Disc Brakes Research Articles

Heat Transfer Analysis of Brake Disc for Compact Electric Vehicles

Heat Transfer Analysis of Brake Disc for Compact Electric Vehicles

Development of Experimental Set up for Temperature Measurement on the Brake Disc of Pulsar 150 cc Motorcycle

From the standpoint of safety, the braking system is an essential part of the motorcycle. The capacity of the brake disc composition to endure excessive frictional and durability to wear rate is the most crucial factor to take into account. Tolerating the maximum temperature that developed as a result of friction is also needed. Hence to increase the performance of brake disc we need to improve the thermal performance of brake disc. Thermal performance of brake disc is depending on the kind of material utilized for manufacturing of brake discs. As we know, brake disc assembly is rotating and moving from one place to another place in the actual application. Hence it is challenging task to do thermal analysis of brake disc experimentally. In this present study experimental setup is proposed for measuring the brake disc's surface temperature which can be useful to do the thermal analysis of the brake disc. DOI: https://doi.org/10.52783/pst.238

Design and Analysis of Active Cooled Brake Disc in Lattice Structure for Additive Manufacturing

Otomotiv, havacılık ve raylı sistemlerde şüphesiz en önemli parçalarından biri fren diskleridir. İlk olarak 1950’li yıllarda kullanılmaya başlanılan diskli fren sistemleri günümüz teknolojisine gelene kadar birçok gelişme gösterse de hala geliştirilmesi devam eden sistemlerdir. Sürtünmeli fren sistemlerinde ısı açığa çıkar. Bu sıcaklık belli bir düzeyin üzerine çıktığında sürtünme elemanı olan balataların özellikleri sebebi ile sürtünme katsayıları azalır. Uzun frenleme (ağır tonajlı araçlarda yokuş aşağı ya da spor araçlarında zorlu parkurlarda) taşıtın durma mesafesini arttırmakta, fren ve teker grubu ekipmanlarının kullanım ömürlerinin azalmasına sebep olmaktadır. Bu sebepten hem sürüş emniyeti hem de taşıt güvenliği açısından fren soğutma yapısı önem arz etmektedir. Bu çalışmada, bir spor arabada kullanılmak üzere geleneksel imalat metotlarına göre tasarlanmış örnek bir fren diskinin soğutma performansının arttırılması ve ağırlık olarak hafifletilmesi için kafes yapı modelleme yaklaşımı uygulanmıştır. Tüm tasarım yaklaşımları, eklemeli imalat teknolojilerinin sunduğu yenilikçi imkân ve kabiliyetler göz önünde bulundurularak ele alınmıştır. İterasyonlar sonucu elde edilen model eklemeli imalat metotlarından seçici lazer ergitme yöntemi ile imal edilecek şekilde ele alındığında kütlece %20 daha hafif, Von-mises gerilmeleri bakımından da %35 daha düşük gerilmeye sahip bir model ortaya çıkmıştır. Ele alınan standart ve kafes yapıda disklere eşit ısı yüklemesinde standart disk yüzeyinde 440 ℃ sıcaklık bulunurken yapılan optimum tasarımda 213 ℃ sıcaklık belirlenmiştir.

Analisis Sistem Pengereman Singaperbangsa Electric Vehicle

Electric cars are vehicles that use an electric motor as the main source of power to move the vehicle. In an electric car, braking is also required. The braking that is usually used in competitions is how the braking is maximal or not maximal during a race over a predetermined distance, and there are many different types of braking that are used, some of which use disc brakes. Therefore, a test was carried out on the influence of speed on braking results in electric cars. The aim of this research is to investigate the effect of speed on the braking results of the Singaperbangsa Electric Vehicle Bersama electric car over a predetermined distance. To determine the effect of speed on braking results, researchers carried out tests by carrying out braking tests with a predetermined track distance of 15 meters with speed variations of 30 km/hour, 40 km/hour and 50 km/hour.

Numerical Investigation of the Thermal Effect of Material Variations on the Brake Disc

Braking is one of the most critical systems for ensuring the safe driving performance of motor vehicles. Among the components that constitute the braking system, the disc is the one with the highest risk of wear. When the braking system is engaged, the physical contact between the brake pad and the disc leads to the generation of high pressure and high temperature. This released heat shortens the material's lifespan. The wearing or fracturing of the brake disc can result in a significant safety vulnerability. Therefore, it is desired for the discs to have better heat dissipation to increase their longevity. In this study, two different designs of brake discs were first examined thermally using the computational fluid dynamics (CFD) method. Subsequently, numerical analyses were conducted under the same boundary conditions by selecting the disc geometry with superior heat dissipation performance and using different materials. The results obtained from the analyses were compared and interpreted. The materials utilized in the study were grey cast iron, carbon steel, stainless steel, and carbon-carbon composite. As a result, it was observed that the carbon-carbon composite exhibited higher resistance to elevated temperatures.

Non-axisymmetric Modeling of a Moving Heat Source for Thermal Stress and Fatigue Analysis of Railway Vehicle Disc Brakes

Railroad vehicles require the use of disc brakes for safety purposes, however, the brakes are susceptible to thermal stress, which ultimately shortens their lifespan. Hence, to accurately predict the life of railway disc brakes in thermal load simulations, the availability of a model that considers spatial and temporal variations of temperature and thermal stress is essential. A non-axisymmetric moving heat source model was successfully developed to address spatial temperature variations (Deressa and Ambie in Urban Rail Transit 8(3–4):198–216, 2022. 10.1007/s40864-022-00176-9), and this study aims to extend this model to predict thermal stress and fatigue life, and assess its effectiveness. The analysis includes braking time thermal analysis, cooling time thermal analysis, and structural analysis. Spatially varying temperature is incorporated into the structural analysis to calculate thermal stress and strain. A fracture mechanics-based fatigue life estimation method is applied to critical areas of the friction surface. The model is implemented on two braking conditions (service and emergency) and two disc geometries (actual and modified). The model successfully resolves spatial heat considerations by estimating maximum stress variations of up to 46 MPa along the disc circumference. Stress differences of 3 MPa and 6 MPa are observed between the leading and trailing edges of the pad trace during late and mid-braking times, respectively. Fatigue life results identify critical positions and directions for fatigue life initiation. Additionally, these results are in accord with previous observations available in the literature. The proposed model can be easily implemented in various sliding friction applications such as drum brakes, engine pistons/cylinders, and camshafts.

Thermal stress simulation and fatigue life of commercial vehicle disk brakes under emergency braking conditions

Commercial vehicle disk brakes operate at a high-temperature and in a heavy-load environment within the braking system. The primary cause of failure is the cracking of the brake disk. In order to study its fatigue damage and service life, a finite element model of disk brake fatigue life was established, and thermal stress coupling simulation analysis was carried out from a practical problem. Based on the temperature and stress fields of the brake disk under emergency braking conditions obtained from the simulation results, the effects of vehicle load, initial speed, temperature, and other factors on brake fatigue life are explored. The fatigue life of the hazardous node can be calculated using the Manson–Coffin model, and then the strain–life (ɛ–N) curve of the material can be fit at high temperature. The fatigue life of brake disks was predicted using the fatigue analysis software FE-SAFE and verified by testing. The results showed that the maximum stress on the surface of the disk brake was the same as the area of the minimum fatigue life, accurately analyzing the fatigue life of the region and predicting the location of fatigue cracks. The results of the research can provide a reference for the design of disk brake engineering and fatigue failure.

Substantiation of the methodology for calculation of rope-capacity cylindrical drums of mine hoistmachine

Purpose. To develop a simplified calculation method for the strengthened split cylindrical drums of mine hoisting machines of the TsR-6.75x6.2/1.95 type. To evaluate the application of the method for calculating the drum of a hoisting machine of a complicated design by averaging the elements. The methods. The drum structure of a mine hoisting machine is divided into ten nodes, eight of which include the shell, frontal, rib strengthening and brake discs (end nodes) and two more – the shaftwith hubs and bearing supports. Based on the analysis of the machine's operation, including an assessment of its stiffness under different types of load, simplified models are created for each component. The original drum assemblies are replaced with simplified ones in order to perform a general calculation to determine the maximum axial displacement of the brake disc edges. Findings. Based on the analysis of the mine hoisting machine operation, averaged models of hoist components were developed and axial displacements were successfully calculated for a simplified drum design. The originality. The error of the simplified calculation method, in particular, the method of averaging with increased thickness of the lobes, which allows obtaining more accurate results for complex structures, is estimated Practical implementation. Due to the need to increase the depth of mining, which leads to the need to expand the dimensions of the drum and complicate its design. In this case, the resource intensity of calculating the axial displacement of brake discs increases. This is necessary for the introduction of disc brakes. However, this complicates the use of standard mid-level computer-aided design tools due to the increase in the size of the finite element mesh, which makes its use impractical. The methodology can be used for mine hoisting machines of the following types TsR-6.75x6.2/1.95 with a split drum, 6750 mm in diameter and 6200 mm wide (of which 1950 mm is the interchangeable part), providing accurate calculations of brake disc edge displacements. This approach is particularly useful for use in mid-range software packages such as SolidWorks Simulation, eliminating the need for resource-intensive software.

A new model of friction brake efficiency of urban vehicles on unpaved roads using an analytical and numerical approach

• The approach estimates the efficiency of disc braking systems of urban vehicles. • The proposed approach takes into account the irregularities of the road surface. • In addition to the surface irregularities, the slip rate is taken into consideration. • The effect of wheel deformation during braking is considered. • The influence of the pressure on the brake disc is considered. This paper supports the implementation of a braking efficiency estimator of urban vehicle on rural roads, based on analytical and numerical approach. A statistical study is defined by the Association Road Managers and Partners (AGEPAR) estimates the rate of unpaved roads in Africa around 72%, which approximately 90% of passengers and goods transport that generally doesn’t respect loading standards. This is a major reason for increase traffic accidents in these countries. Hence the need to define vehicle speed limitations that takes in vehicle parameters and irregularities road. This can be done by defining a predicting model of dynamic behaviour for small vehicles, which constitute the majority of African vehicle fleet. To achieve this, we numerically solve the longitudinal dynamic equations of a vehicle body combine with front and rear axles on a road which has irregularities, opposed to existing models and Field data that are defined on surface roads which have little or no irregularities. The input parameters of the model are the initial vehicle speed, the road profile, inclination angle of road, peak wheel cylinder, wheelbase, centre of gravity height, rising time, brake pads contact area, final drive gear ratio, gearbox gear ratio, moment of inertia of engine, slip ratio, vehicle weight, moment of inertia at on axle and dynamic tyre radius which are assumed similarly and the braking system which is a disc braking system. The suspension is assumed identical and rigid since our study focuses on longitudinal and not vertical dynamics. The results produced by our modelling on paved and unpaved roads are compared with those obtained experimentally by J. R. Choa and the unpaved road data we obtained. The relative differences in braking times are respectively 6.5% and 3.1%. For the stopping distance, these relative differences are 11.5% and 11.9%.

MATHEMATICAL MODEL FOR THERMAL CALCULATION OF VEHICLE DISC BRAKES ON 1ST TYPE TESTS

The article presents the bases of thermal processes mathematical modeling in vehicle disc brakes that in combination with the experiment planning method allowed a complex approach to their thermal calculation.

Research on the automotive braking performance

Due to the rise in vehicle usage, the number of car accidents and the population of injured users have been increasing by years. In order to reduce these problems, this paper has deeply investigated the current development of the optimization of vehicle braking performance. There are two main focuses in this paper - brake type and material selection. Firstly, in terms of brake type, the comparison of two different types, disc brake and drum brake, it is found that disc brakes are the better one regarding properties of wear rate, braking stability and performance at high temperatures. Moreover, the study on different materials shows ceramic composite materials show better performances than copper fiber materials, which are illustrated in the analysis of braking stability, abrasion resistance, and the impact on the environment. Overall, this study provides the deep understanding of the current automobile brake system, contributing to the future development of new generation of brake system.

On Drum Brake Squeal—Assessment of Damping Measures by Time Series Data Analysis of Dynamometer Tests and Complex Eigenvalue Analyses

Brake squeal—an audible high-frequency noise phenomenon in the range between 1 kHz and 15 kHz resulting from self-excited vibrations—is one of the main cost drivers while developing brake systems. Increasing damping is often a crucial factor in the context of self-excited vibrations. Countermeasures applied for preventing brake squeal have been investigated particularly for disk brakes in the past. However, in recent years, drum brakes have once again become more important, partly because of the issue of particle emissions. Concerning noise problems, drum brakes have a decisive advantage compared to disk brake systems in that the outer drum surface is freely accessible for applying damping devices. This paper focuses on the fundamental proving and evaluation of passive damping measures on a simplex drum brake system. To obtain a detailed understanding of the influence of additional damping on the squealing behavior of drum brakes, extensive experimental investigations are performed on a brake with an intentionally introduced high squealing tendency in the initial configuration. This made it possible to investigate the influence of different types of damping measures on their effectiveness. Techniques from the field of big data analysis and machine learning are tested to detect squeal in measured time series data. These techniques were remarkably reliable and made it possible to detect squeal efficiently even in data that was not generated on a traditional costly NVH brake dynamometer. To investigate whether the simulation method usually used for the simulation of brake squeal is applicable to depicting the influence of additional damping in drum brakes, a complex eigenvalue analysis was performed with Abaqus, and the results were compared with those from the experiments.

Study on Service Vibration Characteristics of High-Speed Train Disc Brake under Thermo-Solid Coupling

This paper examines the effects of thermo-solid coupling and the influence of braking parameter changes on the vibration characteristics of high-speed train disc brakes. A multi-flexible body dynamics model of high-speed train disc brakes considering thermo-solid coupling was established to study the vibration characteristics of high-speed train disc brakes during service. The results show that the uneven distribution of temperature and stress produced during the brake disc’s service was the primary cause of the warping deformation of the brake disc, which prevented the brake disc and the brake pads from making sufficient contact and caused vibration while braking. By comparing the analytical findings of whether the model was subject to the coupling effect or not, the influence of thermo-solid coupling on the braking procedure was demonstrated from the standpoint of energy distribution. The severity of the high-speed train brake disc vibration gradually increased along with the braking pressure and initial speed. In addition, vibration aggravated the instability of the braking process, which could lead to thermoelastic instability and is harmful to the braking performance of the brake. These findings provide theoretical support for designing and manufacturing disc brakes for high-speed trains.

The Mutual Influence of Thermal Contact Conductivity and Convective Cooling on the Temperature Field in a Tribosystem with a Functionally Graded Strip.

An analytical model to find the temperature field that has been developed for friction systems consists of a strip and semi-space. The strip is made of a two-component functionally graded material (FGM) with an exponentially changing coefficient of thermal conductivity. In contrast, the material of the semi-space is homogeneous. An appropriate boundary-value problem of heat conduction with constant specific friction power was formulated and solved using the Laplace integral transform method. The model takes into consideration the imperfect thermal friction contact between the strip and the semi-space, and also the convective cooling on the exposed surface of the strip. The appropriate asymptotic solutions to this problem for low and high values of Fourier number were obtained. It is shown how the determined exact solution can be generalized using Duhamel's formula for the case of a linearly reduction in time-specific friction power (a braking process with constant deceleration). Numerical analysis for selected materials of the friction pair was carried out in terms of examining the mutual impact on the temperature of the two Biot numbers, characterizing the intensity of the thermal contact conductivity and convective heat exchange on the exposed surface of the strip. The obtained results can be used to predict the temperature of friction systems containing elements made of FGM. In particular, such systems include modern disc braking systems.

Development of Sensor for the Real-time Monitoring of Brake Pad Wear and Brake Disc Temperature in High Temperature

Development of Sensor for the Real-time Monitoring of Brake Pad Wear and Brake Disc Temperature in High Temperature

Characterization analysis of particles emitted from aircraft using positive matrix factorization

In order to characterize particles emitted from aircraft, we analyzed the elemental composition information of particles collected from aircraft using positive matrix factorization (PMF). The factor profile and source contribution were deduced based on PMF analysis with five factors and 30 random starting points. Factor 1 contains particles derived from engine oil. Factor 2 contains particles originating from the friction between the runway surface and the tire. Factor 3 contains particles deposited on the runway surface, mainly composed of soil components. Factor 4 contains particles derived from the turbine blade. Factor 5 contains particles derived from plant combustion and particles scattered during landing. Engine reversers accounted for more than 85% of the element total value with factor 2, factor 4, and factor 5. The carbon disc brakes had different main factors depending on the sample. For the tire grooves, factor 2 and factor 3 accounted for the majority of the element total value. The PMF analysis revealed that the particles collected from aircraft contained elements with different modes of generation. In addition, it was found that particles derived from plant combustion, which are presumed to have little relevance to particles emitted from aircraft, were included in the particles collected from the engine reverser, carbon disc brakes, and tire grooves.

Influence of the shape of the copper component on the mechanical properties of the friction material used in the disc brakes

Influence of the shape of the copper component on the mechanical properties of the friction material used in the disc brakes

FAILURE OF FRICTION BRAKE PAD AGAINST RAPID BRAKING AND IT’S LIFE ENHANCEMENT

This Disc brake have evolved to be a reliable method of decelerating and stopping a vehicle. There have been different designs of disc brake systems for different applications. This review describes different aspects of the components and the materials used in a disc brake system. Despite all the improvements, there are still many operational issues related to disc brakes that need to be understood in greater detail and resolved. The basic principle used in braking systems is to convert the kinetic energy of a vehicle into some other form of energy. During a braking operation not all the kinetic energy is converted into the desired form, some energy might be dissipated in the form of heat and vibrations. Graphene is still a very new material, especially in friction brake compounds. Due to its unique properties and years of testing, we were able to develop a friction material like no other. In the automotive industry, where every major car maker has already filed several patent applications for friction compounds containing graphene, it's clear to see that it is the future of braking pads. New regulations which start from 2025 will prohibit the use of copper powder in disc pads. Graphene is not only an excellent substitute for copper, but a major upgrade in terms of performance. Key Words: Friction Brakes, Disc Brakes, Braking Systems, Brake pads, Heat Transfer, Heat Management, Wear Testing , Wear modeling, Material Doping, Pin on Disc, etc.

Causes and failure forms of railway wheels

Railway wheels are a crucial part of the system, which provide necessary traction on railway tracks by carrying cyclic loads. Therefore, it is important to understand the various failure mechanisms of railway wheel sets and the causes to prevent the failure for safety issues. All various railway wheel failures such as crack and rim, crack at rim and disc interface, circumferential chipping-off, wheel tread shelling, thermal crack on wheel tread, wheel tread wear, fatigue, creep, wheel gauge widening, and wheel gauge condemning and their corresponding causes also discussed in this manuscript. Further, it gives detailed wheel failure scenarios in tread and disc braking of locomotive, wagon, and coach wheels. The in-depth details of various wheel failure sceneries observed and analyzed from the field, and case studies are also reviewed in detail.

Design of brake failure control on motorcycle disc brakes through an integrated cooling system

The increasing number of traffic accidents is a challenge for driver safety. The biggest factor in traffic accidents in terms of vehicles, one of which is brake failure. The number of cases of failed brakes was 7,083 cases and increased in the following year by 32% or 9,333 cases. The main cause of brake failure is the temperature condition in the brake calipers which overheats, triggering the occurrence of brake vapour lock. So, there is an urgent need for innovative solutions that can overcome the failure of the brakes on motorcycles due to the lack of effectiveness of the cooling system in the callipers. This study aimed to analyze the effectiveness of E-BRACE (electronic brake cooling control system) in preventing brake failure and to describe the design and innovation of E-BRACE as a technology for controlling brake failure through an integrated cooling system. The research was experimentally carried out with functionality tests to describe the effectiveness of E-BRACE. The test revealed that E-BRACE was very effective in stabilizing the temperature in the 9th to 15th-minute range. The highest E-BRACE effectiveness in the 15th minute is 55 %.