Browse Topic: Brake discs

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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
The Effects Of Corrosion On Particle Emissions From A Grey Cast-Iron Brake Disc2022-01-117809/19/2022
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 into 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 exhausted emissions, there is still a concern of the non-exhausted emission, such as brake dust, which can still cause harm to human health and the environment. Despite EVs primarily using regenerative braking, they still require friction brakes to supplement as and when required. Moreover, EV’s will likely continue to use the traditional grey cast iron brake rotor, which is heavy and prone to corrosion which may exacerbate the brake wear emissions. This study concentrates on emissions from a conventional grey cast iron
Ghouri, Ishmaeel, Barker, Richard, Kosarieh, Shahriar, Brooks, Peter, Barton, David
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
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
Re-imagining Brake Rotor Thermal Fatigue Testing to Relate to Field Use2022-01-116309/19/2022
The validation of brake rotors 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 rotor to get very hot, to where the strength of the material from which the rotor is constructed is significantly degraded. There is little debate about whether these procedures work; by and large rotor 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
Antanaitis, David, Langhardt, Jerry
Journal Article
Design, Simulation and Topology Optimization of Rotor Disc2022-26-118805/26/2022
Brake systems are one of the most critical components of any mobile vehicle. They play a vital role in providing safety to the passengers, vehicle and surroundings. It works on basic principle of Pascals Law by applying forced frictional resistance to the rotating members of the vehicle to slow down the speed. Generally, cast iron is used as a primary material for the rotor in different applications. The current study involves the modelling of the Brake disc according to general specifications of All Terrain Vehicle and performing FEA Analysis on brake disc to study different results. The FEA analysis include the static structural to test the rigidity and ruggedness of disc, Steady and Transient Thermal Analysis to study the behavior of disc under varying thermal loads. It includes study of various parameters such as Von Mises Stress, Total Deformation, Thermal Gradient and Total Heat flux across the brake disc to evaluate the performance under extreme conditions. Different types of
Ruparelia, Rudra, Patel, Aarya, Baxi, Neel
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
Investigation of Al2O3-Ni coated cast iron brake rotors under modified brake dynamometer test standards2022-01-030903/29/2022
Due to the reduced or less-frequent usages of the friction brakes and the lower brake rotor temperature on electrical vehicles (EV), corrosion would much likely occur on brake rotors. Using hard braking to clean the corroded rotor surfaces often leads to extra rotor surface wear. Improvement in corrosion and wear resistance is an important technological topic to brake rotors for EVs. Many original equipment manufacturers (OEM) and their suppliers are exploring surface treatments including laser cladding and thermal spray processes on cast iron rotors to combat the corrosion issues. However, mentioned surface coating processes increase the cost of brake rotors and there is a need to search for cost-effective coating processes. In this research, a new Al2O3-Ni composite coating was proposed for preparation of a commercial cast iron brake rotor using both plasma electrolytic aluminating (PEA) and electroless nickel plating (ENP) processes. The added nickel was to fit in the intrinsic
Cai, Ran, Sun, Jiayi, Zhang, Jingzeng, Tjong, Jimi, Foots, Sean, Lavelle, Mark, Nie, Xueyuan
Technical Paper
Driveline Parking Brake Test Procedure for Medium Duty VehiclesJ2690_202110 (Current)10/28/2021
This SAE Recommended Practice establishes uniform test procedures for friction based parking brake components used in conjunction with hydraulic service braked vehicles with a gross vehicle weight rating greater than 4500 kg (10 000 lb). The components covered in this document are the primary actuation and the foundation park brake. Various peripheral devices such as application dashboard switches or indicators are not included. These test procedures include the following: a Brake Related Tests 1 Brake Functional Performance 2 Brake Dynamic Torque Performance 3 Brake Corrosion Resistance 4 Brake Endurance with Torque 5 Brake Endurance without Torque 6 Vibration Resistance 7 Brake Ultimate Static Load 8 Brake Lining Wear Adjuster Function b Actuation Related Tests 1 Mechanical Actuator Functional Performance 2 Mechanical Actuator Endurance 3 Mechanical Actuator Quick Release 4 Mechanical Actuator Ultimate Load 5 Spring Apply Actuator Functional Performance 6 Spring Apply Actuator
Truck and Bus Hydraulic Brake Committee
Recommended Practice
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 on brake disc deformation under asymmetric mechanical loads2021-01-129110/11/2021
The mechanism of automobile brake hot spots is unclear, which is a problem in the brake industry. Complex coupling between friction, heat, contact, and structural is the main difficulty in revealing the mechanism of brake hot spots. This paper proposes a new way to study the mechanism of hot spots by analyzing the deformation behavior of brake discs under asymmetric mechanical load. The actual brake is simplified into a brake disc and friction lining system, and a transient dynamic finite element model under asymmetric mechanical loads is established to analyze the deformation characteristics of brake disc. It is found that the normal deformation of the brake disc under asymmetric mechanical loads consists of two parts: low-frequency bending deformation and high-frequency waviness deformation, which are caused by the squeezing effect of the asymmetric brake pressure on the brake disc and the constraint modal vibration of the brake disc. The influence of rotation speed, the magnitude
Meng, Dejian, Tong, Yongsheng, Zhang, Lijun
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
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
Development of a Modeling Approach to Numerically Predict Filtration Efficiencies of Brake Dust Particle Filters2021-01-128510/11/2021
According to the European Environment Agency, air pollution is the biggest environmental health risk in Europe. Since traffic is one of the main contributors of fine dust, technical solutions are necessary to reduce the particulate emission footprint of vehicles. Also the Health Effects Institute hosted recently an international workshop on non-tailpipe emissions. Brake dust filtration concepts have proven to be a promising solution to significantly reduce fine dust emissions from brakes directly at the source. While CFD simulations for inner-ventilated brakes have become state-of-the-art, a holistic models from particle generation and emission to particle dynamics in the vicinity of the brake is not yet available. However, a good modeling approach of particle tracks is essential to predict filtration efficiencies of brake dust particle filters. It will be shown that based on current literature data and models, and independent of the turbulence model, filtration efficiencies cannot be
Keller, Florian, Krupa, Lukas, Beck, Andreas, Wörz, Tobias, Weller, Benedikt, Kohn, Kevin, Pfannkuch, Steffen, Jessberger, Thomas, Lehmann, Martin, Ashish, S
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
The design process for a formula student car brake disc2021-28-025210/01/2021
In today's world with fast-growing mobility, everything is becoming more compact day by day with ever-increasing technological advances. This paper deals with the design of a disc brake rotor considering the requirement of the student formula team. In this paper, different design iterations shall be realized to have maximum heat flux distribution and at the same time maintain the structural rigidity of the rotor so that it can withstand the torque requirement of an SAE vehicle especially the acceleration test. Solidworks was used for design modeling while Optistruct and Hypermesh were used to perform the CAE Analysis for the brake rotor. In this paper, we will explain various design iterations and how design can be optimized with extensive use of CAE tools by performing structural and thermal analysis, etc. The analytical results from the CAE simulation will help us to determine the slots and hole pattern on the rotor face as well as material selection for the rotor. The numerical
KUMAR, NAVNEET, Pandey, Anurag
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
Coupled CFD simulation of Brake duty cycle for Brake system design2021-26-036009/22/2021
Brake system design is intended to reduce vehicle speed in a very short time by ensuring vehicle safety. In the event of successive braking, brake system absorbs most of vehicles kinetic energy in the form of heat energy at the same time it dissipates heat energy to the surrounding. In this period temperatures on the brake disc shoots to higher side and during successive braking rotor may attain peak temperatures (above allowable limits). High temperatures on rotor disc affects durability & thermal reliability of the brake rotor. Excessive temperature on brake rotors can induce brake fade, disc coning which results in reduced braking efficiency. To address the complex heat transfer and highly transient phenomenon while successive braking, numerical simulations can help to analyse complex 3D flow physics and heat dissipation from rotors in the vicinity of brake system. Front loading of the simulation in initial design stages to optimize rotor design can improve brake design which in
Chaudhary, Alok Subhash, Ghodake, Preetam, khewale, Swapnil
Technical Paper
WHAT WE'RE DRIVING21AUTP02_0802/01/2021
Since its U.S. launch for the '18 model year, the positioning of the Kicks has puzzled me. Though Nissan was anxious to bill it a “crossover,” I think most would call it a “car.” Nissan hardly is alone in this marketing sleight-of-hand. Given American buyers' refusal to tarnish themselves with anything that can't be construed as some kind of truck, it's at least understandable. But here's my rule: no calling it a crossover if it can't be had with all-wheel drive. And confoundingly, inexplicably, stubbornly against all sense, the Kicks is strictly front-drive. Apart from that, the Kicks probably accomplishes some of the mission of grabbing buyers who need to think they're not purchasing a car; Nissan sold a comparatively healthy 58,858 Kicks in 2020.
Magazine Article
BMW reveals its first “M” performance-badged two-wheeler20AUTP11_1111/01/2020
BMW has revealed its first-ever M-badged motorcycle, the M 1000 RR superbike. A heavily reworked version of the already-capable S 1000 RR sportbike, the new machine is riding the trend of track-focused machines, as the motorcycle industry watches sportbike sales follow the same path as sedans in the automotive world. BMW's highly regarded Motorsports division produced its first racecar (the 3.0 CSL) in 1972 and its first road-going car with the mid-engine M1 in 1978. Since then, the Munich-based auto- and motorrad-maker has since produced an M version of nearly every car it has manufactured, the 7 Series being a notable exception.
Seredynski, Paul
Magazine Article
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
Performance Gains of Load Sensing Brake Force Distribution in Motorcycles2019-28-242611/21/2019
Commercial motorcycles and scooters incorporate independent circuits for front and rear brake actuation, thus precluding load-dependent brake force distribution. In all cases of manual brake force modulation between the front and rear wheels, there is poor compensation for the changes in wheel loads on the account of longitudinal weight transfer, thus making it challenging to provide an adequate braking force to each wheel. The ratio in which the braking force should be distributed between the front and the rear wheels is dependent on the motorcycle’s geometry, weight distribution, mechanical sizing of braking system components, and is a variable based on the instantaneous deceleration. This connotes that a fixed bias of front and rear braking forces can be optimized only for a narrow range of motorcycle’s deceleration. Maximum braking performance occurs just prior to wheel lock-up, as a sliding tire provides less grip than a rolling tire. This is also the scenario when both the tires
Chakraborty, Apurva
Technical Paper
A New Appraisal of the Thermomechanical Behaviour of a Hybrid Composite Brake Disc in a Formula Vehicle2019-28-257211/21/2019
The present work promotes a hybrid composite brake disc for thermal and structural analysis of a formula vehicle. In order to reduce the un-sprung weight without compromising the strength, hybrid composite materials were incorporated in the disc plates of the braking system. In the disk brake system, the disc is a major part of a device used for slowing or stopping the rotation of a wheel. Repetitive braking of the vehicle leads to heat generation during each braking condition. Based on the practical understanding the brake disc was remodeled with unique slotting patterns and grooves, using the selected aluminium alloy of (AA8081) with reinforcement particle of 15wt% Silicon carbide (SiC) and 3wt% Graphite (Gr) as a hybrid composite material for this proposed work. By varying slotting pattern and groove angles the transient thermal and structural analysis using ANSYS workbench on the hybrid composite disc plate of disk brake is done. The main purpose of this study is to analyse the
Ranganathan, Soundararajan, Kuppuraj, Sathishkumar, Gopal, Shanthosh, Chandrasakaran, Pradeep
Technical Paper
Nondestructive Measurement of Residual Strain in Connecting Rods Using Neutrons05-12-03-001810/15/2019
Abstract Increasing the strength of materials is effective in reducing weight and boosting structural part performance, but there are cases where the residual strain generated during the process of manufacturing of high-strength materials results in a decline of durability. It is therefore important to understand how the residual strain in a manufactured component changes due to processing conditions. In the case of a connecting rod, because the strain load on the connecting rod rib sections is high, it is necessary to clearly understand the distribution of strain in the ribs. However, because residual strain is generally measured by using X-ray diffractometers or strain gauges, measurements are limited to the surface layer of the parts. Neutron beams, however, have a higher penetration depth than X-rays, allowing for strain measurement in the bulk material. The research discussed within this article consists of nondestructive residual strain measurements in the interior of connecting
Ikeda, Tomohiro, Jeffery, Bunn R., Fancher, Christopher M., Motani, Ryuta, Matsuda, Hideki, Okayama, Tatsuya
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
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
Characteristics of a Brake Disc’s Nonuniform Thermomechanical Responses to an Emergency Braking2019-01-211809/15/2019
Brake discs in service are subjected to the combined thermal and mechanical loadings. Due to the complex interactions of different parts in operating brake systems and various thermal and mechanical boundary conditions, the thermomechanical responses of brake discs are highly nonuniformly distributed across the brake discs. In this paper, a detailed finite element analysis model was developed to understand the thermomechanical responses of a solid brake disc to an emergency braking. The temperature and the stress in the brake disc were then characterized thoroughly in the radial, circumferential and thickness direction of the disc, and it was found that they were all nonuniformly distributed in the three directions. Furthermore, the stress responses of the disc due to the combined thermal and mechanical loadings were separated into thermal stress and mechanical stress, and their particular characteristics to the individual thermal or mechanical loading were identified. That is: the
Yang, Qianjin, Gai, Fulin, Song, Liqiang, Yu, Hui, Zhang, Baozhi
Technical Paper
The Improvement Brake’s Qualities of Vehicle by Developing the Method of the Choosing Frictional Pairs of the Brakes Mechanisms2019-01-214509/15/2019
One of the reasons for the large number of road accidents on highways in Ukraine [1] is the instability of the braking properties due to the unstable characteristics of the brake mechanisms’ friction pairs. The manufacturer produces new automobiles with installed brake pairs (brake pads and their counter bodies), which have passed long-term tests for the stability of the friction coefficient and braking forces distribution of between the axles. This ensures the compatibility of the friction pairs characteristics for front and rear brake mechanisms according to the criteria of heat resistance. During operation, instead of worn-out brake pads, brake discs and drums, drivers can purchase new ones, manufactured as spare parts. However, in the well-known literature there are no methods that allow to check the compatibility of the friction pairs characteristics for front and rear brake mechanisms according to the criteria of heat resistance. In the article a method for choosing a set of
Podrigalo, Mikhail, Klets, Dmytro, Kholodov, Mykhailo, Bogomolov, Viktor, Turenko, Anatoliy, Molodan, Andrii, Rudzinskyi, Volodymyr, Tarasov, Yurii, Mykolai, Aloksa, Hatsko, Vasyl
Technical Paper
The Analysis of Brake Squeal Noise Related to the Friction Properties of Brake Friction Materials2019-01-213209/15/2019
The friction properties related to squeal noise was analyzed with the development histories and simplified computational method. Firstly, the development histories were investigated especially focusing on the case which the friction materials were modified to improve squeal noise occurrence. Based on the histories, the friction properties of selected friction materials were newly measured using dynamometer. The average friction coefficient levels, torque oscillations, the increment of friction coefficient during full-stop, and etc. were compared with the squeal noise occurrence, and the results showed that increase of friction properties cause production of squeal noise. The result suggested that the size of friction energy was important factors related to triggering the squeal noise. Also, the contact conditions between rotor disc and friction materials were significant factors deciding the noise occurrence. We performed simplified computational analysis using MATLAB program to prove
Lee, Sang-mok, Woo, Jung Hoon, Cho, Younggu, Kim, Dong Won
Technical Paper
A Study of the Disc Scoring Generation Principle and Reduction(III)2019-01-211209/15/2019
In the latest works [12], we presented the guideline for reducing Metal pick up(MPU, the main component of disc scoring) by controlling the location of the roughness of disc, the brake pad friction coefficients and the disc slot's size. In this study, the previously studied iron transfer theory to 'Cu free' brake pad and the disc surface roughness controlling methods which are based on the mass production manufacturing process are applied. It is possible to suggest the ways to improve the scoring-free disc without reducing friction coefficient between the disc and pad, and any demerit such as increased wear and airplane noise like conventional slot discs [11].
Jeong, ByeongUk, Ryu, Hyoung Tae, Jung, Kwang Ki, Kim, Chang Jin, Lee, Hyunkyoung
Technical Paper
Inboard Mounted Disc Brake Rotor/Disc Wheel Hub Interface Dimensions - Commercial VehiclesJ2696_201909 (Historical)09/03/2019
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.
Truck and Bus Wheel Committee
Recommended Practice
Effect of Slot and Chamfer Shape of Brake Pad on Mode Coupling2019-01-141903/25/2019
In the present, one of the essential quality concerns in the automotive industry is brake squeal. Brake pad shape is one of the factors affecting to brake vibration and squeal noise. This research aims to study the effect of slot and chamfer shape on mode coupling through the Finite Element Analysis (FEA), impact hammer testing and performance test from dynamometer. The results can be used to develop geometry of the brake pad surface that leads to brake squeal reduction in the design stage. The natural frequencies and mode shape of brake components calculated by FEA are compared with the impact hammer testing to ensure the accuracy of the results. The FE results are also verified through the standard test with a dynamometer.
Yeamdee, Sirapath, Bovornratanaraks, Thiti, Sriwiboon, Meechai, Chantalakhana, Chak, Ratanasumawong, Chanat
Technical Paper
EDITORIAL: The future of motorsports is…quiet19AUTP08_0901/01/2019
Perched up on jackstands, its fat Michelin-shod wheels removed, the Audi e-tron FE05 looks like a multicolored shark out of water. Mechanics are swirling around this battery-electric race car, preparing it for a practice session during the Brooklyn E-Prix-the final race of the 2019 FIA Formula E championship season in New York. Standing just outside the garage perimeter on a hot July morning, I watch clouds of steam swirl around the rear of the car, one of two FE05s campaigned by the Audi Sport ABT Schaeffler team. While charging, the 52 kW-h lithium-ion battery is being force-fed cold air through its radiator side pods to keep it thermally happy. The dry-ice clouds are a familiar pit scene in Formula E racing, a signature of the “JuicePump” charging system from Italian renewable-energy giant Enel that is used by each of the 11 teams in this 13-race global series.
Brooke, Lindsay
Magazine Article
2019 Yamaha Niken steers a radical path18AUTP11_1311/01/2018
When Yamaha debuted the MWT-9 concept three-wheeler at the Tokyo Motor Show in October 2015, many were impressed by its technology and almost unnerving, mantis-like visual presence. Yamaha has a history of stunning concepts for the Tokyo show, so it's likely few thought a production version would ever see real roads. But two years later at the same show, Yamaha unveiled the world's first 3-wheel leaning motorcycle and amazingly, production of the Niken began in the second half of this year. The Niken is a brazen mechanical-engineering statement, in the vein of Yamaha's 1993 forkless GTS1000. Based at the company's HQ in Iwata, Japan, the main Niken development team was comprised of eight Yamaha Motor Company (YMC) staff, four of whom were engineers. Takahiro Suzuki was the Project Leader for Niken development, with chassis development handled by Ryuta Mitsuoka.
Seredynski, Paul
Magazine Article
A New Model Describing the Formation of Heat Cracks in Brake Discs for Commercial Vehicles2018-01-188210/05/2018
During the development process of brake discs for commercial vehicles, heat cracks are a frequent problem. Since no profound model to forecast the occurrence of cracks has been presented yet, their prediction is hardly ever possible. The standardized heat crack test puts the brake disc under severe thermomechanical load and therefore forces it into cracking. In this paper, results from a series of heat crack tests on the dynamometer are presented, which provide insight into the hidden processes that accelerate or slow down the heat crack propagation in brake discs. This includes an extensive experimental setup using a thermographic camera, a set of capacitive displacement sensors, a pyrometer, and sliding thermocouples as well as a unique eddy-current heat crack detector that was developed at TU Darmstadt. Continuous monitoring of disc deformation, surface temperature, and crack propagation at high sampling rates provides the base for a new, profound causal model. The model describes a
Bilgic Istoc, Sami, Winner, Hermann
Technical Paper
On the Wear Dependence of Low-Frequency and High-Frequency Brake Squeal2018-01-190210/05/2018
The dynamics of disc brakes, and in particular their NVH behavior, have long been the focus of research. Measurements by Rhee et al. show that brake pad wear has a significant influence on the occurrence of low and high frequency squealing [1]. It is suspected that low frequency squealing is more likely to occur when the wear difference between the inner and outer brake pads is high. If the two pads incur comparable wear, however, the prevalence of high frequency squealing increases. In order to investigate this hypothesis, this paper focuses on a simplified model of a commercial brake system. First, the friction force between the inner pad and the disc is iteratively adjusted, while the force between the outer pad and the disc is held constant. In a second step, the inner pad’s wear is iteratively increased, while the wear on the outer pad remains unaffected. With the aid of the Complex Eigenvalue Analysis (CEA), the real part of the eigenvalue is used as a quantification measure in
Otto, Johannes, Ostermeyer, Georg, Rhee, Seong
Technical Paper
Lightweight, Wear Resistant, High Thermal Conductivity Metal Matrix Composite Brake Rotors2018-01-187910/05/2018
Aluminum (Al) - silicon carbide (SiC) metal matrix composite (MMC) brake rotors have been investigated for lightweight vehicular applications but have not widely been utilized due to issues with uniformity of distribution of SiC particulates, residual porosity, formation of undesirable phases such as aluminum carbide, and high temperatures incurred during braking that degrade the rotor’s integrity and performance. ATS-MER has overcome these issues with the development of a patented sandwich type structure with wear resistant thin Al-SiC MMC surface layers and a high thermal conductivity aluminum alloy core. Substantial dynamometer and vehicle testing has been performed by a major automobile company with excellent results, including much lower induced temperatures, 96.3 to 99.6% less particulate (dust) generation in comparable testing of cast iron rotors, and almost 10 times the number of maximum cycles possible during testing of cast iron discs. Thus, ATS-MER’s novel Al-SiC MMC brake
Bracamonte, Lori, Withers, James, Smith, Thomas
Technical Paper
Performance Evaluation of Two Wheeler Brake System Using Coupled Thermo-Mechanical Simulation2018-01-189610/05/2018
Safety aspect has been a key requirement in designing braking system. However, non-safety aspect like NVH and thermal performance are gaining equal importance. High engine capacity (cc) motorcycles are prone to thermal and NVH issues as braking energies are more. Therefore, virtual validation of brake disc system by considering both dynamic and thermal load with predefined assumptions is a toughest challenge when confronted with reality boundary conditions. Thus, the paper comes in a unique way of coupling dynamic and thermal load executed between multi body dynamics (MBD) and heat transfer equation which will convey results closer to real time scenario. MBD solves motion and the dynamic influence on heat transfer is calculated using “sliding boundary condition”. A series of repeated braking condition are performed on front brake disc of motorcycle. The results obtained from the analysis shows critical temperature rise. As a consequence, disc thickness variation (DTV) due to thermal
Sukumaran, Suraj, Kalani, Dinesh, Suryavanshi, Yogesh, Kokane, Girish, Deshpande, Moresh, Kharul, Ravindra
Technical Paper
Numerical Study on Fluid Flow and Heat Transfer Characteristics of a Ventilated Brake Disc Connected to a Wheel2018-01-187810/05/2018
The role of a brake disc is to convert the kinetic energy of automobiles into thermal energy caused by friction between the brake pads and disc surfaces. The braking performance of an overheated disc is decreased due to hot judder and fade. Hence, the cooling technology of a brake disc is one of the most important issues related to automobile safety. In the present study, the fluid flow and heat transfer analysis of a ventilated brake disc are conducted numerically. Some geometries of automotive parts such as bearings, hubs and wheels are considered in this study. The commercial code ANSYS CFX is used to simulate the fluid flow and the conjugate heat transfer which includes conduction and convection. To evaluate the cooling performance in each case, the results, including the flow patterns of cooling air inside the wheel and the heat transfer coefficient distribution at the disc surfaces, were investigated and compared for various disc-hub combinations.
Lee, Byung Ju, Chung, Jin Taek, Jung, Yunho, Kim, Honglae, Lee, Seungpyo, Kim, Hee Yeol
Technical Paper
Non-Asbestos Organic (NAO) Disc Pad Wear Behavior: Divergence of Thickness Loss and Weight Loss2018-01-186610/05/2018
There is anecdotal evidence that disc pad wear numbers measured in thickness loss and disc pad wear numbers measured in weight loss do not show the same wear trends after wear or performance testing. However, research papers on this topic are difficult to find. Therefore, this investigation was undertaken to study and document this behavior in detail on high-copper, low-copper and no-copper (or copper-free) NAO pads. In all cases, thickness loss measurements are found to be substantially lower than expected from the weight loss data according to the SAE J2522 test schedule. This divergence is caused by pad swelling in the pad layer adjacent to the friction contact surface during brake testing at high temperatures. In addition to formulation changes, disc pad processing conditions such as mixing time and hot molding pressure are found to affect pad swelling. As pad physical properties, especially in the layer adjacent to the friction contact surface, are expected to dynamically change
Sriwiboon, Meechai, Tiempan, Nipon, Kaewlob, Kritsana, Rhee, Seong
Technical Paper
The Factors Governing Corrosion Stiction of Brake Friction Materials to a Gray Cast Iron Disc2018-01-189910/05/2018
Corrosion stiction at the contact interface between a brake friction material and a gray iron disc under the parking brake condition was investigated by evaluating the possible parameters that affect the shear force to detach the corroded interface. Using production brake friction materials, comprising non-steel and low-steel types, corrosion tests were carried out by pressing the brake pad onto the gray iron disc using a clamp at various conditions. Results showed that the shear force to detach the corroded interface tended to increase with applied pressure and corrosion time. On the other hand, porosity, acidity, and hydrophobicity of the friction material did not show a reliable correlation to the stiction force. The poor correlation of the stiction force with the friction material properties indicated that the stiction force was not determined by a single factor but governed by multiple parameters including surface contact areas and inhomogeneity of the ingredients. Microscopic
Gweon, Jaehyun, Shin, Sanghee, Jang, Ho, Lee, Wangyu, Kim, Dooyeon, Lee, Keeyang
Technical Paper
A Study of the Disc Scoring Generation Principle and Reduction (II)2018-01-189110/05/2018
In the latest paper [10], we presented our work based on experiments studying MPU (Metal Pick Up) of the pad and scoring(scratching) of the disc. The main component of MPU was iron “Fe”. If the roughness of the disc was small, the content of iron “Fe” was increased and the segregation of that was decreased especially in initial condition. In this study, we extended our study based on the results by adding some additional factors such as the location of the roughness of the disc, the coefficients brake pad friction, and disc slots. We made various discs of different roughness boundaries and slots, and pads of pad friction coefficients; and conducted two types of tests for whether a slot is present or not with the other same conditions to confirm the impact of the scoring. We find and believe that our experimental data should serve a useful guideline for reducing MPU of the pad and scoring of the disc.
Jeong, ByeongUk, Ryu, Hyoung Tae, Kim, Chang Jin, Jung, Kwang Ki, Lee, Hyunkyoung
Technical Paper
Properties and Limitation of an Oxide Coated Aluminum Brake Rotor2018-01-187710/05/2018
The electrification of the powertrain and the thereto related recuperation of the electric engine saves the energy in the battery and thus reduces the thermally dissipated brake energy, which leads to lower brake rotor temperatures compared to combustion engine vehicles (ICEVs). These new conditions enable to reconsider brake disc concepts. Including lightweight design in heavy battery electric vehicles (BEVs) and the increasingly reliant corrosion resistance of brake rotors, Aluminum is a promising approach for new brake disc concepts. In the past, Aluminum brake disc concepts have already been deployed. For instance Aluminum Metal-Matrix Composite (Al-MMC) concepts in the Lotus Elise S1 and on the rear axle of the Volvo V40 [1]. The presented concept is a different approach and separates the friction system from the bulk Aluminum brake disc, achieved by coating of the friction rings. By locally reinforcing the friction rings, the good machinability and ductility of the base body is
Gulden, Florian, Gramstat, Sebastian, Stich, Anton, Hoppel, Heinz Werner, Tetzlaff, Ulrich
Technical Paper
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