Dynamic and Thermal Analysis of Rotor Drop on Sleeve Type Catcher Bearings in Magnetic Bearing Systems

2017 ◽  
Vol 140 (2) ◽  
Author(s):  
Xiao Kang ◽  
Alan Palazzolo
Keyword(s):  
Finite Element ◽  
Element Model ◽  
Magnetic Bearing ◽  
Friction Model ◽  
Test Results ◽  
The Finite Element Method ◽  
Sleeve Bearing ◽  
Coulomb Friction Model ◽  
Crucial Part

The catcher bearing (CB) is a crucial part of the magnetic bearing system. It can support the rotor when the magnetic bearing is shut down or malfunctioning and limit the rotor's position when large vibration occurs. The sleeve bearing has the advantages of a relatively large contact surface area, simple structure, and an easily replaced surface. There are already many applications of the sleeve type CBs in the industrial machinery supported by the magnetic bearings. Few papers though provide thorough investigations into the dynamic and thermal responses of the sleeve bearing in the role of a CB. This paper develops a coupled two-dimensional (2D) elastic deformation—heat transfer finite element model of the sleeve bearing acting as a CB. A coulomb friction model is used to model the friction force between the rotor and the sleeve bearing. The contact force and 2D temperature distribution of the sleeve bearing are obtained by numerical integration. To validate the finite element method (FEM) code developed by the author, first, the mechanical and thermal static analysis results of the sleeve bearing model are compared with the results calculated by the commercial software solidworks simulation. Second, the transient analysis numerical results are compared with the rotor drop test results in reference. Additionally, this paper explores the influences of different surface lubrication conditions, different materials on rotor-sleeve bearing's dynamic and thermal behavior. This paper lays the foundation of the fatigue life calculation of the sleeve bearing and provides the guideline for the sleeve type CB design.

Dynamic and Thermal Analysis of Rotor Drop on Sleeve Type Catcher Bearings in Magnetic Bearing Systems

2017 ◽  
Author(s):  
Xiao Kang ◽  
Alan Palazzolo
Keyword(s):  
Thermal Behavior ◽  
Magnetic Bearing ◽  
Friction Model ◽  
Flexible Rotor ◽  
Fem Model ◽  
Sleeve Bearing ◽  
Beam Elements ◽  
Coulomb Friction Model ◽  
Crucial Part

The catcher bearing is a crucial part of the magnetic bearing system. It can support the rotor when the magnetic bearing is shut down or malfunctioning and limit the rotor’s position when large vibration occurs. The sleeve bearing has the advantages of a relatively large contact surface area, simple structure and an easily replaced surface. There are already many applications of the sleeve type catcher bearings in the industrial machinery supported by the magnetic bearings. Few papers though provide thorough investigations into the dynamic and thermal responses of the sleeve bearing in the role of a catcher bearing. This paper develops a coupled elastic deformation — heat transfer finite element (FEM) model of the sleeve bearing acting as a catcher bearing. The FEM model investigates the dynamic and thermal behavior when a flexible rotor drops onto the sleeve catcher bearing. The thermal load caused by the thermal expansion is also considered. The flexible rotor is composed of Timoshenko beam elements. A coulomb friction model is used to model the friction force between the rotor and the sleeve bearing surface. The contact force and 2-D temperature distribution of the sleeve bearing are obtained by numerical integration. To validate the FEM code developed by the author, firstly, both the mechanical and thermal static analysis results of the sleeve bearing model are compared with the results calculated by the commercial software, “SolidWorks Simulation”. Secondly, the transient analysis numerical results are compared with the rotor drop test results in reference 13. Additionally, this paper explores the influences of different surface lubrication conditions, different materials, such as stainless steel, bronze, and aluminum, on rotor-sleeve bearing’s dynamic and thermal behavior. This paper lays the foundation of the fatigue life calculation of the sleeve bearing and provides the guideline for the sleeve type catcher bearing design.

Study on the Effect of Tool Geometrical Parameters on Cutting Forces Based on Finite Element Method

2013 ◽  
Vol 663 ◽  
pp. 580-585
Author(s):  
Zhi Tao Tang ◽  
Tao Yu ◽  
Li Qiang Xu
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Cutting Forces ◽  
Three Dimensional ◽  
Element Model ◽  
Friction Model ◽  
Geometrical Parameters ◽  
Finite Element Software ◽  
Coulomb Friction Model ◽  
Cutting Model

Based on finite element software DEFORM-3D, a three-dimensional oblique cutting model for aerospace aluminum alloy was built. The material’s flow stress behavior was described with Johnson-Cook constitutive equation. The separation of the chips with the workpiece was realized by the combination of adaptive remeshing technique and separation criterion. The material’s failure was defined by adopting Cockcroft & Latham fracture criterion. The tool-chip friction model was the combination of a Coulomb friction model and shear (sticking) friction model. To validate the finite element model, cutting tests were conducted. The effects of tool geometrical parameters such as flank wear, cutting edge inclination and corner radius on cutting forces were analyzed by three-dimensional oblique finite element model.

Calculation of Leakage Coefficient for Hybrid Magnetic Bearing

2012 ◽  
Vol 150 ◽  
pp. 17-23 ◽  
Author(s):  
Er Yong Hou ◽  
Kun Liu
Keyword(s):  
Mathematical Model ◽  
Finite Element ◽  
Magnetic Circuit ◽  
Element Model ◽  
Practical Method ◽  
Magnetic Bearing ◽  
The Finite Element Method ◽  
Magnetic Forces ◽  
Working Principle ◽  
Leakage Coefficient

This paper proposes a novel radial hybrid magnetic bearing (RHMB), whose configuration and working principle are introduced, and its mathematical model is built using the equivalent magnetic circuit method. A simple and practical method for calculating leakage coefficients is proposed to improve the accuracy of the equivalent magnetic circuit method. A 3-D finite element model of the RHMB is established by the software ANSYS and the leakage coefficients of control and bias fluxes are calculated, respectively. Based on the obtained leakage coefficients, magnetic forces on the rotor are calculated using the equivalent magnetic circuit method, and the results are compared with those of experiments and the finite element method. It shows that the magnetic forces obtained using the three methods are in agreement with each other, which verifies the correction of the proposed method in the calculation of leakage coefficients.

FEM Analysis and Optimization of Large Load Suspended Platform

2012 ◽  
Vol 569 ◽  
pp. 415-419
Author(s):  
Xi Jian Zheng ◽  
Yong Shang Han ◽  
Zheng Yi Xie
Keyword(s):  
Finite Element Method ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Finite Element Model ◽  
Fem Analysis ◽  
Element Model ◽  
Test Results ◽  
The Finite Element Method ◽  
Element Analysis ◽  
The Finite Element Model

Based on the Finite Element Method, the suspended platform of temporarily installed suspended access equipment was simplified and the special connection positions were dealt with rigidization and coupling, thus the finite element model of suspended platform was established. Analyzing major structures of finite element model in different section dimensions, the reasonable scheme could be ascertained and the section dimensions of major structures in different materials could be obtained. Combining with the test results, the rationality of finite element analysis could be proved. The study could provide reference for the similar products on design and development.

Rolling Resistance Calculation Procedure Using the Finite Element Method

2019 ◽  
Vol 48 (3) ◽  
pp. 224-248
Author(s):  
Pablo N. Zitelli ◽  
Gabriel N. Curtosi ◽  
Jorge Kuster
Keyword(s):  
Finite Element ◽  
Energy Dissipation ◽  
Rolling Resistance ◽  
Element Model ◽  
The Finite Element Method ◽  
Temperature Changes ◽  
Rubber Compounds ◽  
Different Temperatures ◽  
Materials Used ◽  
Account Temperature

ABSTRACT Tire engineers are interested in predicting rolling resistance using tools such as numerical simulation and tests. When a car is driven along, its tires are subjected to repeated deformation, leading to energy dissipation as heat. Each point of a loaded tire is deformed as the tire completes a revolution. Most energy dissipation comes from the cyclic loading of the tire, which causes the rolling resistance in addition to the friction force in the contact patch between the tire and road. Rolling resistance mainly depends on the dissipation of viscoelastic energy of the rubber materials used to manufacture the tires. To obtain a good rolling resistance, the calculation method of the tire finite element model must take into account temperature changes. It is mandatory to calibrate all of the rubber compounds of the tire at different temperatures and strain frequencies. Linear viscoelasticity is used to model the materials properties and is found to be a suitable approach to tackle energy dissipation due to hysteresis for rolling resistance calculation.

THE ROLE OF FINITE ELEMENT METHOD IN CIVIL ENGINEERING

2018 ◽  
Vol 5 (02) ◽  
Author(s):  
Er. Hardik Dhull
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Approximate Solution ◽  
Analytical Method ◽  
Civil Engineering ◽  
The Finite Element Method ◽  
Engineering Problems ◽  
Building Components ◽  
Element Method

The finite element method is a numerical method that is used to find solution of mathematical and engineering problems. It basically deals with partial differential equations. It is very complex for civil engineers to study various structures by using analytical method,so they prefer finite element methods over the analytical methods. As it is an approximate solution, therefore several limitationsare associated in the applicationsin civil engineering due to misinterpretationof analyst. Hence, the main aim of the paper is to study the finite element method in details along with the benefits and limitations of using this method in analysis of building components like beams, frames, trusses, slabs etc.

Analysis of Hydroelectric Unit’s Upper Bracket Based on Test and FEM

2014 ◽  
Vol 721 ◽  
pp. 131-134
Author(s):  
Mi Mi Xia ◽  
Yong Gang Li
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Element Model ◽  
The Finite Element Method ◽  
Ansys Software ◽  
Element Analysis ◽  
Hydroelectric Unit ◽  
The Finite Element Analysis ◽  
Strain Rosette ◽  
The Finite Element Model

To research the load upper bracket of Francis hydroelectric unit, then established the finite-element model, and analyzed the structure stress of 7 operating condition points with the ANSYS software. By the strain rosette test, acquired the data of stress-strain in the area of stress concentration of the upper bracket. The inaccuracy was considered below 5% by analyzing the contradistinction between the finite-element analysis and the test, and match the engineering precision and the test was reliable. The finite-element method could be used to judge the stress of the upper bracket, and it could provide reference for the Structural optimization and improvement too.

scholarly journals Numerical investigation of the effects of unsupported railway sleepers on train-induced environmental vibrations

2017 ◽  
Vol 36 (2) ◽  
pp. 160-176 ◽  
Author(s):  
Seyed-Ali Mosayebi ◽  
Morteza Esmaeili ◽  
Jabbar-Ali Zakeri
Keyword(s):  
Finite Element ◽  
Element Model ◽  
Two Dimensions ◽  
Railway Track ◽  
Sensitivity Analyses ◽  
Regression Equations ◽  
The Finite Element Method ◽  
Technical Literature ◽  
Support Force ◽  
Comparison Of The Results

Review of technical literature regarding to train-induced vibrations shows that the effects of unsupported railway sleepers on this issue have been less investigated. So, the present study was devoted to numerical investigations of the mentioned issue. In this regard, first the problem of longitudinal train–track dynamic interaction was simulated in two dimensions by using the finite element method and the developed model was validated through comparison of the results with those obtained by previous researchers. In the next stage, a series of sensitivity analyses were accomplished to account for the effects of value of gap beneath the unsupported sleeper(s) and the track support stiffness on increasing the sleeper displacement and track support force. Moreover, the raised sleeper support force was introduced as applied load to a two-dimensional plane strain finite element model of track in lateral section and consequently the train-induced vibrations were assessed. As a result, a series of regression equations were established between the peak particle velocity in the surrounding environment of railway track and the sleeper support stiffness for tracks without unsupported sleepers and with one and two unsupported sleepers.

Design of Static Test Model for Three-Tower Cable-Stayed Self-Anchored Suspension Composed Bridge

2011 ◽  
Vol 243-249 ◽  
pp. 1528-1535
Author(s):  
Yu Zhao ◽  
Yong Jun Zhou ◽  
Jing Sun ◽  
Jin Tao Tang ◽  
Xu Li
Keyword(s):  
Complex System ◽  
Finite Element ◽  
Element Model ◽  
Test Model ◽  
Test Results ◽  
Static Test ◽  
Whole Process ◽  
Aesthetic Appearance ◽  
Load Carrying ◽  
Novel Structures

Cable-stayed self-anchored suspension composed bridges have novel structures and aesthetic appearance with complex system and difficulty for design and construction. In order to acquire a better knowledge of the load-carrying capability of this type of bridges, based on a real bridge and the theory of abnormal similarity, a full-bridge scaled down(1:20) test model was built to simulate the whole process of construction. The test results were preferably fit the theoretical calculation value. It can be seen that the design of the bridge was reasonable, and the accuracy of the calculation of finite element model was verified at the same time. The test and the related results can be used as the reference for the test and design of the similar bridges.

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