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Viewing 151 to 180 of 10024
2014-09-28
Technical Paper
2014-01-2518
Diego Masotti, Ney Ferreira, Patric Neis, Ademir Menetrier, Luciano Matozo, Paulo Varante
Abstract Creep groan is a low-frequency (20-300Hz) self-excited brake vibration caused by stick-slip phenomena at the friction interface observed at very low vehicle speed. The creep groan propensity of friction materials is closely related with the difference (Δμ) between the static (μs) and the kinetic (μk) coefficients of friction. In this study, a NAO brake pad material was used as a base formulation and the abrasives tested were commercial grade of black iron oxide, chromite, zirconium oxide, magnesium oxide and aluminum oxide. Experimental results were obtained by testing seven different friction material formulations, in which the type of abrasives or its hardness or its particle size was changed in order to explore the impact of these variables on the stick-slip occurrence. A laboratory-scale tribometer was used to investigate the influence of different types of abrasives and their physical properties in the stick-slip.
2014-09-28
Technical Paper
2014-01-2520
Qiang Wang, Gang Qi, Guangrong Zhang, Xinyu Pu
Abstract A brake durability experimental method is proposed to simulate a brake durability vehicle road test. Brake judder and noise often occur in brake durability road testing. Brake judder is difficult to address because of its many potential causes, such as assembly run out, component stiffness, lining characteristics, thermal coning/hot spot/thermal instability and corrosion. There are currently several test procedures to predict brake thermal roughness and pad cleaning corrosion performance for preventing brake judder. Brake durability vehicle road testing is performed to check brake NVH and wear; examples include the Mojacar test in Spain and the Huangshan test in China. Brake energy intensity and road vibration are the significant factors that cause brake rotor thickness variation, which generates brake judder in public road testing.
2014-09-28
Journal Article
2014-01-2521
Jaroslaw Grochowicz, Carlos Agudelo, Shanglei Li, Harald Abendroth, Karl-Heinz Wollenweber, Achim Reich
Abstract The efforts of the ISO “Test Variability Task Force” have been aimed at improving the understanding and at reducing brake dynamometer test variability during performance testing. In addition, dynamometer test results have been compared and correlated to vehicle testing. Even though there is already a vast amount of anecdotal evidence confirming the fact that different procedures generate different friction coefficients on the same brake corner, the availability of supporting data to the industry has been elusive up to this point. To overcome this issue, this paper focuses on assessing friction levels, friction coefficient sensitivity, and repeatability under ECE, GB, ISO, JASO, and SAE laboratory friction evaluation tests.
2014-09-28
Journal Article
2014-01-2523
Nils Perzborn, Carlos Agudelo, Georg Peter Ostermeyer
Abstract Inertia dynamometers are commonly used to determine the friction coefficient of brake assemblies. Dynamometers are a well-established platform, allow testing under controlled conditions, exhibit a good correlation to many situations encountered in real driving, and are comparatively economical and less time-consuming than full vehicle test. On the other side of the spectrum is the use of scaled tribometer. These test systems make possible a test without the entire brake corner. This separation allows the investigation of the frictional-contact only (frictional boundary layer) speedily and independently of a given brake system or vehicle configuration. As the two test systems (inertia dynamometers and tribometers) may have different users with possibly different tasks, the question remains regarding how comparable the two systems are. These issues provide incentives to better define the fields of investigations, correlation, and applicability for the two systems.
2014-09-28
Technical Paper
2014-01-2522
Tobias Schramm, Georg Peter Ostermeyer
Abstract There are few principal excitation mechanisms that brake system NVH simulations are based on, especially the high frequency squeal simulations. These mechanisms can be described by some simple mechanical models that exhibit excitation or self-excitation effects induced by friction [1, 2]. These models use very simple friction laws of Coulomb type, described by a friction coefficient that is either a constant or simple functions of some state variables, taking into account a Stribeck characteristic. Measurements from the AK-Master or SAE J2521, however, show that the friction coefficient is not a simple function of some state variables, describing a steady state behavior of friction. In the past several years, material dependent descriptions of the frictional brake interface have started attracting attention [3]. These aspects are greatly influenced by the tribological effects at the frictional interface, which can be characterized by typical wear patterns.
2014-09-22
WIP Standard
J45
This SAE Recommended Practice establishes a uniform procedure for the level surface testing of hand-operated brake systems on recreational noncompetitive snowmobiles. Purpose This procedure offers a method of testing snowmobiles on turf. Turf is preferred over snow because test repeatability is more easily obtained. In addition, tests shall be conducted under winter conditions to ensure that the braking systems remain operative and that the vehicle has no undue tendency to lose stability, overturn, or swerve out of a test lane 1.2 m (4 ft) wider than the vehicle when the brakes are applied. The purpose of the document is to establish brake system capabilities with regard to deceleration or stopping distance versus applied brake lever force, as affected by vehicle speed, brake temperature, and usage.
2014-09-22
WIP Standard
J44
This SAE Recommended Practice establishes performance requirements for hand-operated brake systems on recreational, noncompetition snowmobiles.
2014-09-18
Standard
J1403_201409
The vacuum brake hose is intended for use in the power braking systems of vehicles or as connections on transmission lines in combinations of vehicles or systems thereof. For the purposes of clearly identifying hose classification and for specification simplification, vacuum brake hose is divided into two types: heavy-wall Type H, and light-wall Type L.
2014-09-16
Article
A racecar fitted with a prototype rear suspension will compete in the Sports Car Club of America's 2015 season as a proof-of-concept demonstrator for using thermoplastic composite suspension components in future light-duty vehicle production applications.
2014-09-16
Magazine
All the right connections With 2013 sales of $6.8 billion, Dana is a leading tier one supplier. Ian Adcock catches up with its chief technical and quality officer George Constand. Jaguar's lightweight challenger Ian Adcock uncovers the secrets that make the XE saloon, Jaguar's most important car yet. Boxing clever How composite crashboxes save weight and cost
2014-09-15
Article
Germany's ZF has entered into a definitive agreement to acquire U.S.-based TRW Automotive Holdings Corp. for $13.5 billion, according to a Sept. 15 TRW press release. ZF has stated that TRW will be operated as a separate business division within ZF.
2014-09-15
WIP Standard
J393
This SAE Recommended Practice establishes uniform engineering nomenclature for wheels, hubs, rims, and their components used in truck, bus, and trailer applications. This nomenclature and accompanying drawings are intended to define functional truck wheel, hub, and rim designs. The International Standard (ISO) nomenclature is shown in parentheses when different than SAE J393.
2014-09-15
WIP Standard
J3079
The procedure describes how to measure the deflection of a brake pad, noise insulator, and brake pad assembly.
2014-09-09
Standard
J2522_201409
This SAE Recommended Practice defines an Inertia Dynamometer Test procedure that assesses the effectiveness behavior of a friction material with regard to pressure, temperature and speed for motor vehicles fitted with hydraulic brake actuation. The main purpose of SAE J2522 is to compare friction materials under the most equal conditions possible. To account for the cooling behavior of different test stands, the fade sections are temperature-controlled.
2014-09-09
Standard
J191_201409
This SAE Standard covers hose fabricated from fabric braid and synthetic rubber, assembled with end fittings for use in automotive power steering applications at pressures as indicated in Table 1B, as flexible connections within the temperature range of -40 ×C (-40 ×F) to 121×C (250 ×F) average, 135 ×C (275 ×F) maximum peaks. These hoses are intended for use in applications where reduction in amplitude of pump pressure pulsations is not required.
2014-09-04
Article
Mazda Motor Corp. on Wednesday evening unveiled the fourth-generation MX-5 Miata, which adopts both SkyActiv technology and Mazda’s “Kodo” (or "Soul of Motion") design language. The MX-5, first introduced 25 years ago, maintains Mazda’s original aim of offering the pure driving fun that only a lightweight sports car can provide.
2014-09-03
Book
William C. Messner
Over the years, the DARPA Challenges in the United States have galvanized interest in autonomous cars, making them a real possibility in the mind of the public, but autonomous and unmanned vehicles have been increasingly employed in many roles on land, in the water, and in the air. Military applications have received a great deal of attention, with weaponized unmanned aircraft (drones) being the most prominent. However, unmanned vehicles with varying degrees of autonomy already have many civilian applications. Some of these are quite familiar (such as the Roomba autonomous vacuum cleaner), while others remain largely out of the public eye (such as autonomous farm equipment). Additional applications and more capable vehicles are rapidly coming to the markets in the years ahead. This book examines a number of economically important areas in which unmanned and autonomous vehicles, also understood here as autonomous technologies, are already used or soon will be.
2014-09-02
Magazine
2015 New Vehicle & Technology Preview Automotive Engineering editors take a look at some of the more intriguing new models, including GM's full-size SUVs, BMW's i8 plug-in-hybrid sports car, Acura's TLX sedan, and Ford's F-150 full-size pickup truck. Picturing the map for smoother rides Next-gen A/C As conventional vapor-compression cooling technology faces phase-out, what could take its place? The U.S. Department of Energy's ARPA-e has funded research to help answer this question.
2014-08-29
Article
NIRA Dynamics AB has developed friction algorithms for where the rubber meets the road, and is seeking partners to put them into action for improved safety. Existing driver-assistance systems are “steps in the right direction, but with the new algorithms by NIRA cars can take a large step further and get even smarter,” the company says in an Aug. 28 press release.
2014-08-28
Standard
J1704_201408
This SAE Standard covers motor vehicle brake fluids of the nonpetroleum type, based upon glycols, glycol ethers, and borates of glycolethers, and appropriate inhibitors, for use in the braking system of any motor vehicle such as a passenger car, truck, bus, or trailer. These fluids are not intended for use under arctic conditions. These fluids are designed for use in braking systems fitted with rubber cups and seals made from styrene-butadiene rubber (SBR), or a terpolymer of ethylene, propylene, and a diene (EPDM).
2014-08-28
Standard
J1703_201408
This SAE Standard covers motor vehicle brake fluids of the nonpetroleum type, based upon glycols, glycolethers and appropriate inhibitors, for use in the braking system of any motor vehicle such as a passenger car, truck, bus, or trailer. These fluids are not intended for use under arctic conditions. These fluids are designed for use in braking systems fitted with rubber cups and seals made from styrene-butadiene rubber (SBR), or a terpolymer of ethylene, propylene, and a diene (EPDM).
2014-08-26
Standard
J109_201408
This document has been declared "Stabilized" by the SAE Motorcycle Technical Steering Committee and will no longer be subjected to periodic reviews for currency. Users are responsible for verifying references and continued suitability of technical requirements. Newer technology may exist. This SAE Recommended Practice establishes performance requirements for the service brake systems of all classes of motorcycles intended for highway use.
2014-08-26
WIP Standard
J2547
This SAE Standard covers the minimum requirements for nonmetallic tubing as manufactured for use in air brake systems which tubing is different from that described in SAE J844. It is not intended to cover tubing for any portion of the system which operates continuously below - 40 degrees C or above +93 degrees C, above a maximum working gage pressure of 1.0 MPa, or in an area subject to attack by battery acid. This tubing is intended for use in the brake system for connections, which maintain a basically fixed relationship between components during vehicle operation. Coiled tube assemblies required for those installations where flexing occurs are covered by this document, SAE J1131 and SAE J2494-3, to the extent of setting minimum requirements on the essentially straight tube and tube fitting connections which are used in the construction of such assemblies.
2014-08-20
Standard
J1789_201408
This SAE Standard applies to self-propelled, rider operated, sweepers and scrubbers as defined in SAE J2130 with maximum machine level surface speeds up to 32 km/h. Machines capable of speeds equal to and greater than 32 km/h are not covered by this document.
2014-08-15
Article
To achieve weight savings in vehicles, OEMs and component suppliers are increasingly using ultra-high-strength steel, aluminum, magnesium, plastics, and composites. One strategy is to develop components using a multi-material concept. Ashok Leyland researchers used this approach when developing a bimetal brake drum with cast-iron inner ring and aluminum outer shell.
2014-08-13
Article
Rick Phillips, Senior Director, Commercial and OTR Sales, for Yokohama Tire Corp., provides his thoughts on the company's first U.S. commercial tire plant, scheduled to open in October 2015, as well as what the market can expect in the coming years.
2014-08-12
Article
Replacing the TSX and TL models, the all-new 2015 TLX is positioned at the heart of the Acura sedan lineup, boasting two advanced new powertrains, including a “world’s first” eight-speed DCT with torque converter, and next-generation handling technologies.
2014-08-11
Standard
J1939DA_201408
The J1939 Digital Annex The J1939 Digital Annex, introduced in August 2013, offers key J1939 technical data in an Electronic Spreadsheet that can be easily searched, sorted, and adapted to other formats. J1939DA contains all of the SPNs (parameters), PGNs (messages), and other J1939 data previously published in the SAE J1939 top level document. J1939DA also contains all of the SLOTs, Manufacturer ID Codes, NAME Functions, and Preferred Addresses previously published in the SAE J1939 top level and the J1939-71 document. J1939DA contains the complete technical details for all of the SPNs and PGNs previously published in the SAE J1939-71 document. For all other SPNs and PGNs which are published in a document other than SAE J1939-71, J1939DA lists only basic details along with a reference to the document that contains the complete technical details. J1939DA replaces, and expands upon, the 1939 Companion Spreadsheet (CS1939), which was last published through November 2012.
2014-08-01
Article
Researchers aim to develop a composite crashbox suitable for 1000 parts/day production at low cost and adapted to current mass-market vehicle design. Various matrixes, preform types, and manufacturing processes have been evaluated by axial and 15° off-axis crash tests. Solutions for short-term development are proposed, with 66% weight reduction compared to current steel parts, and an estimated price of less than €5 per saved kg.
2014-08-01
Journal Article
2014-01-9128
Valentin Ivanov, Barys Shyrokau, Dzmitry Savitski, Javier Orus, Rubén Meneses, José-Manuel Rodríguez-Fortún, Johan Theunissen, Karel Janssen
Abstract The paper introduces the results of the development of anti-lock brake system (ABS) for full electric vehicle with individually controlled near-wheel motors. The braking functions in the target vehicle are realized with electro-hydraulic decoupled friction brake system and electric motors operating in a braking mode. The proposed ABS controller is based on the direct slip and velocity control and includes several main blocks for computing of predictive (feedforward) and reactive (feedback) brake torque, wheel slip observer, slip target adaptation, and the algorithm of brake blending between friction brakes and electric motors. The functionality of developed ABS has been investigated on the HIL test rig for straight-line braking manoeuvres on different surfaces with variation of initial velocity. The obtained experimental results have been compared with the operation of baseline algorithm of a hydraulic ABS and have demonstrated a marked effect in braking performance.
Viewing 151 to 180 of 10024

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