the dynamics during their spin-up or spin-down operation. In this article, initially the equations of motion for a spinning shaft with non-constant speed are derived, then the system is discretised, and finally a nonlinear dynamic analysis is performed using multiple scales perturbation method. The system in first-order approximation takes the form of two coupled sets of paired equations. The first pair describes the torsional and the rigid body rotation, whilst the second consists of the equations describing the two lateral bending motions. Notably, equations of the lateral bending motions of first-order approximation coincide with the system in case of constant rotating speed, and considering the amplitude modulation equations, as it is shown, there are detuning frequencies from the Campbell diagram. The nonlinear normal modes of the system have been determined analytically up to the second-order approximation. The comparison of the analytical solutions with direct numerical simulations shows good agreement up to the validity of the performed analysis. Finally, it is shown that the Campbell diagram in the case of spin-up or spin-down operation cannot describe the critical situations of the shaft. This work paves the way, for new safe operational ‘modes’ of rotating structures bypassing critical situations, and also it is essential to identify the validity of the tools for defining critical situations in rotating structures with non-constant rotating speeds, which can be applied not only in spinning shafts but in all rotating structures.

Keywords:Spinning shaft, Non-constant rotating speed, Nonlinear normal modes, Critical speeds, Campbell diagram, Georgiades
Subjects:H Engineering > H100 General Engineering
Divisions:College of Science > School of Engineering
ID Code:30025
Deposited On:14 Dec 2017 13:10

Repository Staff Only: item control page