The Dynamics of Eccentric Vibration Mechanism (Part 2)

2020 ◽  
pp. 173-190
Author(s):  
Leonid Igumnov ◽  
S. Vladimir Metrikin ◽  
V. Irina Nikiforova ◽  
Lubov N. Fevral’skikh
Keyword(s):  
Vibration Mechanism

Parameters research on time-varying stiffness of the ball bearing system without race control hypothesis

2021 ◽  
pp. 095440622110179
Author(s):  
Yongzhen Liu ◽  
Yimin Zhang
Keyword(s):  
Ball Bearing ◽  
Combined Loading ◽  
Time Varying ◽  
Noticeable Effect ◽  
Rotating Speed ◽  
Bearing Stiffness ◽  
Vibration Mechanism ◽  
Control Hypothesis ◽  
Full Consideration ◽  
Bearing System

When the ball bearing serving under the combined loading conditions, the ball will roll in and out of the loaded zone periodically. Therefore the bearing stiffness will vary with the position of the ball, which will cause vibration. In order to reveal the vibration mechanism, the quasi static model without raceway control hypothesis is modeled. A two-layer nested iterative algorithm based on Newton–Raphson (N-R) method with dynamic declined factors is presented. The effect of the dispersion of bearing parameters and the installation errors on the time-varying carrying characteristics of the ball-raceway contact and the bearing stiffness are investigated. Numerical simulation illustrates that besides the load and the rotating speed, the dispersion of bearing parameters and the installation errors have noticeable effect on the ball-raceway contact load, ball-inner raceway contact state and bearing stiffness, which should be given full consideration during the process of design and fault diagnosis for the rotor-bearing system.

A prospective study of anti-vibration mechanism of microfluidic fuel cell via novel two-phase flow model

Energy ◽  
2021 ◽  
Vol 218 ◽  
pp. 119543
Author(s):  
Jingxian Chen ◽  
Peihang Xu ◽  
Jie Lu ◽  
Tiancheng Ouyang ◽  
Chunlan Mo
Keyword(s):  
Fuel Cell ◽  
Prospective Study ◽  
Flow Model ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Two Phase ◽  
Vibration Mechanism ◽  
Microfluidic Fuel Cell ◽  
A Prospective Study

Contact characteristic and vibration mechanism of rolling element bearing in the process of fault evolution

2021 ◽  
Vol 235 (1) ◽  
pp. 19-36 ◽  
Author(s):  
Wenbing Tu ◽  
Jinwen Yang ◽  
Wennian Yu ◽  
Ya Luo
Keyword(s):  
Fault Diagnosis ◽  
Vibration Response ◽  
Rolling Element Bearing ◽  
Bearing Fault Diagnosis ◽  
Rolling Element ◽  
Vibration Mechanism ◽  
Contact Characteristic ◽  
Element Bearing ◽  
Bearing Vibration ◽  
Fault Evolution

The vibration response of rolling element bearing has a close relation with its fault. An accurate evaluation of the bearing vibration response is essential to the bearing fault diagnosis. At present, most bearing dynamics models are built based on rigid assumptions, which may not faithfully reveal the dynamic characteristics of bearing in the presence of fault. Moreover, previous similar works mainly focus on the fault with a specified size without considering the varying contact characteristics as the fault evolves. This paper developed an explicit dynamics finite element model for the bearing with three types of raceway faults considering the flexibility of each bearing component in order to accurately study the contact characteristic and vibration mechanism of defective bearings in the process of fault evolution. The developed model is validated by comparing its simulation results with both analytical and experimental results. The dynamic contact patterns between the rolling elements and the fault, the additional displacement due to the fault and the faulty characteristics within the bearing vibration signal during the fault evolution process are investigated. The analysis results from this work can provide practitioners an in-depth understanding towards the internal contact characteristics with the existence of raceway fault and theoretical basis for rolling bearing fault diagnosis.

Study on Self-Excited Vibration Mechanism of Wheel-Rail Lateral Contact System

2013 ◽  
Vol 427-429 ◽  
pp. 257-261
Author(s):  
Li Xia Sun ◽  
Jian Wei Yao ◽  
Fu Guo Hou ◽  
Xin Zhao
Keyword(s):  
Feedback Mechanism ◽  
Point Of View ◽  
Contact System ◽  
Vibration System ◽  
Lateral Contact ◽  
System A ◽  
Vibration Model ◽  
Excited Vibration ◽  
Vibration Mechanism ◽  
The Stability

In order to investigate self-excited vibration mechanism of wheel-rail lateral contact system, a two DOF elasticity position wheelset lateral vibration model is established which considers the dry friction; the mechanism of the wheelset lateral self-excited vibration is investigated from the energy point of view. It shows that: the bifurcation diagram of this wheel-rail lateral contact system has a supercritical Hopf bifurcation. The energy of self-excited vibration derives from a part of traction energy; the creep rate in the wheel-rail system act as a feedback mechanism in the wheelset lateral self-excited vibration system. The stability of the wheelset self-excited vibration system depends mainly on the total energy removed from and imported into the system.

Lateral Vibration Research for Railway Deck Steel Plate Bridges

2011 ◽  
Vol 243-249 ◽  
pp. 1646-1650
Author(s):  
Wen Ping Li ◽  
Shu Li Chen ◽  
Mu Biao Su
Keyword(s):  
Steel Plate ◽  
Lateral Vibration ◽  
Vibration Model ◽  
Hunting Motion ◽  
Before And After ◽  
Vibration Mechanism ◽  
Track Irregularity ◽  
Lateral Reinforcement ◽  
Resonant Velocity

In this paper, the vehicle-bridge lateral vibration mechanism was analyzed; the vehicle-bridge vibration model was built and the lateral reinforcement schemes of open steel plate bridges were designed. Numbers of analysis were carried out for the lateral vibration of 40m deck steel plate bridges before and after reinforcement, under input of random artificial hunting waves and track irregularity. The results showed that, the frequency of hunting motion is approaching loaded frequency of the girder. The larger lateral amplitude appears on the bridge when the hunting wavelength is around 8~9m and the velocity of the train is around 55~70km/h. The wavelength is longer, the resonant velocity of the bridge is higher.

Theory of Self-Excited Coupled-Mode Vibration of Tainter Gates

2017 ◽  
pp. 463-497
Keyword(s):  
Flow Rate ◽  
Graphical Representation ◽  
Nodal Line ◽  
The Self ◽  
Rate Variation ◽  
Body Rotation ◽  
Coupled Mode ◽  
Bending Mode ◽  
Mode Vibration ◽  
Vibration Mechanism

In general, any mechanism that produces an unbalanced moment may also serve to initiate a rigid body rotation of a Tainter gate about the trunnion pin. From the modal analysis testing on an intact Folsom Dam Tainter gate, and an understanding of the concepts of flow-rate variation pressure and push-and-draw pressure presented in Chapters 4 and 5, respectively, a conceptual model of the vibration mechanism can be formulated. The whole gate rotation induces a flow-rate variation pressure and a coupled inertia torque on the skinplate, as presented in Chapter 4. Both the flow-rate-variation pressure and the inertia torque excite the skinplate to rotate in a bending mode shape about a horizontal nodal line. In the present chapter we will develop the theory behind such an instability mechanism, called the self-excited coupled-mode instability, culminating in the graphical representation of the Folsom Dam gate instability in terms of a dynamic stability criterion diagram under the conditions at which failure occurred.

Transverse Vibration Research for Railway Deck Steel Plate Bridges before and after Reinforcement

2011 ◽  
Vol 255-260 ◽  
pp. 1285-1289
Author(s):  
Wen Ping Li ◽  
Jian Ying Ren ◽  
Mu Biao Su
Keyword(s):  
Computer Simulation ◽  
Transverse Vibration ◽  
Steel Plate ◽  
Transverse Reinforcement ◽  
Vibration Model ◽  
Before And After ◽  
Vibration Mechanism ◽  
Track Irregularity

In this paper, the vehicle-bridge transverse vibration mechanism was analyzed; the vehicle-bridge vibration model was built and the transverse reinforcement schemes of open steel plate bridges were designed. Numbers of analysis were carried out for the transverse vibration of 40m deck steel plate bridges before and after reinforced, under input of random artificial hunting waves and track irregularity. The results show that when the hunting wavelength is 8.5m and the velocity of the train is around 50.4~75.6, the transverse amplitudes decrease differently after reinforcement. The effectiveness of various reinforcement types is evaluated by using the computer simulation programs.

scholarly journals Mechanical Vibration Mechanism Motion Simulation of Ultrasonic Composite Vibration Polishing Equipment

2018 ◽  
Vol 237 ◽  
pp. 01014
Author(s):  
Wan Hongqiang ◽  
Han Peiying ◽  
Ge Shuai ◽  
Fancong Li ◽  
Zhang Simiao
Keyword(s):  
Theoretical Analysis ◽  
Theoretical Basis ◽  
Mechanical Vibration ◽  
Motion Simulation ◽  
Connecting Rod ◽  
Adams Software ◽  
Piston Mechanism ◽  
Working Principle ◽  
Vibration Mechanism ◽  
Ansys Workbench

In order to design a kind of mechanical vibration part with stable motion in ultrasonic composite vibration polishing equipment. firstly, the main working principle of ultrasonic composite vibration polishing equipment is briefly introduced. Secondly, the mechanical vibration structure of the design is analyzed theoretically, again, using ADAMS software to simulate the crankshaft connecting rod piston mechanism. When the crankshaft speed is 750r/min, the stroke of the piston is 90mm, which is similar to the theoretical analysis value. Finally, using ANSYS Workbench software to analyze the crankshaft statics. The analysis shows that the design of the mechanical vibration structure is reasonable, which provides a theoretical basis for the study of the mechanical vibration structure of ultrasonic composite vibration polishing equipment.

Dynamic Modeling and Vibration Analysis of the Drum Washing Machine Based on Four-Terminal Parameter Method

2012 ◽  
Vol 501 ◽  
pp. 179-184
Author(s):  
Jun Fei Wu ◽  
Hui Li ◽  
Xue Zheng Yang ◽  
Xu Ping Zhang
Keyword(s):  
Steady State ◽  
Dynamic Model ◽  
Parameter Method ◽  
Steady State Response ◽  
Dynamics Model ◽  
Washing Machine ◽  
Basic Principles ◽  
State Response ◽  
Theoretical Support ◽  
Vibration Mechanism

In this study, the drum washer’s dynamic model has been conducted using Four-terminal parameter method. Firstly, the basic principles and advantages of the four-terminal parameters has been explained, and we have analyzed the vibration mechanism of the drum washer. Secondly, the drum washer was simplified ,and we extracted its dynamic model. Thirdly, we solve each of its components by using the four-terminal parameter method,and according to the connection between the components, determine each component and the system’s four-terminal parameters .Then, deduce the system’s matrix equations,get the complex steady-state response and steady-state response under sinusoidal excitation of the system. Last, input the drum washer’s actual parameters ,we can see that four-terminal parameter method dynamics model is correct. In a word, it is easy to analyze the vibration of complex systems. This paper is designed to provide theoretical support for the design of the drum washer’s damping device.

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