Browse Topic: Brake shoes
This SAE Recommended Practice is intended for measuring the static brake torque performance of a pnuematically actuated brake assembly, friction material, and drum/disc combination on an inertia brake dynamometer
The SAE J2521 procedure applies to high-frequency squeal noise occurrences for on-road passenger cars and light trucks below 4540 kg of GVWR. The procedure incorporates high-temperature and low-temperature test matrixes but does not fully account for the effects of the environment on brake squeal. For this test procedure, squeal occurs when the peak noise level is at least 70 dB(A) between 1.25 kHz and 16 kHz for tests using full suspension corners or full axle assemblies or between 2 kHz and 16 kHz for brakes not using a full suspension corner. Before using this recommended practice for chassis dynamometer testing, review in detail the specifics related to at least (a) instrumentation, including in-cabin microphones, (b) threshold levels for noise detection, (c) temperature control priority between the front and rear axles, (d) vehicle loading and load distribution, (e) cooling air and environmental conditioning, and (f) detailed nomenclature and labeling of channels and sensors
The static coefficient of friction between lining and shoe plays a fundamental role in the lining fixing project, which is the most important parameter for the riveted joint calculation. For the lining riveting, the rivet needs to ensure that friction material and shoe remain in contact through the normal force applied on the surfaces, but the rivet should not be exposed to shear forces. Thus, the brake torque transmission must occur through the static coefficient of friction between lining and shoe, not allowing relative slips or movements between the pair in contact. Therefore, the present study aims to understand the influence of the static friction coefficient between lining and shoe as a function of the lining internal superficial roughness, from the evaluation of different roughness conditions - contact area with shoe -. The static coefficient of friction between lining and shoe is a complex measurement to be performed, due to the cylindrical geometry of the drum brake system, so
This study aims to present a numerical structural validation procedure for the drum brake spider component. To implement the procedure, the ANSA, ABAQUS, Fe-Safe, and Minitab engineering software were used for stress analysis, fatigue life calculation, and statistical validation using Weibull distribution. The results obtained from these tools allowed us to determine with acceptable error the spot failure of the component and the number of cycles until the occurrence of the failure. The input data to support the pre-processing of the numerical model and obtain the virtual results were determined from the application and analysis of the following methods: determination of the stress strain curve of the Spheroidal Graphite Iron (SG) material of the component, applied to Theory of Critical Distance (TCD) of fracture mechanics and evaluation of the behavior of Nodular Cast Iron under fatigue life. Given the non-linear characteristics under the conditions of use, the need for correction of
The aim of this paper was the proposal of a numerical procedure for the structural evaluation and durability validation of brake shoes, employing fatigue and finite element softwares that are able to predict the failure locations (and number of cycles to failure) with acceptable accuracy. The software Abaqus was used in the calculation of the stress and strain fields whereas the software fe-safe was employed in the evaluation of fatigue life. Accelerated tests were performed on a bench test that has been designed to match the operating conditions of the vehicles were the brake shoes are assembled. In those cases where only local plasticity is expected (rather than generalized plasticity) the procedure can somewhat be simplified by running linear elastic finite element analysis (instead of full non-linear), which is often called pseudo-elastic analysis [1]. Then the pseudo stresses and strains are corrected at post-processing time by means of the Neuber’s rule and Ramberg-Osgood
Lift axle is essentially provided in commercial vehicles to increase the vehicle’s load-carrying capacity. The axle is lowered in the case of a high payload and the load is evenly distributed among the wheels both on fixed axles and the lift axle. This ability to lift the axle implies better maneuverability in turns, better fuel consumption, and less wear and tear on the tires and brake shoes. Also, it will reduce the damage to the road surfaces. This lowering and lifting of the lift axle are controlled by a series of valves together called the Lift Axle Control System (LACS). This LACS must consider the vehicle load condition, the ignition state, and gear state to decide if the axle must be lifted or lowered. This paper deals with the modeling and simulation of the LACS system at the vehicle level and optimize the design for the respective desired design solution
This SAE Recommended Practice (RP) specifies a dynamometer test procedure to characterize wear rates of automotive service brake linings (brake shoes) and disc brake pads
This SAE Recommended Practice is intended for testing of external automatic brake adjusters as they are used in service, emergency, or parking brake systems for on-highway vehicle applications
The paper is devoted to the study of the influence of braking devices over the stability of braking properties of the cars. A technique is proposed for assessing the stability of braking devices using the generalized braking torque equation, which allows the selection of a rational type of braking devices and optimization of the geometric parameters thereof at the design stage of the cars. Stability assessment of the braking torque is carried out according to the criterion of the sensitivity of the braking torque to a change in the coefficient of friction between the friction surfaces of the braking mechanism. Using the dimensionless functions and coefficients depending on the geometric parameters of the friction pairs and the feedback sign in the braking mechanism, it was found that the braking mechanism with one active and one passive pad has less sensitivity to a change in the friction coefficient than the braking mechanism with two active pads. The analysis of the influence of the
On account of the traditional friction brake for heavy-duty truck (HDT), the massive quantity of heat accumulating constantly because of frequent using of friction brake system in the long and steep downhill road leads to brake temperature rising rapidly. Affected by structure frictional couple installed in the closed environment of the brake drum, it is difficult to dissipate the heat in time via heat conduction, heat radiation and heat convection, and the heat fade phenomenon of the brake emerges easily. The HDT would be in danger because of braking efficiency descending. This paper proposes an active water-cooled drum brake system (AWBS) to solve the problem. According to the principle of engineering thermodynamics, the structure and size of the back-stretching water jacket of brake shoe and the inner riveted the friction plate of brake drum are designed with restrained of GB 12676-2014 ‘Technical requirements and testing methods for commercial vehicle and trailer braking systems
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
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
The air brake system is still the most common brake system in use in heavy diesel vehicles. For safety and economic reasons it is imperative to understand the performance and durability (especially fatigue and wear) of every component of a drum brake, particularly the brake shoes. In applications where torque is lower than 20kNm brake shoes are made of ductile metals such as SAE 1030 steel. For such ductile materials Brown-Miller and Fatemi-Socie are the most recommended methods for fatigue crack initiation life prediction. The next pages discuss the validation of these fatigue methods in the case study of a 325mm brake shoe
Subject document is specifically intended for service brakes and service brakes when used for parking and/or emergency brakes (only) that are commonly used for automotive-type, ground-wheeled vehicles exceeding 4536 kg (10000 pounds) gross vehicle weight rating (GVWR). Subject specification provides the off-vehicle procedures, methods, and processes used to objectively determine suitability of tactical and combat ground-wheeled vehicle brake systems and selected secondary-item brake components (aka, aftermarket or spare parts), including brake “block” for commercial applications only, specifically identified within subject document. Subject specification is primarily based on known industry and military test standards utilizing brake inertia dynamometers. Targeted vehicles and components include, but may not be limited to, the following: a Civilian, commercial, military, and militarized-commercial ground-wheeled vehicles such cargo trucks, vocational vehicles, truck tractors, trailers
This Recommended Practice is derived from the FMVSS 105 vehicle test and applies to two-axle multipurpose passenger vehicles, trucks, and buses with a GVWR above 4540 kg (10000 pounds) equipped with hydraulic service brakes. There are two main test sequences: Development Test Sequence for generic test conditions when not all information is available or when an assessment of brake output at different inputs are required, and FMVSS Test Sequence when vehicle parameters for brake pressure as a function of brake pedal input force and vehicle-specific loading and brake distribution are available. The test sequences are derived from the Federal Motor Vehicle Safety Standard 105 (and 121 for optional sections) as single-ended inertia-dynamometer test procedures when using the appropriate brake hardware and test parameters. This recommended practice provides Original Equipment Manufacturers (OEMs), brake and component manufacturers, as well as aftermarket suppliers, results related to brake
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
This SAE Recommended Practice covers equipment capabilities and the test procedure to quantify and qualify the shear strength between the friction material and backing plate or brake shoe for automotive applications. This SAE Recommended Practice is applicable to: bonded drum brake linings; integrally molded disc brake pads; disc brake pads and backing plate assemblies using mechanical retention systems (MRS); coupons from drum brake shoes or disc brake pad assemblies. The test and its results are also useful for short, semi-quantitative verification of the bonding and molding process. This Recommended Practice is applicable during product and process development, product verification and quality control. This Recommended Practice does not replicate or predict actual vehicle performance or part durability
This Recommended Practice applies to on-road vehicles with a GVWR below 4540 kg equipped with disc brakes
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
This SAE Recommended Practice establishes a uniform procedure for the level road test of the brake systems of all classes of motorcycles intended for highway use
This document specifies minimum performance and durability requirements for satisfactory vehicle usage, and it is applicable to wheel cylinder assemblies from commercial production, after production shipment, shelf storage, and remanufacture (factory rebuild
During the development of a new friction material, besides the interface between lining/drum is also fundamental take in account all aspects involving the attachment of the linings on the brake shoes. This paper presents an optimization approach to the development and manufacturing parameters of brake linings, applied on medium and heavy duty commercial vehicles, aiming to assure the correct specification of the riveted joint clamp forces. These evaluations were conducted based on the quality tools documents and the theoretical aspects of the product usage as well as the modeling of key elements of the referred mechanism throughout various known applications. A calculation methodology was developed based on brake geometry, its generated forces and braking reactions required for each vehicle family. Taking in consideration the mathematical modeling of lining riveting process, the study incorporated calculated parameters on the production of new parts to proceed with bench and
The SAE J2521 procedure is applicable to high frequency squeal noise occurrences for on-road passenger car and light trucks below 4,540 kg of GVWR. The procedure incorporates high temperature and low temperature test matrixes, but does not fully account for the effects of the environment on brake squeal. Much research is currently underway in this area and can potentially be incorporated in future revisions. For the purposes of this test procedure, squeal is defined as peak noise levels equal to or above 70 dB(A) between 1.25 kHz and 16 kHz for tests using a full suspension corners or full axle assemblies, or between 2 kHz and 16 kHz for brakes not using a full suspension corner. Before using this Recommended Practice for chassis dynamometer testing, review in detail the specifics related to at least (a) instrumentation including in-cabin microphones, (b) threshold levels for noise detection, (c) temperature control priority between front and rear axles, (d) vehicle loading and load
This code provides a test procedure for obtaining and determining extremely high brake fluid temperature encountered in the brake system of a vehicle that is equipped with disc brakes. Vehicles in normal operation may or may not produce brake fluid temperatures that are obtained in this procedure
This performance standard specifies a universal method of measuring the dimensional change of friction materials to determine the effects of temperature. The test applies to both, disc and drum type linings commonly used in hydraulic and air brake systems for automotive or commercial vehicle applications. This standard describes two main test procedures. Method A, where the friction material is in contact with a heated surface to simulate the heat input to the pad that occurs during actual usage. Method B uses an oven to heat the freestanding material and is an approximate procedure requiring less instrumentation. Method A is recommended for disc brake pad assemblies, noise insulators, or flat coupons; while Method B is recommended for curved drum brake linings
This document establishes recommended practices to validate acceptable corrosion performance of metallic components and assemblies used in medium truck, heavy truck, and bus and trailer applications. The focus of the document is methods of accelerated testing and evaluation of results. A variety of test procedures are provided that are appropriate for testing components at various locations on the vehicle. The procedures incorporate cyclic conditions including corrosive chemicals, drying, humidity, and abrasive exposure. These procedures are intended to be effective in evaluating a variety of corrosion mechanisms as listed in Table 1. Test duration may be adjusted to achieve any desired level of exposure. Aggravating conditions such as joint rotation, mechanical stress, and temperature extremes are also considered. This document does not address the chemistry of corrosion or methods of corrosion prevention. For information in these areas, refer to SAE J447 or similar standard
This Recommended Practice is derived from the FMVSS 105 vehicle test and applies to two-axle multipurpose passenger vehicles, trucks and buses with a GVWR above 4 540 kg (10 000 lbs) equipped with hydraulic service brakes. There are two main test sequences: Development Test Sequence for generic test conditions when not all information is available or when an assessment of brake output at different inputs are required, and FMVSS Test Sequence when vehicle parameters for brake pressure as a function of brake pedal input force and vehicle-specific loading and brake distribution are available. The test sequences are derived from the Federal Motor Vehicle Safety Standard 105 (and 121 for optional sections) as single-ended inertia-dynamometer test procedures when using the appropriate brake hardware and test parameters. This recommended practice provides Original Equipment Manufacturers (OEMs), brake and component manufacturers, as well as aftermarket suppliers, results related to brake
The purpose of this study is to propose an effective model to estimate the excitation force accompanied with stick-slip between shoe and disc, considering the strain distribution on contact surface of the shoe, and then to propose an effective concept to design the brake which reduced the brake squeal under practical use. In order to investigate the influence of configuration of the hole, three types of discs were prepared in which the size of holes was different. The SPL (Sound Pressure Level) and the frequency of squeal for three types of discs were measured when the brake squeal was observed at conditions of low sliding speed. The change of stability of the brake shoe passing on hole was analyzed by 2-D simplified brake system model. In order to investigate how the strain distribution of the shoe affected on the excitation force caused by stick-slip, FE (Finite-element) and FDTD (Finite-difference time-domain) analysis were utilized to simulate the elastic wave propagation in the
This document is derived from the Federal Motor Vehicle Safety Standards 105 and 135 vehicle test protocols as single-ended inertia-dynamometer test procedures. It measures brake output, friction material effectiveness, and corner performance in a controlled and repeatable environment. The test procedures also include optional sections for parking brake output performance for rear brakes. It is applicable to brake corners from vehicles covered by the FMVSS 105 and 135 when using the appropriate brake hardware and test parameters. The FMVSS 135 is applicable to all passenger cars and light trucks up to 3500 kg of GVWR. The FMVSS 105 is applicable to all passenger cars, multi-purpose vehicles, buses, and trucks above 3500 kg of GVWR. This document does not include testing for school bus applications or vehicles equipped with hydraulic brakes with a GVWR above 4540 kg
Subject document is specifically intended for service brakes and service brakes when used for parking and/or emergency brakes (only) that are commonly used for automotive-type, ground wheeled vehicles exceeding 4536 kg (10 000 US lb) Gross Vehicle Weight Rating (GVWR). Subject specification provides the off-vehicle procedures, methods, and processes used to objectively determine suitability of tactical and combat ground wheeled vehicle brake systems and selected secondary-item brake components (a.k.a. aftermarket or spare parts), including brake “block” for commercial applications only, specifically identified within subject document. Subject specification is primarily based on known industry and military test standards utilizing brake inertia dynamometers. Targeted vehicles and components include, but may not be limited to the following: a Civilian, commercial, military, and militarized-commercial ground wheeled vehicles such cargo trucks, vocational vehicles, truck tractors, trailers
This SAE Recommended Practice establishes a uniform procedure for the level road test of the brake systems of all classes of motorcycles intended for highway use
This SAE Recommended Practice covers equipment capabilities and the test procedure to quantify and qualify the shear strength between the friction material and backing plate or brake shoe for automotive applications. This SAE Recommended Practice is applicable to: bonded drum brake linings; integrally molded disc brake pads; disc brake pads and backing plate assemblies using mechanical retention systems (MRS); coupons from drum brake shoes or disc brake pad assemblies. The test and its results are also useful for short, semi-quantitative verification of the bonding and molding process. This Recommended Practice is applicable during product and process development, product verification and quality control. This Recommended Practice does not replicate or predict actual vehicle performance or part durability
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 (10 000 lb) of GVWR. This recommended practice includes the pass/fail criteria of Standard No. 121
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