A Dynamic Model of Friction Draft Gear

2014 ◽  
Author(s):  
Qing Wu ◽  
Maksym Spiryagin ◽  
Colin Cole
Keyword(s):  
Dynamic Modeling ◽  
Field Test ◽  
Modeling And Prediction ◽  
Heavy Haul ◽  
Draft Gear ◽  
Train Dynamics ◽  
Simulation Results ◽  
Model Of Friction ◽  
Heavy Haul Trains ◽  
Force Displacement

Friction draft gears are the most widely used draft gears. Modeling and prediction of their dynamic behavior are of significant assistance in addressing various concerns. Longer, heavier and faster heavy haul trains mean larger in-train forces and more complicated force patterns, which require further improvements of dynamic modeling of friction draft gears to assess the longitudinal train dynamics. In this paper a force-displacement characteristics model named “base model” was described. The base model was simulated after the analyses of a set of field-test data. Approaches to improve the base model to a full advanced draft gear model were discussed; preliminary simulation results of an advanced draft gear model were also presented.

Methodology for Optimization of Friction Draft Gear Design

2014 ◽  
Author(s):  
Qing Wu ◽  
Colin Cole ◽  
Maksym Spiryagin
Keyword(s):  
Dynamics Simulation ◽  
Rolling Stock ◽  
System Failures ◽  
Gear Design ◽  
Simulation Techniques ◽  
Coupling System ◽  
Heavy Haul ◽  
Draft Gear ◽  
Train Dynamics ◽  
Heavy Haul Trains

Evidence gathered from industry indicates that railway coupling system failures have become a limitation for further developments of heavy haul trains. Friction draft gears have implications for both longitudinal train dynamics and rolling stock fatigue; therefore, optimization of friction draft gears could be a possible solution to conquer the limitation. In this paper, a methodology for optimization of friction draft gear design based on an advanced friction draft gear model is proposed. The methodology proposes using simulation techniques such as longitudinal train dynamics simulation and a Genetic Algorithm to develop improved parameters.

Development and validation of a new code for longitudinal train dynamics simulation

2020 ◽  
pp. 095440972092349
Author(s):  
Nicola Bosso ◽  
Matteo Magelli ◽  
Nicolò Zampieri
Keyword(s):  
Experimental Tests ◽  
Dynamics Simulation ◽  
Essential Information ◽  
Signaling Systems ◽  
Railway Systems ◽  
Heavy Haul ◽  
Train Dynamics ◽  
And Performance ◽  
Heavy Haul Trains ◽  
Development And Validation

Longitudinal train dynamics have a significant impact on both safety and performance of railway systems. Numerical simulation of long heavy haul trains can thus provide essential information for the development of diagnostic and signaling systems as well as coupling elements and braking systems. Long trains are usually modeled by considering only the longitudinal degree of freedom and by adding extra resistant forces to represent the track curvature and gradients. The prediction of in-train forces represents the most critical aspect in modeling the longitudinal dynamics of long trains made up of several vehicles. In fact, coupling elements have non-linear force–deflection characteristics, with different behavior in loading and unloading states, thus featuring a hysteretic loop. Look-up tables storing data from experimental tests are generally used to model these elements; however, other strategies, such as fitting curves and white-box models are witnessed in the literature. Recently, an international benchmarking of longitudinal train dynamics simulator was established in order to compare the output results obtained by different models with the same input data. The research group from Politecnico di Torino performed the simulations using the multibody software Simpack, but computational inefficiencies and numerical divergences occurred. To overcome these issues, a new dedicated in-house code was developed in the MATLAB environment. The paper focuses on the description of this new code and its validation, which was carried out by performing the simulations according to the benchmark inputs and comparing the results with the outputs from the other participants.

scholarly journals DYNAMIC FRICTION BEHAVIOR IN PRE-SLIDING REGIME OF PNEUMATIC ACTUATORS

2017 ◽  
Vol 7 (1) ◽  
pp. 50-68
Author(s):  
Tran Xuan Bo ◽  
Do Viet Long ◽  
Hideki Yanada
Keyword(s):  
Mathematical Model ◽  
Friction Model ◽  
Experimental Setup ◽  
Lugre Model ◽  
Friction Behavior ◽  
Pneumatic Actuators ◽  
Simulation Results ◽  
Model Of Friction ◽  
Force Displacement ◽  
Pneumatic Cylinders

This paper focuses on investigating friction behavior in pre-sliding regime and developing a new mathematical model of friction for fluid power actuators. Using pneumatic cylinders with different sizes, an experimental setup is built to measure friction force-displacement characteristics in presliding regime under various conditions of pressures in the cylinder chambers. A new mathematical model of friction for the pneumatic cylinders is proposed by incorporating a hysteresis function into the new modified LuGre model. The experimental results show that when the pressures are varied, friction of the pneumatic cylinders in pre-sliding regime is represented by behavior of a nonlinear spring. In addition, hysteresis behavior with nonlocal memory is obtained in the friction forcedisplacement characteristics and that the size of the hysteresis loop is increased with increasing pressures in the cylinder chambers. The simulation results show that the new friction model can accurately simulate the friction behavior of the pneumatic cylinders in pre-sliding regime as well as sliding regime.

scholarly journals Influence of Draft Gear Modeling on Dynamics Simulation for Heavy-Haul Train

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Cheng Lei ◽  
Jia Liu ◽  
Lisheng Dong ◽  
Weihua Ma
Keyword(s):  
Impact Test ◽  
Dynamics Simulation ◽  
Lookup Table ◽  
Bench Test ◽  
Spring Model ◽  
Change Rate ◽  
Heavy Haul ◽  
Draft Gear ◽  
Table Model ◽  
Simulation Results

In order to study the impedance characteristics of the frictional draft gear, MT-2 draft gear is studied, and its mechanical properties are analyzed firstly. Then, the mathematical models of two common draft gears are established based on the data collected from the vehicle impact test, and the effects of the two modeling methods on the simulation results are compared through the shunting impact test and the bench test simulation. Researches show that, under various experimental conditions, the simulated draft gear characteristic curve of the lookup table model moves along a fixed trajectory regardless of the change rate of the draft gear stroke, while simulation results of the wedge-spring model depend on the change rate of the draft gear stroke and are more consistent with the experimental results, reflecting the dynamic characteristics of the draft gear and suggesting better adaptability and wider application. Finally, the “1 + 1” grouped 20,000-ton heavy-haul combined train model is established, with its draft gear characteristics under the full-braking condition on flat straight track analyzed. Calculation results and test results of the lookup table model and the wedge-spring model are compared, indicating that using the wedge-spring model to calculate the longitudinal dynamics performance is more accurate. The influence of the modeling on the longitudinal impulse simulation of the train after air braking is also studied, revealing that the variation trends of the coupler force curves of two models are basically the same, but the amplitude and frequency of the longitudinal impulse are different.

A fast simulation approach to assess draft gear loads for heavy haul trains during braking

2021 ◽  
pp. 1-20
Author(s):  
Jony J. Eckert ◽  
Ícaro P. Teodoro ◽  
Luis H. Teixeira ◽  
Thiago S. Martins ◽  
Paulo R. G. Kurka ◽  
...  
Keyword(s):  
Simulation Approach ◽  
Fast Simulation ◽  
Heavy Haul ◽  
Draft Gear ◽  
Heavy Haul Trains

Field test and numerical analysis of Insulated rail joints in heavy-haul railway

2021 ◽  
Vol 298 ◽  
pp. 123905
Author(s):  
Hong Xiao ◽  
Guangpeng Liu ◽  
Dongwei Yan ◽  
Yue Zhao ◽  
Jiaqi Wang ◽  
...  
Keyword(s):  
Numerical Analysis ◽  
Field Test ◽  
Heavy Haul ◽  
Heavy Haul Railway

Heating Performance Research in the Running-In Process of Wet Friction Clutch

2014 ◽  
Vol 614 ◽  
pp. 12-15
Author(s):  
Yu Fei Liu ◽  
Xiu Chao Bai ◽  
Xin Li ◽  
Yong Liang Lei
Keyword(s):  
Simulation Model ◽  
Temperature Control ◽  
Temperature Rise ◽  
Analysis Model ◽  
Heating Performance ◽  
Wet Friction ◽  
Friction Clutch ◽  
Simulation Results ◽  
Model Of Friction ◽  
Performance Research

The heating in the running-in process of wet friction clutch is the key to research in this kind of products. In this paper, based on the shifting clutch composed of metal and paper-based friction liner, using MATLAB/SIMULINK software, the simulation model of friction clutch and the analysis model of conducting heat were established. Thus, the corresponding relationships were obtained, which were the total friction power and clutch temperature variation with the time during the running-in process. According to the simulation results, the main influencing factors on temperature control of wet friction clutch were analyzed during running-in process, and the results could provide reference for reasonable temperature rise control for the clutch.

Numerical simulation and field test study of desulfurization wastewater evaporation treatment through flue gas

2014 ◽  
Vol 70 (7) ◽  
pp. 1285-1291 ◽  
Author(s):  
Jia-jia Deng ◽  
Liang-ming Pan ◽  
De-qi Chen ◽  
Yu-quan Dong ◽  
Cheng-mu Wang ◽  
...  
Keyword(s):  
Field Test ◽  
Flue Gas ◽  
Cfd Simulation ◽  
Electrostatic Precipitator ◽  
Negative Impact ◽  
Positive Impact ◽  
Field Tests ◽  
Gas Temperature ◽  
Simulation Results ◽  
Desulfurization Wastewater

Aimed at cost saving and pollution reduction, a novel desulfurization wastewater evaporation treatment system (DWETS) for handling wet flue gas desulfurization (WFGD) wastewater of a coal-fired power plant was studied. The system's advantages include simple process, and less investment and space. The feasibility of this system has been proven and the appropriate position and number of nozzles, the spray droplet size and flue gas temperature limitation have been obtained by computational fluid dynamics (CFD) simulation. The simulation results show that a longer duct, smaller diameter and higher flue gas temperature could help to increase the evaporation rate. The optimal DWETS design of Shangdu plant is 100 μm droplet sprayed by two nozzles located at the long duct when the flue gas temperature is 130 °C. Field tests were carried out based on the simulation results. The effects of running DWETS on the downstream devices have been studied. The results show that DWETS has a positive impact on ash removal efficiency and does not have any negative impact on the electrostatic precipitator (ESP), flue gas heat exchanger and WFGD. The pH values of the slurry of WFGD slightly increase when the DWETS is running. The simulation and field test of the DWETS show that it is a feasible future technology for desulfurization wastewater treatment.

scholarly journals Dynamic modeling of a small open Joule cycle reciprocating Ericsson engine: simulation results

2013 ◽  
Vol 1 (3) ◽  
pp. 109-117 ◽  
Author(s):  
F. Lontsi ◽  
O. Hamandjoda ◽  
K. F. Djanna ◽  
P. Stouffs ◽  
J. Nganhou
Keyword(s):  
Dynamic Modeling ◽  
Engine Simulation ◽  
Simulation Results

Dynamic Modeling of a High-Dynamic Flight Simulator

2014 ◽  
Vol 687-691 ◽  
pp. 610-615 ◽  
Author(s):  
Hui Liu ◽  
Li Wen Guan
Keyword(s):  
Dynamic Modeling ◽  
Degrees Of Freedom ◽  
Flight Simulator ◽  
Inverse Dynamic ◽  
Dynamic Formulation ◽  
Time Histories ◽  
Rotational Degrees Of Freedom ◽  
High Dynamic ◽  
Euler Approach ◽  
Simulation Results

High-dynamic flight simulator (HDFS), using a centrifuge as its motion base, is a machine utilized for simulating the acceleration environment associated with modern advanced tactical aircrafts. This paper models the HDFS as a robotic system with three rotational degrees of freedom. The forward and inverse dynamic formulations are carried out by the recursive Newton-Euler approach. The driving torques acting on the joints are determined on the basis of the inverse dynamic formulation. The formulation has been implemented in two numerical simulation examples, which are used for calculating the maximum torques of actuators and simulating the time-histories of kinematic and dynamic parameters of pure trapezoid Gz-load command profiles, respectively. The simulation results can be applied to the design of the control system. The dynamic modeling approach presented in this paper can also be generalized to some similar devices.

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