Brake Block Chamfer

2011 ◽  
Author(s):  
Keyword(s):  
Brake Block

Noise-related roughness of railway wheel treads-full-scale testing of brake blocks

2000 ◽  
Vol 214 (2) ◽  
pp. 63-77 ◽  
Author(s):  
M Petersson
Keyword(s):  
Cast Iron ◽  
Hot Spots ◽  
Testing Machine ◽  
Full Scale ◽  
Spatial Distributions ◽  
Material Transfer ◽  
Railway Wheel ◽  
Rolling Noise ◽  
Brake Block ◽  
Abrasive Property

Results from full-scale tread braking experiments on an inertia dynamometer (brake testing machine) are presented. Eighteen prototypes of brake blocks are investigated. Two braking characteristics relating to the influence of the blocks on the wheel tread are studied: generation of hot spots and generation of roughness (corrugation, waviness). Wheel tread temperatures are measured during braking using an infrared (IR) technique. The wheel roughness is measured after each brake cycle when the wheel has cooled down. A roughness indicator, RλCA, relates measured roughness to expected rolling noise as generated by the wheel in operation. A correlation between the spatial distributions of temperatures and roughnesses is normally found: stronger for cast iron blocks and composition blocks and weaker for sinter blocks. The cast iron blocks are found to produce high tread roughness levels, partly owing to material transfer from brake block to wheel tread. The composition blocks are found to result in lower roughness levels than the cast iron blocks. Finally, the sinter metal blocks are found to lead to the lowest roughness levels, a fact which is probably due to the abrasive property of these blocks. Friction coefficients during braking are also measured.

scholarly journals An integrated numerical framework to investigate the running safety of overlong freight trains

2020 ◽  
Vol 235 (1) ◽  
pp. 47-60
Author(s):  
Visakh V Krishna ◽  
Daniel Jobstfinke ◽  
Stefano Melzi ◽  
Mats Berg
Keyword(s):  
Compressive Force ◽  
Radio Communication ◽  
Freight Train ◽  
Running Safety ◽  
Loading Patterns ◽  
Train Operation ◽  
Train Dynamics ◽  
Fail Safe ◽  
P Type ◽  
Brake Block

Long freight trains up to 1500 m in length are currently not in regular operation in Europe. One of the important reasons for the same is high inter-wagon forces generated during the operation, especially when pneumatic (P-type) brake systems are used. For long trains with multiple locomotives at different positions along the train, radio communication with necessary fail-safe mechanisms can be used to apply the brakes. Long freight train operation on a given line is subjected to various attributes such as braking/traction scenarios, loading patterns, wagon geometries, brake-block materials, buffer types, track design geometries, etc., which are referred to as heterogeneities. The complex longitudinal train dynamics arising in the train due to various heterogeneities play a major role in determining its running safety. In this context, the maximum in-train force refers to the maximum force developed between any two wagons along the train during operation. The tolerable longitudinal compressive force is the maximum compressive force that can be exerted on a wagon without resulting in its derailment. Here, the authors adopt a bottom-up approach to model pneumatic braking systems and inter-wagon interactions in multibody simulation environments to study the complex longitudinal train dynamics behavior and estimate maximum in-train forces and tolerable longitudinal compressive forces, subjected to various heterogeneities. These two force quantities intend to facilitate a given freight train operation by providing guidelines regarding the critical heterogeneities, that currently limit its safe operation. In doing so, the authors propose the notion to have an operation-based approval for long freight trains using the simulations-based tool.

A STUDY ON THE FAILURE ANALYSIS OF CAST IRON BRAKE BLOCKS THAT ARE USED FOR RAILWAY APPLICATIONS

2006 ◽  
Vol 20 (25n27) ◽  
pp. 4535-4540
Author(s):  
CHANG-MIN SUH ◽  
BYUNG-WON HWANG ◽  
WOO-HO BAE
Keyword(s):  
Cast Iron ◽  
Hot Spots ◽  
Hot Spot ◽  
Frictional Heat ◽  
Failure Behavior ◽  
Surface Cracks ◽  
Element Analysis ◽  
Actual Application ◽  
The Matrix ◽  
Brake Block

In order to clarify the cracking and failure behavior of gray cast iron brake blocks that are used for the railway applications, macro- and micro observations regarding the cracks and the micro-structure of the used brake blocks were examined. Three brake blocks, which have different degrees of hot spots and cracking during the actual application, were selected for testing. In addition, a thermal-mechanical coupled finite element analysis (FEA) was applied to calculate the temperature and the stress field in the brake blocks during braking. As a result, it was observed that surface cracks were initiated at the hot spots and propagated into the matrix. From the observation of dispersed graphites close to the crack path, it can be said that the deterioration of materials due to the frictional heat of braking made it easy to initiate cracks at the hot spot. The hardness of the brake block was recommended to be under 85 by the Rockwell B scale in order to prevent hot spots and crack initiation. From the FEA, the procedure for the occurrence of hot spots and cracks was successfully simulated by assuming the surface roughness on the slid surface of the brake block.

Rail Vehicles Brake Components Test Bench Utilisation

2013 ◽  
Vol 486 ◽  
pp. 379-386 ◽  
Author(s):  
Juraj Gerlici ◽  
Tomáš Lack
Keyword(s):  
Cast Iron ◽  
Friction Coefficient ◽  
Test Bench ◽  
Rolling Contact ◽  
Friction Materials ◽  
Braking System ◽  
Rail Vehicles ◽  
Type K ◽  
Technical Solutions ◽  
Brake Block

Reduction of noise due to rolling contact of wheel and rail for fright cars is one of the principal tasks of the European railways to be solved. Experts of railways, industries and universities were engaged during the last about ten years to search for technical solutions. An important noise reduction of fright cars can be achieved by replacing the cast iron brake shoes by composite brake shoes. Doing that, two directions have been taken into consideration. This is due to the fact, that at that time most composite brake shoes were based on friction coefficients were far away from that ones of the cast iron brake shoes. Applying such friction materials on existing vehicles would have as a consequence the change of braking forces acting on the wheels. These types of brake shoes (K-block) show a friction coefficient which is higher than that one of cast iron. As a consequence the application of the silent composite brake blocks of type K affords the adaptation of the braking system of the vehicle, what is cost intensive. For these reason, the application of K-brake block was proposed for new built vehicles. For existing vehicles solutions having the same friction coefficient as the cast iron brake shoes were requested (LL-Brake doing in this way, the modification of the braking equipment of existing fright cars could be avoided.

Further Mechanical Aids for the Foundry

1951 ◽  
Vol 165 (1) ◽  
pp. 27-41
Author(s):  
A. S. Beech
Keyword(s):  
Mass Production ◽  
Production Shop ◽  
Moulding Machine ◽  
Mechanical Devices ◽  
Brake Block ◽  
Storage Hopper

New mechanical and semi-mechanical devices put into practice in the foundry between 1942 and 1949 are described. They include in the mass-production shop, the moulding machine, brake block production and a modern knocking-out station, sand preparation and reconditioning and a multiple-belt storage hopper. Mechanization in the jobbing foundry is also discussed.

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