Wheel Temperature Reduction During Freight Car Braking

2016 Joint Rail Conference ◽

10.1115/jrc2016-5819 ◽

2016 ◽

Author(s):

Monique F. Stewart ◽

Som P. Singh ◽

David R. Andersen ◽

Rou Wen ◽

Graydon F. Booth

Keyword(s):

Heat Removal ◽

Preliminary Design ◽

Service Environment ◽

Wheel Rim ◽

Disc Brakes ◽

Freight Car ◽

Maintenance Requirements ◽

Drum Brakes ◽

Railway Wheels ◽

Considerable Detail

Since the adoption of 286,000 lb gross rail load (286K GRL) car service, an increase in wheel thermal damage and shelling has been observed. This is attributed to the increased braking horsepower in 286K GRL service as compared to the 263K GRL service environment. This study investigated possible designs and methods of braking that could lead to reduced heat input to the tread of freight car wheels in order to mitigate this damage and reduce its occurrence to a level closer to that seen with 263K GRL car service. Fifteen potential concepts to lower the thermal input to wheels and/or accelerate heat removal from the tread were identified and evaluated using the following engineering categories: simplicity of design, maintenance requirements, weight considerations, material and manufacturing costs, controllability of braking effort, and market acceptability. Five final concepts — axle-mounted disc, cheek disc, wheel rim, axle-mounted drum, and high convection coating — were developed through preliminary design and thermal analysis to confirm their effectiveness in meeting the objectives. Four concepts for alternative braking methods — axle-mounted disc brakes, cheek disc brakes, wheel rim clasp brakes, and axle-mounted drum brakes — were analyzed in considerable detail. Of the four concepts presented, the first three appear to be feasible and would be potential candidates for further detailed investigations/evaluation. It is shown that as the demand on railway wheels to withstand increased mechanical and thermal loads grows, there are viable braking enhancements that can help manage the stress state in freight car wheels.

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Y25 freight car bogie models properties analysis by means of computer simulations

MATEC Web of Conferences ◽

10.1051/matecconf/201815703014 ◽

2018 ◽

Vol 157 ◽

pp. 03014 ◽

Cited By ~ 4

Author(s):

Tomáš Lack ◽

Juraj Gerlici

Keyword(s):

Tangential Stress ◽

Computer Simulations ◽

Simulation Analysis ◽

The Other ◽

Bogie Frame ◽

Friction Dampers ◽

Research Results ◽

Railway Wagon ◽

Freight Car ◽

Railway Wheels

The article deals with the results of the simulation analysis of a railway wagon bogie model. We analysed four freight wagon bogie variants for its dynamics properties research. The bogie models correspond in general to the Y25 bogie concept. The models were created in SIMPACK software enhanced by the RAIL module. From the research results depicted in the graphs we found out, that the newly designed bogie variant gives the best results when compared to the other analysed versions. The newly designed model consists of a standard Y25 bogie frame with two Lenoire friction dampers. This bogie is equipped with longitudinal linkages on both sides. These linkages are completed with a radial torsion binding, torsion rod, between side bogie parts. The contact of railway wheels and rails generates active forces affecting the surface contact, affecting the size of the normal and tangential stress, wear surfaces of the wheel/rail, or directly the size of the derailment.

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The Influence of Wheel/Rail Contact Conditions on the Microstructure and Hardness of Railway Wheels

The Scientific World JOURNAL ◽

10.1155/2014/209752 ◽

2014 ◽

Vol 2014 ◽

pp. 1-16 ◽

Cited By ~ 12

Author(s):

Paul Molyneux-Berry ◽

Claire Davis ◽

Adam Bevan

Keyword(s):

Rolling Contact Fatigue ◽

Contact Fatigue ◽

Rolling Contact ◽

Dynamic Simulations ◽

Near Surface ◽

Wheel Rim ◽

Ferrite Fraction ◽

Proeutectoid Ferrite ◽

Tangential Forces ◽

Railway Wheels

The susceptibility of railway wheels to wear and rolling contact fatigue damage is influenced by the properties of the wheel material. These are influenced by the steel composition, wheel manufacturing process, and thermal and mechanical loading during operation. The in-service properties therefore vary with depth below the surface and with position across the wheel tread. This paper discusses the stress history at the wheel/rail contact (derived from dynamic simulations) and observed variations in hardness and microstructure. It is shown that the hardness of an “in-service” wheel rim varies significantly, with three distinct effects. The underlying hardness trend with depth can be related to microstructural changes during manufacturing (proeutectoid ferrite fraction and pearlite lamellae spacing). The near-surface layer exhibits plastic flow and microstructural shear, especially in regions which experience high tangential forces when curving, with consequentially higher hardness values. Between 1 mm and 7 mm depth, the wheel/rail contacts cause stresses exceeding the material yield stress, leading to work hardening, without a macroscopic change in microstructure. These changes in material properties through the depth of the wheel rim would tend to increase the likelihood of crack initiation on wheels toward the end of their life. This correlates with observations from several train fleets.

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A Parametric Modeling Approach for the Preliminary Design of Automotive Disc Brakes

10.4271/2003-01-3330 ◽

2003 ◽

Cited By ~ 2

Author(s):

Richard A. Swift

Keyword(s):

Parametric Modeling ◽

Preliminary Design ◽

Modeling Approach ◽

Disc Brakes

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Preliminary design and assessment of a heat pipe residual heat removal system for the Reactor Driven Subcritical Facility

Nuclear Engineering and Technology ◽

10.1016/j.net.2021.06.013 ◽

2021 ◽

Author(s):

Wenwen Zhang ◽

Kaichao Sun ◽

Chenglong Wang ◽

Dalin Zhang ◽

Wenxi Tian ◽

...

Keyword(s):

Heat Pipe ◽

Heat Removal ◽

Preliminary Design ◽

Heat Removal System ◽

Removal System ◽

Residual Heat

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Design and Heat Transfer Analysis of Automotive Disc Brakes

Heat Transfer: Volume 3 ◽

10.1115/ht2003-47362 ◽

2003 ◽

Author(s):

J. Jancirani ◽

S. Chandrasekaran ◽

P. Tamilporai

Keyword(s):

Heat Transfer ◽

Thermal Loading ◽

Operating Conditions ◽

Heat Transfer Analysis ◽

Disc Brake ◽

Braking System ◽

Wide Range ◽

Disc Brakes ◽

Construction Operation ◽

Drum Brakes

In the recent scenario of braking system for automobiles, disc brake takes up a wide range of applications, because of its simplicity in construction, operation and not self energizing as in the case of drum brakes. Since the disc brakes takes up a wide range of application, it is essential to ensure the reliable function of the braking system under varied operating conditions. The reliable function of the disc brake system is purely depends on the system based design. In this work, a linear regression technique is used for the optimal design of the disc brake rotor for varied operating conditions. Various forces involved during braking, energy generated during braking and the corresponding effective stopping distances were also calculated using appropriate governing relations and equations. In the varied operating conditions, the heat energy generated during braking should be driven away form the working surfaces of the components. To analyze this thermal loading and cooling phenomenon, a conventional convective heat transfer approach was also formulated and developed in this work. The analytical findings of the above approaches are demonstrated at the end and it is found to be quite satisfactory.

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Brake Test Dynamometer Programming

Proceedings of the Institution of Mechanical Engineers ◽

10.1243/pime_proc_1978_192_039_02 ◽

1978 ◽

Vol 192 (1) ◽

pp. 377-385 ◽

Cited By ~ 1

Author(s):

D. Hatch ◽

M.W. Moore

Keyword(s):

Control System ◽

Coefficient Of Friction ◽

Friction And Wear ◽

Commercial Vehicle ◽

Comprehensive Assessment ◽

Material Behaviour ◽

Disc Brakes ◽

Standard Deviations ◽

Drum Brakes

In testing, conflict often arises between adequate simulation of interacting variables and the need to achieve precise repeatability. The development of a control system is described in which firstly an X-Y plotter and later a punched chart is used to programme an inertia dynamometer. Simultaneously a continuous plot of material behaviour is obtained. Friction and wear data from both disc brakes and large commercial vehicle drum brakes are shown, and demonstrate the comprehensive assessment of material behaviour. The standard deviations between tests for wear and for coefficient of friction are 0.005mm (0.0002 in) and 0.003 respectively.

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Design Outline for a Lightweight Inside Frame Freight Car Truck

ASME 2011 Rail Transportation Division Fall Technical Conference ◽

10.1115/rtdf2011-67029 ◽

2011 ◽

Author(s):

Thomas H. Engle

Keyword(s):

North American ◽

Roller Bearing ◽

Design Study ◽

Freight Car ◽

Pennsylvania Railroad ◽

Maintenance Requirements ◽

Economic Considerations

Inside frame trucks were historically unacceptable on freight cars, because of bearing maintenance problems which the modern roller bearing eliminated. This paper is a design study showing the potential advantages of a modern inside frame truck particularly in improvements in reducing weight and maintenance requirements, and was inspired by a short wheelbase inside bearing four wheel truck that the auhor designed to replace the original single axle trucks on an updated version of the Iron Highway articulated integral train. The new truck had to be interchangeable with the original without frame or car structure: a four wheel truck in a two wheel space! The design was completed, operation simulated, and a truck built, but the development stopped, for economic reasons, prior to equipping a demonstration train. This effort, though, suggested that an AAR compatible version of that truck might be advantageous, and this paper outlines how and why such a truck might be built. The paper is divided into six sections: 1) Background in the Iron Highway; 2) Requirement dictating conversion to a 4 wheel truck; 3) Design of a 286,000lb. GRL North American freight truck; 4) Maintenance considerations; 5) Economic Considerations; and 6) an Annex describing testing by the Pennsylvania Railroad of Timken inside frame roller bearing trucks 80 years ago.

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High-resolution observations of metastable γ’ precipitation in Al-15at.%Ag

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100167482 ◽

1996 ◽

Vol 54 ◽

pp. 1004-1005

Author(s):

N. V. Larcher ◽

I. G. Solorzano

Keyword(s):

Discontinuous Precipitation ◽

Equilibrium Phase ◽

Quantitative Description ◽

Present Contribution ◽

Α Phase ◽

The Matrix ◽

Aging Sequence ◽

Matrix Precipitation ◽

Considerable Detail ◽

Kinetics Of

It is currently well established that, for an Al-Ag alloy quenched from the α phase and aged within the metastable solvus, the aging sequence is: supersaturated α → GP zones → γ’ → γ (Ag2Al). While GP zones and plate-shaped γ’ are metastable phases, continuously distributed in the matrix, formation of the equilibrium phase γ takes place at grain boundaries by discontinuous precipitation (DP). The crystal structure of both γ’ and γ is hep with the following orientation relationship with respect to the fee α matrix: {0001}γ′,γ // {111}α, <1120>γ′,γ, // <110>α.The mechanisms and kinetics of continuous matrix precipitation (CMP) in dilute Al-Ag alloys have been studied in considerable detail. The quantitative description of DP kinetics, however, has received less attention. The present contribution reports the microstructural evolution resulting from aging an Al-Ag alloy with Ag content higher than those previously reported in the literature, focusing the observations of γ' plate-shaped metastable precipitates.

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