scholarly journals Response analysis of random base excitation ona magnetic bearing rotor system

2019 ◽  
Vol 293 ◽  
pp. 04004
Author(s):  
Jinping Chen ◽  
Li Zhang ◽  
Yanyan Luo ◽  
Haining Zhang ◽  
Jun Liu
Keyword(s):  
Collision Detection ◽  
Random Excitation ◽  
Magnetic Bearing ◽  
Rotor System ◽  
Response Analysis ◽  
Random Response ◽  
Practical Application ◽  
External Disturbances ◽  
Response Characteristics ◽  
Auxiliary Bearing

The magnetic bearing-rotor system is subject to various external disturbances in practical application. Under certain control conditions, the random response characteristics of the magnetic bearing-rotor system are a particular concern. This paper analyzes the response characteristics of base of the magnetic bearing subjected to acceleration random excitation in the horizontal direction. First, the magnetic bearing-rotor system model is deduced. Then, the random response of the rotor under acceleration random excitation is derived. The probability of the collision of the rotor between the auxiliary bearing is calculated and the example is given. The paper conclusion provides a theoretical basis for the collision detection and prediction of the magnetic bearing-rotor system.

scholarly journals Dynamic Modelling and Response Characteristics of a Magnetic Bearing Rotor System With Auxiliary Bearings

1995 ◽  
Author(s):  
April M. Free ◽  
George T. Flowers ◽  
Victor S. Trent
Keyword(s):  
Dynamic Modelling ◽  
Magnetic Bearing ◽  
Rotor System ◽  
Rolling Element Bearing ◽  
Test Facility ◽  
Iron Core ◽  
Critical Feature ◽  
Response Characteristics ◽  
Rolling Element ◽  
Auxiliary Bearing

Abstract Auxiliary bearings are a critical feature of any magnetic bearing system. They protect the soft iron core of the magnetic bearing during an overload or failure. An auxiliary bearing typically consists of a rolling element bearing or bushing with a clearance gap between the rotor and the inner race of the support. The dynamics of such systems can be quite complex. It is desired to develop a rotordynamic model which describes the dynamic behavior of a flexible rotor system with magnetic bearings including auxiliary bearings. The model is based upon an experimental test facility. Some simulation studies are presented to illustrate the behavior of the model. In particular, the effects of introducing sideloading from the magnetic bearing when one coil fails is studied. These results are presented and discussed.

scholarly journals Dynamic Characteristics of Air Cycle Machine Rotor System

2018 ◽  
Vol 2018 ◽  
pp. 1-16 ◽  
Author(s):  
Dongjiang Han ◽  
Long Hao ◽  
Jinfu Yang
Keyword(s):  
Critical Speed ◽  
Dynamic Balance ◽  
Exciting Force ◽  
Rotor System ◽  
Parameters Optimization ◽  
Response Analysis ◽  
Response Characteristics ◽  
Bearing Stiffness ◽  
Harmonic Response Analysis ◽  
Modal Method

Parameters optimization in the critical speed region has the important influence on operational stability of an air cycle machine. Effects of bearing stiffness and unbalanced exciting force on critical speed and response characteristics are investigated by the modal method and harmonic response analysis. Resonance separation phenomenon in the critical speed region is analyzed in detail. When difference exists in the phase of unbalanced exciting force, resonance separation appears in the conical whirling speed region. The characteristics after resonance separation are closely related to the phase difference value and amplitude of unbalanced exciting force. The paper provides theoretical and experimental foundations for resonance separation analysis and also provides data support for dynamic balance and dynamic design of the rotor system.

The Random Response Analysis of Structure Subjected to Non-Stationary Seismic Excitation

2012 ◽  
Vol 446-449 ◽  
pp. 3287-3290
Author(s):  
Hao Wu ◽  
Xun An Zhang
Keyword(s):  
Ground Motion ◽  
Random Excitation ◽  
Seismic Excitation ◽  
Earthquake Ground Motion ◽  
Response Analysis ◽  
Rock Surface ◽  
Random Response ◽  
Spectrum Prediction ◽  
Hilbert Huang Transform ◽  
Evolutionary Spectrum

The evolutionary power spectrum which can reflect the non-stationary characteristics of earthquake ground motion is estimated by the Hilbert-Huang Transform (HHT), and with reference to the experiential statistical method, an evolutionary spectrum prediction model for given earthquake magnitude and distance is established based on the 121 near-source acceleration records at rock surface with large magnitude from the ground motion database of western U S. The pseudo excitation method is adopted to acquire the solution for structure random response under specific non-stationary seismic excitation. The results demonstrate that the non-stationary contents included in seismic excitation will enlarge greatly the random response of structure in comparison with uniform modulation random excitation.

Analysis of supercritical pitchfork bifurcation in active magnetic bearing-rotor system with current saturation

2021 ◽  
Vol 104 (1) ◽  
pp. 103-123
Author(s):  
Xiaoshen Zhang ◽  
Zhe Sun ◽  
Lei Zhao ◽  
Xunshi Yan ◽  
Jingjing Zhao ◽  
...  
Keyword(s):  
Pitchfork Bifurcation ◽  
Magnetic Bearing ◽  
Rotor System ◽  
Active Magnetic Bearing ◽  
Current Saturation
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