scholarly journals Modeling the Depth of Surface Cracks in Brake Disc

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3890
Author(s):  
Wojciech Sawczuk ◽  
Mateusz Jüngst ◽  
Dariusz Ulbrich ◽  
Jakub Kowalczyk
Keyword(s):  
Cast Iron ◽  
Crack Depth ◽  
Brake Disc ◽  
Disc Brake ◽  
Surface Cracks ◽  
Braking System ◽  
Brake Discs ◽  
Regression Functions ◽  
Metallic Object

The article presents the state of knowledge and research in the field of surface cracks occurring in disc braking systems of rail and car vehicles. The craze formed during the operation of vehicles is particularly dangerous and leads to breaking the disc into several pieces. It may lead to a loss of braking force and damage to the entire disc brake caliper. The main aim of the research is to identify surface cracks in brake discs made of cast iron and use experimental methods to estimate their depth. Research were conducted on the disc braking system developed by the authors. In examining the location and depth of cracks, the penetration method, ultrasound, as well as a special probe were used. This device measures the crack depth based on the electrical resistance between two points on the surface of the metallic object. The tests showed that the first microcracks on the brake discs appeared after 309 braking tests on the test stand. In addition, it was observed that the surface cracks length of the disc increased linearly to depth until they reached about 11.5–12 mm with corresponded to crack lengths in the range of 65–70 mm. However, determination of the regression functions presented in the article allows to estimate the depth of surface cracks up to 70 mm long on cast iron brake discs by measuring their length.

EVALUATION OF THE HOMOGENEITY OF THE WORKING SURFACE OF CAST IRON BRAKE DISCS

Tribologia ◽  
2017 ◽  
Vol 276 (6) ◽  
pp. 33-37
Author(s):  
Grzegorz KINAL ◽  
Marta PACZKOWSKA
Keyword(s):  
Cast Iron ◽  
Corrosive Wear ◽  
Point Of View ◽  
Brake Disc ◽  
Braking Performance ◽  
Brake Pads ◽  
Braking System ◽  
Brake Discs ◽  
The One ◽  
Friction Surfaces

This article deals with the one of the most important elements of modern braking systems, which is a brake disc. A brake disc is the one of more stressed parts of the braking system, and its quality and design largely determine the braking performance of the vehicle. The article describes the technology of manufacturing disc brake pads that is important from the point of view of the wear processes occurring between two friction surfaces: the brake disc and the brake pad lining. The research of the cast iron ventilated brake disc surface measured the values of the selected roughness parameters at this site. In the context of measurements, it was also determined to be able to maintain a certain value of selected geometric parameters at a given location for the group of brake discs tested of a specific type and manufactured by a particular manufacturer. The work was carried out in the aspect of the research to create a surface layer to protect the brake discs from the effects of corrosive wear.

Optimizing Proportions of Railway Brake Discs by Temperature Transients Evaluation

1988 ◽  
Vol 202 (2) ◽  
pp. 91-99 ◽  
Author(s):  
S Missori ◽  
A Sili
Keyword(s):  
Thermal Cycle ◽  
Brake Disc ◽  
Disc Brake ◽  
Simple Method ◽  
Brake Discs ◽  
Brake Application ◽  
Dimensional Parameters ◽  
Maximum Temperatures ◽  
Commercial Size

When evaluating the performances of railway brake discs, the ability to accumulate and spread heat to the air plays a major role, since wear of synthetic lining and disc deterioration are strongly dependent on maximum temperatures attained on the surface in contact with the friction pad. The energy developed during brake application gives rise to an increase of disc temperature, which can be correlated to braking power, braking sequences and durations and to disc features. Maximum temperatures are attained on the friction surface of the disc. Determination of the thermal cycle subsequent to brake application can be considered preliminary to the study of lining and disc wear. The present work proposes a simple method using finite difference numerical analysis to evaluate the efficiency of the brake disc in dissipating the heat, both on a constant speed and an up-to-stop brake application. The effect of the various dimensional parameters, such as number of ribs, disc thickness and ribs width, is considered with the aim of achieving a first rough optimization of the required size of disc brake. The results related to a commercial size disc brake are given.

scholarly journals Defining the Temperature Change of the Brake Disc

2018 ◽  
Vol 11 (3) ◽  
pp. 119-131
Author(s):  
M. Menyhártné Baracskai
Keyword(s):  
Thermal Analysis ◽  
Temperature Change ◽  
High Performance ◽  
Travel Speed ◽  
Brake Disc ◽  
Disc Brake ◽  
Radial Temperature ◽  
Braking System ◽  
Power Machine ◽  
Brake Discs

In the article the thermal analysis of the brake disc and separator disc of a high performance power machine will be presented. As example an agricultural vehicle with weight of 30000 kg and maximum travel speed of 40 km/h will be taken. At stopping the vehicle, the braking system located in the wheel body becomes activated. The traversing of the piston forces the brake discs to friction. Therefore significant amount of heat is generated, which needs to be derived from the system. The article presents the construction of the disc brake system. Providing boundary condition, the radial temperature change of the cooled part of the brake disc will be defined.

Performance of Hybrid Reinforced Metal Matrix Composite Brake Disc: Simulation Approach

2021 ◽  
Vol 1025 ◽  
pp. 77-81
Author(s):  
Wei Kang Gan ◽  
Nanang Fatchurrohman
Keyword(s):  
Cast Iron ◽  
Metal Matrix ◽  
Structural Performance ◽  
Brake Disc ◽  
Matrix Composites ◽  
Simulation Approach ◽  
Ansys Software ◽  
Braking System ◽  
Brake Discs ◽  
Usage Efficiency

A brake disc has an significant role in the vehicle and it is used to stop or decrease the velocity of the vehicle. The demand of metal matrix composites (MMCs) is greatly increased in fabricating the brake disc since it possesses a low density and high thermal conductivity. Over-heating will lead to the malfunction of the braking system and affect the safety of vehicle. Reduced weight of brake disc can decrease the use of fuel of the vehicle thus improve the fuel usage efficiency. This paper is focussed to determine the suitability of AlSiCGr hybrid MMCs compared to cast iron in terms of thermal and structural properties for brake disc. Both design of brake discs was proposed and modelled using CATIA and then imported to ANSYS software for structural and thermal analysis. The simulation results showed that AlSiCGr hybrid MMCs brake disc has higher thermal and structural performance compared to the original cast iron brake disc.

Experimental Study of Convective Heat Transfer in Standard and Cross-Drilled Brake Discs With Radial Vane and X-Lattice Cores

2018 ◽  
Author(s):  
Hongbin Yan ◽  
Shangsheng Feng ◽  
Wei-Tao Wu ◽  
Tian Jian Lu ◽  
Gongnan Xie
Keyword(s):  
Heat Transfer ◽  
Experimental Comparison ◽  
Brake Disc ◽  
Disc Brake ◽  
Cooling Performance ◽  
Flow And Heat Transfer ◽  
Brake Discs ◽  
Flow Through ◽  
The Cross ◽  
Transfer Mechanisms

To improve the cooling performance of disc brake systems, cross-drilled holes penetrating across the rubbing discs are separately introduced into a commercial radial vane brake disc (as reference) and a novel X-lattice cored brake disc. Prototype samples of both the reference and cross-drilled brake discs are fabricated. A rotating test rig is designed and constructed to characterize and compare the cooling performance of the brake discs with infrared thermography. Within the typical operating range of a vehicle, e.g., 200–1000 rpm, the experimental results show that the introduction of cross-drilled holes can substantially enhance brake disc cooling. For the radial vane brake disc, the overall Nusselt number is enhanced by 31%–44%; for the X-lattice cored brake disc, the cross-drilled holes only lead to 9%–18% enhancement. As the radial vane brake disc and the X-lattice cored brake disc with cross-drilled holes exhibit similar cooling performance, flow through the cross-drilled holes has a more prominent effect on the former than the latter. Corresponding fluid flow and heat transfer mechanisms underlying the enhanced heat transfer by cross-drilled holes and the different effects of cross-drilled holes on the two distinct brake discs are explored. The experimental comparison and the thermo-fluidic physics presented in this paper are beneficial for engineers to further improve disc brake cooling.

Modelling of grey cast iron for application to brake discs for heavy vehicles

2016 ◽  
Vol 231 (1) ◽  
pp. 35-49 ◽  
Author(s):  
Gaël Le Gigan ◽  
Magnus Ekh ◽  
Tore Vernersson ◽  
Roger Lundén
Keyword(s):  
Cast Iron ◽  
Elevated Temperatures ◽  
Kinematic Hardening ◽  
Frictional Heating ◽  
Material Model ◽  
Tensile Tests ◽  
Brake Disc ◽  
Brake Discs ◽  
Different Temperatures ◽  
Tension And Compression

Cast iron brake discs are commonly used in the automotive industry, and efforts are being made to gain a better understanding of the thermal and mechanical phenomena occurring at braking. The high thermomechanical loading at braking arises from interaction between the brake disc and the brake pads. Frictional heating generates elevated temperatures with a non-uniform spatial distribution often in the form of banding or hot spotting. These phenomena contribute to material fatigue and wear and possibly also to cracking. The use of advanced calibrated material models is one important step towards a reliable analysis of the mechanical behaviour and the life of brake discs. In the present study, a material model of the Gurson–Tvergaard–Needleman type is adopted, which accounts for asymmetric yielding in tension and compression, kinematic hardening effects, viscoplastic response and temperature dependence. The material model is calibrated using specimens tested in uniaxial cyclic loading for six different temperatures ranging from room temperature to 650 °C. A special testing protocol is followed which is intended to activate the different features of the material model. Validation of the model is performed by using tensile tests and thermomechanical experiments. An application example is given where a 10° sector of a brake disc is analysed using the commercial finitie element code Abaqus under a uniformly applied heat flux on the two friction surfaces. The results indicate that the friction surface of the hat side and the neck can be critical areas with respect to fatigue for the uniform heating studied.

scholarly journals Design and analysis of disc brake system in high speed vehicles

2021 ◽  
Vol 12 ◽  
pp. 19
Author(s):  
Anil Babu Seelam ◽  
Nabil Ahmed Zakir Hussain ◽  
Sachidananda Hassan Krishanmurthy
Keyword(s):  
Stainless Steel ◽  
Cast Iron ◽  
High Speed ◽  
Heat Dissipation ◽  
Optimal Choice ◽  
Grey Cast Iron ◽  
Brake Disc ◽  
Disc Brake ◽  
Brake Rotor ◽  
Grey Cast

Brakes are the most important component of any automobile. Brakes provide the ability to reduce or bring automobile to a complete stop. The process of braking is usually achieved by applying pressure to the brake discs. The main objective of this research paper is to propose an appropriate design and to perform analysis of a suitable brake rotor to enhance the performance of the high-speed car. The design of the brake disc is modelled using Solid works and the analysis is carried out using Ansys software. The analysis has been conducted by considering stainless steel and grey cast iron using same brake rotor design so that optimal choice of brake disc can be considered. The analysis considered involves static structural analysis and steady state thermal analysis considering specific parameters on brake rotor to increase the life of brake rotor. From the analysis it is found that the performance and life of disc brake depends upon heat dissipation. From the analysis results it can be concluded that grey cast iron has performed better as compared to stainless steel as this material has anti-fade properties which improves the life of the brake rotor.

scholarly journals Dynamic analysis of three autoventilated disc brakes

2017 ◽  
Vol 37 (3) ◽  
pp. 102-114 ◽  
Author(s):  
Ricardo A. García-León ◽  
Eder Flórez-Solano
Keyword(s):  
Simulation Software ◽  
Maximum Temperature ◽  
Brake Disc ◽  
Mechanical Parts ◽  
Cooling Channels ◽  
Braking System ◽  
Disc Brakes ◽  
Brake Discs ◽  
Different Types ◽  
Kinetics Of

The braking system of a car must meet several requirements, among which safety is the most important. It is also composed of a set of mechanical parts such as springs, different types of materials (Metallic and Non Metallic), gases and liquids. The brakes must work safely and predictably in all circumstances, which means having a stable level of friction, in any condition of temperature, humidity and salinity of the environment. For a correct design and operation of brake discs, it is necessary to consider different aspects, such as geometry, type of material, mechanical strength, maximum temperature, thermal deformation, cracking resistance, among others. Therefore, the main objective of this work is to analyze the dynamics and kinetics of the brake system from the pedal as the beginning of mathematical calculations to simulate the behavior and Analysis of Finite Elements (FEA), with the help of SolidWorks Simulation Software. The results show that the third brake disc works best in relation to the other two discs in their different working conditions such as speed and displacement in braking, concluding that depending on the geometry of the brake and the cooling channels these systems can be optimized that are of great importance for the automotive industry.

Research on the Development of the Welding Reconditioning Procedure for Friction Liner on the Passenger Coaches

2021 ◽  
Vol 110 ◽  
pp. 15-24
Author(s):  
Carmen Popișteanu ◽  
Dumitru Titi Cicic ◽  
Gheorhe Solomon
Keyword(s):  
Cast Iron ◽  
Service Life ◽  
Welding Process ◽  
Brake Disc ◽  
Risk Class ◽  
Braking System ◽  
Precise Analysis ◽  
Dimensional Shape ◽  
Braking Force

SNTFC CFR SA owns a fleet of 841 passenger coaches, which it maintains through usual overhauls and repairs at high safety levels provided by the national railway regulations and instructions. One of the most important systems of a wagon is the braking system. One part of this system is also the friction liner, its role being to support the friction gasket that applies the braking force on the brake disc. This friction liner is made of cast iron and is a component included in risk class 1A, according to OMT 290/2000, with a service life of 10 years. Depending on the degree of wear and safety in operation, one may decide to replace it with a new part or intervention to return to the initial dimensional shape. Considering the importance of this friction liner, a very precise analysis must be performed, and this should show the steps necessary to reintroduce the part into operation. The performed analysis is a welding reconditioning procedure, which must be applied with precision. The paper indicates all the stages and results we looked for by applying a reconditioning procedure for the particular situation of using the welding process by means of tables / graphs and of results obtained as of detailed works.

scholarly journals Coatings for Automotive Gray Cast Iron Brake Discs: A Review

Coatings ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 552 ◽  
Author(s):  
Omkar Aranke ◽  
Wael Algenaid ◽  
Samuel Awe ◽  
Shrikant Joshi
Keyword(s):  
Cast Iron ◽  
Melting Point ◽  
Gray Cast Iron ◽  
Gray Cast ◽  
Exhaust Emission ◽  
Material Surface ◽  
Brake Disc ◽  
Braking Performance ◽  
Brake Discs ◽  
Disc Material

Gray cast iron (GCI) is a popular automotive brake disc material by virtue of its high melting point as well as excellent heat storage and damping capability. GCI is also attractive because of its good castability and machinability, combined with its cost-effectiveness. Although several lightweight alloys have been explored as alternatives in an attempt to achieve weight reduction, their widespread use has been limited by low melting point and high inherent costs. Therefore, GCI is still the preferred material for brake discs due to its robust performance. However, poor corrosion resistance and excessive wear of brake disc material during service continue to be areas of concern, with the latter leading to brake emissions in the form of dust and particulate matter that have adverse effects on human health. With the exhaust emission norms becoming increasingly stringent, it is important to address the problem of brake disc wear without compromising the braking performance of the material. Surface treatment of GCI brake discs in the form of a suitable coating represents a promising solution to this problem. This paper reviews the different coating technologies and materials that have been traditionally used and examines the prospects of some emergent thermal spray technologies, along with the industrial implications of adopting them for brake disc applications.

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