The Effects of Wheelset Position and Operating Environment on Rolling Contact Fatigue

2008 ◽  
Author(s):  
Scott M. Cummings ◽  
Paul Krupowicz
Keyword(s):  
Environmental Factors ◽  
Impact Load ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Contact Forces ◽  
Rolling Contact ◽  
Minor Role ◽  
Operating Environment ◽  
Lead Position ◽  
Defect Prevention

The Wheel Defect Prevention Research Consortium (WDPRC) conducted analyses of wheel impact load detector (WILD) data to explore how wheelset position and operating environment affect rolling contact fatigue (RCF). The typical three-piece freight car truck used in North America produces higher tangential wheel/rail contact forces on the wheelset in the lead position than on the wheelset in the trail position of a truck as a car negotiates a curve. An analysis of WILD data shows that these higher forces are contributing to more shelling damage on wheelsets that are consistently in the lead position of a truck. Datasets in which the cars are frequently oriented with the A-end leading show the largest percentage of elevated WILD readings in the lead position of the lead truck (axle 4) followed by the lead position of the trail truck (axle 2). Likewise, datasets in which the cars are frequently oriented with the B-end leading show the largest percentage of elevated WILD readings in the lead position of the lead truck (axle 1) followed by the lead position of the trail truck (axle 3). Additionally, datasets in which there is an equal mix of car orientations show a much more evenly distributed location of elevated WILD readings. Another analysis of WILD data from five trainsets of nearly identical cars shows that any differences in wheel tread damage due to component differences are insignificant in comparison to the differences in wheel tread damage associated with environmental factors. While this analysis does not address component specification differences that could potentially have a large influence on shelling (such as M-976 trucks in comparison to standard trucks), it does show that environmental factors can play a large role in wheel tread damage. Car routing and loading characteristics were investigated as possible wheel damage factors. It appears that cars running on routes through terrain with longer, steeper grades may be prone to increased wheel shelling, probably due to thermal mechanical shelling (TMS). Side-to-side imbalanced loading appears to play a minor role in wheel shelling for two of the five trainsets.

Parametric Simulation of Rolling Contact Fatigue

2008 ◽  
Author(s):  
Scott M. Cummings ◽  
Patricia Schreiber ◽  
Harry M. Tournay
Keyword(s):  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Rolling Contact ◽  
Wear Model ◽  
Primary Methods ◽  
Vehicle Performance ◽  
Track Geometry ◽  
Advantages And Disadvantages ◽  
Defect Prevention ◽  
Design Speed

Simulations of dynamic vehicle performance were used by the Wheel Defect Prevention Research Consortium (WDPRC) to explore which track and vehicle variables affect wheel fatigue life. A NUCARS® model was used to efficiently examine the effects of a multitude of parameters including wheel/rail profiles, wheel/rail lubrication, truck type, curvature, speed, and track geometry. Results from over 1,000 simulations of a loaded 1,272 kN (286,000-pound) hopper car are summarized. Rolling contact fatigue (RCF) is one way that wheels can develop treads defects. Thermal mechanical shelling (TMS) is a subset of wheel shelling in which the heat from tread braking reduces a wheel’s fatigue resistance. RCF and TMS together are estimated to account for approximately half of the total wheel tread damage problem [1]. Other types of tread damage can result from wheel slides. The work described in this paper concerns pure RCF, without regard to temperature effects or wheel slide events. Much work has been conducted in the past decade in an attempt to model the occurrence of RCF on wheels and rails. The two primary methods that have gained popularity are shakedown theory and wear model. The choice of which model to use is somewhat dependent on the type of data available, as each model has advantages and disadvantages. The wear model was selected for use in this analysis because it can account for the effect of wear on the contacting surfaces and is easily applied to simulation data in which the creep and creep force are available. The findings of the NUCARS simulations in relation to the wear model include the following: • Degree of curvature is the single most important factor in determining the amount of RCF damage to wheels; • The use of trucks (hereafter referred to as M-976) that have met the Association of American Railroads’ (AAR) M-976 Specification with properly maintained wheel and rail profiles should produce better wheel RCF life on typical routes than standard trucks; • In most curves, the low-rail wheel of the leading wheelset in each truck is most prone to RCF damage; • While the use of flange lubricators (with or without top of rail (TOR) friction control applied equally to both rails) can be beneficial in some scenarios, it should not be considered a cure-all for wheel RCF problems, and may in fact exacerbate RCF problems for AAR M-976 trucks in some instances; • Avoiding superelevation excess (operating slower than curve design speed) provides RCF benefits for wheels in cars with standard three-piece trucks; • Small track perturbations reduce the overall RCF damage to a wheel negotiating a curve.

Thermal Effects on Wheel Performance Based on Twin Disc Testing

2020 ◽  
Author(s):  
Dingqing Li ◽  
Monique Stewart
Keyword(s):  
Thermal Effects ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Contact Forces ◽  
Rolling Contact ◽  
Test Machine ◽  
Testing Program ◽  
Different Types ◽  
Different Temperatures ◽  
Surface Performance

Abstract This paper presents the results and findings from a testing program conducted to investigate how temperature at the wheel-rail interface may affect wheel surface performance; i.e., development of rolling contact fatigue (RCF) and wear. Under this testing program, a twin disc test machine was used to test two different types of wheel specimens (cast and forged) under a range of temperatures (ambient to 800° F) and slip ratios from 0 to 0.75 percent. This testing program included a total of 32 tests, covering two wheel materials, four different temperatures, four slip ratios, and various traction coefficients as a ratio of longitudinal and vertical wheel/rail contact forces.

Influence of Track Properties on Railway Vehicles Wheel Rolling Contact Fatigue

2008 ◽  
Author(s):  
Mahdi Mehrgou ◽  
Asghar Nasr
Keyword(s):  
Rolling Contact Fatigue ◽  
Tangential Force ◽  
Contact Fatigue ◽  
Contact Forces ◽  
Rolling Contact ◽  
Vehicle Dynamic ◽  
Wheel Load ◽  
Wheel Rolling ◽  
Railway Passenger ◽  
Vehicle Dynamic Simulation

Track properties such as rail inclination, cant and gage width have significant effects on the shape and size of the contact area, actual rolling radius and also on the contact forces. These effects have an important role on rolling contact fatigue (RCF) which is known to be the main reason for large portion of wheel set failures and expenses. In this study the wheel/rail dynamic interaction of an Iranian railway passenger wagon under different track features are investigated through simulations using ADAMS\Rail commercial software. The calculated results regarding contact load data and contact properties of the wheel and rail are used for fatigue analysis to calculate RCF damage to the wheels using damage criteria based on previous studies. Two major parameters believed to have serious roles on RCF are the contact stress and the tangential force in the contact patch. These parameters are obtained from vehicle dynamic simulation studies. This paper describes and compares effects of different track geometries in curved and tangent tracks on RCF of three different wheel profiles S1002, P8 and IR1002. It is to identify which combinations of wheel load, wheel and rail profiles and vehicle dynamic characteristics cause RCF more severely.

Rail RCF and the Effects of Different Wheel Profiles

2008 ◽  
Author(s):  
Mehdi Mehrgou ◽  
Asghar Nasr
Keyword(s):  
Dynamic Simulation ◽  
Rolling Contact Fatigue ◽  
Tangential Force ◽  
Contact Fatigue ◽  
Simulation Software ◽  
Contact Forces ◽  
Rolling Contact ◽  
Dynamic Interactions ◽  
Railway Passenger ◽  
Vehicle Dynamic Simulation

Wheel lateral profile has considerable effects on the wheel/rail dynamic interactions such as the shape and size of the contact area, instantaneous rolling radius and contact forces. Theses themselves have indirectly important roles on the rolling contact fatigue (RCF) which is known to be the main reason for large portion of rail maintenance costs. In this study the wheel/rail dynamic interaction of an Iranian railway passenger wagon under three different wheel profiles are investigated using ADAMS\Rail commercial simulation software. The dynamic simulation results regarding contact load and contact features of the wheel and rail are used for fatigue analysis to calculate RCF damage to the rail using reliable damage criteria reported in the literature. The two major parameters having serious roles on the RCF are believed to be the contact stress and the tangential force at the contact patch. These parameters are obtained from vehicle dynamic simulation studies. This paper describes and compares the effects of three different wheel profiles known as S1002, P8 and IR1002 on the rail RCF in both the curved and tangent sections of a track. The primary results clearly identify the effects of wheel profile on the RCF.

scholarly journals Optimizing wheel profiles and suspensions for railway vehicles operating on specific lines to reduce wheel wear: a case study

2020 ◽  
Vol 51 (1) ◽  
pp. 91-122 ◽  
Author(s):  
Yunguang Ye ◽  
Yu Sun ◽  
Shiping Dongfang ◽  
Dachuan Shi ◽  
Markus Hecht
Keyword(s):  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Optimal Choice ◽  
Contact Forces ◽  
Rolling Contact ◽  
Wheel Wear ◽  
Material Loss ◽  
Railway Vehicles ◽  
Wheel Profile ◽  
Designing Method

AbstractThe selection of a wheel profile is a topic of great interest as it can affect running performances and wheel wear, which needs to be determined based on the actual operational line. Most existing studies, however, aim to improve running performances or reduce contact forces/wear/rolling contact fatigue (RCF) on curves with ideal radii, with little attention to the track layout parameters, including curves, superelevation, gauge, and cant, etc. In contrast, with the expansion of urbanization, as well as some unique geographic or economic reasons, more and more railway vehicles shuttle on fixed lines. For these vehicles, the traditional wheel profile designing method may not be the optimal choice. In this sense, this paper presents a novel wheel profile designing method, which combines FaSrtip, wheel material loss function developed by University of Sheffield (USFD function), and Kriging surrogate model (KSM), to reduce wheel wear for these vehicles that primarily operate on fixed lines, for which an Sgnss wagon running on the German Blankenburg–Rübeland railway line is introduced as a case. Besides, regarding the influence of vehicle suspension characteristics on wheel wear, most of the studies have studied the lateral stiffness, longitudinal stiffness, and yaw damper characteristics of suspension systems, since these parameters have an obvious influence on wheel wear. However, there is currently little research on the relationship between the vertical suspension characteristics and wheel wear. Therefore, it is also investigated in this paper, and a suggestion for the arrangement of the vertical primary spring stiffness of the Y25 bogie is given.

scholarly journals Modelling of Frictional Conditions in the Wheel–Rail Interface Due to Application of Top-of-Rail Products

Lubricants ◽  
2021 ◽  
Vol 9 (10) ◽  
pp. 100
Author(s):  
Gerald Trummer ◽  
Zing Siang Lee ◽  
Roger Lewis ◽  
Klaus Six
Keyword(s):  
Simulation Model ◽  
Coefficient Of Friction ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Operating Conditions ◽  
Contact Forces ◽  
Rolling Contact ◽  
Application Site ◽  
Small Scale ◽  
The Coefficient Of Friction

The coefficient of friction between a wheel tread and the top of the rail should be maintained at intermediate levels to limit frictional tangential contact forces. This can be achieved by applying top-of-rail products. Reducing the coefficient of friction to intermediate levels reduces energy consumption and fuel costs, as well as damage to the wheel and rail surfaces, such as, e.g., wear, rolling contact fatigue, and corrugation. This work describes a simulation model that predicts the evolution of the coefficient of friction as a function of the number of wheel passes and the distance from the application site for wayside application of top-of-rail products. The model considers the interplay of three mechanisms, namely the pick-up of product by the wheel at the application site, the repeated transfer of the product between the wheel and rail surfaces, and the product consumption. The model has been parameterized with data from small-scale twin disc rig experiments and full-scale wheel–rail rig experiments. Systematic investigations of the model behaviour for a railway operating scenario show that all three mechanisms may limit the achievable carry-on distance of the product. The developed simulation model assists in understanding the interplay of the mechanisms that govern the evolution of the coefficient of friction in the field. It may aid in finding optimal product application strategies with respect to application position, application amount, and application pattern depending on specific railway operating conditions.

scholarly journals Investigation on Wheel-Rail Contact and Damage Behavior in a Flange Bearing Frog with Explicit Finite Element Method

2019 ◽  
Vol 2019 ◽  
pp. 1-17
Author(s):  
Yuan Gao ◽  
Ping Wang ◽  
Yibin Liu ◽  
Jingmang Xu ◽  
Zhiguo Dong ◽  
...  
Keyword(s):  
Finite Element ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Numerical Procedure ◽  
Contact Forces ◽  
Rolling Contact ◽  
Fe Model ◽  
Wheel Load ◽  
Explicit Finite Element ◽  
Contact Behavior

Flange bearing frogs are designed to provide continuous rolling surfaces for trains traveling on the through line, but the interaction between wheel and rail in a diverging line is more complex than that for a common crossing, especially including flange bearing mode and multipoint contact during the transition. The wheel load will be transited from tread to flange and back to tread, which will intensify the wheel-rail interaction. In this paper, a numerical procedure is presented for the analysis of wheel-rail rolling contact behavior and damage prediction for the flange bearing frog. The three-dimensional explicit finite element (FE) model of a wheel passing the flange bearing frog is established to obtain the dynamic wheel-rail interaction in both the facing and the trailing move. The evolution of contact forces, the distribution of adhesion-slip regions, and shear surface stress and microslip at the contact patch are revealed. Then, the competition relationship between RCF (rolling contact fatigue) and wear of a flange bearing frog is analyzed. The results of numerical simulations can contribute to an understanding of the mechanism of the transient rolling contact behavior and provide guidance in design optimization for flange bearing frogs.

Influence of Short-Pitch Wheel/Rail Corrugation on Rolling Contact Fatigue of Railway Wheels

2005 ◽  
Vol 219 (3) ◽  
pp. 177-187 ◽  
Author(s):  
J C O Nielsen ◽  
A Ekberg ◽  
R Lundén
Keyword(s):  
High Frequency ◽  
High Speed ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Numerical Procedure ◽  
Contact Forces ◽  
Rolling Contact ◽  
Rail Corrugation ◽  
Low Pass ◽  
Railway Wheels

A numerical procedure to integrate simulation of high-frequency dynamic train-track interaction and prediction of rolling contact fatigue (RCF) impact is presented. Features of the included models and possibilities of applications are outlined. The influence of short-pitch rail corrugation and wheel out-of-roundness (OOR) on RCF of a high-speed passenger train is investigated. It is shown how the corrugation and the OOR will have a profound effect in that levels of wheel and rail irregularities that have been measured in the field may be sufficient to generate subsurface-initiated RCF. In particular, the high-frequency content of the contact forces is of importance. Errors induced by neglecting such high-frequency components in measurements and/or simulations are investigated by comparing RCF indices based on contact forces that have been low-pass filtered with various cut-off frequencies. To avoid cracking due to RCF, a maximum roughness level in the wavelength interval up to 10 cm is sought. To limit the effects of corrugation, grinding practices have been altered leading to a significant decrease in RCF.

Prediction of Rolling Contact Fatigue Using Instrumented Wheelsets

2008 ◽  
Author(s):  
Scott M. Cummings
Keyword(s):  
Urban Areas ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Rolling Contact ◽  
Data Set ◽  
Track Geometry ◽  
Defect Prevention ◽  
Leading Position ◽  
Research Consortium ◽  
Research Initiatives

The measured wheel/rail forces from four wheels in the leading truck of a coal hopper car during one revenue service roundtrip were used to by the Wheel Defect Prevention Research Consortium (WDPRC) to predict rolling contact fatigue (RCF) damage. The data was recorded in March 2005 by TTCI for an unrelated Strategic Research Initiatives project funded by the Association of American Railroads (AAR). RCF damage was predicted in only a small portion of the approximately 4,000 km (2,500 miles) for which data was analyzed. The locations where RCF damage was predicted to occur were examined carefully by matching recorded GPS and train speed/distance data with track charts. RCF is one way in which wheels can develop tread defects. Thermal mechanical shelling (TMS) is a subset of wheel shelling in which the heat from tread braking reduces a wheel’s fatigue resistance. RCF and TMS together are estimated to account for approximately half of the total wheel tread damage problem [1]. Other types of tread damage can result from wheel slides. The work described in this paper is concerning pure RCF, without regard to temperature effects or wheel slide events. It is important that the limitations of the analysis in this paper are recognized. The use of pre-existing data that was recorded two years prior to the analysis ruled out the possibility of determining the conditions of the track when the data was recorded (rail profile, friction, precise track geometry). Accordingly, the wheel/rail contact stress was calculated with an assumed rail crown profile radius of 356-mm (14 inches). RCF was predicted using shakedown theory, which does not account for wear and is the subject of some continuing debate regarding the exact conditions required for fatigue damage. The data set analyzed represents the wheel/rail forces from two wheelsets in a single, reasonably well maintained car. Wheelsets in other cars may produce different results. With this understanding, the following conclusions are made. - RCF damage is predicted to accumulate only at a small percentage of the total distance traveled. - RCF damage is predicted to accumulate on almost every curve 4 degrees or greater. - RCF damage is primarily predicted to accumulate while the car is loaded. - RCF damage is predicted to accumulate more heavily on the wheelset in the leading position of the truck than the trailing wheelset. - No RCF damage was predicted while the test car was on mine property. - Four unique curves (8 degrees, 7 degrees, 6 degrees, and 4 degrees) accounted for nearly half of the predicted RCF damage of the loaded trip. In each case, the RCF damage was predicted to accumulate on the low-rail wheel of the leading wheelset. - Wayside flange lubricators are located near many of the locations where RCF damage was predicted to accumulate, indicating that simply adding wayside lubricators will not solve the RCF problem. - The train was typically being operated below the balance speed of the curve when RCF damage was predicted to occur. - The worst track locations for wheel RCF tend to be on curves of 4 degrees or higher. For the route analyzed in this work, the worst locations for wheel RCF tended to be bunched in urban areas, where tight curvature generally prevails.

Rolling Contact Fatigue of Wheel and Rail

2012 ◽  
Vol 54 (5) ◽  
pp. 304-312
Author(s):  
Florian Dörner ◽  
Otto Kleiner ◽  
Christian Schindler ◽  
Peter Starke ◽  
Dietmar Eifler
Keyword(s):  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Rolling Contact
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