DETERMINATION OF THE RUBBING LOCATION IN A MULTI-DISK ROTOR SYSTEM BY MEANS OF DYNAMIC STIFFNESS IDENTIFICATION

2001 ◽  
Vol 248 (2) ◽  
pp. 235-246 ◽  
Author(s):  
F. CHU ◽  
W. LU
Keyword(s):  
Dynamic Stiffness ◽  
Rotor System ◽  
Stiffness Identification

Vibration Analysis of Multi-Disk Multi-Profiled Shaft-Rotor Systems

2014 ◽  
Vol 612 ◽  
pp. 17-22 ◽  
Author(s):  
P.M.G. Bashir Asdaque ◽  
R.K. Behera ◽  
Jakeer Hussain Shaik
Keyword(s):  
Dynamic Characteristics ◽  
Transfer Matrix Method ◽  
Matrix Method ◽  
Vibration Analysis ◽  
Shear Force ◽  
Bending Moment ◽  
Rotor System ◽  
Step Response ◽  
Rotor Systems

Cantilevered shaft-rotor systems consisting of multi disks and multi profiled shafts are considered. In this paper the procedures for the determination of the deflection, slope, shear force and bending moment at the extremities of the shaft are employed. Critical speeds or whirling frequency conditions are computed using transfer matrix method (TMM). For particular shaft-lengths, rotating speeds and shaft-profiles, the response of the system is determined for the establishment of the dynamic characteristics. A built-in shaft-rotor system consisting of two disks and two different profiled shafts is investigated for illustration purposes. Step response of the multi profiled shaft-rotor system is also found out.

Technical Note: Rolling dynamic stiffness and damping characteristics of small-sized pneumatic tyres

2000 ◽  
Vol 214 (3) ◽  
pp. 243-248 ◽  
Author(s):  
V. H. Saran ◽  
V. K. Goel
Keyword(s):  
Normal Load ◽  
Dynamic Stiffness ◽  
Technical Note ◽  
Inflation Pressure ◽  
Laboratory Technique ◽  
Damping Coefficients ◽  
Damping Characteristics ◽  
Stiffness And Damping

In this paper, a laboratory technique for determination of rolling dynamic stiffness and damping coefficients of small-sized, bias-ply tyres has been discussed. The effect of normal load, inflation pressure and speed on four different tyres has been reported. The results show similar trends to those reported by other investigators.

scholarly journals Performance for rotor system of hybrid electromagnetic bearing and elastic foil gas bearing with dynamic characteristics analysis under deep learning

PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0244403
Author(s):  
Xiangxi Du ◽  
Yanhua Sun
Keyword(s):  
Dynamic Characteristics ◽  
Ambient Pressure ◽  
Dynamic Stiffness ◽  
Magnetic Bearing ◽  
Rotor System ◽  
Fault Classification ◽  
Batch Size ◽  
Maximum Displacement ◽  
Gas Bearing ◽  
Electromagnetic Bearing

The bearing-rotor system is prone to faults during operation, so it is necessary to analyze the dynamic characteristics of the bearing-rotor system to discuss the optimal structure of the convolutional neural network (CNN) in system fault detection and classification. The turbo expander is undertaken as the research object. Firstly, the hybrid magnetic bearing-rotor system is modeled into the form of four stiffness coefficients and four damping coefficients, so as to analyze and explain the dynamic characteristics of the system. Secondly, the ambient pressure is introduced to analyze the dynamic characteristics of the elastic foil gas bearing-rotor system based on the changes in the dynamic stiffness and dynamic damping of the gas bearing. Finally, the CNN is introduced to be applied in the detection of faults of bearing-rotor system through determining the parameters of the constructed CNN. The results show that the displacement of the rotor increases and the stiffness decreases with the acceleration of the speed of the electromagnetic bearing. The maximum displacement of the rotor can reach 135μm, and the maximum stiffness can be reduced to 35×105N/m. Increase of ambient pressure causes enhancement of main stiffness of the gas bearing, and the main damping decreases accordingly. Analysis of the classification accuracy and loss function based on the CNN model shows that the convolution kernel size of 7*1 and the batch size of 128 can realize the best performance of CNN in fault classification. This provides a data support and reference for studying the dynamic characteristics of the bearing-rotor system and for the optimization of CNN structure in fault classification and detection.

Analysis of aerostatic spindle radial vibration error based on microscale nonlinear dynamic characteristics

2019 ◽  
Vol 25 (14) ◽  
pp. 2043-2052 ◽  
Author(s):  
Dongju Chen ◽  
Na Li ◽  
Ri Pan ◽  
Jihong Han
Keyword(s):  
Dynamic Model ◽  
Nonlinear Dynamic ◽  
Degrees Of Freedom ◽  
Dynamic Stiffness ◽  
Prediction Method ◽  
Rotor System ◽  
Rotation Error ◽  
Spindle Rotation ◽  
Microscale Effect ◽  
Aerostatic Spindle

This paper presents a method of predicting the radial rotary error of an aerostatic spindle based on the microscale-effect to investigate the influence of gas film fluctuation on the rotation accuracy of the aerostatic spindle. First, the gas bearing of the spindle is simplified as a spring-damping system with two degrees of freedom perpendicular to each other. Additionally, the aerostatic spindle bearing-rotor system is established by considering the forced vibration and deflection vibration of the rotor. Subsequently, the microscale-effect is introduced into the dynamic model of the gas film flow, and the dynamic Reynolds equation of the gas film is established in the microscale. Moreover, the nonlinear dynamic stiffness and dynamic damping coefficient are obtained by the perturbation method. The nonlinear dynamic parameters in the microscale are introduced into the dynamic model of the bearing-rotor system and all the vibration errors are obtained. By comparison with the conventional case, it is found that the spindle gyration error increased and that the response delay occurred when the microscale-effect is considered. Moreover, the influence of the supply pressure and speed on the vibration of the spindle is also analyzed. An experiment measuring the spindle rotation error is carried out. The experimental results reveal that the prediction method of the nonlinear spindle rotation error in the microscale is more accurate, and that the errors are 5.8% and 9.6%.

A hybrid method for dynamic stiffness identification of bearing joint of high speed spindles

2016 ◽  
Vol 57 (1) ◽  
pp. 141-159 ◽  
Author(s):  
Yongsheng Zhao ◽  
Bingbing Zhang ◽  
Guoping An ◽  
Zhifeng Liu ◽  
Ligang Cai
Keyword(s):  
Hybrid Method ◽  
High Speed ◽  
Dynamic Stiffness ◽  
Stiffness Identification
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