scholarly journals Estimating the Damage of Railway Carriage Wheels Equipped with Disc Brakes

2021 ◽  
Author(s):  
Márton Krénusz ◽  
Róbert Kovács ◽  
Miklós Krémer
Keyword(s):  
Material Properties ◽  
Thermal Simulation ◽  
Martensite Formation ◽  
Contact Patch ◽  
Disc Brakes ◽  
Protection Systems

The aim of this paper is to estimate the damage of railway carriage wheels caused by lock-up braking. First, we investigate the typical characteristics of wheel-rail contact including the parameters of contact patch, longitudinal creep and coefficient of adhesion. Then we show the current requirements concerning the wheel-slide protection systems and determine the points which should be reviewed. To predict the effect of the sliding phenomenon, material properties are needed, as well. Afterwards, a simplified thermal simulation is built to estimate where martensite formation may occur.

scholarly journals Differences between standards related to fire protection systems design

Tehnika ◽  
2021 ◽  
Vol 76 (3) ◽  
pp. 386-392
Author(s):  
Radoje Jevtić
Keyword(s):  
Fire Protection ◽  
Material Properties ◽  
Systems Design ◽  
Protection Systems ◽  
The World ◽  
In Fire

Fire protection and design of fire protection systems present very important engineering tasks in protection of human lives, animals and material properties. Because of its great significance, everything in fire protection and fire protection systems design must be defined by appropriate standards. There are several different standards in use in different countries around the world. Very often, in solvation of different fire protection tasks, there are many questions asked which standard should be used. There are many similarities between standards, but there are also many differences between standards. Also, some standards don't define at all some cases that can be found in fire protection. This paper was written to present solutions for some particular tasks by some valid standards (EN 54, BS, NPB 88-2001, VDE 088-2 and NFPA 72) in fire protection and differences between them in the same cases.

scholarly journals Periodical Inspection Frequency of Protection Systems of Machinery – Case Studies / Częstość Kontroli Okresowych Systemów Ochronnych Do Maszyn – Przykłady Praktyczne

2012 ◽  
Vol 23 (1) ◽  
pp. 109-120 ◽  
Author(s):  
Marek Dźwiarek ◽  
Olgierd Hryniewicz
Keyword(s):  
Control System ◽  
Case Studies ◽  
Material Properties ◽  
Safety Function ◽  
Protection Systems ◽  
Wear And Tear ◽  
Simplified Procedures ◽  
Parameter Values ◽  
System Capability

Abstract Long-lasting exploitation of a machine usually brings about wear and tear of its subsystems due to deteriorated material properties and mechanical wearing, which means that all safety functions should be periodically inspected for finding any changes in parameter values that could reduce the control system capability to perform its function. Therefore in the CIOP-PIB and IBS PAN the simplified procedures were formulated that aimed at the insurance of maintaining the required availability of safety function throughout the lifetime of machinery. The paper presents practical examples of application of these procedures to different architectures of the systems. Those examples proved usability of developed procedures.

A GUI-Based Computer Model for Simulation of Vibration in Automotive Caliper-Disc Brakes

2000 ◽  
Author(s):  
Glenn Meinhardt ◽  
Kambiz Farhang
Keyword(s):  
User Interface ◽  
Graphical User Interface ◽  
Computer Model ◽  
Material Properties ◽  
Energy Input ◽  
Disc Brake ◽  
Structural Components ◽  
Brake Pads ◽  
Constant Stiffness ◽  
Disc Brakes

Abstract Two computer models are presented that simulate the vibration response of an automotive caliper-disc brake system during braking. The computer programs, each represented by simulation block diagrams, are designed to solve a set of seven ordinary second order coupled differential equations. The first program analyzes the equations using a constant stiffness value for all structural components. The second program allows the user to modify the polynomials describing the contact normal and shear stiffnesses of both brake pads independently. The programs are modified and executed using a graphical user interface (GUI), which allows the user to modify all parameters of the simulation. This includes energy input, caliper and pad dimensional and material properties, and plot (output) parameters.

Grain boundary segregation in metals

1992 ◽  
Vol 50 (2) ◽  
pp. 1204-1205
Author(s):  
C.L. Briant
Keyword(s):  
Fracture Surface ◽  
Grain Boundary ◽  
Grain Boundaries ◽  
Material Properties ◽  
Electron Spectroscopy ◽  
High Vacuum ◽  
Boundary Segregation ◽  
Grain Boundary Segregation ◽  
Local Concentration ◽  
The One

Grain boundary segregation is the process by which solute elements in a material diffuse to the grain boundaries, become trapped there, and increase their local concentration at the boundary over that in the bulk. As a result of this process this local concentration of the segregant at the grain boundary can be many orders of magnitude greater than the bulk concentration of the segregant. The importance of this problem lies in the fact that grain boundary segregation can affect many material properties such as fracture, corrosion, and grain growth.One of the best ways to study grain boundary segregation is with Auger electron spectroscopy. This spectroscopy is an extremely surface sensitive technique. When it is used to study grain boundary segregation the sample must first be fractured intergranularly in the high vacuum spectrometer. This fracture surface is then the one that is analyzed. The development of scanning Auger spectrometers have allowed researchers to first image the fracture surface that is created and then to perform analyses on individual grain boundaries.

Relationships Between Grain Boundary Structure and Material Properties

1980 ◽  
Vol 38 ◽  
pp. 366-369
Author(s):  
Brian Ralph ◽  
Barlow Claire ◽  
Nicola Ecob
Keyword(s):  
Grain Boundary ◽  
Material Properties ◽  
Main Property ◽  
Grain Structure ◽  
Boundary Structure ◽  
Grain Boundary Structure ◽  
Property Changes

This brief review seeks to summarize some of the main property changes which may be induced by altering the grain structure of materials. Where appropriate an interpretation is given of these changes in terms of current theories of grain boundary structure, and some examples from current studies are presented at the end of this paper.

Sign in / Sign up

Export Citation Format

Share Document