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.

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.

Automotive Glass Exciter Technology for Acoustic Application

2014 ◽  
Author(s):  
Babak Ebrahimi ◽  
Amir Khajepour ◽  
Todd Deaville
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Experimental Studies ◽  
Element Model ◽  
Fe Model ◽  
Component Level ◽  
Modeling And Analysis ◽  
Electric Actuator ◽  
Conventional Systems ◽  
Fine Tune

This paper discusses the modeling and analysis of a novel audio subwoofer system for automotive applications using the automobile windshield glass. The use of a piezo-electric actuator coupled with a mechanical amplifier linked to a large glass panel provides a highly efficient method of producing sound. The proposed subwoofer system has the advantage over existing conventional systems of not only reducing the weight of the automobile, but also a significant power savings resulting in an increase of expected fuel economy. Among various design challenges, the glass-sealing design is of huge importance, as it affects the system dynamic response and so the output sound characteristics. The main goal in this manuscript is to evaluate different glass-sealing design configurations by providing a comprehensive Finite Element model of the system. To do so, a comprehensive, yet simplified FE model is developed, and experimental studies are performed in the component level to fine-tune and verify the model. Harmonic response of the system for each sealing configuration design is obtained in the frequency range of 0–200 Hz, and the results are compared and discussed. The finite element model is also beneficial in preliminary design of other components as well as the exciter placement, and predicting the performance of the overall system.

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.

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.

Integrated Process of Laser-Assisted Machining and Laser Surface Heat Treatment

2013 ◽  
Vol 135 (6) ◽  
Author(s):  
Bin Shi ◽  
Helmi Attia
Keyword(s):  
Heat Treatment ◽  
Finite Element ◽  
Element Model ◽  
Surface Heat ◽  
Laser Surface ◽  
Fe Model ◽  
Two Dimensional ◽  
Numerical Investigations ◽  
Laser Assisted Machining ◽  
Dimensional Finite Element

A process is proposed for integrating the laser-assisted machining (LAM) and laser surface heat treatment (LSHT) in a single operation. Experimental and numerical investigations were carried out. LSHT tests were performed to investigate the effect of the process parameters on the microstructure evolution and hardenability. A methodology and an empirical model for prediction of hardened depth were proposed. A two-dimensional finite element (2D-FE) model was developed to predict the phase transformation during the LAM and LSHT processes. The optimization of the LAM process was also investigated using the developed finite element model.

Modeling and Analysis of Weld Geometries, Size and Gap on Weld-Induced Thermal Stresses in a Solid Round-on-Flat Plate Fillet Weld

2017 ◽  
Author(s):  
Suhash Ghosh ◽  
Chittaranjan Sahay ◽  
Haider Al-Mamoury
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Thermal Stresses ◽  
Rapid Heating ◽  
Three Dimensional ◽  
Welding Process ◽  
Element Model ◽  
Fe Model ◽  
Fillet Weld ◽  
Modeling And Analysis

In this paper a finite element model is presented which describes the effects of fillet weld geometry on the thermal stresses. In a separate research, development of a finite element model for simulating welding-induced thermal stresses is discussed. This nonlinear FE model employs fully coupled three-dimensional thermo-mechanical formulation, including interfacial element to simulate the weaker solidified molten weld pool. Due to the nature of the welding process, heat generation from moving heat source, rapid heating and cooling gives rise to high stresses in the weld. This research investigates the effect of weld shape & size, weld gap, (l/d ratio) depth of weld to size ratio on the generated thermal stresses. The size of the round and flat stocks has been varied to investigate their effects of the stresses as well as to determine the thick-to-thin geometry limits based on acceptable design limits of thermal stresses.

A computational design-of-experiments study of hemming processes for automotive aluminium alloys

2005 ◽  
Vol 219 (10) ◽  
pp. 711-722 ◽  
Author(s):  
G Lin ◽  
K Iyer ◽  
S J Hu ◽  
W Cai ◽  
S P Marin
Keyword(s):  
Finite Element ◽  
Design Of Experiments ◽  
True Strain ◽  
Computational Design ◽  
Element Model ◽  
Surface Strain ◽  
Fe Model ◽  
Surface Cracking ◽  
Dimensional Finite Element ◽  
Roll Out

Hemming is a three-step sheet-folding process utilized in the production of automotive closures. It has a critical imact on the performance and perceived quality of assembled vehicles. Using a two-dimensional finite element model, this paper presents a design-of-experiments (DOE) study of the relationships between important hemming process parameters and hem quality for aluminium alloy AA 6111-T4PD flat surface-straight edge hemming. The quality measures include roll-in/roll-out of the hem edge as well as the maximum true strain on the exposed bent surface. The finite element (FE) model combines explicit and implicit procedures in simulating the three forming subprocesses (flanging, pre-hemming, and final hemming) along with the corresponding springback (unloading). The results show that the pre-hemming die angle and the flanging die radius have the greatest influence on hem edge roll-in/roll-out, while pre-strain and the flanging die radius impact the maximum surface strain significantly. The computational DOE results also provide the basis for process parameter selection to avoid hem surface cracking and particular insights for achieving acceptable formability.

scholarly journals Dynamic Finite Element Model Updating for On-load Tap Changer based on Super-model

2019 ◽  
Vol 256 ◽  
pp. 04001
Author(s):  
Zhiyuan Liu ◽  
Hongseng Zou ◽  
Miao Hui ◽  
Chen Dapeng ◽  
Guo Lin
Keyword(s):  
Finite Element ◽  
Dynamic Behavior ◽  
Model Updating ◽  
Element Model ◽  
Optimization Method ◽  
Simplified Model ◽  
Fe Model ◽  
Modeling And Analysis ◽  
Tap Changer ◽  
Load Tap Changer

A method is presented for dynamic model updating of on-load tap changer (OLTC). Based on a sensitivity-based optimization method, the initial simplified finite element (FE) model of OLTC component is updated using the analytical results of the FE super-model. The objective of model updating is to reduce the frequency difference between the simplified FE model and the super-model, and to make the simplified model accurately represent dynamic characteristics of the super-model. The updated simplified models can be further used in the modeling and analysis of the whole OLTC model. The results, taking the base of OLTC as example, indicate that the dynamic behavior of the updated simplified model match well with that of the super-model. Subsequently, the dynamic behavior of OLTC assembled with the updated parts is further predicted by modal analysis. The presented method improves the calculation efficiency, as well as accuracy, which has broad application prospects for dynamic prediction of complex structures in engineering.

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.

Sign in / Sign up

Export Citation Format

Share Document