Finite Element Modeling and Analysis of Friction-Wedge Dampers During Suspension Pitch Modes

2008 ◽  
Vol 130 (2) ◽  
Author(s):  
Y. Q. Sun ◽  
C. Cole
Keyword(s):  
Finite Element ◽  
Element Model ◽  
Friction Damping ◽  
Damping Force ◽  
Modeling And Analysis ◽  
Damping Characteristics ◽  
Wedge Shape ◽  
Dimensional Finite Element ◽  
Simulation Results ◽  
Elasticity Effects

A two-dimensional finite element model has been developed to investigate the friction damping characteristics of suspensions with so-called “constant-damping” friction wedges widely used in three-piece bogie wagons in Australia. The model was used to simulate the suspension during pitch modes. The simulation results show that the friction damping force in the suspension pitch modes is dependent on the friction conditions on the wedge contact surfaces, wagon speed, and the wedge shape and elasticity effects including the stuck state. The suspension pitch movements of a three-piece bogie with dry friction wedges can cause wedge rotation and partial separation of wedge contacting surfaces, which seriously affects the wedge friction damping effectiveness. The curved shape of wedge angular surface can significantly improve the friction damping characteristics of three-piece bogie suspensions.

Finite Element Modeling and Analysis of Friction Wedge Damping During Suspension Bounce Modes

2009 ◽  
Vol 131 (5) ◽  
Author(s):  
Y. Q. Sun ◽  
C. Cole
Keyword(s):  
Finite Element ◽  
Static Problem ◽  
Element Model ◽  
Fe Model ◽  
Friction Damping ◽  
Damping Force ◽  
Friction Forces ◽  
Modeling And Analysis ◽  
Damping Characteristics ◽  
Dimensional Finite Element

A two-dimensional finite element model (2D FEM) has been developed to improve the modeling and understanding of the friction damping characteristics of freight bogie suspensions. The specific suspension considered utilizes friction dampers with constant preload force as are widely used in three-piece bogie wagons in Australia. Unlike simpler models commonly used in rail vehicle dynamics, the FE model developed can accommodate distributed normal forces across the wedge surfaces. The model was tested in bounce modes and compared with the normal equations used to model wedge friction forces, which treat the forces on the wedge as a static problem. The simulation results using the 2D FEM model showed that the friction damping force is not constant and changes when the suspension is in motion. It was also shown that the force changes magnitude during the loading and unloading situations. The factors, which affect the change in friction force, are the friction characteristics on wedge contact surfaces, the direction and change in tangent force on wedge angular surface, the elastic deformation of the wedge, the wedge relative movement, and the wedge structure arrangement. The FE model assumptions are investigated and insights on wedge friction and creepage discussed.

scholarly journals A Three-Dimensional Finite-Element Model of a Human Dry Skull for Bone-Conduction Hearing

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Namkeun Kim ◽  
You Chang ◽  
Stefan Stenfelt
Keyword(s):  
Finite Element ◽  
Bone Conduction ◽  
Three Dimensional ◽  
Human Head ◽  
Element Model ◽  
Fe Model ◽  
Lateral Direction ◽  
Dimensional Finite Element ◽  
Simulation Results ◽  
Three Dimensional Finite Element

A three-dimensional finite-element (FE) model of a human dry skull was devised for simulation of human bone-conduction (BC) hearing. Although a dry skull is a simplification of the real complex human skull, such model is valuable for understanding basic BC hearing processes. For validation of the model, the mechanical point impedance of the skull as well as the acceleration of the ipsilateral and contralateral cochlear bone was computed and compared to experimental results. Simulation results showed reasonable consistency between the mechanical point impedance and the experimental measurements when Young’s modulus for skull and polyurethane was set to be 7.3 GPa and 1 MPa with 0.01 and 0.1 loss factors at 1 kHz, respectively. Moreover, the acceleration in the medial-lateral direction showed the best correspondence with the published experimental data, whereas the acceleration in the inferior-superior direction showed the largest discrepancy. However, the results were reasonable considering that different geometries were used for the 3D FE skull and the skull used in the published experimental study. The dry skull model is a first step for understanding BC hearing mechanism in a human head and simulation results can be used to predict vibration pattern of the bone surrounding the middle and inner ear during BC stimulation.

Finite Element Analysis of Resisting Explosive Loading for Mine Escape Capsule

2012 ◽  
Vol 446-449 ◽  
pp. 2206-2209
Author(s):  
Jin Long Wang
Keyword(s):  
Finite Element ◽  
Shock Waves ◽  
Simulation Analysis ◽  
Three Dimensional ◽  
Element Model ◽  
Explosive Loading ◽  
Element Analysis ◽  
Dimensional Finite Element ◽  
Simulation Results ◽  
Three Dimensional Finite Element

Three-dimensional finite element model of the mine escape capsule is established. With the different values of explosion shock waves, simulation analysis of the entry locker is performed by using ABAQUS. The simulation results indicate that the mine escape capsule is safe and available if the surge pressure of shock waves is less than 3.5Mpa.

Three Dimensional Finite Element Modeling and Analysis of Different Subway Tunnels Stray Current Fields

2014 ◽  
Vol 8 (1) ◽  
pp. 124-132
Author(s):  
Guo Wang ◽  
Xiao-Xiang Pei
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Element Model ◽  
Shield Tunnel ◽  
Geological Condition ◽  
Subway Tunnel ◽  
Stray Current ◽  
Modeling And Analysis ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

In order to analyze the distribution rules and influence of stray current on subway rectangulartunneland subway Shield tunnel, threedimensional models were built separately. By changing the values of carry-current, ansys was used toanalyzeunder different geological conditions.Simulations show that the potential attenuation is nonlinear from the subway tunnel to the surrounding underground.The potential of the same location of surrounding media is different with different carry-current.The amount of leakage stray current of rectangular tunnel is less than Shield tunnel under same geological condition and same carry-current. Each points stray current in situation of surrounding soil media subway tunnel shield can be analyzed by the three-dimensional finite element model, and provide the basis for the protection range of stray current and the protection at a specific location.

Hysteretic damping characteristics of a mechanical tensioner: Modeling and experimental investigation

2018 ◽  
Vol 233 (7) ◽  
pp. 1890-1902 ◽  
Author(s):  
Hao Zhu ◽  
Yumei Hu ◽  
Yangjun Pi ◽  
Weidong Zhu
Keyword(s):  
Mathematical Model ◽  
Finite Element ◽  
Finite Element Model ◽  
Three Dimensional ◽  
Element Model ◽  
Damping Characteristics ◽  
Hysteretic Damping ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element ◽  
The Mathematical Model

The aim of this article is to investigate hysteretic damping characteristics of a typical tensioner used in engine accessory drive systems. An experiment device is developed to measure the friction coefficients of three contact pairs within the tensioner. Statistic results of test data show that the friction coefficient is linearly dependent on normal forces, and thus a linear function is used to describe it. An exact mathematical model and an accurate three-dimensional finite element model are proposed in this study to calculate the relationship of friction torque and rotation angle as well as the damping characteristics of the tensioner. The mathematical model and three-dimensional finite element model are verified through an experiment. Comparison indicates that both the mathematical and finite element model can accurately predict the working torque of the tensioner during operation process, while the finite element model has better accuracy in predicting the damping characteristics than the mathematical model.

Finite Element Analysis of Nonuniformity of Tires with Imperfections5

2007 ◽  
Vol 35 (3) ◽  
pp. 226-238 ◽  
Author(s):  
K. M. Jeong ◽  
K. W. Kim ◽  
H. G. Beom ◽  
J. U. Park
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Three Dimensional ◽  
Element Model ◽  
Radial Force ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Dimensional Finite Element ◽  
Force Variation ◽  
Three Dimensional Finite Element

Abstract The effects of variations in stiffness and geometry on the nonuniformity of tires are investigated by using the finite element analysis. In order to evaluate tire uniformity, a three-dimensional finite element model of the tire with imperfections is developed. This paper considers how imperfections, such as variations in stiffness or geometry and run-out, contribute to detrimental effects on tire nonuniformity. It is found that the radial force variation of a tire with imperfections depends strongly on the geometrical variations of the tire.

scholarly journals Investigation of the Thickness Differential on the Formability of Aluminum Tailor Welded Blanks

Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 875
Author(s):  
Jie Wu ◽  
Yuri Hovanski ◽  
Michael Miles
Keyword(s):  
Experimental Data ◽  
Finite Element ◽  
Numerical Model ◽  
Plastic Strain ◽  
Finite Element Model ◽  
Equivalent Plastic Strain ◽  
Element Model ◽  
Dome Height ◽  
Tailor Welded Blanks ◽  
Simulation Results

A finite element model is proposed to investigate the effect of thickness differential on Limiting Dome Height (LDH) testing of aluminum tailor-welded blanks. The numerical model is validated via comparison of the equivalent plastic strain and displacement distribution between the simulation results and the experimental data. The normalized equivalent plastic strain and normalized LDH values are proposed as a means of quantifying the influence of thickness differential for a variety of different ratios. Increasing thickness differential was found to decrease the normalized equivalent plastic strain and normalized LDH values, this providing an evaluation of blank formability.

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