Stiffness and Damping Analysis of a Single EHL Contact Between the Rolling Element and Raceways Under Wider Load and Speed Ranges

2012 ◽  
Author(s):  
Yuyan Zhang ◽  
Xiaoli Wang
Keyword(s):  
Viscosity Coefficient ◽  
Equivalent Stiffness ◽  
Solution Convergence ◽  
Vibration Model ◽  
Rolling Element ◽  
Inlet Length ◽  
Motion Characteristics ◽  
Stiffness And Damping ◽  
Increasing Load ◽  
Ehl Contact

The numerical analysis for the equivalent stiffness and damping of a single EHL contact between the rolling element and raceways under wider load and speed ranges is presented. The unsteady EHL model and free vibration model are applied to describe the motion characteristics of the rolling element. The inlet length and dimensionless natural frequency are determined according to the corresponding working load and speed. The DC-FFT method is implemented in order to increase the computational efficiency associated with elastic deformations and the semi-system approach is applied to ensure solution convergence under severe conditions which makes the analysis of stiffness and damping in the larger ranges of load and speed possible. The numerical results demonstrate that the stiffness increases with the increasing load and decreases with speed. However, the changes of the damping are complex, which are different in various load and speed ranges, especially under heavier load and higher speed. It is also indicated that the stiffness and damping increases with the increase in ambient viscosity and the decrease in pressure-viscosity coefficient.

Dynamic Behaviors of the Elastohydrodynamic Lubricated Contact for Rolling Bearings

2012 ◽  
Vol 135 (2) ◽  
Author(s):  
Yu-Yan Zhang ◽  
Xiao-Li Wang ◽  
Xiao-Liang Yan
Keyword(s):  
Viscosity Coefficient ◽  
Rolling Bearings ◽  
Transform Method ◽  
Dynamic Behaviors ◽  
Solution Convergence ◽  
Fast Fourier Transform Method ◽  
Vibration Model ◽  
Rolling Element ◽  
Inlet Length ◽  
Stiffness And Damping

The dynamic behaviors of a single elastohydrodynamic lubricated (EHL) contact between a rolling element and raceways under wider load and speed ranges are analyzed numerically based on the transient EHL model and the free vibration model. The discrete convolution and fast fourier transform method is implemented in order to increase the computational efficiency associated with elastic deformations and the semisystem approach is applied to improve the solution convergence under severe conditions. The change of mutual approach is selected as the standard of bearing vibrations and the inlet length and dimensionless natural frequency corresponding to the working load and speed are determined. The numerical results demonstrate that the stiffness increases with the increasing load and decreases with speed. However, the changes of damping are different in various working conditions, especially under heavier load and higher speed. It is also indicated that the stiffness and damping increase with the increase in ambient viscosity and the decrease in pressure-viscosity coefficient.

Reducing Vibration Analysis on Travel Stabilizing System of Wheel Loader Based on ProE and ADAMS

2011 ◽  
Vol 199-200 ◽  
pp. 839-844 ◽  
Author(s):  
Ge Ning Xu ◽  
Bing Wu
Keyword(s):  
Vibration Analysis ◽  
Influence Factor ◽  
Characteristic Parameter ◽  
Simulation Method ◽  
Equivalent Stiffness ◽  
Wheel Loader ◽  
Vibration Model ◽  
Stiffness And Damping

The mathematical vibration model of travel stabilizing system of wheel loader which was added to reduce spillage of material was built firstly. The equivalent stiffness and damping of travel stabilizing system were deduced, and influence factor was analyzed. In order to solver the characteristic parameter of the mathematical vibration model, the simulation method based on Pro/E and ADAMS was adopted. The result indicates selecting the appropriate parameter of accumulator is the important factor of the effect of travel stabilizing system. This paper is basic of further research on travel stabilizing system.

scholarly journals Research on Dynamic Modeling and Application of Kinetic Contact Interface in Machine Tool

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Dan Xu ◽  
Zhixin Feng
Keyword(s):  
Dynamic Modeling ◽  
Equivalent Stiffness ◽  
Theoretic Analysis ◽  
Dynamic Experiment ◽  
Machining Center ◽  
Fitting Method ◽  
Vibration Model ◽  
Stiffness And Damping ◽  
Elastic Mechanics ◽  
In Virtue Of

A method is presented which is a kind of combining theoretic analysis and experiment to obtain the equivalent dynamic parameters of linear guideway through four steps in detail. From statics analysis, vibration model analysis, dynamic experiment, and parameter identification, the dynamic modeling of linear guideway is synthetically studied. Based on contact mechanics and elastic mechanics, the mathematic vibration model and the expressions of basic mode frequency are deduced. Then, equivalent stiffness and damping of guideway are obtained in virtue of single-freedom-degree mode fitting method. Moreover, the investigation above is applied in a certain gantry-type machining center; and through comparing with simulation model and experiment results, both availability and correctness are validated.

Research on Stiffness and Damping Characteristics of Fixed Oily Porous Materials Joint Interface

2011 ◽  
Vol 422 ◽  
pp. 575-579
Author(s):  
Chong Nian Qu ◽  
Liang Sheng Wu ◽  
Jian Feng Ma ◽  
Yi Chuan Xiao
Keyword(s):  
Porous Material ◽  
Porous Materials ◽  
Parallel Plate ◽  
Joint Interface ◽  
Force Model ◽  
Equivalent Stiffness ◽  
Contact State ◽  
Damping Characteristics ◽  
Stiffness And Damping ◽  
Damping Model

In this document, using the anti-squeezed force model in the narrow parallel plate when fluid is squeezed, the equivalent stiffness and damping model is derived. It is further verified that it can increase the stiffness and damping while there are oil between the joint interfaces theoretically. Because the contact state of oily porous material can divide into liquid and solid parts, the document supposes that it is correct and effective to think the stiffness and damping of the two parts as shunt connection.

Vibration model of rolling element bearings in a rotor-bearing system for fault diagnosis

2013 ◽  
Vol 332 (8) ◽  
pp. 2081-2097 ◽  
Author(s):  
Feiyun Cong ◽  
Jin Chen ◽  
Guangming Dong ◽  
Michael Pecht
Keyword(s):  
Fault Diagnosis ◽  
Rolling Element Bearings ◽  
Vibration Model ◽  
Rolling Element ◽  
Rotor Bearing ◽  
Bearing System

A nonlinear dynamic vibration model of a defective bearing: the importance of modelling the angle of the leading and trailing edges of a defect

2020 ◽  
pp. 147592172096395
Author(s):  
Francesco Larizza ◽  
Carl Q Howard ◽  
Steven Grainger ◽  
Wenyi Wang
Keyword(s):  
Numerical Model ◽  
Surface Defects ◽  
Vibration Response ◽  
Rolling Element Bearing ◽  
Analytical Models ◽  
Bearing Defect ◽  
Defect Profile ◽  
Vibration Model ◽  
Trailing Edges ◽  
Rolling Element

Rolling element bearings eventually become worn and fail by developing surface defects, such as spalls, dents and pits. Previous researchers have tested bearings with defects that have sharp [Formula: see text] rectangular edges that were used to develop analytical models of a defective bearing. These models have limitations that require smooth surfaces and constant curvature of the bearing components; as well as assuming the defect profile. A method has been created to capture the surface topography of a bearing defect. A numerical model has been developed for a rolling element bearing that uses the measured defect profile and removes the limitations of models by previous researchers that use analytical expressions for contact area and force. The predicted vibration response of a bearing with a defect that has sloped leading and trailing edges on the outer and inner raceway was compared with experimental results. It was found that the new numerical model was able to predict the vibration response of a defective bearing. The defect topographies and the developed model have been made publicly available.

Study on mechanical properties of high damping viscoelastic dampers

2019 ◽  
Vol 22 (14) ◽  
pp. 2925-2936 ◽  
Author(s):  
Yun Chen ◽  
Chao Chen ◽  
Qianqian Ma ◽  
Huanjun Jiang ◽  
Zhiwei Wan
Keyword(s):  
Mechanical Properties ◽  
Shear Strain ◽  
Strain Amplitude ◽  
Hysteretic Behavior ◽  
Loading Frequency ◽  
Equivalent Stiffness ◽  
Viscoelastic Dampers ◽  
Wide Range ◽  
High Damping Rubber ◽  
Stiffness And Damping

The mechanical properties of the viscoelastic damper made of high damping rubber produced in China are investigated in order to provide the basis for its application. At first, the test on material properties of high damping rubber is conducted. The Mooney–Rivlin model, the Yeoh model and the Prony series are applied for simulating the nonlinear behavior of the high damping rubber with the aid of software ABAQUS. Then, three viscoelastic dampers with different sizes are tested under cyclic loading. The effects of strain amplitude and loading frequency on hysteretic behavior of dampers are analyzed. Viscoelastic dampers possess large deformation capability, stable energy-dissipation capacity and good fatigue-resisting property. The effect of strain amplitude is much more significant than loading frequency. The hysteretic behavior of the dampers is simulated by the Bouc–Wen model and the model of the equivalent stiffness and damping, respectively. The prediction results by using the Bouc–Wen model are in good agreement with the experimental results, which indicates that the Bouc–Wen model is applicable to simulate the mechanical properties of high damping viscoelastic dampers with a wide range of shear strain. As to the model of equivalent stiffness and damping, it has the advantages of clear concept and simple calculation. However, the good accuracy of prediction can be obtained only when the shear strain is not greater than 60%.

Research on Vibration Model of Special Vehicle Based on Dual-Mass System

2013 ◽  
Vol 385-386 ◽  
pp. 89-92 ◽  
Author(s):  
Ya Jun Shao ◽  
Qin He Gao ◽  
Hong Jie Cheng
Keyword(s):  
Characteristic Curve ◽  
Suspension System ◽  
Mass System ◽  
Nonlinear Characteristics ◽  
Actual Structure ◽  
Vibration Model ◽  
Special Vehicle ◽  
Set Up ◽  
Stiffness And Damping ◽  
The Mathematical Model

Taking a special vehicle vibration system as the research object, according to the actual structure of the chassis, the spring damping and stiffness of the nonlinear characteristics and the tire vertical elastic accounted, a nonlinear vibration model of special vehicle based on dual-mass-system is set up. The tire radial stiffness value is analyzed in Ansys, a simulation is performed by leading the mathematical model of suspension system into Adams, a characteristic curve of stiffness and damping of suspension system is obtained.

Nonlinear Grey-box Identification of a Landing Gear based on Drop Test Data

2020 ◽  
Author(s):  
Elias Dias Rossi Lopes ◽  
Helon Vicente Hultmann Ayala
Keyword(s):  
Control Design ◽  
Simulated Data ◽  
Federal Aviation Administration ◽  
Landing Gear ◽  
Drop Test ◽  
Equivalent Stiffness ◽  
Gear Design ◽  
Drop Tests ◽  
Adequate Evaluation ◽  
Stiffness And Damping

In many aircraft applications, especially on an antiskid control design, it is important to understand and consider the gear walk phenomenon, which is characterized by the deflection on the landing gear structure due the high braking force acting at the tire contact with the ground. This phenomenon is observed on drop tests, and its prediction on landing gear design depends on an adequate evaluation of the equivalent stiffness and damping of the structure, which is difficult, since they depend on the mechanism configuration. In this paper, it is presented a grey-box identification methodology for estimating these parameters of the landing gear, based on simulated data of a drop test. As the drop tests are mandatory obligatory for certificating modern aircraft according to e.g. Federal Aviation Regulations (FARs) by the Federal Aviation Administration (FAA), we hope to introduce a method based on measurements that are available at the design phase. The method will be useful to decrease men/hour costs and increase reliability by enabling better and more accurate anti-skid design.

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