Browse Topic: Disc brakes

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Friction Performance Analysis of Mine Wet Multi-Disc Brake02-17-01-000110/28/2023
Abstract This article takes the wet multi-disc brake used in mining Isuzu 600P as the research object, establishes a simplified three-dimensional model of its key components through SOLIDWORKS and imports it into ANSYS Workbench to establish the flow field and structure field model of the wet brake. Based on the fluid–solid coupling, the finite element simulation of the temperature field and stress field of the friction pair of the wet brake under different braking pressures, braking initial speeds, and fluid viscosities was carried out, and then the position changes of the friction pairs at high temperature hot spots and high stress points were analyzed to determine the stability of its friction performance. Finally, by comparing the temperature change curves of the same point during the braking process under different braking conditions, the validity of the finite element analysis results is verified. The results show that the flow field pressure inside the wet brake is opposite to
Zhang, Chuanwei, Jin, Xiaohe, Zhao, Dawei, Liu, Jinpeng
Journal Article
Brake Noise CAE Enhancement with the Synergy between Design of Experiments and Machine Learning2025-01-012405/05/2023
The digitalization of industrial systems has led to increased data availability. Machine learning (ML) methodologies are now commonly used for data analysis in industrial contexts. Not all contexts have abundant data; sometimes data collection can be scarce or expensive. DOE is a technique that provides an informative dataset for ML analysis when data are limited. It involves systematically designing experiments to collect relevant data points with regression models. Disc brake noise is a challenging problem in vehicle noise, vibration, and harshness (NVH). Different noise events occur under various operating conditions and across frequencies (1-16 kHz). To enhance computer-aided engineering (CAE) techniques for brake noise, ML is used to generate additional data. Sequential experimentation in DOE aligns well with ML’s ability to continuously learn and improve as more data become available. DOE is applied in CAE to collect data for training ML models. ML helps find patterns in high
Song, Gavin, Venugopal, Narayana, Vlademar, Michael
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
The Validation of an Empirical Disc Brake Model with Full-Vehicle Brake Tests2022-01-508210/06/2022
The brake of a vehicle is of particular importance for vehicle safety. Brake inspection is an essential part of the periodic technical inspection and contributes to road safety. The current vehicle brake inspection methods are mostly tied to brake tester and check the vehicle brake in a workspace that does not have much practical relevance. Therefore, an attempt is made to develop dynamic inspection methods for automotive brakes, which are based on driving tests. To develop these dynamic inspection methods, a vehicle model is used, which includes an empirical brake model that takes into account the various dependencies of the coefficient of friction of the friction pairing of automotive disc brakes. The model is later validated with full-vehicle brake maneuvers from different velocities and under different conditions and shows good results.
Schramm, Tobias, König, Pascal, Kubenz, Jan, Prokop, Günther
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
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
Systems of automatic brake torque reduction on the wheels of one axle of the car2021-01-126610/11/2021
Braking mechanisms are the most unstable elements of a vehicle's braking system. Instability of braking torques on the wheels of one axle of the vehicle leads to the appearance of the braking forces unevenness, and then- to the vehicle skidding during braking. At one time, the appearance of open-type disc brakes made it possible to reduce the unevenness of the braking forces on the sides of the car due to their higher characteristics of energy intensity and stability. However, the lack of feedback between the left and right disc brakes mounted on the same axle of the vehicle does not allow reducing the unevenness of the braking forces to an acceptable minimum. The authors of the work studied and proposed several systems for automatic reduction of the braking torques unevenness for braking mechanisms mounted on the wheels of one axle. The following options are proposed: - hydrostatic system for automatic reduction of braking torques unevenness on the wheels of the car front axle
Podrigalo, Mikhail, Kholodov, Mykhailo, Stepanov, Victor, Soloviov, Oleh, Aleksandrov, Yevgeniy, Volontsevych, Dmytro, Morozov, Oleksandr
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
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
Dimensional Compatibility for Commercial Vehicles Fitment of Complete Wheels in Drum Brake Applications - Truck and BusJ1865_202011 (Current)11/04/2020
This SAE Recommended Practice defines a clearance line for establishing dimensional compatibility between drum brakes and wheels with 19.5 inch, 22.5 inch, and 24.5 inch diameter rims. Wheels designed for use with drum brakes may not be suitable for disc brake applications. The lines provided establish the maximum envelope for brakes, including all clearances, and minimum envelope for complete wheels to allow for interchangeability. This document addresses the dimensional characteristics only, and makes no reference to the performance, operational dynamic deflections, or heat dissipation of the system. Valve clearances have not been included in the fitment lines. Bent valves may be required to clear brake drums. Disc brake applications may require additional running clearances beyond those provided by the minimum contour lines. Mounting systems as noted are referenced in SAE J694.
Truck and Bus Wheel Committee
Recommended Practice
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
Dimension Compatibility for Commercial Vehicle Wheels to Air Disc Brake Calipers - Truck and BusJ2803_202006 (Current)06/05/2020
This SAE Recommended Practice defines the boundary line for establishing dimensional compatibility between air disc brake calipers and 22.5 x 8.25 inch disc wheels, including bent valve stems on steel wheels and manufacturer recommended valve stems on aluminum wheels. The line establishes the minimum wheel with valve stem envelope to allow interchangeability. The line does not accommodate customer-specific wheels (such as OEM-specific stylized wheels) or customer-specific brakes. This document addresses dimensional characteristics only and makes no reference to the performance, operational dynamic deflections or heat dissipation of the system. It is up to the system integrator to ensure sufficient clearance exists between the caliper, wheel and valve stem to provide safe operating conditions. Mounting systems as noted are referenced in SAE J694.
Truck and Bus Wheel 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
Development challenges of hydraulic brakes for commercial vehicles2019-36-001301/13/2020
The automotive research and development environment is increasingly challenging and complex, full of new technologies, regulations and customized customer needs. In addition, the cargo transportation market is very dynamic and competitive, becoming complex the strategies for companies in this segment. According to Anfavea (2018), this trend, especially in large urban centers, has driven the intention to use light commercial vehicles to capillize deliveries in destinations with a high demographic concentration and traffic limited to medium and heavy vehicles. In this scenario, the demand for diversified products is increasing in order to overcome the main tradeoff: “minimizing the size of the trucks and maximize the load capacity”. It brings the number of complex projects. The brake system is greatly impacted in these developments mainly because light commercial vehicles are situated in a weight range that we can call "identity crisis" if on the one hand they need an upgrade compared to
Vetter, Narã Vieira, Carlos de Oliveira, Antonio, Fontes, Eduardo Henrique Souza, Nogueira, Felipe, Fonseca, Guilherme Henrique, Nuss de Souza, Luis Fernando, Oliveira dos Reis, Rodrigo de, Manenti, Vangelo Cardoso
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
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
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
A Predictive Tool to Evaluate Braking System Performance Using Thermo-Structural Finite Element Model06-12-03-001410/14/2019
The braking phenomenon is an aspect of vehicle stopping performance where with kinetic energy due to the speed of the vehicle is transformed into thermal energy produced by the brake disc and its pads. The heat must then be dissipated into the surrounding structure and into the airflow around the brake system. The thermal friction field during the braking phase between the disc and the brake pads can lead to excessive temperatures. In our work, we presented numerical modeling using ANSYS software adapted in the finite element method (FEM), to follow the evolution of the global temperatures for the two types of brake discs, full and ventilated disc during braking scenario. Also, numerical simulation of the transient thermal analysis and the static structural analysis were performed here sequentially, with coupled thermo-structural method. Numerical procedure of calculation relies on important steps such that Computational Fluid Dynamics (CFD) and thermal analysis have been well
Belhocine, Ali, Wan Omar, Wan Zaidi
Journal Article
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
Aging Effect on Disc Pad Properties2019-01-210809/15/2019
One low-copper formulation and one copper-free formulation were made into disc pads, and both of them were cured under 4 different conditions. These pads had no backing layer and no scorched layer. Pad thickness, dynamic modulus and natural frequencies were continuously monitored over a period of 12 months. After 12 months at room temperature, pad thickness, dynamic modulus and natural frequencies all increased to higher values. The low-copper formulation increased relatively rapidly during the first 60 days and the copper-free formulation increased relatively rapidly for the first 90 days, and then slowly thereafter. Two competing processes are found to be taking place simultaneously; internal stress relief leading to pad expansion and cross-linking of the resin leading to pad shrinkage. As the pad properties are changing continuously, the timing of property measurement becomes an important issue for quality assurance. Implications of these changing properties are discussed for
Sriwiboon, Meechai, Rhee, Seong K., Kaewlob, Kritsana, Tiempan, Nipon
Technical Paper
Stability of Wheel Tractors during Braking2019-01-214209/15/2019
The dynamic distribution of normal reactions between the axles of the wheeled tractor has a significant impact on the stability against skidding and the wheeled tractor braking effectiveness. At the same time, the clarification of the normal reactions distribution between the axles allows to choose more rational braking forces distribution between the axles. It is shown that the best way to ensure the highest braking efficiency is the braking mode when the rear wheels of the tractor are at the blocking limit. An assessment of the expediency of installing brake mechanisms on only one axle of the tractor was made. The increase of braking efficiency of wheeled tractors with all brake wheels provided that they ensure directional stability is considered. The laws of braking forces distribution between the axles of wheel tractors for different sequence of wheels locking are determined. Using the method of partial accelerations an improved method for estimating the effect of a brake system on
Podrigalo, Mikhail, Kholodov, Mykhailo, Klets, Dmytro, Dubinin, Yevhen, Savchenkov, Borys, Koryak, Alexander, Rudzinskyi, Volodymyr, Viktoriia, Zadorozhnia, Polianskyi, Oleksandr
Technical Paper
Research on Integrated Performance Design for the Braking System2019-01-212009/15/2019
Medium or higher commercial vehicles weight will be increased by 5 to 6 times compared to kerb weight depending on their load carrying capacity. Therefore, a pneumatic braking device is used that produces a greater braking force than hydraulic pressure. Pneumatic braking system is a device that performs mechanical braking using air pressure and shall be designed to an appropriate level, taking into account the multi-physics of air and mechanical phenomena. In addition, the dynamics of the vehicle during braking should be considered due to different vehicle behavior depending on the load carrying capacity. This study utilizes SIL(Software In the Loop) for a comprehensive review of the pneumatic braking performance of vehicles.
Han, Wookhyun, Yang, Kee-Young
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
Squeal Noise Improvement by High Damping & High Stiffness under Layer Material2019-01-211109/15/2019
The purpose of this research is to clarify how damping characteristics of Under Layer (hereafter “UL”) material in the brake pads (hereafter “PAD”) influences brake squeal noise performance. In this study, UL material structure and dynamic viscoelasticity, for two different types of UL formulations are investigated. In addition, PAD damping ratio and squeal noise performance for multiple UL formulations are verified. As a result, the raw material orientation is determined based on manufacturing method, and it causes the UL material’s anisotropic properties. Dynamic viscoelasticity are dependent on the direction in which they are measured. In particular, the loss modulus, which is the damping element of dynamic viscoelasticity, is higher in the direction of the raw material orientation for the high damping and high stiffness UL formulation. In addition, it was confirmed that this loss modulus in the direction of the raw material orientation is effective for bending vibration. In the
Nishioka, Masato, Johnson, Leanne, Rosalez, Sean, Suzuki, Shusuke
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
Inertia Dynamometer Rotor Crack Test Procedure for Air Disc BrakesJ3080_201905 (Current)05/17/2019
This Recommended Practice applies to commercial vehicles equipped with air disc brakes and above 4536 kg of Gross Vehicle Weight Rating. Other assessments on the friction material or rotor related to wear, durability, correlation to product life, noise, judder, compliance to specific regulations, etc., are not part of this RP (Recommended Practice).
Truck and Bus Foundation Brake Committee
Recommended Practice
Development of Parametrically Integrated Software Platform for Passenger Car Brake System2019-01-123104/02/2019
The hydraulic servo brake system for passenger car plays a central role in occupant protection, which directly affects the automotive active safety and road handling. In this paper, an integrated parameterized software platform of hydraulic servo brake systems is proposed to realize fast and efficient braking system development. At first, according to the structure and working principle of the hydraulic servo brake system, the relationship among amount of fluid required for brake caliper, pedal feel and performance of the brake system is analyzed. Then, based on kinematics and dynamics of the hydraulic servo brake system, a simulation model for analyze pedal feel and amount of fluid required for brake caliper is built in AMESim, which is composed of brake pedal, vacuum booster, brake master cylinder, brake hoses and brake calipers, etc. In addition, the accuracy of the simulation model is verified by bench tests, and the significantly influential factors on the amount of fluid required
Pan, Jin, Guo, Xuexun, Zhou, Wei, Pei, Xiaofei, Pan, Hao, Zhang, Jie
Technical Paper
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
Analysis of Changes in Disc-Brake Squeal Characteristic due to Regenerative Braking Simulation on Brake-Inertia-Dynamometer2019-26-020301/09/2019
Brake is very crucial functional part of automobile, therefore need a robust testing for validation in order to ensure its failsafe functionality under harsh circumstances. For performance testing and foundation brake system design optimization purpose Brake-Inertia-Dynamometer (BID) being used extensively since its inception, and from last two decades for optimization of brake Noise, Vibration, and Harshness (NVH) performance too. In brake NVH the major issue is brake squeal or squeak generation, which is very difficult to predict its occurrences and standardized its prerequisite conditions. Since, brake is the only device which is designed for power absorption in automobile and therefore the regenerative braking concept come to the picture for energy conservation. The loss of energy in braking in case of Hybrid Electric Vehicle (HEV) and Electric Vehicle (EV) is more crucial and hence implementation of regenerative-braking is more discernible in HEVs and EVs to enhance the efficiency
Chilbule, Chaitanya, Weiss, Dieter
Technical Paper
High-Preload Deflection and Compressibility Test Procedures for Friction MaterialsJ2468_201811 (Current)11/12/2018
This standard specifies a method for testing and measuring the deflection of friction materials assemblies and compressibility of friction materials. This standard applies to disc brake pad assemblies and its coupons or segments, brake shoe lining and its coupons or segments, and brake blocks segments used in road vehicles. This SAE test method is consistent in intent with the ISO 6310 and the JIS 4413.
Brake Linings Standards Committee
Technical Standard
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
Study on Brake Disc Dynamics under Asymmetric Thermal Loads2018-01-190110/05/2018
In order to explore the generation mechanism of hot-spots on the automotive brake disc, disc tests under non-frictional thermal loads are carried out on the brake dynamometer test bench. In the tests, the oxy-acetylene flame is used as the heat source, and the distribution characteristics of the disc temperature and displacement are measured and analyzed. To confirm the mechanism of the disc deformation, a disc thermal buckling model using finite element method is established, and the key factors for the disc thermal buckling under thermal loads are further analyzed. It is found that the temperature circumferential gradient is small but the temperature radial gradient is large. The disc presents waviness deformation mode with 5th order in circumferential direction, which is the first thermal buckling mode of the disc. A method using spatial frequency spectrum has been proposed to find the critical time and load of thermal buckling. The heat source power and the rotational speed have no
Meng, Dejian, Liu, Jialin, Zhang, Jingyi, Zhang, Lijun
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
A Study on Trigger of Small Friction Noise in Disc Brake Squeal2018-01-187210/05/2018
Disc brake squeal is caused by flutter of dynamic unstable systems under small disturbance. Therefore the research of small disturbance is very important technical issues for disc brake squeal reduction. The experimental set-up for basic research was developed based on the actual disc brake squeal vibration mode in experiment and its theoretical analysis, which replaces actual caliper and pads to cantilever type pad-caliper. Disc brake squeal depends on the natural frequency of cantilever type pad-caliper, which occurred at 2.7 kHz, 2.0 kHz and 5.3 kHz for each cantilever length L=40 mm, 50 mm and 80 mm in each friction test. In friction tests L=40 mm and 50 mm, cantilever type pad-caliper vibrates with the 1st order bending vibration mode and disc vibrates with the 1st or 2nd order bending vibration mode. In friction test L=80 mm, cantilever type pad-caliper vibrates with the 2nd order bending vibration mode and disc vibrates with the 4th order bending vibration mode. Theoretical
Nishiwaki, Masaaki, Yamamoto, Yukio
Technical Paper
Design Optimization of the Disc Brake for Squeal Noise Reduction2018-01-187410/05/2018
In this paper, squeal noise reduction method of the disc brake was proposed. And, its effectiveness was described. Pad motion was studied with pad abutment types comparison. The brake design was optimized by using the design of experiment method. The effectiveness of the optimum design was clarified by the noise tests with a dynamometer.
Park, Jintack
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
Inertia Calculation for Single-Ended Inertia-Dynamometer TestingJ2789_201809 (Historical)09/26/2018
This procedure provides methods to determine the appropriate inertia values for all passenger cars and light trucks up to 4540 kg of GVWR. For the same vehicle application and axle (front or rear), different tests sections or brake applications may use different inertia values to reflect the duty-cycle and loading conditions indicated on the specific test.
Brake Dynamometer Standards Committee
Recommended Practice
Brake Fade Reduction in a Brake Drum System for Motorcycles2018-01-502807/10/2018
In developing countries, motorcycles have become the most economically efficient choice for commuting. A variety of braking systems in motorcycles like Brake drum and Disk brake have once again become the deciding criteria for wise economic selection of a motorcycle. Due to the low cost of a brake drum compared with a disk brake, a median income group customer segment commonly prefers to buy the brake drum versions rather than disk brake. However the performance of the brake drum is inferior to the disk brake. One major inferior performance feature is brake fade. For a target customer segment, it always becomes a challenge for OEMs to provide the desired braking at sufficiently low costs for customers of that segment, while with the drum braking system, usually the user ends up with loss of brake effectiveness due to overheating, which in turn is produced by repeated braking actions. In this paper, a methodology to minimize brake fade was devised. By redesigning the brake drum (BD) for
Routaray, Ramakanta
Technical Paper
Experimental Investigation of Low-Frequency Vibration Patterns in Automotive Disk Brake Systems: Utilization Study for Modal Simulation Methods2018-01-151306/13/2018
Increasing demands on automotive comfort as well as diminishing vehicle noise levels draw new attention towards low-frequency vibration and noise issues of disk brake systems such as creep groan and moan. In view of this problem, the experimental investigation of relevant phenomena is within the scope of this article. The related experiments concerning two different setups have been performed at a drum driven suspension and brake test rig. Both assemblies consisted of a front axle corner including all parts of the integrated brake system. In order to gain understanding of characteristic triggering mechanisms and fundamental subsystem interactions, and moreover, to verify the suitability of modal methods for simulative evaluations of creep groan or moan, specifically elaborated Operating Deflection Shape (ODS) techniques have been applied. Via analyses of four different creep groan emergences, global stick-slip cycles between disk and pads are revealed. For two dissimilar vibrations in
Pürscher, Manuel, Huemer-Kals, Severin, Fischer, Peter
Technical Paper
Output-Only Modal Analysis for System Identification before Break Squeal2018-01-150306/13/2018
Typically, squealing brakes are identified at squealing conditions for FE model validation by an operational deflection shape analysis (ODS). The deflection shapes and the squealing frequency depend strongly on various internal and external boundary conditions. If the model requires more modal information about the brake system than the ODS delivers an additional experimental modal analysis (EMA) can be conducted at standstill. In total, both analyses - ODS and EMA - cover only two distinctive operation points of the brake and do not provide further information. Plus, both are special cases since the usual brake condition should be a quiet braking process. To validate the internal and external boundary conditions of the brake system it is useful to have more operation points for model alignment. Because it is difficult to measure the excitation during such a quiet braking action only an operational modal analysis (OMA) can be used to identify the brake system at any arbitrary brake
Siegl, Benjamin, Bauer, Jens
Technical Paper
Lattice Brake Disc Instability Analysis Using Transient Complex Eigenvalue Method in Terms of Excitation Applied to the Pad2018-01-009104/03/2018
This paper describes an integrated approach to the analysis of brake squeal with newly lattice brake disc design. The procedure adopted to define the lattice properties by considering the periodicity cell of lattice plates, present equations of motion and modes response of a periodic lattice disc in principal coordinates on the rotating disc which excited by distributed axial load. The non-linear contact problem is carried out based on a typical passenger car brake for vanned and lattice brake disc types as it undergoes a partial simulation of the SAE J2521 drag braking noise test. The experimental modal analysis (EMA) with impact hammer test is used to obtain the brake rotor modal properties and validated finite element Free- Free State and stability analysis. The fugitive nature of brake squeal is analyzed through the complex eigenvalue extraction technique to define dynamic instability. The likelihood of squeal noise occurrence is quantified by the definition of a single indicator
KARAMOOZIAN, AMINREZA, Tan, Chin, Wang, liangmo
Technical Paper
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