Forced responses analysis of a rotor system with squeeze film damper during flight maneuvers using finite element method

2018 ◽  
Vol 122 ◽  
pp. 233-251 ◽  
Author(s):  
Bingbing Han ◽  
Qian Ding
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Rotor System ◽  
Squeeze Film ◽  
Squeeze Film Damper ◽  
Forced Responses ◽  
Element Method

scholarly journals The oscillating and electrostatic characteristics of microelectromechanical system cantilever structure analyzed based on the air gap domain

2018 ◽  
Vol 37 (4) ◽  
pp. 725-747 ◽  
Author(s):  
Jianlian Cheng ◽  
Kai Li ◽  
Zhuang Zhang ◽  
Yufeng Gu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Numerical Study ◽  
Damping Ratio ◽  
Electrostatic Actuation ◽  
Compact Model ◽  
Squeeze Film ◽  
The Finite Element Method ◽  
Cantilever Structure ◽  
Element Method

Extensive modeling and simulation of the damping phenomenon, electrostatic actuation, and structural vibration analysis are performed. The governing partial differential equations of cantilever plate are obtained, and the resonant frequencies are calculated from the equilibrium equations. The damping forces of squeeze film are analyzed by obtaining the damping ratio and spring constant. Electrostatic actuation is applied to oscillate the cantilever to ensure that the displacement of the plate is above the thermal noise floor. Electrostatic actuating forces, displacement, and capacitance are calculated both numerically and analytically from the Poisson’s equations. Squeeze film damping effects naturally occur if structures are subjected to loading situations such that a very thin film of fluid is trapped within structural joints, interfaces, etc. An accurate estimate of squeeze film effects is important to predict the performance of dynamic structures. Squeeze film effects are simulated by the finite element method. The accuracy of the compact model is studied by comparing its response to the numerical results calculated with the finite element method. The agreement is very good in a wide frequency band. The numerical study and the compact model are directly applicable in predicting the damping force and damping factors of squeeze film.

Theoretical and Numerical Modal Analysis for Nuclear Coolant Pump and its Scaled Rotor System

2010 ◽  
Vol 44-47 ◽  
pp. 985-991
Author(s):  
Chun Ming Gong ◽  
Hong Shen ◽  
Zheng Qiang Yao
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Modal Analysis ◽  
Theoretical Method ◽  
Rotor System ◽  
The Finite Element Method ◽  
Coolant Pump ◽  
Similarity Law ◽  
Nuclear Coolant ◽  
Element Method

This paper presents a theoretical transfer matrix method for the modal analysis of nuclear coolant pump, and base on certain similarity law, a scaled rotor system is designed so as to simulate the characteristics of the real nuclear coolant pump, especially the vibration characteristics. Following that, the finite element method is used to verify the accuracy of the above theoretical method since there are a few simplifications in theoretical method compared with the finite element method. Finally the natural vibration frequencies and vibration modes of both nuclear coolant pump and the designed scaled rotor system are attained, which have high similarity with each other, and which confirm the accuracy of the two methods that are used in this article.

Modeling and Analyzing for Rotor System with Imbalance-Misalignment Coupling Faults Based on Nonlinear Finite Element Method

2013 ◽  
Vol 312 ◽  
pp. 292-295
Author(s):  
Fu Ze Xu ◽  
Xue Jun Li ◽  
Guang Bin Wang ◽  
Yi Lin He
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Rotor System ◽  
Nonlinear Finite Element ◽  
Rolling Element Bearing ◽  
Nonlinear Finite Element Method ◽  
Time Frequency ◽  
Coupling Faults ◽  
Study Results ◽  
Element Method

This thesis constructs the dynamical model of the imbalance-misalignment coupling faults and the finite element model of the rotor system which are supported by rolling element bearing. It analyses the impacts from the coupling faults to the system on the basis of nonlinear finite element method, dynamic theory and Newmark-beta numerical integration method. It also studies the influence of the unbalance, misalignment and coupling faults to the system by applying the dynamic response chart and time-frequency properties. The study shows that there exist unstable high and low harmonic components, the unbalanced signal overshadowed by misalignment. It also discovers that besides the working frequency, there also exist tow times frequency and other high doubling components on the response spectra with two times frequency for the most. All those study results provide some theoretical reference for the fault diagnosing of the rotor bearing system, the vibration control and the stability research.

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