scholarly journals Study on Gage Widening Methods for Small-Radius Curves

2021 ◽  
Vol 11 (12) ◽  
pp. 5334
Author(s):  
Pu Wang ◽  
Daolin Si ◽  
Shuguo Wang ◽  
Qiang Yi
Keyword(s):  
Lateral Force ◽  
Small Radius ◽  
Track Maintenance ◽  
Rail Wear ◽  
Curve Radius

Existing gage widening standards and the influence of gage widening on the curve passing performance of trains and rail wear were examined. The existing gage widening theory can determine the minimum curve radius that needs to be widened, the widening value required by curves with different radii, and whether multiaxle locomotives can pass small-radius curves. However, it does not quantify the influence of the gage widening value on the curve passing performance and track maintenance workload. The range of the minimum curve radius that needs to be widened is 220–350 m, whereas some countries adopt a radius of 600 m; the maximum gage widening range is 15–20 mm, and few countries adopt gage widening values exceeding 30 mm. When the gage widening value increases from 0 to 10 mm, the lateral force of the curved wheel or rail with a radius less than 300 m is reduced by 16–20%, and that with a radius exceeding 300 m is reduced by 10–15%. The results of this study reveal that using proper gage widening values can reduce the lateral force of the wheel or rail and improve the curve passing performance. In the rail lifecycle, the implementation of the current gage widening standard requires only one gage adjustment operation, whereas the implementation of the original gage widening standard requires doubling gage adjustment operations.

scholarly journals WHEEL–RAIL WEAR INVESTIGATION ON A HEAVY HAUL BALLOON LOOP TRACK THROUGH SIMULATIONS OF SLOW SPEED WAGON DYNAMICS

Transport ◽  
2018 ◽  
Vol 33 (3) ◽  
pp. 843-852 ◽  
Author(s):  
Yan Quan SUN ◽  
Maksym SPIRYAGIN ◽  
Colin COLE ◽  
Dwayne NIELSEN
Keyword(s):  
Dynamic Behaviour ◽  
Railway Track ◽  
Contact Friction ◽  
Slow Speed ◽  
Wear Process ◽  
Contact Wear ◽  
Rail Wear ◽  
Heavy Haul ◽  
Curve Radius ◽  
Heavy Haul Railway

Heavy haul railway track infrastructure are commonly equipped with balloon loops to allow trains to be loaded/unloaded and/or to reverse the direction of travel. The slow operational speed of trains on these sharp curves results in some unique issues regarding the wear process between wheels and rails. A wagon dynamic system model has been applied to simulate the dynamic behaviour in order to study the wheel–rail contact wear conditions. A wheel–rail wear index is used to assess the wear severity. The simulation shows that the lubrication to reduce the wheel–rail contact friction coefficient can significantly reduce the wear severity. Furthermore, the effects of important parameters on wheel–rail contact wear including curve radius, wagon speed and track superelevation have also been considered.

An iterative methodology for the prediction of dynamic vehicle–track interaction and long-term periodic rail wear

2018 ◽  
Vol 232 (6) ◽  
pp. 1718-1730 ◽  
Author(s):  
Andreas Carlberger ◽  
Peter T Torstensson ◽  
Jens CO Nielsen ◽  
Anders Frid
Keyword(s):  
General Purpose ◽  
Domain Model ◽  
Small Radius ◽  
Wear Depth ◽  
Commercial Software ◽  
Operational Conditions ◽  
Rail Corrugation ◽  
Rail Wear ◽  
Wide Range

In this study, a versatile numerical method for the prediction of long-term growth of rail roughness is presented and its functionality is demonstrated for the development of rail corrugation on small radius curves. The procedure includes two sub-modules: (1) a time-domain model for the simulation of dynamic vehicle–track interaction in a wide range of frequencies by using a commercial software for multibody dynamics and (2) a post-calculation of sliding wear based on the Archard’s model in combination with a non-Hertzian and transient wheel–rail contact model. The structural flexibility of the wheelset is accounted for by using the finite element method. The rail wear generated by a large number of passing trains is assessed by recurrently updating the rail surface based on the wear depth calculated in each post-processing step. The current work sets out from a previous study in which a model for the prediction of long-term growth of rail roughness on small radius curves was developed in a general-purpose programming language. By transferring the model into a commercial software, the aim is to develop an engineering tool that is more applicable for different operational conditions, such as various vehicle and track designs and track alignments. The proposed method is verified by comparing the simulation results against those obtained with the pre-existing software. Conditions similar to a 120 m radius curve on the Stockholm metro exposed to corrugation growth on the low rail are considered. The corrugation is found to be generated by the leading wheelsets. The prevailing wavelength-fixing mechanisms are identified and discussed.

Automobiles on Horizontal Curves: Experiments and Observations

1998 ◽  
Vol 1628 (1) ◽  
pp. 50-56 ◽  
Author(s):  
Emmanuel Felipe ◽  
Francis Navin
Keyword(s):  
Latin Square ◽  
Lateral Position ◽  
Comfort Level ◽  
Lateral Acceleration ◽  
Small Radius ◽  
Vehicle Speed ◽  
Large Radius ◽  
Horizontal Curves ◽  
Upper Limits ◽  
Curve Radius

Statistical information on the basic variables involved in driving through a horizontal curve was obtained using a 4×4 Latin square design experiment to measure the action of automobile drivers in test track horizontal curves. The independent variables used in the test curves were speed (comfortable, fast); pavement surface (dry, wet); driver (male, female); and curve radius (16 m, 26 m, 60 m, 100 m). The measured output was the driver’s selected speed and corresponding lateral acceleration. In addition, the passengers indicated their comfort level on a four-point semantic scale. Expert drivers also drove the test curves to establish the upper limits of the driver-vehicle-tire system. Field observations of four curves along a two-lane rural mountain highway measured driver vehicle speed, lateral acceleration, and lateral position. The results indicate that, for a comfortable ride, drivers are limited by their comfortable lateral acceleration on small radius curves and seek the “environmental speed” on large radius curves.

Research on Stability Strengthening Scheme of Continuous Welded Rail on Bridge in the Small Radius Curve Section

2014 ◽  
Vol 505-506 ◽  
pp. 106-110 ◽  
Author(s):  
Biao Wang ◽  
Jin Hui Xu ◽  
Li Wang ◽  
Ping Wang
Keyword(s):  
Stability Problem ◽  
Small Radius ◽  
Track Structure ◽  
Curve Section ◽  
Fem Model ◽  
Continuous Welded Rail ◽  
Small Resistance ◽  
The Stability ◽  
Curve Radius

To solve the stability problem of continuous welded rail (short for CWR) on bridge in the small radius curve section, a sleeper connector structure was proposed, which is used to connect sleepers together and strengthen the stability of CWR. A FEM model was established to study the effect of the CWR stability strengthening scheme. This study result shows that the integrity of the track structure and the stability of CWR in the small radius curve section of which the radius is from 250m to 600m will be both improved by the strengthening scheme, and the larger the curve radius is, the better the CWR stability improvement will be. In order to guarantee the strength of sleeper connector and connecting bolt, it is suggested that the sleeper connectors at beam gaps should not be connected, and small resistance fasteners should be used in strengthening area.

Study on Using Numerical Method to Predict Wear Volume of Rail

2011 ◽  
Vol 335-336 ◽  
pp. 339-342
Author(s):  
Cai Yun Wang ◽  
Peng Shen ◽  
Qi Yue Liu
Keyword(s):  
Numerical Method ◽  
Simulation Experiment ◽  
Reference Value ◽  
Rolling Contact ◽  
Wear Behaviour ◽  
Wear Volume ◽  
Contact Wear ◽  
Rail Wear ◽  
Calculation Results ◽  
Curve Radius

This paper describes an numerical method and simulation experiment investigation on the rail wear affected by the curve radius and axle load etc. the effects of curve radius and axle load on The effects of axle load and curve radius on total slippage of contact particles and friction work of wheel/rail are investigated with numerical methods are analyzed by kalker’s program CONTACT. The effect of curve radius and axle load on rolling wear behaviour of rail is investigated by simulation experiment. It is indicated that axle load and curve radius are important factors to effect rolling contact wear of wheel-rail, and there is a linear relationship between wear volume of rail and friction work of wheel/rail; The preliminary empirical formula between wear volume of rail sample and friction work is given by analysis the experimental and calculation results, the formula offers a certain reference value for researching wear of wheel-rail and predicting wear volume of rail.

Wheel–rail stochastic dynamics and rail wear analysis of small radius curved sections of a tram line based on generalized probability density evolution

2020 ◽  
pp. 095440972094753
Author(s):  
Zhi-ping Zeng ◽  
Xu-dong Huang ◽  
Jun-dong Wang ◽  
Fu-shan Liu ◽  
Wei-dong Wang ◽  
...  
Keyword(s):  
Dynamic System ◽  
Probability Density ◽  
Small Radius ◽  
Stochastic Dynamic ◽  
Density Evolution ◽  
Rail Wear ◽  
Sample Set ◽  
Probability Density Evolution ◽  
Generalized Probability ◽  
Track Irregularities

Compared with ordinary railways, the curve radius of tram lines tends to be smaller, with minimum values of only 30 m. Therefore, wheel–rail interaction is more intense and complicated in sections of small radius tram line curves. Using a stochastic variable sample set based on a generalized probability density evolution method, the stochastic variable–spectrum representation method was used to generate a time-domain sample set of stochastic track irregularities. By inputting the stochastic set of track irregularities into a tram-track coupled dynamic system model, the stochastic dynamic response of the coupled dynamic system can be obtained. Moreover, by substituting the stochastic dynamic system response into the generalized probability density evolution formula, the process of probability density evolution of each evaluation index can be obtained by the finite difference method. Finally, the dynamic response of the tram-track coupled dynamic system can be evaluated by the probability distribution of each index. By setting a series of specific groove rail wear values, a tram-track coupled dynamic analysis was carried out, and compared with the specification requirements, vehicle safety limits under different wear values were obtained. This research has great engineering value for guiding the routine maintenance of small radius curve sections of trams.

The Effects of the Lateral Instability of High Center of Gravity Freight Cars

1968 ◽  
Vol 90 (4) ◽  
pp. 727-735
Author(s):  
D. Wiebe
Keyword(s):  
Lateral Force ◽  
Center Of Gravity ◽  
Body Motion ◽  
Lateral Instability ◽  
Vertical Side ◽  
Track Maintenance ◽  
Car Body ◽  
Lift Off ◽  
Lateral Resonance ◽  
High Center

High center of gravity freight cars experience extreme weight shift from side to side as a result of lateral resonance on track with cross-level differences from alternately staggered joints, as well as soft or other local variations in either rail. Dynamic measurements from tests made on test track with controlled 3/4-in. cross-level difference changes illustrate the force and motion magnitudes resulting from resonant and near resonant operating speeds; side bearing loads of 138,000 lb and spring group loads of 100,000 lb, accompanied by center plates separating and wheels lifting. The rotational energy input to the car body can be approximated for a given motion cycle and is proportional to the product of the amplitudes of the track profile and the car body motion. The high lateral (horizontal) forces on the truck at the side bearing and center plate make the truck unstable and cause wheels to lift off the rail on one side. This lateral force at a given end of the car is proportional to the corresponding vertical side bearing load. Freight cars traveling at resonant speed are especially prone to derail on curved track under high wheel-rail friction conditions. Forces and motion generated between the car body, truck, and the track, cause high cyclical stresses and severe wear between components that can shorten equipment life and cause severe track maintenance problems.

Wheel-Rail Contact Wear, Work, and Lateral Force for Zero Angle of Attack—A Laboratory Study

1984 ◽  
Vol 106 (4) ◽  
pp. 319-326 ◽  
Author(s):  
Sudhir Kumar ◽  
D. L. Prasanna Rao
Keyword(s):  
Angle Of Attack ◽  
Point Contact ◽  
Lateral Force ◽  
Wear Volume ◽  
Wear Process ◽  
Railroad Industry ◽  
Contact Wear ◽  
Rail Wear ◽  
Work Done ◽  
Wear Index

Most of the wear indices, used in the railroad industry for predicting wheel/rail wear, are functions of angle of attack between wheel and rail. Further, the wear problem has been studied in terms of wear coefficients which relate the wear volume to the work done in the wear process. The wear-work principle, as applicable to wear indices and coefficients, is enunciated and its implications are discussed. An analysis of the wheel/rail interaction as a two point contact problem is presented. To establish the validity of the theory and applicability of the indices, results from a series of four experiments on a quarter scale laboratory rig are reported. The experiments are with “zero angle of attack” and an externally applied lateral load on the wheel, representing the idealized operation of a perfect radial truck. It is observed that contrary to the prediction, based on most of the suggested indices, there is noticeable wear of both wheel and rail even under zero angle of attack. It is concluded that lateral forces should be explicitly included in wear index formulation. Calculated values of wear coefficients, in the range 7.7E-5 to 38.0E-5 for the case of total contact slip and 21.6E-5 to 120.8E-5 for the case of adhesive or micro slip, indicate the effect of plastic flow in the contact when the Holm-Archard relation is assumed valid. Approximate validity of the Derby wear index, based on energy considerations, indicates that indices which are primarily functions of angle of attach are not quite valid for predicting field wheel/rail wear. It is also concluded that the wear-work principle as formulated in the paper can be considered to be reasonably valid.

The Dynamics Studies of a Four-Axle Bogie of Locomotive

2013 ◽  
Vol 753-755 ◽  
pp. 1745-1750
Author(s):  
Xiao Xia Zhang ◽  
Yu Qiang Ma
Keyword(s):  
Lateral Force ◽  
Small Radius ◽  
Wear Factor ◽  
Car Body ◽  
Wheel Rim ◽  
High Adhesion ◽  
Dynamic Performances ◽  
Excellent Stability

A type of bogie structure was proposed for the eight-axle locomotive, of which the middel bogie forme was used to connect the two B0 bogie and support the car body with three suspensions. A single drawbar connect the B0 bogie and car body directly to transfer the longitudinal forces. This structure is simple and feasibility, which can achieve high adhesion availabillity and good dynamic performances. Three suspension can achieve a excellent stability of car body. Comparing with a same speed and axle load class 2C0 locomotive, the wheelset lateral force and wheel rim wear factor are reduced by about 35% at the R300m small radius curves, and the wheelset lateral force is decreased by 15%, and the rim wear factor is reduced by 23% at the R800m curves.

scholarly journals Innovative wheel tread design aimed to tramcar-track interaction improvement when passing curves of a small radius

2018 ◽  
Vol 157 ◽  
pp. 03010 ◽  
Author(s):  
Vladimír Hauser ◽  
Olena S. Nozhenko ◽  
Kateryna O. Kravchenko ◽  
Mária Loulová ◽  
Juraj Gerlici ◽  
...  
Keyword(s):  
Patent Application ◽  
Small Radius ◽  
Utility Model ◽  
Lateral Direction ◽  
Curved Track ◽  
S Curve ◽  
Curve Radius

Tramways in cities often ride in track curves of a small radius, which is followed by an increased effect of the vehicle on the track. In the rail - wheel contact often occurs creep in longitudinal as well as in lateral direction, which causes increase of riding resistance, wear in rail – wheel contact and noise operation. Exactly with the aim to reduce these undesirable effects we designed a tram bogie with steered wheelsets and with the double wheel tread. This inventions are registered by authors under Utility Model Nr. u201609015 and Patent Application Nr. a201701589. Description of proposed process of passing vehicle through strongly curved track is given in this paper. A comparison of creep velocities in rail - wheel contact results obtained by computer multibody simulations for a tram vehicle riding through a S-curve are presented. Purposefulness of proposed invention is investigated by constructing vehicle ride resistance dependence to the track curve radius.

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