Browse Topic: Brake discs
Gray cast iron is a cost-effective engineering material widely used for heavy duty engine blocks and brake rotor discs in vehicles. Thermomechanical fatigue (TMF) frequently occurs during vehicle operation due to temperature fluctuations in brake rotors. To speed up the design of the component, design structurally sounding brake rotors, and prevent premature thermally induced cracking, it is critical to investigate TMF behavior of the gray cast iron. This study presents a series of fatigue tests, including isothermal low cycle fatigue (LCF) tests at temperatures up to 700°C, as well as in-phase (IP) and out-of-phase (OP) TMF tests across various temperature ranges. Because of the asymmetric behavior in tension and compression, creep behaviors in both tension and compression and oxidation are also studied. These behaviors are the key to enable simulation of thermally induced cracks in rotors.
The improvement of heat dissipation performance of ventilated brake discs is vital to braking safety. Usually, the technical approaches shall be material optimization or structural improvement. In this paper, a simulation model of the heat transfer of brake discs is established using STAR-CCM+ software. Cast iron, aluminum metal matrix composite (Al-MMC), and carbon-ceramic composite materials (C-SiC) are compared. The results show that: Al-MMC has better thermal conductivity so that a more uniform temperature gradient distribution shall be formed; C-SiC has poorer heat capacity yet, according to previous studies, it has better thermal stability, which is the ability to ensure its friction factor under high-temperature condition; cast iron performs better with convective heat transfer rate, which enhances the heat transfer between the surface and surrounding flow field. Based on the results, this paper proposes four types of material combined brake discs using different friction
This paper introduces an innovative in-wheel electric drive system designed for all-wheel drive Formula Student Electric racing cars. The system utilized AMK's DD5-14-10-POW-18600-B5 model as the driving motor, with a gearbox transmission ratio of 13.2 determined through Optimum Lap simulation. A two-stage gear reducer was integrated into a unified hub-spoke assembly, which connected directly to the ten-inch carbon fiber rim. In this paper, three conventional FSEC planetary gear reducer shafting designs are introduced, and a new shafting structure is proposed. Then the four structures are compared in multiple dimensions. Subsequently, we designed the shafting of the gear group, determined the size parameters of the shafting structure and the bearing type, and completed the verification. The planetary carriers were integrated with the wheel-edge suspension columns. Meanwhile, a special floating brake disc mounting method was employed, which increased the brake disc's heat capacity by
Disc brakes play a vital role in automotive braking systems, offering a dependable and effective means of decelerating or halting a vehicle. The disc brake assembly functions by converting the vehicle's kinetic energy into thermal energy through friction. The performances of the brake assembly and user experience are significantly impacted by squeal noise and wear behaviour. This paper delves into the fundamental mechanisms behind squeal noise and assesses the wear performance of the disc brake assembly. Functionally graded materials (FGMs) are an innovative type of composite material, characterized by gradual variations in composition and structure throughout their volume, leading to changes in properties such as mechanical strength, thermal conductivity, and corrosion resistance. FGMs have emerged as a groundbreaking solution in the design and manufacturing of brake rotors, addressing significant challenges related to thermal stress, wear resistance, and overall performance. These
This SAE Recommended Practice is derived from common methods used within the industry and is not intended to validate a given design or configuration. This SAE Recommended Practice applies to vehicles below 4540 kg of gross vehicle weight rating.
Brake disc temperature is a critical factor influencing the performance and wear characteristics of braking systems in automobiles. Hence it is very important to optimize the correlation of brake disc temperature prediction with test. In this study critical parameters of Brake Disc temperature evaluation are identified, and algorithm is used to optimize the critical parameters to achieve the correlation of prediction with experiment data. Through a series of controlled experiments and simulations, disc temperatures are monitored under different braking conditions and simultaneously input parameters for prediction are optimized to achieve the correlation. Statistical methods were applied to evaluate the observed correlations and to model the predictive behavior of brake disc temperatures. Finally, A front-loading tool is developed to optimize the brake disc keeping target thermal capacity via algorithm. The findings of this study are expected to contribute to the enhancement of brake
The essential aspect of an automobile is its braking system. Brakes absorb the kinetic energy of the rotating parts, i.e., wheels, and dissipate this energy into the surroundings in the form of heat. This entire process is quite complex, and the brake disc is subjected to extreme thermal and structural stresses along with deformation, which might damage the disc. This paper presents a structural and thermal analysis of an Audi Q3 brake disc using an ANSYS 2021-R1. The present brake disc is designed using SOLIDWORKS software. Composite materials are added in the ansys material library by adding their respective characteristics. The thermal analysis mainly focused on temperature variation and directional heat flux. The structural study was conducted to understand the stresses developed during braking and the deformations observed. Along with a comprehensive structural and thermal analysis, this work has also estimated the life of the brake disc, the factor of safety, and the real-time
When the brakes are released and the vehicle starts, the brakes and suspensions vibrate and the car body resonates at 10 to 300 Hz, which is called brake creep groan. This low-frequency noise is more likely to occur in high-humidity environments. As vehicles become quieter with the introduction of EVs, improving this low-frequency noise has become an important issue. It is known that the excitation force is the stick-slip between the brake rotor and pads, but there are few studies that directly analyze stick-slip occurring in a vehicle. Acoustic emission (AE) is a phenomenon in which strain energy stored inside a material is released as elastic stress waves, and AE sensing can be used to elucidate the friction phenomena. In this study, the AE sensing is used to analyze changes in the stick-slip occurrence interval and generated energy when creep groan occurs. As a result, it was confirmed that the AE signal increased with high humidity. Furthermore, the friction phenomena during creep
To combat corrosion and wear issues of automotive brake discs, many manufacturers have introduced various surface treatment technologies, such as thermal spraying, laser cladding, and ferritic nitrocarburizing (FNC). Besides those surface treatment technologies, a plasma electrolytic aluminating (PEA) process has also shown to be effective in producing alumina-based ceramic coatings on cast iron substrates, providing an enhanced corrosion resistance. In this study, the PEA-coated brake rotor and FNC-treated brake rotor were comparatively tested in various corrosion conditions, including an electrochemical corrosion test and simulative corrosion experiment, before and after a road driving test. A scanning electron microscope (SEM) and an energy-dispersive X-ray (EDX) were used to observe and analyze morphology and chemical compositions of the surfaces and cross-sections of the tested rotors. The results showed that the new PEA-coated brake rotor demonstrated the best corrosion
The assessment of brake friction materials extends beyond squeal noise and thermal roughness testing as it play crucial role in other brake noise phenomena such as creep groan and dynamic grunt. These low frequency noise types are significant as they directly affect passengers comfort levels. Creep groan noise defined as audible stick-slip noise at low vehicle speed during partial brake application, typically encountered in dense traffic conditions. Dynamic grunt is another form of stick-slip noise observed during high-speed braking and it is noticeable just prior to vehicle’s complete stop. This noise is indicative of frictional interaction between the brake pad and disc under deceleration scenario. Comparative analysis of two distinct brake friction materials was conducted utilizing both NVH dynamometer and real-world vehicle testing. The NVH dynamometer procedure was designed to evaluate the creep groan and dynamic grunt phenomena under controlled environmental conditions. For the
Niobium (Nb) alloyed Grey cast iron in combination with Ferritic Nitrocarburize (FNC) case hardening heat treatment is proposed to improve wear resistance and reduce brake dust generation of brake rotors. Standard Eutectic and Hypereutectic Grey irons alloyed with Niobium were evaluated in comparison to baseline unalloyed compositions. Brake speed snub sensitivity tribological testing was performed on a matrix including Niobium alloyed, Unalloyed, FNC, Non FNC, Non-Asbestos Organic (NAO) friction and Low metallic (Low Met) friction materials. Full size brake rotors were evaluated by Block Wear and Corrosion Cleanability. Improved wear, corrosion resistance and reduced brake dust debris were demonstrated by the Niobium alloyed FNC brake rotor combinations. Corrosion is an important consideration when evaluating brake performance. Combining cyclic corrosion and brake rotor testing provides the best comparison with field exposure.
Brake drag in disc brakes occurs during the off-brake-phase, when the brake is not applied but friction contacts between brake disc and pads persist. First and foremost, the resulting drag torque increases energy consumption, where a few Newton meters can have a significant impact on the crucial factor – range – of battery-electric-vehicles. Moreover, brake wear is accelerated in conjunction with enlarged taper-wear of the pads. Additional wear can also imply increased brake particle emissions which are going to be limited by upcoming regulations due to their potential health risk. In this light different countermeasures aim to create and maintain a sufficient air gap between brake disc and pads when the brake is released to avoid residual friction contacts. Among others these include optimization of piston retraction by adjusting the seal-grooves and integrating pad springs into the caliper to push the pads back. State of the art to analyze the effectiveness of countermeasures are
Many performance sport passenger vehicles use drilled or grooved cast iron brake rotors for a better braking performance or a cosmetic reason. Such brake rotors would unfortunately cause more brake dust emission, appearing with dirty wheel rims. To better understand the effects of such brake rotors on particle emission, a pin-on-disc tribometer with two particle emission measurement devices was used to monitor and collect the emitted airborne particles. The first device was an aerodynamic particle sizer, which is capable of measuring particles ranging from 0.5 to 20 μm. The second device was a condensation particle counter, which measures and collects particles from 4 nm to 3 μm. The testing samples were scaled-down brake discs (100 mm in diameter) against low-metallic brake pads. Two machined surface conditions (plain and grooved) with uncoated or ceramic-coated friction surfaces were selected for the investigation. The results showed that the grooved friction surface led to a higher
The most used rotor material is gray cast iron (GCI), known for its susceptibility to corrosion. The impact of corrosion on the braking system is paramount, affecting both braking performance and the emission of particulate matter. The issue becomes more severe, especially when the brakes are left stationary or unused for extended durations in humid conditions, as seen with electric vehicles (EVs). Brake disc corrosion amplifies the risk of corrosion adhesion between contacting surfaces, leading to substantial damage, increased quantity and mass of non-exhaust particulate emissions, and decreased braking effectiveness. In addition, brake pads' friction material plays a crucial role in generating the necessary stopping force, creating friction that transforms kinetic energy into heat. However, heightened pressure during braking elevates rotor temperatures, contributing to the degradation of the friction material. This degradation manifests in decreased mechanical strength, heightened
Designing a brake disc is a very challenging job. Besides to being a key item in vehicle safety, we are referring to a product that goes through several manufacturing processes and during its application it is exposed to extreme conditions of mechanical stress, temperature and vibration. The raw material for a large portion of commercial brake discs is normally gray cast iron with the possibility of adding alloy elements. This material is characterized by having high resistance to wear due to friction and having practically zero plasticity. As it is a material without a plastic working regime, it is very important to properly size the product for use, once the material’s resistance limit is reached, a catastrophic failure in operation may be inevitable. Quality control systems in casting and machining have great importance in the development of the disc, but physical tests are always essential in this type of product. Dynamometer tests are great options for validating brake discs, due
This recommended practice is derived from common test sequences used within the industry. This procedure applies to all on-road passenger cars and light trucks up to 4 540 kg of GVWR. This recommended practice does not address other aspects such as performance, NVH, and durability. Test results from this recommended practice should be combined with other measurements and dynamometer tests (or vehicle-level tests), and acceptance criteria to validate a given design or configuration.
Abrasion of the Electromechanical brake (EMB) brake pad during the braking process leads to an increase in brake gap, which adversely affects braking performance. Therefore, it is imperative to promptly detect brake pad abrasion and adjust the brake gap accordingly. However, the addition of extra gap adjustment or sensor detection devices will bring extra size and cost to the brake system. In this study, we propose an innovative EMB gap active adjustment strategy by employing modeling and analysis of the braking process. This strategy involves identifying the contact and separation points of the braking process based on the differential current signal. Theoretical analysis and simulation results demonstrate that this gap adjustment strategy can effectively regulate the brake gap, mitigate the adverse effects of brake disk abrasion, and notably reduce the response time of the braking force output. Monitoring is critical to accurately control EMB clamping force. Pressure transducers are
Just as NASA needs to reduce mass on a spacecraft so it can escape Earth’s gravity, automotive manufacturers work to reduce weight to improve vehicle performance. In the case of brake rotors, lighter is better for a vehicle’s acceleration, reliable stopping, and even gas mileage. Orbis Brakes Inc. licensed a NASA-patented technology to accomplish that and more. This revolutionary brake disc design is at least 42 percent lighter than conventional cast iron rotors, with performance comparable to much more expensive carbon-ceramic brakes.
Disc brakes are the most popular type of brakes used in the two-wheeler segment and are easily available in the market. The improper brakes result in serious problems in vehicles. The main idea of this paper is to design a braking system for a two-wheeler application. The paper discusses the design, analysis, and simulation of disc brakes. The disc is first selected using the standard brake disc calculation. To verify the selection of disk, torque at wheel and torque at the disc are compared. Thermomechanical (Transient) analysis is done on ANSYS 2021 to check for the effect of braking force applied by the disc on the rotor disc. The mathematical model of the ABS model is done on Scilab Xcos. The main aim of studying the system using a mathematical model is to verify if the selected disc brakes are safe enough to be installed on a two-wheeler. The mathematical model also has stopping distance and the stopping time as the output which validates the selection of the disc. Hence best
An ever-increasing need for effective transportation requires improved safety and maintenance systems. The braking component in an automobile is one of the most important safety features that manufacturers can provide. One of the key factors that influence the performance of the brakes is heat dissipation. For Brake, cooling is the most important factor governing the brake’s performance and longevity. Moreover, poor thermal performance unequivocally leads to blurring of brakes, fast wear, thermal splits and variation of thickness in the disc. To understand the design-oriented factors that affect the brake cooling, a model was developed in Solid Works and imported to CFD modeling to analyze the aerodynamic thermal flow behavior of a ventilated disc brake rotor. Here a complex design is studied and incorporated in the brake rotor to alter the aerothermal flow behavior of the brake rotor. The design is the combination of various existing brake rotors available. The results obtained are
The braking system is a major part of dealing with Go-karts, where speed and control combine to create an enthusiastic experience. This research article discusses the design and analysis of the braking system of a go-kart vehicle. In this case, constraints are based on rulebooks, and optimisation is performed depending on the requirements. The process flow also carries material selection for components and an analysis to determine their structural and thermal properties. This study also includes a comparison of brake rotors and their specifications to meet the higher performance. The design combines mechanical and hydraulic principle-based components to balance efficiency, cost, and maintenance requirements. In this investigation into the braking system, various design and analysis softwares are used. This study offers a concept for an optimized braking system with enough information to construct the go-kart vehicle's braking system.
In this article, an improved brake cooling simulation method is introduced. By this method, the vehicle parameters, such as weight, height of the center of gravity, wheelbase, and the like can be included to calculate the braking thermal load under different operating conditions. The effect of the brake kinetic energy regeneration (BKER) on the braking thermal load can also be calculated by this method. The calculated braking thermal load is then input to a coupled 3D simulation model to conduct flow and thermal simulation to calculate brake disc temperature. It is demonstrated that by this simulation method, the difference between the brake disc temperatures obtained from simulation and vehicle test can be controlled below 5%.
Composite ceramic brake discs are made of ceramic material reinforced with carbon fibers and offer exceptional advantages that translate directly into higher vehicle performance. In the case of an electric vehicle, it could increase the range of the vehicle, and in the case of conventional internal combustion engine vehicles, it means lower fuel consumption (and consequently lower CO2 emissions). These discs are typically characterized by complex internal geometries, further complicated by the presence of drilling holes on both friction surfaces. To estimate the aerothermal performance of these discs, and for the thermal management of the vehicle, a reliable model for predicting the air flowing across the disc channels is needed. In this study, a real carbon-ceramic brake disc with drilling holes was investigated in a dedicated test rig simulating the wheel corner flow conditions experimentally using the particle image velocimetry technique and numerically. The simulation was performed
Brake wear emissions gained significant relevance with the upcoming Euro7 type approval within the European Union for brake emission measurement on the test bed. While the controlled brake test bed approach provides consistent results, real-driving emission (RDE) measurements are needed to better understand actual emission behavior due to varying vehicle and environmental conditions. The EU has already announced its interest in RDE testing. Here we present the results of an RDE brake wear sampling system with minimal thermal impact, where particles are only sampled from one side of the brake disc, characterized on a laboratory sampling system. The investigations aim to validate symmetric particle release and to confirm that doubling the measured RDE results effectively represents the reference emissions on the test bed. The discovered positive correlation between brake temperature and PN, PM2.5, and PM10 emissions under different cooling settings emphasizes the importance of our system
In recent years, brakes emission tests have become increasingly standardized to meet progressively stricter intra and inter laboratory reproducibility requirements. In particular, following the recent EURO 7 regulation proposal, WLTP-Brake cycle has surged as EU standard braking sequence to determine emission factors of investigated brake systems. Furthermore, the UN GTR (United Nations Global Technical Regulation) on Laboratory Measurement of Brake Emissions for Light-Duty Vehicles collects all the information needed to perform emission tests in laboratory. This includes design specifications for the testing platforms as well as the typology and configuration of measuring instruments. Notably, laboratory emission tests are also increasingly used to collect particulates for chemical characterization, since the compositional information is crucial to: i) provide correct assessment of their toxicological and environmental behavior; and ii) better understand tribological and emission
Brake squeal is a common phenomenon across all types of vehicles. It becomes prominent in the absence of other noise sources, as in the case of electric vehicles. Earlier simulation attempts date back to late nineties and early 2000s. Identification of unstable modes of the coupled system of brake rotor and pads, and occasionally some caliper components, was the primary goal. Simulating the rotation of the rotor along with squeezing of the pads was attempted in a multi-body dynamics tools with flexible representation of rotor and pads. Though this gave some insights into the dynamics of stopping mechanism, squeal required capturing the nonlinearities of the contact in a more rigorous sense. Also, efforts were made to capture noise from vibrations using boundary- and finite- element methods [1]. In this attempt at digitalizing a brake dynamometer, the author used a nonlinear implicit solver to mimic the dynamics and transient vibro-acoustic solver to convert transient vibrations to
The prediction of natural frequencies is a crucial aspect of engineering design and analysis. Traditional methods involve finite element analysis (FEA) which is a standard method for calculating natural frequencies of dynamic systems. For each design variant, FEA calculation can be time-consuming and computationally expensive. In this study, we propose a novel method for predicting the natural frequencies of design variants using transfer learning and artificial neural networks (ANN). The proposed method involves the use of FEA to generate the stiffness and mass matrices of the brake disc, which are then used as inputs to the neural network. However, the prediction can become tedious when there is a change in the design. To address this, we employ transfer learning followed by linear regression using a design variant of the previous structure as test data. The neural network learns through transfer learning and fine-tunes its outputs using regression for final frequency prediction. The
Despite efforts to reduce disc brake noise occurrence, it remains a significant concern in the automotive industry, particularly in the current era of electric vehicles, where it can be an intermittent issue. There is no standard solution available for every noise frequency, as it depends on various conditions and parameters that need to be experimentally identified and addressed. This paper specifically focuses on addressing low-frequency noise. During dynamic conditions, the contact pressure becomes uneven, leading to uneven pad wear and making the disc brake system susceptible to noise. In noise rigs, the paper selects the most suitable shim and pad geometry based on trials that analyze the interaction between the shim and pad. In conventional practice, shim modification was performed using computer-aided engineering, but obtaining accurate pressure patterns in dynamic conditions with CAE is challenging due to certain assumptions. Through dynamometer trials, the paper identifies
As the regulations aiming to limit air pollution become stricter, the battle against non-exhaust emissions known to be harmful to human health and the environment is attracting more focus and extending worldwide. EVs are equipped with a hybrid braking system combining regenerative and hydraulic braking to provide the same performance as traditional vehicles. Whenever the regenerative braking torque is insufficient to give the necessary deceleration rate, the hydraulic and electromechanical braking torque is applied. Thus, the recuperative braking of EVs reduces the need for brakes. As the brakes are not used as often, dust and rust will accumulate and impede their performance, so brake problems can arise from not using them enough. Due to the extra weight of EVs compared to ICEVs, more particulates are released through increased corrosion and friction on the braking system. Grey cast iron brake rotors rust quickly, and excessive corrosion causes heavy damage to the rotor’s surface
During validation of a new brake lining on a light duty truck application, the brake rotor exhibited high lateral runout on the friction surfaces. As the engineering team investigated the issue more carefully, they noticed the rotor lateral runout was also changing from revolution to revolution. The team ran testing on multiple light pickup vehicles and found differences in the amount of rotor runout variation. The rotor lateral runout and runout variation can cause vibration and pulsation of the passenger seat and the steering wheel. To identify the root cause of the high level of rotor lateral runout and runout variation, measurement data was collected and analyzed from the vehicle level test. During further analysis, some of the runout variation corresponded to a wheel bearing internal frequency. The bearing internal geometry was studied to confirm what factors affected the runout variation. The team also conducted testing to see how the mating components may have affected the wheel
ABSTRACT High performance fiber reinforced ceramic rotors have the potential to greatly improve metrics in heavy vehicles such as braking distance, acceleration time, maximum speed, fuel consumption, improved handling, and increased vehicle maximum loads. Three types of carbon ceramic composite brake rotor materials were created using polymer infiltration pyrolysis (PIP) for carbon fiber reinforced silicon oxicarbide, reactive melt infiltration (RMI) for carbon fiber reinforced silicon carbide, and electric field assisted sintering (EFAS) for carbon fiber reinforced silicon carbide-zirconium diboride to investigate the manufacturing of 396mm diameter heavy vehicle brake rotors. The microstructure of parts created by each manufacturing method were discussed and contrasted. The EFAS manufactured rotor created the highest quality part due to extremely fast processing times, uniform material microstructure, and fusing of adjacent fibers in the carbon fiber network. Thermal conductivity was
This SAE Recommended Practice establishes dimensions and tolerances for the interface between inboard mounted disc brake rotors and disc wheel hubs. This document is intended for inboard mounted disc brake rotors and disc wheel hubs for Class 5, 6, 7, and 8 commercial vehicles. Special and less-common applications are not covered.
This procedure covers vehicle operation and electric dynamometer (dyno) load coefficient adjustment to simulate track road load within dynamometer inertia and road load simulation capabilities.
The braking system in a vehicle is one of the most crucial parts for proper and safe operation. It is required to slow down or stop the vehicle and work by converting the kinetic energy of the wheel to heat. It is essential to dissipate the generated heat for optimal working and the long life of the disc brakes. Heat generated is due to friction between the brake pad and disc. Due to overheating of brakes due to prolonged braking and heavy braking, brake fade occurs. This leads to boiling of the brake fluid, gassing, and glazing of brake pads, hence reducing braking performance. Therefore, in this study, we used computer simulations to determine the best design that allows for the most heat dissipation by analyzing four different conventional disc brake designs. It was found that the slotted disc brake design had the maximum value of heat transfer coefficient (87.2% more than that of the vented disc brake) and also correspondingly the most decrease in the maximum temperature (39.56
This SAE Recommended Practice is intended for measuring the static brake torque performance of a pnuematically actuated brake assembly, friction material, and drum/disc combination on an inertia brake dynamometer.
The SAE J2521 procedure applies to high-frequency squeal noise occurrences for on-road passenger cars and light trucks below 4540 kg of GVWR. The procedure incorporates high-temperature and low-temperature test matrixes but does not fully account for the effects of the environment on brake squeal. For this test procedure, squeal occurs when the peak noise level is at least 70 dB(A) between 1.25 kHz and 16 kHz for tests using full suspension corners or full axle assemblies or between 2 kHz and 16 kHz for brakes not using a full suspension corner. Before using this recommended practice for chassis dynamometer testing, review in detail the specifics related to at least (a) instrumentation, including in-cabin microphones, (b) threshold levels for noise detection, (c) temperature control priority between the front and rear axles, (d) vehicle loading and load distribution, (e) cooling air and environmental conditioning, and (f) detailed nomenclature and labeling of channels and sensors.
The validation of brake discs has remained, to this day, heavily reliant on “Thermal Abuse” or “Thermal Cracking” type testing, with many procedures so dated that most engineers active in the industry today cannot even recall the origin of the test. These procedures - of which there are many variants - all share the trait of greatly accelerating durability testing by performing repeated high power (high speed and high deceleration) brake applies to drive huge temperature gradients and internal stress, and often allowing the disc to get very hot, to where the strength of the material from which the disc is constructed is significantly degraded. There is little debate about whether these procedures work; by and large disc durability issues in the field are extremely rare. However, without the connection to the duty cycle in the field, it is extremely difficult to interpret results (especially since many standards allow significant cracking before a failure is declared), and this can lead
Brake wear particles are recognized as one of the dominant sources of road transport particulate matter emissions and are linked to adverse health effects and environmental impact. The UNECE mandated the Particle Measurement Program to address this issue, by developing a harmonized sampling and measurement methodology for the investigation of brake wear particles on a brake dynamometer (dyno). However, although the brake dyno approach with tightly controlled test conditions offers good reproducibility, a multitude of changing vehicle and surrounding conditions make real-driving emissions measurement a highly relevant task. Here we show two different prototypes for on-road particle measurement with minimal impact of the measurement setup on the emission behavior, tested on a brake dyno. The prototypes cover only a part of the brake disc and allow for installation with minimal interventions on a commercial passenger car, while still closely following the harmonized methodology for brake
With the spread of new trends such as autonomous driving and vehicle subscription service, drivers may pay less attention to the maintenance of the vehicle. Brake pads being safety critical components, the wear condition of all service brakes is required by regulation to be indicated by either acoustic of optical devices or a means of visually checking the degree of brake lining wear [1]. Current application of the wear indicator in the market uses either sound generating metal strip or wire harness based pad wear sensor. The former is not effective in generating clear alarm to the driver, and the latter is not cost effective, and there is a need for more effective and low cost solution. In this paper, a pad wear monitoring system using MOC(Motor On Caliper) EPB(Electric Parking Brake) ECU is proposed. An MOC EPB is equipped with a motor, geartrain and an ECU. The motor current when applying the parking brake is influenced by the mechanical load at the brake pad side of the system. So
Recently, increasing system complexity and various customer demands result in the need for highly efficient vehicle development processes. Once the brake torque is predicted accurately during the driving scenario in the earlier stage, it will be able to prevent the changing the vehicle or brake system design to satisfy the legal regulation and customer requirement. As brake torque performance target allocate brake pad friction coefficient level and characteristic, the accurate friction coefficient prediction should be preceded for accurate prediction for brake torque. Generally, the friction coefficient of the brake pad is known to vary nonlinearly depending on the physical properties of the disc and the pad, as well as the brake disc rotational speed, the disc temperature, and the hydraulic pressure. Furthermore, it varies depending on the driving scenario even when other conditions are the same. Therefore, it is necessary to apply new methods to solve these challenges. In this study
Reducing exhaust emissions has been a major focus of research for a number of years since internal combustion engines (ICE) contribute to a large number of harmful particles entering the environment. As a way of reducing emissions and helping to tackle climate change, many countries are announcing that they will ban the sale of new ICE vehicles soon. Electrical vehicles (EVs) represent a popular alternative vehicle propulsion system. However, although they produce zero exhaust emissions, there is still concern regarding non-exhaust emission, such as brake dust, which can potentially cause harm to human health and the environment. Despite EVs primarily using regenerative braking, they still require friction brakes as a backup as and when required. Moreover, most EVs continue to use the traditional grey cast iron (GCI) brake rotor, which is heavy and prone to corrosion, potentially exacerbating brake wear emissions. This study concentrates on emissions from a conventional grey cast iron
This document describes standard test methods, analysis methods, and reporting methods for measuring the resonant modes of automotive disc brake rotors and drums for design/development and production verification of these components.
This SAE Recommended Practice establishes uniform engineering nomenclature for wheels, hubs, rims, and their components used in truck, bus, and trailer applications. This nomenclature and accompanying drawings are intended to define functional truck wheel, hub, and rim designs. For nomenclature specific to “passenger-type” disc wheels, refer to SAE J1982. The International Standard (ISO) nomenclature is shown in parentheses when different than SAE J393.
This SAE Aerospace Information Report (AIR) provides information on landing gear operation in cold temperature environments. It covers all operational aspects during ground handling, takeoff, and landing. It includes effects on tires, brakes, shock struts, seals, and actuators.
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