Browse Topic: Brake pads

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Brake Pad Life Monitoring System using Machine learning2024-26-003201/16/2024
In vehicles, Brake Pad is an important part for controlled driving and safety. Brake Pads are made up of friction materials which wear with use. Excessive pad wear may lead to increase the brake response time and NVH issues. Currently it is not feasible for customers to check the amount of brake pad wear without the support from experienced personnel as the unit is not visible from outside. In general no feature is provided by Indian OEMs for brake pad life estimation and indication. This paper proposes a hybrid machine learning approach to predict brake pad remaining useful life. It comprises of 3 modules namely weight, temperature and wear module. Weight module is based on mathematical formulation using longitudinal vehicle dynamics to estimate the weight of the vehicle which is essentially required to calculate kinetic energy dissipated during braking. Temperature and wear module are deep neural network based machine learning modules. The technology is developed in a simplified
Iqbal, Shoaib, BHAMBRI, MIHIR, lahase, Rahul
Technical Paper
Comparative Numerical Study on Heat Dissipation Behaviour of Conventional Disk Brake Designs for High-Performance Requirements.2022-28-042211/09/2022
The braking system of a vehicle is one of the most crucial parts for proper and safe operation. It is required to slow down and/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. Most of the complications and failures with a brake disc are due to problems with heat distribution and heat level absorbed by the disc. The heat is generated due to friction between the brake pad and disc. Due to overheating of brakes due to prolonged braking and heavy braking, brake fade occurs which leads to boiling of the brake fluid, gassing, and glazing of brake pads and hence reducing braking performance. Therefore, in this project, our aim is to determine the best design that allows for the most heat dissipation by analyzing four different disc brakes using computer simulations i.e CFD to study the effect on airflow and convection and FEA for thermal analysis. This
Arora, Rishabh, Rao, Vikram, Sharma, Rishab, Chahal, Rujul, Singh, Manvesh
Technical Paper
Tutorial: Corrosion Phenomena in Brake Systems: From Basics to Future Challenges1334510/11/2022
Corrosion on braking systems is an important issue in the automotive sector. In particular, short term corrosion of the grey cast iron discs can lead to undesired corrosion attack at dealers, while long term corrosion might impair comfort and durability of the braking system. Moreover, corrosion attack of the grey cast iron might cause stiction phenomena between the breaking pad and disc leading to possible damage of the pad. Corrosion phenomena became more important for electrified power train vehicles. In this tutorial, will try to explain the basis of the electrochemical mechanism, some characterization techniques and the interaction on the stiction phenomena between the brake pad sample and the rotor (gray cast iron). Also, another aspect that will be considered is the rust removal conditions and simulations when we are considering Electric Vehicles. The goal is to give to the audience an overview from the basics of the electrochemistry to the experimental conditions test that will
Sin, Agusti
Video
Kinetics of Moisture Adsorption and Its Impact on Brake Pad Compression Modulus and Compressibility: Compression Modulus vs. Dynamic Modulus and Friction Variation2022-01-116509/19/2022
The kinetics of moisture adsorption is studied for copper-free brake pads. The pad weight gain is found to increase linearly with the square root of exposure time to humidity at a given temperature – the higher the humidity, the higher the weight gain. As the moisture content in the pad increases, the tangent modulus increases while the secant modulus decreases, resulting in decreasing compressibility associated with the tangent modulus of compression and increasing compressibility associated with the secant modulus of compression – compressibility defined as a reciprocal of compression modulus. Compression modulus and dynamic modulus are compared, and implications for friction coefficient variation are discussed. A rate constant of adsorption is proposed to define and compare moisture sensitivity of friction materials.
Rhee, Seong Kwan, Rathee, Aman, Singh, Shiv Raj, Sharma, Devendra
Technical Paper
Brake Pad Wear Monitor using MOC(Motor On Caliper) EPB ECU2022-01-116709/19/2022
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, a wear indicator is required by the regulation. Current application of the wear indicator in the market uses whether 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 now 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, by analyzing the time history of the current it is possible to measure the clearance between brake pad and disc induced by the pad wear
Lee, Soohyuk
Technical Paper
Effect of Humidity Levels on the Compressibility of Automotive Brake Friction Materials2022-01-116409/19/2022
The load-deflection relationship of automotive brake friction materials (also known as “compressibility”) is a characteristic which may both influence and advise as to brake performance, including driver experience, noise and vibration behavior, and manufacturer quality control. It has been reported that changes in environmental humidity may significantly alter friction material compressibility in a formulation-dependent fashion – effects which are important considerations for testing protocols and real-world applicability. Greening’s presentation includes a rigorous investigation of humidity-dependent properties across differing friction materials and manufacturers, taking advantage of the high resolution and excellent repeatability of the Greening Model 1140 Compressibility Test Machine. Sets of brake pads from (at least) two different manufacturers and of varied material type (non-asbestos organic, semi-metallic, low-metallic, etc.) will be weighed to assess changes to moisture
Sendler, Edward, Greening, Brent, Greening, Chuck
Technical Paper
Enhancing Meta Model of the Brake Pad Friction Coefficient using the Explainable Machine Learning2022-01-117509/19/2022
As 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 rotational speed of the brake disc, the disc temperature, and the hydraulic pressure. Furthermore, it varies depending on the driving scenario even the same condition. Therefore, there was a need for a new method : machine learning to solve this problem. A Mixed Effect
Cho, Sunghyun, Bang, Sunghoon, Jang, Jiwoo, Kim, Youngjae
Technical Paper
Estimating Brake Pad Life in Regenerative Braking Intensive Vehicle Applications2022-01-116109/19/2022
Regenerative braking without question greatly impacts brake pad service life in the field, in most cases extending it significantly. Estimating its impact precisely has not been an overriding concern - yet – due in part to the extensive sharing of brake components between regen-intensive battery-electric and hybrid vehicles, and their more friction-brake intensive internal combustion engine powered sibling. However, a multitude of factors are elevating the need for a more accurate estimation, including the emerging of dedicated electric vehicle architectures with opportunities for optimizing the friction brake design, a sharp focus on brake particulate emissions and the role of regenerative braking, a need to make design decisions for features such as corrosion protection for brake pad and pad slide components, and the emergence of driver-facing features such as Brake Pad Life Monitoring. Tackling this question raises questions such as “is the proven braking energy and temperature
Antanaitis, David, Robere, Matthew
Journal Article
Methodology and application on load monitoring using strain-gauged bolts in brake calipers2022-01-112103/29/2022
As technology evolves, the number of sensors and available data on vehicles grow exponentially. In this context, it is essential to use sensors for monitoring key components, increasing safety and reliability, and gathering data useful for mechanical dimensioning and control systems. This paper presents an application of strain-gauged bolts brake calipers fixation of two electric vehicles. With this approach it was possible to obtain the loads applied to the brake pads and correlate them with braking behavior, therefore gaining insights on braking conditions and system state. The goal of the study is analyzing the strengths and limitations of the method and proposing developments to deploy it in real applications. This topic is particularly important and novel for electric vehicles, where powertrains can create positive and negative torques and generate complex interactions with braking system. Strain-gauges are a long-known technology applied in many fields, and its usage in bolts and
de Carvalho Pinheiro, Henrique, Sisca, Lorenzo, Carello, Massimiliana, Ferraris, Alessandro, Airale, Andrea Giancarlo, Falossi, Marco, Carlevaris, Alberto
Technical Paper
Research on Brake Pads Particle Emissions and Temperature Reduction of a Brake Disc in Air Controlling System.2022-01-039003/29/2022
This paper addresses the brake pad particles emitted during the braking process of a vehicle in motion. The frictional-constant contact between the disc brake and brake pads generates thermal energy as a result of increased temperature within the brake disc causing wear of the brake pads. Emission of brake pad particles into the atmosphere leads to an increase in air pollution in the environment and hence becomes hazardous to the human body. In this paper, the wheel brake disc is installed in a ventilated system where the specific airflow encompassing the disc brake accounts for thermal performance and pad particle emission from the brake pads. The mathematical model of the fundamental parameters of the brake disc and ventilation is established and the behavior of heat transfer coefficient, heat generation, heat flux, temperature rise, airflow rates, brake disc cooling time, inlet and outlet speed on the ventilation system with the brake disc are carried using computational fluid
sarvar, Yovkachov, Fayzullayevich, Jamshid Valiev
Technical Paper
Measurement and evaluation of the conversion of thermal energy generated on the contact surface of the brake disc into electrical energy using a thermoelectric generator2022-01-021303/29/2022
The heat generated by the friction between the brake discs and the brake pad, causes the disc’s temperature to rise which affects braking performance. This generated heat flux from the contact surface of the vehicle’s brake disc does not only affect braking performance but also tend be wasted and pollute the environment. However, an accurate system is needed to make efficient use of this generated heat flux, that is usually wasted. Thermoelectric generators (TEGs) are solid-state gadgets utilized in the conversion of heat to electricity. Hence, the aim of this study is to convert the heat flux generated at the disc contact surface into electrical energy by employing a thermoelectric generator. Additionally, to store the harvested energy to power the battery which in turn charges the temperature monitoring systems. Thermoelectric generators were positioned at different geometrical points of the brake discs to achieve optimal efficiency and energy storage possibilities. A static model is
Fayzullayevich, Jamshid Valiev, Agyeman, Philip, Frimpong, Justice
Technical Paper
The Numerical Analysis of Brake Pad Related to The Properties of Composite Brake Pad Friction Material.2022-01-036503/29/2022
This project outlines the effect of changing Young’s modulus, Poisson’s ratio, and shear modulus on the natural frequencies of brake pads. It aims to improve the understanding of the influence of friction material properties on the natural frequencies and observe how the natural frequency changes with the changes in the properties of the composite brake pad friction material. In addition, two different brake pad models (Pad-A and Pad-B) were designed using CATIA V5 software to study whether different pad aspect ratios can affect the influence of friction material properties on the natural frequencies. The finite element analysis (FEA) was utilized to derive the natural frequencies and mode shapes using ABAQUS software. In addition, an experimental modal analysis (EMA) was performed on Pad-A to evaluate the accuracy of the FEA. Furthermore, the factorial analysis was applied on the obtained natural frequencies for each pad to find out the material properties that have the main effect on
Ravanbod, Mohammad
Technical Paper
Chemistry of the Brake Emissions: Influence of the Test Cycle2021-01-130010/11/2021
The reliable chemical characterization of non-exhaust emissions generated by brakes is of fundamental importance in order to provide correct information for source apportionment studies as well as for their toxicological and environmental assessment.[1,2,3] Nowadays, the best option to obtain samples of PM10 emissions composed only by material worn from the tribological interface, i.e. the braking disc (BD) and friction material (FM) rubbing surfaces, is to sample them on suitable collection filters at a dedicated dyno-bench, during a standard braking test cycle. In particular, the use of enclosed dyno-bench is necessary for excluding other spurious contributions from the environment, while defined test cycles are necessary to simulate standard driving conditions.[4] Nevertheless, different braking cycles are usually characterized by different overall temperature profiles or energy indexes, which in the end have significant influence on the wear and the oxidation of the materials
Mancini, Alessandro, Tsyupa, Bozhena, Pin, Sonia, Bandiera, Marco, Bertasi, Federico, Federici, Matteo, Bonfanti, Andrea, Perricone, Guido, Gigli, Lara, Bolzacchini, Ezio
Technical Paper
Investigations on the deposition behaviour of brake wear particles on the wheel surface.2021-01-130110/11/2021
The deposition behavior of brake wear particles on the surface of a rim and the mechanisms involved have not been fully researched. Similarly, it has not yet been answered how high the proportion of particles deposited on the wheel surface is compared with the particles emitted by the brake and what influences this. This information is a prerequisite for evaluating measurements of particle number and particle mass on the inertia dynamometer and comparing them with real emission behavior. The aim of this study is to verify the deposition behavior of brake particles on the surface of wheels. For this purpose, the real deposition behavior is first determined by on-road tests. For particle sampling, collection pads are adapted at different positions of a front and rear axle wheel. In addition to an RDE-compliant test cycle, urban, rural and motorway sections are used to evaluate speed-dependent influences. Microscopic analysis is used to determine the particle number concentration and
Hesse, David, Hamatschek, Christopher, Feißel, Toni, Sachse, Hannes, Augsburg, Klaus, Gramstat, Sebastian
Technical Paper
Divergence of Thickness Losses and Weight Losses of Disc Pads for Passenger Cars: High-Copper NAOs and Copper-Free Low Mets2021-01-129010/11/2021
The current investigation was undertaken to find out if lighter-weight passenger car disc pads would exhibit wear behaviors similar to pickup truck pads and commercial heavy truck drum linings in terms of the permanent volume expansion of the friction material contact surface region. 2 high-copper Non-Asbestos Organic formulations and 3 copper-free Low-Met formulations were tested according to the SAE J2522 test procedure. In all cases, the measured pad thickness loss was found to be less than the thickness loss calculated from the weight loss, indicating pad volume expansion, in full agreement with the results from the pickup truck and heavy trucks. One needs to consider pad property changes associated with the volume expansion if good correlations are to be found between pad properties and brake friction, wear and NVH.
Rathee, Aman, Singh, Shiv Raj, Sharma, Devendra, Rhee, Seong Kwan
Technical Paper
A Contribution to the Understanding of Friction and Squeal of Automotive Brakes: Wear Particle Generation and Deformation of Sliding Surface Region Influencing the Friction Coefficient2021-01-128810/11/2021
Copper-free disc pads of 9 different compositions were made using a traditional hot molding process and tested to study frictional behavior. It is found that the friction coefficient consists primarily of two parts; one part controlled by the plastic deformation of the friction surface region of the disc and pad, and the second part controlled by the total wear of the disc and pads. As the plastic deformation and the wear are non-linear with respect to the load and sliding speed, the friction coefficient becomes a non-linear function of the load and speed. Under moderate braking conditions, the plastic deformation part is more significant in determining the friction coefficient while under more severe braking conditions, the wear contribution becomes more significant.
Rhee, Seong Kwan, Sriwiboon, Meechai, Kaewlob, Kritsana, Tiempan, Nipon
Technical Paper
Investigation of the rational area of friction surfaces in contact of friction linings for disc brakes of passenger cars2021-01-129510/11/2021
It is important for assessing the service life of the braking mechanisms of passenger cars that are in operation is the establishment of the speed and the value of the permissible wear of the friction surfaces, which ensures the durability of the brake. The purpose of the study is to assess effect of area friction surfaces on resource of vehicle braking mechanisms. This will extend the service life of the disc brakes on cars. In the work, the regularities of wear of mating parts of disc brakes were established depending on the change in the geometric parameters of the friction surfaces and operating modes during their operation. It was found that the service life of disc brakes can be increased by 1.16 times with an increase in the area of frictional contact by 15 %, for passenger cars DAEWOO LANOS and LADA PRIORA. A comparative assessment of the wear of the new DAEWOO LANOS and LADA PRIORA brake pads, which perform cyclic emergency braking, is provided. Recommendations have been
Aleksandr, Nazarov, Krivoshapov, Sergey, Misyura, Nikolay, Belov, Valentin, Zuiev, Vladimir, Nazarov, Ivan, Nikolay, Sergienko
Technical Paper
Thermomechanical Instabilities in Metal Free Friction Materials Using a Nonlinear Transient Simulation Approach2021-01-128610/11/2021
The invention of metal-free friction materials is gaining popularity in the manufacturing of brake pads and clutch friction discs because of the negative factors associated with metals such as copper. To gain more insight into the failure mechanism of the recent invention during brake or clutch applications, a nonlinear transient thermomechanical model is established using ABAQUS. The model is based on a two-dimensional configuration for an investigation on the onset of TMI (Thermo-Mechanical Instability) during sliding contact in such material. The model is validated by comparing the transient simulation results for a full-contact regime to the result from the existing eigenvalue method. A parametric study is carried out to examine how the thermal conductivities and the elastic moduli influence TMI. The simulation results show that the thermal conductivities in the transverse direction can stabilize the system. Conversely, the elastic moduli in the transverse direction were found to
Koranteng, Kingsford, Shaahu, Joseph-shaahu, Yi, Yun-Bo
Technical Paper
Decoding Genuine Ceramic Pad Formulations – materials and processing2021-01-127710/11/2021
Decoding Genuine Ceramic Pad Formulations - materials and processing Bharat S. Tomar, Dr. Sharafat Ali, Dr. Keith Ellis, Yogesh Chaudhary Allied Nippon Private Limited, Sahibabad, Ghaziabad 201010, UP, India --------------------------------------------------------------------------------------------------------------- ABSTRACT The need for development of genuine ceramic composite for PV application arose to overcome the challenges associated with traditional semi-metallic pads. The main focus is to achieve better performance, pad and disc wear along with low dust in comparison to semi-metallic pads. In general, brake pads convert kinetic energy to thermal energy through friction and operating temperature in semi-metallic brake pads is higher due to presence of steel having high thermal conductivity. Over the last decade, the customer preference has moved over to ceramic pads due to light coloured pad surface, low disc and pad wear and low dust in comparison to semi-metallic pads. The
Tomar, Bharat, Ali, Sharafat, Ellis, Keith, Choudhary, Yogesh
Technical Paper
A Molecular Dynamics Study of Tribological Properties of Silicon Carbide as a Metal-Free Friction Material2021-01-128410/11/2021
Friction materials containing metal ingredients used in automotive industry can cause unfavorable environmental impacts. Existing laws and regulations require phase out of heavy metals in brake pads. Substitutions for metals in friction materials, however, may introduce operational safety issues. In the current study, a molecular dynamics model based on LAMMPS has been developed to study the effect of material composition, density and geometric configurations on the tribological, mechanical and thermal properties of silicon carbide under various contact conditions at the atomic level. Successful simulations are performed to predict the elastic modulus, thermal conductivity, wear rate and coefficient of friction, with the incorporation of interfacial contact between surface asperities. The predicted properties can help enhance the performance of engineered metal free friction materials against thermal-mechanical failures. The following factors have been taken into consideration in the
Zhang, Yizhan, LeNeave, Cortney, Yi, Yun-Bo
Technical Paper
An Investigation of Property Changes of Copper-Free Brake Pads During Wear Testing: Pressure and Temperature Dependence of Pad Modulus, and the Correlation Between Modulus and Friction Coefficient2021-01-127610/11/2021
Earlier publications have demonstrated that pad and disc properties change during storage and also during the SAE J2522 Brake Effectiveness Test Procedure. The current investigation was undertaken to find out how the properties change under milder braking conditions, using the SAE J2707 Wear Test Procedure. A copper-free formulation was selected for the investigation and tested on an inertia dynamometer using a front caliper designed for a passenger car. The pad dynamic modulus changed up or down throughout the test, depending on the test conditions. The pad dynamic modulus, the pad natural frequencies and the disc natural frequencies all decreased by the end of the test. Under high-speed, high-deceleration and high-temperature braking conditions, the pad surface region permanently expands, which results in reduced dynamic modulus and also leads to reduced pad thickness loss as compared with pad weight loss. A good correlation is established between the friction coefficient and the pad
Sriwiboon, Meechai, Koetniyom, Saiprasit, Rhee, Seong Kwan, Sukultanasorn, Jittrathep, Kaewlob, Kritsana
Technical Paper
Transfer Film Composition and Characteristics in Copper-Free NAO Brake Pads2021-01-127810/11/2021
Copper-free non-asbestos-organic (NAO) brake pads have been developed to satisfy the copper content regulations in North America. Copper-free NAO brake pads are required to have a stable friction coefficient owing to the electrification of the control systems, as well as to exhibit improved wear resistance to reduce brake dust emissions. Our previous study indicated that the transfer film formed on the rotor surface affects both the friction coefficient stability and amount of wear. In this study, we investigated how different types of inorganic fillers affect the transfer film formation and its composition in a wear test controlled by temperature. It was confirmed that the main component of the transfer film was iron oxide derived from the rotor. Furthermore, the contained components changed according to the appearance of the rotor surface after each wear test. When the brake pad contained potassium lithium titanate, a transfer film was formed uniformly and stably, the amount of wear
Nishimura, Keiichiro, Masuda, Katsuyuki, Yamamura, Taizo, Hara, Yasuhiro, Ono, Manabu, Sasaki, Shinya
Technical Paper
Comparing and analysing the static and thermal characteristics of brake disc for three different materials2021-28-025310/01/2021
In automobiles, the most commonly used braking system is disc brake. In the brake disc, rotor is the rotating part of a wheel's disc brake assembly, against which the brake pads are applied by the driver through mechanical action. So, the disk is the important component in either slowing down or stopping the vehicle. These discs were commonly made of cast iron conventionally. But the limitations with respect to cast iron are that they have less corrosion resistance and heavy in weight. In order to overcome the above-said complications, alternate materials for disc have to be found. The main objective of this paper is to analyze the characteristics of three different materials and compare their results and suggest a suitable material that highly influences the conventional material and has better performance under on-road rigorous braking conditions. In order to find an alternative material for Cast Iron (CI), EN31, Ti-6Al-4V(Ti alloy) acts as a potential candidate in offering great
K, Kaviyarasan, R, Soundararajan, Richter R, Abhisheak, K, Siva, Purusothaman, S, S, Shiva Gurunathan
Technical Paper
Effect of various synthetic and natural fibers for the production of copper-free automotive brake pads2021-28-027410/01/2021
In recent years, asbestos and copper free brake pads have attracted researchers due to its adverse environmental risks which make it mandatory for the manufacturers to look for a reliable replacement. It is essential to identify new combination of synthetic and natural fibers for the potential automotive brake pads. Experiments were planned to produce various frictional composites (1) glass fiber (2) carbon fiber (3) basalt fiber (4) hemp fiber with standard additional materials through hot pressing technique. The developed form of brake pads were tested as per ASTM and industrial standard practices like hardness, wear and friction. Also worn surface analysis was performed using a scanning electron microscope. Most noteworthy tribometric operating parameters like load (10-40N), sliding velocity (1-5m/s) were being considered and wear mechanism for various types of composites and their performances are being discussed. In order to prove the application suitability, recovering synthetic
R, Soundararajan, Soundarrajan, Karthik, Rengaraj, Jeyakumar, gopal, Shanthosh
Technical Paper
Tribological evaluation of organic frictional composites filled with various nano- solid lubricants2021-28-025910/01/2021
Incorporation of organic fibers originate from plants in polymer composite is not new as they provide eco-friendly lighter composite and it have gained attention over a period of time because of the specific applications. The augmenting demanded by automotive sectors for wear and frictional areas where the conservation of energy is concerned is expected one with the addition of nano – solid lubricants. Our aim is to highlight the possibility of organic basalt fiber reinforced polymer composites along with three possible combination of nano – solid lubricants like graphite/graphene/ molybdenum disulfide was chosen and to fabricate tribo-materials through hot press technique. The outcome of the tribological tests (by varying load and sliding velocity) indicates that the responses of these three organic fiber based polymer composites have been effectively modified by nano-solid lubricants leading to significant enhancement as tribo materials is highlighted in higher level of load and
R, Soundararajan, Javid Firnas, Sait, Naveen raj, Nandakumar, pradeep s, sabapathy
Technical Paper
Stability of hybrid composite plates with cut-out2021-28-017610/01/2021
Composites being high in strength to weight ratio is preferred for automobiles. Hybrid Composites due to its fatigue resistance, low cost and reduction in notch sensitivity makes it eligible for application in automotive industry. Hybrid composites are used in automotive anti roll-bar, brake friction material and pistons and strut bars. Carbon epoxy being costly is reinforced with glass epoxy to achieve the desired effect of weight reduction along with saving the cost. In this paper stability analysis of hybrid composite plate with elliptical cut-out is studied. Comparison between different boundary conditions that is combination of simply supported and clamped for the considered rectangular plate is being done. The effects of orientation of cut-out, stack up sequence effect, angle ply, laminate thickness effect, width of plate, changes in aspect ratio of plate as well as cut-out is being studied. Comparisons of perforated and non-perforated conditions are studied and accordingly
Gore, Renuka, Bhaskara Rao, Lokavarapu
Technical Paper
Brake Groan Noise Investigation and Optimization Strategy for Passenger Vehicles2021-26-030109/22/2021
Groan is a low frequency noise generated when moderate brake pressure is applied between the surfaces of the brake disc and the brake pad at a low-speed condition. Brake groan is often very intense and can cause large numbers of customer complaints. During a groan noise event, vehicle structure and suspension components are excited by the brake system and result in a violent event that can be heard and felt during brake application. The cause of noise is friction variation of stick-slip phenomenon between friction material and disc. This paper discusses the approach for prediction and mitigation of brake groan noise for passenger vehicles having disc brakes. To identify the brake groan noise frequency, vehicle testing with operating condition for reproducing the groan noise is carried out and also impact frequency response analysis is performed to identify natural frequency of each chassis component like brake, suspension stud, lower control arm, knuckle etc. The finite element corner
Doundkar, Vikas, Iqbal, Shoaib
Technical Paper
Impact of Wheel Cover Design on Brake Component Temperature2021-26-051109/22/2021
Typically during a braking maneuver vehicle converts kinetic energy into heat energy. Heat energy thus generated must be dissipated in order to prevent brake overheating. One of the primary factors influencing the temperature of brake components is the amount of ventilation in wheel covers. The objective of this paper is to study the impact on temperature of brake discs and pads by varying ventilation area of wheel cover in Brake Dynamometer. The methodology focuses on collecting objective data in different vehicle models with multiple wheel cover designs. The results are analyzed to study the trend of brake disc and pad temperature with respect to ventilated area of wheel cover. The present work is further correlated with different segment wheel sizes and steel and alloy wheel.
Chaudhary, Roshan, Sharma, Anurag, Rawat, Vandana, Gupta, Sumit, Bhope, Anand, Kumar, Rajeev
Technical Paper
Study of Heat Generation in Brake Pad with and without Slots using Numerical and Experimental Analysis2021-26-034509/22/2021
Abstract: In recent days the usage of disc brake is increased acutely in commercial vehicle applications apart from the passenger vehicles. The main advantage of using disc brake is reducing the stopping distance, temperature and wear between the disc and pad. During braking the kinetic energy of the vehicle is converted into thermal energy due to the friction between disc and pad. To maintain the temperature between the disc and pad is critical for the over all performance of the disc brake and safety of the vehicle. The process of vehicle braking is a dynamically thermal-structure coupling problem which is complex in nature. In this study, temperature between the disc and pad is determined using Finite Element Analysis for various disc and pad configuration. As per recent vehicle norms by the government the axle load is increased by 20 % which requires increased braking force and will leads to high temperature in the rotor pad interface. Considering the vehicle tonnage, braking force
T, Sukumar, Suresh, Anandkumar, Mariappan, Dhanavel, Govindarasu, Anbarasu
Technical Paper
Snowmobile Service Brake SystemJ44_202103 (Current)03/16/2021
This SAE Standard establishes a uniform testing procedure and performance requirements for the level surface testing of hand-operated service brake systems on snowmobiles.
Snowmobile Technical Committee
Technical Standard
Whatever the video Title isSAE-PP-0036603/12/2021
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Sathe, Prakash
Pre-Print Article
Validation of Compressibility Test Systems for Friction MaterialsJ3079/1_202101 (Current)01/13/2021
This SAE Recommended Practice (RP) applies to the validation process for test systems used to measure deflection (compressibility, creep, or swell and growth) of friction materials and friction material assemblies. The materials or assemblies can fit passenger cars, light trucks, and commercial vehicles equipped with hydraulic or air brake systems, using disc or drum brakes.
Brake Linings Standards Committee
Recommended Practice
An Experimental Setup for Investigations on the Boundary Layer Dynamics2020-01-161710/05/2020
The frictional behavior of a tribological contact is influenced by the dynamics in the forming boundary layer. Recurring structures, built up through self-organizing effects, were found in various frictional systems. To investigate those phenomena on a macroscopic scale and to better understand dynamical processes such as the formation and decay of contact patches, the first revision of the Wear Debris Investigator (WDI) was introduced in 2017. A friction gap is formed between two coaxial horizontally arranged discs. To mimic the presence of particles, artificial wear dust is fed into the gap. With a camera the formation of the boundary layer is recorded in situ. An implemented normal force and torque sensor enables to recognize correlations between the formed boundary layer and the occurring frictional forces. Numerous measurements revealed an insufficient precision of the previous WDI. Consequently, an innovative measurement and load unit was developed and implemented on the WDI
Ostermeyer, Georg-Peter, Rickhoff, Felix
Journal Article
Air Brake Performance and Wear Test Code Commercial Vehicle Inertia DynamometerJ2115_202008 (Current)08/20/2020
This SAE Standard provides test procedures for air and air-over-hydraulic disc or drum brakes used for on-highway commercial vehicles over 4536 kg (10000 pounds) GVWR. This recommended practice includes the pass/fail criteria of Federal Motor Vehicle Safety Standard No. TP-121D-01.
Truck and Bus Foundation Brake Committee
Technical Standard
Air Brake Performance and Wear Test Code Commercial Vehicle Inertia DynamometerJ2115_202008-TEST-REC (Historical)08/20/2020
This SAE Standard provides test procedures for air and air-over-hydraulic disc or drum brakes used for on-highway commercial vehicles over 4536 kg (10000 pounds) GVWR. This recommended practice includes the pass/fail criteria of Federal Motor Vehicle Safety Standard No. TP-121D-01.
Truck and Bus Foundation Brake Committee
Technical Standard
Measurement of Copper and Other Elements in Brake Friction MaterialsJ2975_202007 (Current)07/23/2020
This procedure describes a method for generating, preparing and analyzing samples of new and unused brake friction materials for their chemical constituents.
Brake Linings Standards Committee
Recommended Practice
Low-Duty Inertia Dynamometer Hydraulic Brake Wear Test Procedures for Vehicles Above 4536 kg (10000 pounds) of GVWRJ3006_202005 (Current)05/26/2020
This Recommended Practice is derived from OEM and tier-1 laboratory tests and applies to two-axle multipurpose passenger vehicles, or trucks with a GVWR above 4536 kg (10 000 pounds) equipped with hydraulic disc or drum service brakes. Before conducting testing for a specific brake sizes or under specific test conditions, review, agree upon, and document with the test requestor any deviations from the test procedure. Also, the applicable criteria for the final test results and wear rates deemed as significantly different require definition, assessment, and proper documentation; especially as this will determine whether or not Method B testing is needed. This Recommended Practice does not evaluate or quantify other brake system characteristics such as performance, noise, judder, ABS performance, or braking under extreme temperatures or speeds. Minimum performance requirements are not part of this recommended practice. Consistency and margin of pass/fail of the minimum requirements
Truck and Bus Hydraulic Brake Committee
Recommended Practice
Model-Based Brake Disc Temperature Prediction on High Speed Testing Mode and Circuit2020-01-021404/14/2020
A brake is a mechanical device that inhibits the motion by absorbing energy from a moving system. It is used for slowing or stopping a moving vehicle, wheel, axle, or to prevent its motion, most often accomplished by friction energy. Commonly, most brakes use friction between two surfaces pressed together to convert the kinetic energy of the moving object into heat, though other methods of energy conversion may be employed. If braking is repeated or sustained in high load or high-speed conditions, the motion will be unstable and can lead to a loss of stopping power because the disc capability for braking is not enough. These phenomena are generally defined as brake fading. Brake fade is caused by an overheating brake system. This paper describes the thermal modeling and process to predict the disk temperature under a condition which causes the fade characteristics. Also, the model of disc temperature prediction developed with consideration of acceleration and deceleration from the
Jeong, PilYoung, Lee, Jaekil, Oswald, Mario, Kellner, Stefan
Technical Paper
Flow Field Experimental Study in Brake Discs with Aerodynamic Ventilation Columns06-13-01-000402/27/2020
This work presents a new design of ventilation pillars in ventilated brake discs. The use of National Advisory Committee for Aeronautics (NACA) aerodynamic profiles is proposed. Of the references consulted, there is no standard or procedure that indicates how the pillars should be installed in the ventilated discs. Therefore, it is proposed using the Kaplan’s error triangles theory of turbo hydraulic machinery to have a geometrically orderly way of placing the NACA 66-209 profiles from the suction diameter to the discharge diameter. To validate this new design, a 1:1 scale acrylic disc model was constructed, and tests were conducted in water using the particle tracking velocimetry technique to characterize the water model. The water experiment was performed at test speeds of 35, 41, 48, and 54 rpm. From the experiment in water, it is possible to visualize the flow field from the suction diameter to the model discharge diameter and scale the results to the prototype in air. Being 54 rpm
Rivera López, Jesús Eduardo, Gutiérrez Paredes, Guadalupe Juliana, Quintero Orozco, Abner, Tamayo Meza, Pedro Alejandro, Orozco Durán, Gabriela Esmeralda, Arciniega Martínez, José Luis
Journal Article
Regressions of brake pads compressibility from experimental data2019-36-001401/13/2020
One of the critical characteristics in a brake pad is its deformation when subjected to compressive loads. This deformation is called compressibility, which can be obtained quantitatively through compression cycles performed by a specific test bench. However, such testing is costly and long enough not to meet the demand of manufacturers of friction materials. To overcome this difficulty, this work presents regressions for the estimation of compressibility through the natural frequencies of the pads, since they can be obtained quickly and at low cost through a simple modal analysis. The theoretical basis for the correlation between compressibility and natural frequencies includes the theory of elasticity - which defines an inverse relationship between strain and stiffness - and the theory of vibrations, which defines the natural frequencies of a mechanical system as a function of its mass matrices and stiffness. Since the dependent variable (compressibility) and explanatory variable
Suetti, André Garcia Lima
Technical Paper
Influence of Pads and Brake Disc wear on Brake Squeal Noise2019-36-000501/13/2020
The present work aims to investigate the influence of wear of the pads and brake disc on the brake squeal behavior with the help of the Finite Element tool. Brake discs basically work by the pressure of the brake pads against a rotating disc. The friction between the pads and the disc causes the latter to decelerate, but it can also cause dynamic instabilities of the system giving rise to noises. Among the main noise in vehicle brake systems, there is the squeal noise, which is usually associated with the coupling of two neighboring natural modes. One possible way to identify unstable modes is by extracting complex eigenvalues from the system. An unstable mode can be identified when, in the result of the extraction of the complex eigenvalues, the real part of the eigenvalue is positive. In the present work, a brake system (disc and positioned pads and their respective materials and friction coefficients) was duly modeled and validated. The validation was done by means of a correlation
dos Anjos, Marco Túlio Batista, Gutiérrez, Juan Carlos Horta, Ferreto, Cláudio Junior, Silva, Felipe Dornellas, Donadon, Lázaro Valentin
Technical Paper
Brake noise analysis on tractive axle of 6x2 tractor vehicle2019-36-000801/13/2020
This study aims at analyzing the causes of noise in a heavy vehicle brake system (6x2 tractor) and proposing solutions to improve comfort during braking as it is known that, during the activation of the automotive brakes, noise can be generated in different frequency bands that can cause discomfort to the user and the study of how to reduce it is considerably important to bring more comfort in its use. As a working methodology, firstly, comparative analysis of dimension and material were performed between the axle assembly that presented noise and another axle assembly of a vehicle with no noise adopted as reference. This information was used as the basis for the frequency and acceleration virtual analysis that were validated with vehicle instrumentation and data acquisition. In parallel, vehicle tests with different brake friction materials were conducted. The answers of the dimension and material analysis from the axles assemblies highlighted the specificities of each of them but did
Fortuna Pizzi, Rafael, Soares Júnior, Getúlio, Tonetti Anselmo, Pablo, Do Nascimento, Vagner, dos Santos, Roger Lusa, Severo Antunes, Diego, Masotti, Diego, Horta Gutierrez, Juan Carlos
Technical Paper
Road Vehicles - Friction Materials - Finished Brake Pad Normalized Elastic Constant of Friction MaterialJ3175_201911 (Current)11/20/2019
This SAE standard specifies a method for testing and measuring a normalized elastic constant of brake pad assemblies using ultrasound. This document applies to disc brake pad assemblies and its coupons or segments used in road vehicles.
Brake Linings Standards Committee
Technical Standard
Analysis of Metal Pick-Up Formation Process within Automotive Brake Pad05-13-01-000311/19/2019
Metal Pick-Up (MPU) is a problematic phenomenon in automotive disc brakes. MPU generally forms as some metal lumps on the surface of the brake pad. If brake pads have MPU, during braking they would cause grooving of the disc rotor, generating brake noise and deteriorating the performance of the brake. The previous literature has so far reported that the source of the MPU is an Fe component from a disc rotor or brake pads. However, only a few of the generation mechanisms of MPU have been proven. We investigate MPU to completely elucidate the mechanism of MPU generation by using different analyses than the previous literature. First, to find out the source of MPU generation, we focus on the chemical reaction of a certain component with wear debris during braking, and some of the verification experiments are conducted under the conditions of simulated friction interface. Second, to clarify the change in the form of the MPU growth process, the crystal structure of MPU is analyzed in detail
Noda, Hirokazu, Takei, Takahiro
Journal Article
Fatigue Life Prediction of Heavy Duty Automobile’s Brake Drum through Coupled Thermo-Mechanical Analysis2019-28-003110/11/2019
The aim of this paper is to demonstrate the methodology to simulate the induced stresses/strains due to thermo-mechanical loading of automobile brake drum.. The brake drum undergoes mechanical load due to applied brake pressure and thermal load due to friction generated between brake pad and brake drum while brake is applied. This coupled thermo-mechanical loading affects the life of the brake drum as the stiffness of the brake drum is reduced. The conventional method of simulating this problem is done using Lagrangian discretization in which the load is applied and inertia effect due to angular velocity is applied to a drum at static condition. In contrast, in this paper Eulerian discretization is adopted for finite element analysis, in which drum brake model is discretized as spatially dependent that facilitates actual rotation of brake drum with simultaneous application of brake load resulting more precise simulation. A sequentially coupled transient thermo-mechanical analysis is
Annamalai, Krishnamoorthy, Naiju, Chooriyaparambil Damodaran
Technical Paper
Squeal Noise Improvement by High Damping & High Stiffness under Layer Material2019-01-2111.109/15/2019
This research focused on damping characteristics of Under Layer (UL) material to improve squeal noise performance. The study clarified that the raw material orientation causes anisotropy in dynamic viscoelasticity, especially with high damping and high stiffness UL material. Also, the loss modulus value, which is the damping element of dynamic viscoelasticity, corresponds with the raw material orientation and it is effective for damping for bending vibration. As a result, by using high damping and high rigidity UL material, the pad damping ratio was increased which leads to improved squeal noise.
Technical Paper
Brake Rotor Corrosion and Friction Cleaning Effect on Vehicle Judder Performance2019-01-211509/15/2019
Brake disc corrosion has emerged as an important field of study within the automotive industry due to the wide range of lining materials that are currently used worldwide, and their inherent rust-cleaning properties. The presence of oxide layers irregularly deposited on the cast iron disc surfaces usually leads to a forced, braking-induced vibration that can reach the driver’s position as a pronounced annoyance. Hence, the friction material composition directly impacts on the judder performance during the early corrosion-removal stage. This study incorporates both dynamometer and vehicle tests into the definition of a predictive methodology that allows corrosion-induced vibrations to be investigated at both system and vehicle levels. The oxide film is artificially generated by means of a salt spray chamber under steady-state climate conditions in order to guarantee a repetitive and robust procedure. The vibration response of the system is objectively evaluated in the form of caliper
Molina Montasell, Narcís, Ferrer, Bernat
Technical Paper
Frequency Inspection of Brake System Components2019-01-211709/15/2019
Frequency inspection has long been a tool utilized by manufacturers of brake system components as a means of quality control. This is important to combat perceived defectiveness of a system that experiences issues, such as brake squeal, as well as to identify actual defects in the parts going out to customers. Every component has its own resonance frequencies based on the dynamics of that component. Knowledge of the resonance frequencies of each component provides insight that can prevent manufacturers from sending out defective units, whether they be perceived defects or actual defects. NVH engineers who understand these phenomena perform theoretical analysis and acquire experimental data in the lab to gain insight into their parts that will eventually be produced on the assembly line. Unfortunately, the frequency requirements, and the consequences thereof, defined by the NVH engineers can still remain somewhat of a mystery to the manufacturing engineers who are tasked with applying
Cagle, Robert
Technical Paper
Objective Method for Crack Detection in Brake Friction Material2019-01-211309/15/2019
Friction material manufacturing is a complex process where numerous raw materials are mixed, pressed, and cured to make brake pads. It is important to have a consistent manufacturing process that can produce a brake pad that satisfies the vehicle braking requirements. A basic and critical requirement for any brake pad is structural integrity with no internal cracks. In this work a series of processing changes were made to intentionally produce internal cracks in the friction material. Various pad crack detection methods were studied, and their advantages and disadvantages are discussed in detail. One of the crack detection methods used an ultrasonic measuring instrument which gives objective data in the form of calculated modulus of elasticity and signal loss. The details of the machine and how the measurements are obtained are discussed. The modulus calculation is also described. Additionally, random pads with and without cracks were selected and checked using subjective and objective
Divakaruni, Saikiran, Yuhas, Donald, Vorres, Carol, Kaatz, Richard
Technical Paper
Divergence of Thickness Loss vs. Weight Loss, Friction and Wear Behavior of Heavy Truck Brake Blocks: Development of a New Test Procedure for the Chase Tester2019-01-210709/15/2019
Heavy truck brake blocks are found to swell (or expand) permanently during testing or usage, especially so at high temperatures, thus leading to longer durability as measured by thickness loss, similar to light vehicle disc pads. This swelling phenomenon occurs continuously in the layer adjacent to the friction surface during testing or usage; not a one time event. The thickness loss estimated from the weight loss is always greater than measured thickness loss. Brake block wear does not increase linearly with increasing normal load, and the load-sensitivity of block wear is very much dependent on the products. A new test procedure has been developed for generating friction-vs.-temperature and wear-vs.-temperature data at a constant temperature employing intermittent braking on the Chase Brake Lining Quality Tester (SAE J661) and friction material wear can be compared on equivalent-work basis.
Rathee, Aman, Sharma, Devendra Kumar, Singh, Shivraj, Rhee, Seong Kwan
Technical Paper
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