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

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.

Author(s):  
Ali Belhocine ◽  
◽  
Oday Ibraheem Abdullah ◽  

In this work, numerical simulations of the transient thermal and the static structural analysis were performed here sequentially, with the coupled thermo-structural method. Numerical procedure of calculation relies on important steps such that the CFD thermal analysis has been well illustrated in 3D, showing the effects of heat distribution over the brake disc. Three different brake disc materials were selected in this simulation and a comparative analysis of the results was conducted in order to derive the one with the best thermal behavior. Finally, the resolution of the coupled thermomechanical model allows us to visualize other important results of this research such as; the deformations, and the equivalent Von Mises stress of the disc, as well as the contact pressure of the brake pads. Following our analysis and the results we draw from it, we derive several conclusions. The choice allowed us to deliver the best suitable of the brake rotor to ensure and guarantee the good braking performance of vehicles.


Coatings ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 552 ◽  
Author(s):  
Omkar Aranke ◽  
Wael Algenaid ◽  
Samuel Awe ◽  
Shrikant Joshi

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.


Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3890
Author(s):  
Wojciech Sawczuk ◽  
Mateusz Jüngst ◽  
Dariusz Ulbrich ◽  
Jakub Kowalczyk

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.


2021 ◽  
Vol 1025 ◽  
pp. 77-81
Author(s):  
Wei Kang Gan ◽  
Nanang Fatchurrohman

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.


Author(s):  
Gaël Le Gigan ◽  
Magnus Ekh ◽  
Tore Vernersson ◽  
Roger Lundén

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.


Tribologia ◽  
2019 ◽  
Vol 286 (4) ◽  
pp. 113-119
Author(s):  
Waldemar TUSZYŃSKI ◽  
Michał GIBAŁA ◽  
Andrzej GOSPODARCZYK ◽  
Stanisław KOZIOŁ ◽  
Krzysztof MATECKI ◽  
...  

For the sake of driving safety, the right choice of the brake pad friction material and its manufacturing processes to obtain the appropriate tribological properties is a matter of priority for brake pad manufacturers. Determination of the tribological properties is best done in component tests, i.e. in the setup: brake pads – brake disc. At the request of one of the domestic brake pad manufacturers, as part of the POIR project, an inertia dynamometer for testing friction and wear of brake pads and brake discs was developed and manufactured, which was given the symbol T-33. A test methodology was developed based on the “Cold application section” procedure described in SAE J2522:2003. The T-33 inertia dynamometer is designed for testing brake pads and brake discs intended for five vehicles representing the passenger vehicle class and vans. The paper presents the new test stand, test methodology, and results of verification tests of the T-33 dynamometer (interlaboratory comparison tests) performed on the Cinquecento vehicle brake setup.


2019 ◽  
Vol 3 (36) ◽  
pp. 280-296
Author(s):  
Ali Belhocine ◽  
Asif Afzal

In this work, we will present numerical modeling using the ANSYS software adapted for finite element method, to follow the evolution of the global temperatures for the two types of brake discs, full and ventilated disc during a braking scenario. Also, the numerical simulation of the transient thermal analysis and the static structural one is performed here sequentially with the coupled thermo-structural method. A numerical procedure of calculation relies on important steps such that the CFD thermal analysis is well illustrated in 3D, showing the effects of heat distribution over the brake disc. This CFD analysis will help us in the calculation of the values of the thermal coefficients (h) that will be exploited in the 3D transient evolution of the brake disc temperatures. Three different brake disc materials were selected in this simulation and a comparative analysis of the results was conducted in order to derive the one with the best thermal behavior. Finally, the resolution of the coupled thermomechanical model allows us to visualize other important results of this research such as; the deformations, and the equivalent stresses of Von Mises of the disc, as well as the contact pressure of the brake pads. Following our analysis and the results we draw from it, we derive several conclusions. The choice will allow us to deliver the best suitable design of the brake rotor to ensure and guarantee the good braking performance of vehicles.


2017 ◽  
Vol 68 (10) ◽  
pp. 2397-2401 ◽  
Author(s):  
Costel Dorel Florea ◽  
Ioan Carcea ◽  
Ramona Cimpoesu ◽  
Stefan Lucian Toma ◽  
Ioan Gabriel Sandu ◽  
...  

We obtained a new Fe-C material, a cast iron with high chromium content. The experimental material was analyzed by microstructural (SEM electronic) and chemical (EDAX characteristic X-ray dispersive energy analysis) point of view. The addition of chromium is aimed to increase the corrosion resistance and durability of FC250 castings used on industrial scale in the manufacture of automotive brake discs. The material was obtained using an industrial scale furnace. The experimental results showed a substantial increase in corrosion resistance by the addition of chromium.


2017 ◽  
Vol 37 (3) ◽  
pp. 102-114 ◽  
Author(s):  
Ricardo A. García-León ◽  
Eder Flórez-Solano

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.


2018 ◽  
Vol 11 (3) ◽  
pp. 119-131
Author(s):  
M. Menyhártné Baracskai

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.


Sign in / Sign up

Export Citation Format

Share Document