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Viewing 151 to 180 of 10739
2016-06-15
Technical Paper
2016-01-1779
Sergio Carvajal, Daniel Wallner, Reinhard Helfrich, Michael Klein
Abstract Numerical methods for brake squeal analysis are widely accepted in industry. The use of complex eigenvalue analysis is a successful approach to predict the appearance of squeal noise. Using simulation in an early design stage reduces time to market, saves costs, and improves the physical behavior and robustness of the brake system. State of the art of brake simulation comprises sampling for many parameter sets in a wide range of interesting values. Based on high performance, stability maps can be created in short time containing many results, which gives a deep insight into the brake behavior under varying parameters. An additional benefit of sampling is the possibility to detect parts with high potential for improving the NHV comfort. In the sequel, mathematical optimization methods like topology optimization or shape optimization are used for systematic improvements.
2016-06-15
Technical Paper
2016-01-1834
Florian Fink, Gregor Koners
Abstract This paper describes the prediction process of wheel forces and moments via indirect transfer path analysis, followed by an analysis of the influence of wheel variants and suspension modifications. It proposes a method to calculate transmission of noise to the vehicle interior where wheel forces and especially moments were taken into account. The calculation is based on an indirect transfer path analysis with geometrical modifications of the frequency response functions. To generate high quality broadband results, this paper also points out some of the main clearance cutting criteria. The method has been successfully implemented to show the influence of wheel tire combinations as well as the influence of suspension modifications. Case studies have been performed and will be presented in this paper. Operational noise and vibration measurements have been carried out on Daimler NVH test tracks. The frequency response functions were estimated in an acoustic laboratory.
2016-06-15
Technical Paper
2016-01-1832
Ramakrishna Kamath
Intermediate shaft assembly is used to connect steering gear to the steering wheel. The primary function of the intermediate shaft is to transfer torsional loads. There is a high probability of noise propagating through the Intermediate shaft to the driver. The current standard for measuring the noise is by performing vehicle level subjective evaluations. If improperly clamped at either of the yokes, a sudden change in the direction of the torsional load on the Intermediate shaft can generate a displeasing noise. Noise can also be generated from the constant velocity joint. Intermediate shaft noise can be measured using a microphone or can be correlated to acceleration values. The benefit of measuring the acceleration over sound pressure level is the reduction of complexity of the test environment and test set up. The nature of the noise in question requires the filtering of low frequency data. This paper presents a new test procedure that has been developed by General Motors.
2016-06-15
Technical Paper
2016-01-1765
Kelly Savva, Ahmed Haris, Eliot Motato, Mahdi Mohammadpour, Stephanos Theodossiades, Homer Rahnejat, Patrick Kelly, Alexander Vakakis, Lawrence Bergman, Donald McFarland
Abstract Legislation on vehicle emissions and the requirements for fuel efficiency are currently the key development driving factors in the automotive industry. Research activities to comply with these targets point to engine downsizing and new boosting technologies, which have adverse effects on the NVH performance, durability and component life. As a consequence of engine downsizing, substantial torsional oscillations are generated due to high combustion pressures. Meanwhile, to attenuate torsional vibrations, the manufacturers have implemented absorbers that are tuned to certain frequency ranges, including clutch dampers, Dual Mass Flywheel (DMF) and centrifugal pendulum dampers. These devices add mass/inertia to the system, potentially introducing negative effects on other vehicle attributes, such as weight, driving performance and gear shiftability.
2016-06-15
Journal Article
2016-01-1827
Giorgio Bartolozzi, Marco Danti, Andrea Camia, Davide Vige
Abstract The time to market in the automotive industry is constantly decreasing pushing the carmaker companies to increase the efforts in numerical simulations and to decrease the number of prototypes. In the NVH field, this time constraint reflects in moving the well-established finite element simulations towards the so called “full-vehicle simulations”. Specifically, the CAE techniques should be able to predict the complete behavior of the vehicles in mission conditions, so to reproduce some usual tests, such as the “coast down” test on different roads. The aim of this paper is to present a methodology to improve rolling noise simulations exploiting an integrated full-vehicle approach. An accurate modeling of all the subsystems is needed, with particular attention to the wheels and the suspension systems. Therefore, the paper firstly covers the modeling approach used to obtain the FE models of tires and suspension system.
2016-06-15
Journal Article
2016-01-1777
Sebastian Oberst, Zhi Zhang, Joseph CS Lai
Abstract Despite significant progress made in the past 20 years in discovering some of the mechanisms of brake squeal, it remains difficult to predict the underlying friction-induced instabilities reliably. Most numerical analyses are based on linear deterministic analyses of structural vibrations such as the complex eigenvalue analysis (CEA). However, nonlinear multi-scale processes govern friction contact with high sensitivities to operating and/or environmental conditions. In addition, uncertainties in the material properties and boundary conditions such as contact and friction laws are rarely considered. Hence, it is quite common to underpredict or overpredict the number of instabilities and extensive brake noise dynamometer tests are still required in industry to ensure acceptable brake noise performance. In this paper, simplified finite element brake models are used to illustrate the role of nonlinearity in brake squeal.
2016-06-14
Article
BWI Group believes its second-generation Magneto Rheological (MR) powertrain mount helps meet downsized-powertrain NVH challenges.
CURRENT
2016-06-14
Standard
J1860_201606
This SAE Recommended Practice applies to those air brake system valves used to control the vehicle service brakes and test procedures defined by SAE J1859 to measure performance characteristics. This Recommended Practice adheres to standard industry practice of using English units for specifying valve characteristics.
CURRENT
2016-06-14
Standard
J1859_201606
This SAE Recommended Practice establishes uniform test procedures for determining input-output characteristics for those pilot-operated and mechanically actuated, modulating-type valves and through-type valves used in the service brake control system.
2016-06-11
Article
Novel oxidation ovens could triple production-line throughput while slashing energy use.
2016-06-02
Magazine
A 24-hour battle of speed and efficiency At Le Mans this month, amped-up hybrid prototype racecars from Audi and Toyota face a revamped Porsche 919 hybrid, while Ford hopes to recapture glory with its new GT-R. Pushing the ICE forward, gradually Emergent technologies from BorgWarner, Eaton and Mahle aim for greater efficiency in gasoline and diesel engines. Smile, you're on Magna camera! Magna Electronics is rapidly expanding production of its made-in-U.S.A. onboard cameras to keep pace with booming OEM demand for safety and vehicle-autonomy vision-systems technology. Multi-material body solutions: Possibilities and manufacturing challenges The body-in-white is a prime target for lightweighting and many automakers are pursuing unique and effective multi-material approaches, but improved design tools and processes might yield greater gains.
CURRENT
2016-05-24
Standard
AIR4762A
This Aerospace Information Report (AIR) describes conditions under which freezing (frozen) brakes can occur and describes operating procedures which have been used to prevent or lessen the severity or probability of brake freezing. This document also identifies design features that some manufacturers implement to minimize the occurrence of freezing brakes. This document is not an Aerospace Recommended Practice (ARP) and therefore does not make recommendations based on a consensus of the industry. However, part of this document’s purpose is to describe the design and operational practices that some are using to minimize the risk of frozen brakes. NOTE: The following information is based upon experience gained across a wide-range of aircraft types and operational profiles, and should NOT take precedence over Aircraft Flight Manual or Flight Operations Procedures.
CURRENT
2016-05-24
Standard
J2724_201605
This procedure describes a method for measuring the fraction of underlayer (also referred to as backing layer) existing at any given height above the a disc brake friction materials shoe plate. Measuring underlayer distribution is useful for computing useable lining thickness and for friction material quality management.
2016-05-19
Article
PACCAR and Allison Transmission engineers are working together on an engineering program to release the fully automatic Allison TC10 in Kenworth T680 and T880 and Peterbilt Models 567 and 579 with both PACCAR and Cummins engines.
2016-05-18
WIP Standard
J1204
This SAE Recommended Practice provides uniform procedures and minimum performance requirements for fatigue testing ferrous and aluminum wheels intended for normal highway use on travel, camping, and boat and light utility trailers drawn by passenger cars, light trucks, and multipurpose vehicles. (See Figures 1 and 2.) For procedures and minimum performance requirements for wheels used on trucks, see SAE J267, and for wheels used on passenger cars, see SAE J328. For the application of passenger car and light ruck wheels [inset less than 0.10 m (0.33 ft)] to this trailer service, use this procedure. For the application of heavier truck wheels [inset 0.10 m (0.33 ft) or mre] use SAE J267. Mobile home service is outside the scope of this document. There are two basic test procedures described, a cornering fatigue test and radial fatigue test. The cornering test is directed at the wheel disc; whereas the radial test also examines the rim and attachment portion of the wheel.
2016-05-17
Article
Michelin Auto Inflate is a wheel-mounted tire management solution that allows fleets to automatically maintain optimal tire pressure.
2016-05-17
Article
VibraTite VC3 from ND Industries is designed for use on internal and external threads of virtually any material or finish.
2016-05-13
Article
ZF sees many advantages and possibilities of knowledge transfer across divisions, as almost all technologies from the automotive sector also can be used in trucks, buses and off-highway vehicles, according to Dr. Klaus Geißdörfer, EVP of the Industrial Technology Division.
CURRENT
2016-05-13
Standard
J1982_201605
This SAE Recommended Practice establishes uniform engineering nomenclature for the most common wheel constructions, and their components used on passenger cars, light trucks, and multipurpose vehicles. These wheel constructions are welded “Disc Wheels”, “Cast Wheels” and “Forged Wheels”. This nomenclature and the accompanying drawings are intended to define fundamental wheel terms rather than to provide a comprehensive tabulation of all wheel design types.
2016-05-12
Article
Although some commercial vehicle fleets and owners remain skeptical about autonomous driving and the implications for their big rigs traveling down the highway, much of the technology is already available to make it a real possibility, states WABCO's Jon Morrison.
CURRENT
2016-05-12
Standard
J2923_201605
This Recommended Practice applies to on-road vehicles with a GVWR below 4540 kg equipped with disc brakes.
2016-05-10
WIP Standard
J1817
This SAE Recommended Practice describes a marking system to distinguish long-stroke from standard stroke for service, parking, and combination air-brake actuators, roto-chambers, and components. Said actuators are used for applying cam and disc-type foundation brakes by slack adjuster means.
CURRENT
2016-05-06
Standard
AIR5358A
This document describes fluids used in landing gear shock struts with extreme pressure and antiwear additives that have been added for improved lubrication.
CURRENT
2016-05-06
Standard
AIR4905A
The purpose of this document is to present general considerations for the design and use of aircraft wheel chocks. The design and use of aircraft wheel chocks is a good deal more complicated than it may appear at first glance.
2016-05-05
Article
While connected technologies for passenger vehicles are moving toward more widespread, everyday use, the benefits of improved performance, safety, durability, and fuel economy offered by connected vehicles are rapidly gaining a foothold in the off-highway market as well, says Dana's George Constand.
2016-05-05
Magazine
New dawn at Honda R&D President Yoshiyuki Matsumoto aims to invigorate Honda's technology and product-development organization with 'full soul.' Automated driving meets regulation: NHTSA and the next 50 years The challenges and opportunities on the road to 'zero deaths' demand a new level of federal automotive safety technical standards, and a new safety-defect reporting and recall system. NHTSA and the U.S. Congress must act boldly and quickly to make it happen. Autonomous driving meets regulation: Hands off, eyes off, brain off Euro NCAP'S president warns that without coherent policies, the growing availability of automated technologies may result in piecemeal technology development-and unintentional consequences. Designer yin meets engineer yang Efficient and effective vehicle development means even closer collaboration between the two former sparring partners.
CURRENT
2016-05-02
Standard
AMS5110K
This specification covers a carbon steel in the form of wire supplied as coils of wire or as finished springs.
CURRENT
2016-04-27
Standard
J2562_201604
This SAE Recommended Practice provides uniform laboratory procedures for biaxial fatigue testing of wheels intended for normal highway use and temporary use on passenger car vehicles and light trucks and minimum cycle requirement for ferrous wheels for ballasted passenger car applications. The appendices provide scalable load files that are applicable to ballasted passenger cars and ballasted light trucks. A load file for unballasted passenger cars will be added to this document.
CURRENT
2016-04-27
Standard
J2530_201604
This SAE Recommended Practice provides performance, sampling, and certifying requirements, test procedures, and marking requirements for aftermarket wheels intended for normal highway use on passenger cars, light trucks, and multipurpose passenger vehicles. For aftermarket wheels on trailers drawn by passenger cars, light trucks or multipurpose vehicles, see SAE J1204. These performance requirements apply only to wheels made of materials included in Table 1 and Table 2. New nomenclature and terms are added to clarify wheel constructions typically not used in OEM applications. The testing procedures and requirements are based on SAE standards listed in the references.
2016-04-25
Article
ZF TRW recently announced through its joint venture, Brakes India Ltd, that it has won the first business award for its Electric Park Brake (EPB) system in India. Launching with a major global vehicle manufacturer, the technology will start production in 2017, marking the first launch of its kind for the Indian market, the supplier claims.
Viewing 151 to 180 of 10739

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