Dynamic response analysis of the brake disc of a high-speed train with wheel flats

2021 ◽  
pp. 095440972110317
Author(s):  
Zhiwei Wang ◽  
Jiliang Mo ◽  
Micheale Yihdego Gebreyohanes ◽  
Kaiyun Wang ◽  
Junyong Wang ◽  
...  
Keyword(s):  
Stress State ◽  
High Speed ◽  
Dynamic Properties ◽  
High Stress ◽  
Rigid Bodies ◽  
Response Analysis ◽  
Brake Disc ◽  
Dynamics Model ◽  
Coupled Dynamics ◽  
Brake Discs

To study the vibration characteristics and stress state of brake discs during vehicle operations, a spatial trailer car-track coupled dynamics model was developed with the consideration of flexible brake disc. In the model, the components of a trailer car are considered as rigid bodies. Flexible models of the brake disc and wheelset were established using the finite element method. The trailer car-track coupled dynamics model is validated using experimental test results. The effects of wheelset flexible deformation on the dynamic properties of brake discs were investigated with the excitations of track irregularity and wheel flats. Furthermore, the brake disc was systematically evaluated and discussed under the condition of wheel flats in the coupled dynamics system. The results indicate that compared to rigid wheelsets with wheel flats, flexible wheelsets can cause the brake disc to vibrate more severely with higher stress. The severe vibration and high stress state of the brake disc could cause it to crack in the region near the bolts. The established dynamics model can be further developed and employed to assess the dynamics of the brake systems of high-speed trains.

Motor car–track spatial coupled dynamics model of a high-speed train with traction transmission systems

2019 ◽  
Vol 137 ◽  
pp. 386-403 ◽  
Author(s):  
Zhiwei Wang ◽  
Guiming Mei ◽  
Qing Xiong ◽  
Zhonghui Yin ◽  
Weihua Zhang
Keyword(s):  
High Speed ◽  
High Speed Train ◽  
Dynamics Model ◽  
Transmission Systems ◽  
Coupled Dynamics

Failure Mechanisms of TGV Brake Discs

2007 ◽  
Vol 345-346 ◽  
pp. 697-700 ◽  
Author(s):  
Gérard Degallaix ◽  
Philippe Dufrénoy ◽  
Jonathan Wong ◽  
Paul Wicker ◽  
Frédéric Bumbieler
Keyword(s):  
High Speed ◽  
Thermal Loading ◽  
Test Bench ◽  
Infrared Camera ◽  
Second Step ◽  
Brake Disc ◽  
Disc Brakes ◽  
Brake Discs ◽  
High Speed Trains ◽  
Very High

The CRISFIS project (supported by ADEME agency) consists in jointly studying the squealing and cracking aspects of the high power disc brakes for TGV very high speed trains. This paper deals with the progress concerning the cracking part. An experimental and modelling strategy is adopted in order to better understand and predict brake disc cracking. Braking tests conducted on an industrial scale-one test bench are presented. In a first step, the influence of the pad-type on the thermal loading applied to the disc is studied by means of an infrared camera and thermocouples embedded in the pads and in the disc. In a second step, the thermal maps extracted from thermographic monitoring are used as input data for thermal-mechanical calculations. Finally, the results of modelling and tests are compared to the damage observed on the brake discs.

scholarly journals Nonlinear Dynamic Analysis of Lifting Mechanism of an Electric Overhead Crane during Emergency Braking

2020 ◽  
Vol 10 (23) ◽  
pp. 8334
Author(s):  
Congmin Niu ◽  
Huajiang Ouyang
Keyword(s):  
High Speed ◽  
Virtual Work ◽  
Thermal Power ◽  
Nonlinear Dynamic Analysis ◽  
Maximum Load ◽  
Rigid Bodies ◽  
Dynamic Responses ◽  
Response Analysis ◽  
Emergency Braking ◽  
Braking Process

Mechanical brakes are essential for electric cranes when emergency braking occurs. This paper presents, for the first-time, a dynamic response analysis of emergency braking events of electrical cranes that has modelled crane components as flexible and rigid bodies. Based on the Hamilton principle, a nonlinear and non-smooth dynamic model is derived from a modified Lagrangian function and the virtual work of non-conservative forces. The dynamic responses of a 32-ton overhead travelling crane during the emergency braking process of its lifting mechanism with two service brakes determined by simulating realistic operations. The numerical results show that the loads acting on components of the crane during the braking process depend on the braking capacity and the action time of the mechanical brakes, as well as the magnitude and the initial position of the payload. When a dual-brake scheme of the lifting mechanism is adopted, the maximum load of the high-speed links and the maximum thermal power of the mechanical brake appear in the emergency braking process when one of the two brakes fails to work. In addition, it is found to be a false belief that the lower the initial speed, the lower the maximum loads acting on components of cranes become during the braking process.

scholarly journals RESEARCH ON MATERIAL FLOW-STRESS BEHAVIOR AND THE DIE-FORGING PROCESS FOR FORGED-STEEL BRAKE DISCS FOR HIGH-SPEED TRAINS

2021 ◽  
Vol 55 (6) ◽  
Author(s):  
Zhenhong Li ◽  
Chenxing Zhang ◽  
Chenyu Wang ◽  
Yingna Huang
Keyword(s):  
Flow Stress ◽  
Process Parameters ◽  
High Speed ◽  
Brake Disc ◽  
Test Machine ◽  
Forming Process ◽  
Finite Element Software ◽  
Die Forging ◽  
Brake Discs ◽  
High Speed Trains

Due to the large size and complicated features, the brake discs of high-speed trains are difficult to forge, so a reasonable design of the process and the die parameter are prerequisites for successful forming. The flow stress of 23CrNiMoV, a forged-steel brake disc material for high-speed trains, was investigated by a uniaxial compression experiment on a Gleeble 1500 test machine. Based on the obtained flow-stress data, a series of numerical simulation analyses of the die forging of high-speed-train brake discs were carried out by using finite-element software. The effects of forging temperature, flash groove parameters and forming speed on the flow filling, forming load and temperature change of metal during die forging were studied. The simulation results were optimized and better process parameters were obtained. Based on the obtained process parameters, the simulation of the forming process was completed and a better forming quality was obtained.

scholarly journals Simulation Analysis and Verification of Temperature and Stress of Wheel-Mounted Brake Disc of a High-Speed Train

2020 ◽  
Author(s):  
Junsheng Qu ◽  
Wenjing Wang ◽  
Ziyu Dong
Keyword(s):  
High Speed ◽  
Plane Deformation ◽  
Tensile Load ◽  
Middle Part ◽  
Bolted Joints ◽  
Bench Test ◽  
Brake Disc ◽  
Mechanical Coupling ◽  
Brake Discs ◽  
Braking Process

Abstract During the braking process, a large amount of heat energy is generated at the friction surfaces between the brake disc and pads and rapidly dissipates into the disc volume. In this paper, a three-dimensional thermo-mechanical coupling model of high-speed wheel-mounted brake discs containing bolted joints and contact relationships is established. The direct coupling method is used to analyse the temperature and stress of the brake discs during an emergency braking event with an initial speed of 300 km/h. A full-scale bench test is also conducted to monitor the temperatures of the friction ring and bolted joints. The simulation result shows that the surface temperature of the friction ring reaches its peak value of 413.7°C after 102 s of braking, which agrees well with the bench test result. The maximum alternating thermal stress occurs in the bolt hole where the maximum circumferential compressive stress is -658 MPa and the maximum circumferential tensile stress is 134 MPa. During the braking process, the out-of-plane deformation of the middle part of the friction ring is larger than that of the edge, which increases the axial tensile load of the connecting bolt. This work provides support for the design of brake discs and connecting bolts.

scholarly journals A Study on Depth Sizing for Surface Cracks in KTX Brake Disc Using Rayleigh Wave

2019 ◽  
Vol 2019 ◽  
pp. 1-15
Author(s):  
Yun-Taek Yeom ◽  
Min-Soo Kim ◽  
Hak-Joon Kim ◽  
Sung-Jin Song ◽  
Ho-Yong Lee ◽  
...  
Keyword(s):  
Rayleigh Wave ◽  
Public Transportation ◽  
High Speed ◽  
Inspection System ◽  
Brake Disc ◽  
High Speed Railway ◽  
Brake Discs ◽  
Safety And Reliability ◽  
Railway System ◽  
Length Width

Korea Train eXpress (KTX), high-speed railway system, provides an important platform for public transportation and connects major metropolitans in Korea. KTX aiming towards next-generation transportation system has plans to increase the operation times. However, with increasing operation times, safety and reliability of the railways especially inspection of brakes systems becomes important. Therefore, in this study, a KTX brake disc inspection system using the Rayleigh wave is developed to characterize the cracks in the discs. The performance of the inspection system is evaluated on the KTX brake discs specimen having fabricated cracks as well as natural cracks. The result shows that the proposed algorithm successfully characterizes the crack types and estimated the length, width, depths and gap between cracks with good accuracy.

A numerical simulation on dynamic behavior of pushing chain mechanism

2015 ◽  
Vol 230 (11) ◽  
pp. 1902-1909 ◽  
Author(s):  
Leiyu Zhang ◽  
Yang Yang
Keyword(s):  
Numerical Simulation ◽  
High Speed ◽  
Dynamic Properties ◽  
Traction Force ◽  
Chain Mechanism ◽  
Dynamics Model ◽  
Extended Chain ◽  
Initial Stage ◽  
Speed Performance ◽  
Dynamics Models

The pushing chain mechanism is a novel telescoping mechanism used to push objects from one position to another rapidly. For obtaining a long telescoping distance, this mechanism adopts a helicoids case which can store links as many as possible. In order to analyze the dynamic properties and the pushing stability of the pushing chain, the dynamics models of its extraction from the helicoids case and engagement with the sprocket are established. Meanwhile, the dynamics model of the extended chain during the pushing process is deduced. A numerical simulation of the full dynamics model is performed using MATLAB. The simulation results show that the drive forces influenced by the polygon effect transit from drastic oscillations to smooth fluctuations. The traction force acted on the chain in the helicoids case drops down to zero gradually with time. The links of the extended chain have a transverse vibration around the pushing line and the amplitudes reach a maximum at the middle. However, the pushing velocity rises quickly at the initial stage and begins to stabilize with small fluctuation. The pushing chain mechanism has good pushing stability and high-speed performance.

Power Consumption Analysis of High-Speed Train’s Brake Discs

2013 ◽  
Vol 765-767 ◽  
pp. 120-124
Author(s):  
Xiao Yu Zhu ◽  
Jian Yong Zuo
Keyword(s):  
Power Consumption ◽  
High Speed ◽  
Aerodynamic Drag ◽  
Brake Disc ◽  
High Speed Train ◽  
Air Inlet ◽  
Resistance Torque ◽  
Brake Discs ◽  
Rotational Parts ◽  
Traction Power

Apart from the aerodynamic drag produced by transitional motion of high-speed train, the rotational parts of the train, especially the ventilated discs mounted on axles, would also cause resistance torques due to air pumping effect, which consume traction power. In this paper the train running process is divided into traction, uniform running and braking three phases, then the power consumed by the brake discs as well as the proportion of which in total traction or braking power during the three periods is calculated based on kinetic energy theorem. The results indicate that, during traction and uniform running period, the power consumption of brake discs shares 2.84% and 12.87% of total traction power, and in brake stage, the proportion is 0.78%. What is more, in the uniform running phase, the proportion of brake discs power consumption caused by resistance torque can reach to 7.68%. If the air inlet of brake disc is blocked during traction and uniform running period to weaken air pumping effect, the useless power consumption can be effectively reduced and the traction efficiency can be improved.

A three-dimensional coupled dynamics model of the air spring of a high-speed electric multiple unit train

2016 ◽  
Vol 231 (1) ◽  
pp. 3-18 ◽  
Author(s):  
Zhuang Qi ◽  
Fu Li ◽  
Dalian Yu
Keyword(s):  
High Speed ◽  
Ride Comfort ◽  
Lateral Displacement ◽  
Three Dimensional ◽  
Coupled Model ◽  
Nonlinear Behaviour ◽  
Dynamics Model ◽  
Air Spring ◽  
Coupled Dynamics ◽  
Multiple Unit

Although air springs are widely applied on high-speed electric multiple unit (EMU) trains, there is no accepted method to model the dynamics of these air springs. In this paper, a three-dimensional (3D)-coupled dynamics model of an air spring used on a high-speed EMU train was created through the derivation of thermodynamics equations and using a curve-fitting method. Experimental and simulated stiffness tests were performed to verify the accuracy of the 3D-coupled model, which was then implemented in the MBS vehicle dynamics model. The influence of the nonlinear behaviour of the air spring on the vehicle’s dynamic performance was analyzed by a dual-simulation approach using the 3D-coupled model of the air spring and the dynamics model of the vehicle. From the results, it can be concluded that the air spring can improve the vehicle’s vertical ride comfort, due to its ability to adjust the vertical stiffness and damping based on the level of vibration. However, the vehicle’s ability to negotiate curves is reduced due to an increase in the air spring’s lateral and longitudinal stiffness, a result of the lateral displacement of the car body. Furthermore, the operation of the leveling valve in the 3D-coupled model can slightly reduce the vehicle’s overturning coefficient, which is a phenomenon that the normal air spring models cannot simulate. Finally, the 3D-coupled model was applied to simulate a leakage process, which is a complex series of chain reactions, in the air spring system. The calculation results indicate that, even though the ride comfort is severely degraded by the leakage, the vehicle’s running safety can still be guaranteed.

Thermographic Investigation of Hot Spots in Railway Brake Discs

2008 ◽  
Vol 385-387 ◽  
pp. 669-672 ◽  
Author(s):  
Jeong Guk Kim ◽  
Byeong Choon Goo ◽  
Sung Cheol Yoon ◽  
Sung Tae Kwon
Keyword(s):  
Hot Spots ◽  
High Speed ◽  
Hot Spot ◽  
Infrared Camera ◽  
In Situ Monitoring ◽  
Brake Disc ◽  
Brake Discs ◽  
Thermographic Investigation ◽  
Experimental And Theoretical Studies

Damage evolution due to generation of hot spots on railway brake disc was investigated using the infrared thermography method. A brake disc with gray cast iron, which is currently used in Korea, was employed for this investigation. A high-speed infrared camera was used to measure the surface temperature of brake disc as well as for in-situ monitoring of hot spot evolution. From the thermographic images, the observed hot spots and thermal damage of railway brake disc during braking operation were qualitatively analyzed. Moreover, in this investigation, the previous experimental and theoretical studies on hot spots phenomenon were reviewed, and the current experimental results were introduced and compared with theoretical prediction.

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