Numerical prediction of the development of rail wear on high-speed railways

2019 ◽  
Vol 234 (9) ◽  
pp. 927-944
Author(s):  
Pu Wang ◽  
Shuguo Wang ◽  
Liang Gao
Keyword(s):  
High Speed ◽  
Numerical Prediction ◽  
Operating Conditions ◽  
Rolling Contact ◽  
Wear Depth ◽  
Curve Section ◽  
High Speed Railway ◽  
Rail Wear ◽  
The Difference ◽  
Circular Curve

In this paper, a numerical prediction model was established to investigate the development of rail wear on high-speed railways, and a corresponding program was written using Matlab. According to Archard’s material wear theory, the wear depth distribution in the wheel–rail contact patch and along the rail profile was calculated based on a simulation of vehicle–track dynamics and a wheel–rail rolling contact analysis. In the dynamics model, various structural components and the complex nonlinear interactions between components were precisely simulated to ensure consistency with reality. Simulations were then conducted for every possible load case, and dimensionless weight factors were introduced to model the diverse operating conditions of a high-speed railway. An adaptive step algorithm was adopted to iteratively update the rail profile and reduce cumulative deviation or errors, improving the stability and reliability of the numerical model. Finally, a case study was conducted to investigate the development of wear in different track sections on a high-speed railway using the developed model. The results indicated that in the circular curve and transition sections, the side wear of the outer rail was obvious, and the wear of the inner rail was relatively smaller and mostly distributed in the middle of the railhead. The wear of the outer rail was more severe in the circular curve section compared to that in the transition sections. The closer to the rail shoulder, the greater the difference between the wear in the circular curve section and that in the transition section. In the tangent section, the wear of both rails was similarly distributed in the middle of the railhead and far less severe than in either the circular curve or transition sections. The agreement between the calculated results and field observations verified the rationality of the established rail wear model, which shows promise for improving the maintenance planning of high-speed railways and furthering the understanding of the rail wear processes.

Numerical prediction of rail wear development in high-speed railway turnouts

2020 ◽  
Vol 234 (10) ◽  
pp. 1299-1318
Author(s):  
Pu Wang ◽  
Shuguo Wang ◽  
Daolin Si
Keyword(s):  
Cross Sections ◽  
High Speed ◽  
Numerical Prediction ◽  
Rolling Contact ◽  
Dynamics Simulation ◽  
Wear Depth ◽  
Variable Cross ◽  
High Speed Railway ◽  
Wear Rates ◽  
Rail Wear

Wear of rails in turnouts is a common problem during the operation of high-speed railways. It can seriously affect the running safety of trains and the service lives of wheels and turnout rails. In this study, a numerical prediction model for rail wear development in high-speed railway turnouts was established. According to the material wear theory developed by Archard, the wear depth distribution in the wheel–rail contact patch was calculated based on a vehicle–turnout coupling dynamics simulation and wheel–rail rolling contact analysis. For the dynamics model, various components of the vehicle and complex nonlinear interactions between the components were simulated in detail to guarantee consistency with reality. The combination relationship of the switch and stock rails and the irregular and variable cross-sections of the rails in the switch panel of the turnout were considered. Spatial interpolation was used to achieve three-dimensional transitions between adjacent irregular cross-sections to model the compromised rails in the turnout. In addition, the stiffness and damping characteristics of the track in the turnout zone were taken into account. The rail wear rates for every characteristic section of the switch panel were calculated by the superposition model for rail profile wear. An adaptive-step algorithm was adopted in the iterative computations to update the rail profiles for every characteristic section position, which could reduce the cumulative errors and effectively improve the stability and reliability of the numerical model. Finally, case studies were conducted to investigate the wear developments of the switch and stock rails of high-speed turnouts using the developed model. In addition, the rail wear status of turnouts in the Shanghai–Nanjing high-speed railway was measured. The numerical prediction results are consistent with those of the actual situations in the field, verifying the rationality of the established model. This work shows the potential for guiding the maintenance and optimal design of turnouts and improving the understanding of the formation mechanism and influencing factors of rail wear in turnouts.

Numerical analysis of the effect of track parameters on the wear of turnout rails in high-speed railways

2016 ◽  
Vol 232 (3) ◽  
pp. 709-721 ◽  
Author(s):  
Jingmang Xu ◽  
Ping Wang ◽  
Jian Wang ◽  
Boyang An ◽  
Rong Chen
Keyword(s):  
Friction Coefficient ◽  
Wear Rate ◽  
High Speed ◽  
Numerical Procedure ◽  
Dynamic Interaction ◽  
Operating Conditions ◽  
Rolling Contact ◽  
Wear Model ◽  
Rail Wear ◽  
Railway Turnout

In this study, a numerical procedure is developed to predict the wear of turnout rails, and the effect of track parameters is investigated. The procedure includes simulation of the dynamic interaction between the train and the turnout, the rolling contact analysis, and the wear model. The dynamic interaction is simulated with the validated commercial software Simpack that uses a space-dependent model of a railway turnout. To reproduce the actual operating conditions of a railway turnout, stochastic variations in the input parameters are considered in the simulation of the dynamic interaction. The rolling contact is analyzed with the semi-Hertzian method and improved FASTSIM algorithm, which enable the contact model to deal with situations of multipoint contact and nonelliptic contact. Based on the Archard’s wear law, the wear model requires the calculation of normal/tangential stresses and a relative slide on the contact patches. The numerical procedure is performed for the selected sections of the vehicle, which runs through the railway turnout in the diverging route. By using the numerical procedure, the effect of track parameters (track gage, rail inclination, and friction coefficient) on the wear of turnout rails is analyzed. The results show that the wear of the front wheelset is more serious than the wear of the rear wheelset for a single vehicle. The degree of wear of switch rails is more severe than that of the stock rails and the difference is more obvious for the front wheelset of the switch rails. The wear of switch rails is mainly concentrated on the rail gage corner, while the wear of stock rails is mainly concentrated on the rail crown. For the analysed CN60-1100-1:18 turnout and the high-speed vehicle CRH2 in China, the rail wear rate could be slowed down by increasing the track gage and decreasing the rail inclination. Alternatively, the rail wear rate could be slowed by decreasing the friction coefficient; however, the variation of wear depth is quite small for friction coefficients that are larger than 0.3.

Research on Railway Bridge Evaluation Index

2013 ◽  
Vol 838-841 ◽  
pp. 1126-1129
Author(s):  
Zhao Lan Wei ◽  
Guo Jun Liu ◽  
Zu Yin Zou
Keyword(s):  
High Speed ◽  
Evaluation Index ◽  
Railway Bridge ◽  
High Speed Railway ◽  
Railway Bridges ◽  
Bridge Evaluation ◽  
Normal Speed ◽  
The Difference

Each related index was compared in three specifications, including Fundamental code for design on railway bridge and culvert, Code for rating existing railway bridges, and Code for design of high speed railway. The reasons of the difference existed in indexes was revealed, especially between high speed railway bridge and normal speed railway bridge.

Effect of substrate surface roughness on the wear of molybdenum disulphate coated rolling contact bearings

2021 ◽  
Vol 63 (9) ◽  
pp. 848-854
Author(s):  
Bahar Gokce ◽  
Necdet Geren ◽  
Mahmut Izciler
Keyword(s):  
High Temperature ◽  
Molybdenum Disulfide ◽  
Substrate Surface ◽  
Operating Conditions ◽  
Rolling Contact ◽  
Wear Testing ◽  
Wear Depth ◽  
Phosphate Coating ◽  
Depth Measurement ◽  
Friction Moment

Abstract The objective of the present experimental work is to investigate the influence of subsurface roughness on the friction and wear performance of high-temperature ball bearing. Bearings, which are used in high-temperature applications, are affected by several operating conditions. Some factors under high-temperature conditions such as short grease life, thin-film thickness at low speed, and insufficient internal clearance can drastically reduce bearing service life due to an increase in surface friction. For this reason, rolling contact bearings are coated with molybdenum disulfide. Before the molybdenum disulfide (MoS2) coating, phosphatization is applied to the bearings. Because the phosphate layer is micro-porous, it assures that molybdenum disulfide is entrapped in the interstitials between the phosphates. Also, phosphate coating provides a much larger surface area for the lubricant to attach to. In this study, several process steps, sandblasting, manganese phosphate coating, molybdenum disulfide coating, friction moment testing, wear testing, wear depth measurement, SEM, and XRD analyses were carried out. Wear tests and friction moment tests were applied to the rings of bearings of varied raceway roughness. This process ultimately provides molybdenum disulfide coated bearings optimum raceway roughness parameters for good wear resistance and optimum boundary lubrication.

Study on Rolling Contact Behaviors of Three Kinds of Railway Wheel Treads

2010 ◽  
Vol 118-120 ◽  
pp. 151-155
Author(s):  
Wen Jian Wang ◽  
Qing Fei Zeng ◽  
Jun Guo ◽  
Qi Yue Liu
Keyword(s):  
High Speed ◽  
Three Dimensional ◽  
Comprehensive Analysis ◽  
Rolling Contact ◽  
Contact Theory ◽  
Matching Effect ◽  
High Speed Railway ◽  
Railway Wheel ◽  
Elastic Bodies ◽  
Numerical Program

The rolling contact behaviors between LMA, S1002 and XP55 wheelset and track in static rolling contact are analyzed using the rolling contact theory of three-dimensional elastic bodies with non-Hertz form and numerical program of CONTACT. The numerical results indicate that three kinds of wheel treads have different difference of rolling radius and equivalent taper. The rolling contact behaviors between three kinds of wheel treads and CHN60 rail have obvious difference. The comprehensive analysis indicates that the matching effect of LAM wheel tread and CHN60 rail is relatively superior. Furthermore, it is suggested that new wheel tread should be designed and optimized for the high-speed railway.

Evaluation of Surface Defects of Wheel and Rail for Korean High-Speed Railway

2010 ◽  
Vol 654-656 ◽  
pp. 2499-2502 ◽  
Author(s):  
Chan Woo Lee ◽  
Seok Jin Kwon
Keyword(s):  
High Speed ◽  
Surface Defects ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Rolling Contact ◽  
Railway Vehicle ◽  
High Speed Railway ◽  
Main Research ◽  
Rail Systems ◽  
Micro Cracks

Wheels of the railway vehicle play the important role for driving train through wheel-rail interaction. Especially wheel profile is one of the most important design factors to rule the running stability and safety of train. Accordingly, the control of rolling contact fatigue-related defects is an ongoing concern for both safety and cost reasons. This process is referred to as ratcheting. Wear of wheel and rail surfaces occur due to a mixture of adhesive, abrasive and corrosive processes. In wheel/rail systems with little wear, such failure is manifested by the appearance of closely spaced micro-cracks. In the present paper, a evaluation of surface defects of wheel and rail for Korean high-speed railway. The main research application is the wheel-rail maintenance of Korea high-speed train.

scholarly journals Study on the impact of the Beijing–Shanghai high-speed railway on regional economic equity based on economic performance

2021 ◽  
Author(s):  
Heng Yang ◽  
Qiong Tong ◽  
Pan Zhao
Keyword(s):  
High Speed ◽  
Optimal Allocation ◽  
Research Result ◽  
Difference In Differences ◽  
High Speed Railway ◽  
Regional Economic ◽  
Big Cities ◽  
The Difference ◽  
The Impact ◽  
Economic Equity

AbstractAccording to the panel data of stations along the Beijing–Shanghai high-speed railway (BSHR) from 2008 to 2018, the influence of BSHR on regional economy of cities along the line is analyzed, and the influence of the opening of the BSHR on regional economic equity of cities along the line, through constructing the difference-in-differences model. The research result shows that the opening of the BSHR greatly promotes the growth of the GDP per capita of the site cities along the line and the optimal allocation of resources, such as labor, information and technology, and accelerates the two-way flow of factors of production between big cities and small and medium-sized cities at stations along the high-speed railway, makes high-quality resources from small and medium-sized cities flow to big cities along the line, while some backward resources from big cities gradually tilt toward small- and medium-sized cities along the line. In short, the opening of BSHR promotes the economic growth of the cities along the line, shortens the economic gap between the cities, is conducive to realizing regional economic equity.

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