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Technical Paper
2014-09-28
Taeho Jung, Jeongkyu Kim
Abstract Rust accumulated on disc surfaces causes brake judder and grind noise. This paper deals with grind noise(wire brush brake noise) in vehicles which is a low frequency vibration and broadband noise problem at 100∼1kHz that appears in low vehicle speed. Recently, the customer complaints have increased for grind and creep groan noise more than squeal noise. Low frequency brake noise is a combined effect of brake and suspension systems working with each other. The noise transfer path is also important. Experimental results are confirmed through ODS, Modal, TPA and 3D acoustic camera for noise transmission path. Finally, reduction methods of grind noise are presented.
Technical Paper
2014-09-28
Prashant Mahale, Aziz Bohari, Raajha M P
Abstract Brake noise is an emerging concern in Indian Auto-industry; with brake squeal being the most evident form of brake NVH. Squeal noise generation attributes to many parameters including kinematics of braking parts during pressure application, structural dynamic behavior which in turn depends on coupling at resonant frequencies of different parts of a brake assembly, material of brake parts, operating clearances in the mating parts etc. The genesis of brake squeal lies in the generation of unstable frictional forces during braking event. These frictional forces induce uncontrolled amplification of brake parts vibration, which in turn tend to produce perceivable sound or noise. The magnitude this vibration induced squeal depends on co-efficient of friction, braking pressure, speed and temperature of friction material. It is known from typical squeal evaluations on dynamometer that at different temperatures of friction, the ability/ occurrence, of squeal is different, typically in the range of 50°C to 200°C.
Technical Paper
2014-09-28
Nils Gräbner, Merten Tiedemann, Utz Von Wagner, Norbert Hoffmann
Abstract Industry and academia agree that brake squeal is a nonlinear phenomenon. Consequently, using solely linear finite-element (FE) models and assessing the tendency of a brake system to squeal exclusively on the stability of the trivial solution is not appropriate. However, the latter approach - in the brake community known as complex eigenvalue analysis (CEA) - is extensively used in industry. Until now, nonlinear simulation approaches considering existence and stability of periodic solutions are mostly limited to minimal models. Among the variety of reasons for this the complexity of large-scale nonlinear models as well as the identification of nonlinear material and system parameters are crucial. This contribution discusses the relevance of nonlinearities in friction brake noise, vibration, harshness (NVH) and presents a novel simulation approach for brake squeal. On the basis of experimental results it is pointed out that the consideration of nonlinearities in simulation as well as new methods for numerical studies are necessary to cope with the system-inherent phenomena.
Technical Paper
2014-09-28
Hidetoshi Shimizu, Yasunori Oura, Tatsuya Suzuki, Yoshinori Sano
Abstract SAE J2521 noise tests are conducted to examine the impact of shim and grease on brake squeal generation. The impact of adhesive (bonded) shim, clip-on shim and grease for noise generation are examined. Low frequency squeal is eliminated by the application of grease on both adhesive (bonded) shims and clip-on shims. The role of shim and grease for reducing brake squeal is discussed. Adhesive (bonded) shims were found to be effective for high frequency squeal (pad bending mode) by increasing damping. Grease is effective for low frequency squeal (pad rigid mode). The mechanism to eliminate low frequency squeal by the application of grease is investigated. Friction between the shim and caliper piston/finger is reduced. Pads contact directly to the anchor bracket. As a result the contact stiffness is increased. The mechanism is confirmed by experiments.
Article
2014-09-24
The use of quenched and tempered steels for dumper bodies reduces weight and fuel consumption while increasing payload capacity and wear life.
Article
2014-09-22
Internal combustion engines are poised for dramatic breakthroughs in improving efficiency with lower emissions, due in part to low-temperature combustion regimes. Such regimes show great efficiency and emissions potential, but they present optimization and control challenges.
Standard
2014-09-18
This SAE Standard sets forth the procedures to be used in measuring sounds levels and determining the time weighted sound level at the operator's station(s) of specified off-road self-propelled work machines. This document applies to the following work machines which have operator stations as specified in SAE J1116: • Crawler Loader • Grader • Log Skidder • Wheel Loader • Crawler Tractor with Dozer • Pipelayer • Dumper • Wheel Tractor with Dozer • Trencher • Tractor Scraper • Backhoe • Sweeper • Roller/Compactor • Hydraulic Excavator • Pad Foot Wheel Compactor with Dozer • Excavator and Wheel Feller-Buncher The instrumentation requirements and specific work cycles for these machines are described. The method used to calculate the time weighted average sound level at the operator station(s) is specified for Leq(5), or optional exchange rates, during continuous operation in a work cycle representing continuous medium to heavy work. The work cycles provide a repeatable reproduceable means to uniformly measure working machines against a “yard stick.
Standard
2014-09-17
The scope of this SAE Standard is the definition of the functional, environmental, and life cycle test requirements for electrically operated backup alarm devices primarily intended for use on off-road, self propelled work machines as defined by SAE J1116 (limited to categories of 1) construction, and 2) general purpose industrial). This purpose of this document is to define a set of performance requirements for backup alarms, independent of machine usage. The laboratory tests defined in this document are intended to provide a uniform and repeatable means of verifying whether or nor a test alarm meets the stated requirements. For on-machine requirements and test procedures, refer to SAE J 1446.
Article
2014-09-08
Additional $35 million will fund the company’s unique research center an additional five years, concentrating on a ‘safe transition’ to future of automated and connected vehicle technologies.
Article
2014-08-18
Material laws and orientation information are coupled in a single finite element analysis to predict the performance of the hybrid composite beam under a dynamic three point bending load.
Article
2014-08-18
LC411-USBH low-profile compression load cells from Omega enable 1000 readings per second and feature a USB output to connect directly to a computer.
Article
2014-08-13
Model 3340 G-Logger three-channel, portable data acquisition system from Silicon Designs, Inc. (SDI) offers powerful Fast Fourier Transform (FFT) analysis and display, as well as real-time acceleration and GPS data collection and viewing, all within the same compact package.
Standard
2014-08-13
Various SAE vehicle sound level measurement procedures require use of a sound level meter which meets the Type 1 or Type 2 requirements of ANSI S1.4-1983 (see 2.1.1.1), or an alternative system which can be proved to provide equivalent test data. The purpose of this SAE Recommended Practice is to provide a procedure for determining if a sound data acquisition system (SDAS) has electro-acoustical performance equivalent to such a meter. By assuring equivalent performance of the test instrumentation, the equivalence of test data is assured. Two general configurations of sound data acquisition systems will be encompassed (see Figure 1). The first configuration consists of instrument sections which perform as a sound level meter. The second configuration is a system which records data for later processing. The intent of this document is to establish guidelines which permit the test engineer to insure equivalence of sound data acquisition systems to a sound level meter. It requires that the test engineer have a working knowledge of the characteristics of the sound data being measured.
Article
2014-08-12
AC17 test reporting begins in 2015. Initially it "gifts" applicable CAFE A/C efficiency credits, but leads to mandatory use. Industry also looks to reduce A/C-induced EV range loss from solar loading using films, glass, pre-ventilation.
Article
2014-08-12
Johnson Controls has opened a new crash test facility at its automotive seating headquarters in Plymouth, MI. One of the highlights of the facility is a Seattle Safety ServoSled that allows the automotive supplier to offer what it claims is the most accurate, standardized safety testing of seats globally through collaboration with its other testing facilities located in Burscheid, Germany; Changchun and Shanghai, China; and Yokohama, Japan.
Article
2014-08-04
HBM Inc.’s new industrial measurement amplifier enables users to make precise, dynamic measurements of raw and filtered torque, frequency, pulse, speed, and angle of rotation.
Article
2014-08-04
The SAB 32 shield connection clip from Conta-Clip provides a quick, simple connection when cables require shielding from interference.
Article
2014-08-04
The R&S SMW200A high-end vector signal generator from Rohde & Schwarz supports frequencies up to 20 GHz.
Article
2014-08-04
Sonoscan’s AW322 200 automated system for ultrasonic inspection of MEMS wafers images and identifies internal gap-type defects down to 5µm in size.
Article
2014-08-04
The Model XLUS88 subminiature, bidirectional tension/compression load cell from tecsis LP operates from 150 g to 1000 lb.
Article
2014-07-30
The Electric Power Research Institute has announced a collaboration with 8 automakers and 15 utilities to develop and demonstrate an open grid integration platform for plug-in electric vehicles (PEVs).
Article
2014-07-29
To develop an electric powertrain with a minimum noise level and minimized whining it is necessary to have accurate CAE simulation and precise criteria to assess whining noise.
Article
2014-07-23
In development of an advanced test engine to demonstrate fuel-saving and emissions-reducing technologies, the EPA is using ANSYS FORTÉ CFD software, giving its engineers the ability to quickly and inexpensively make multiple design iterations.
Article
2014-07-16
Ram’s official move to adopt the SAE J2807 towing standard for validating all three (1500, 2500, and 3500) of its pickup weight classes raises the competitive bar for the industry's other pickup players. Meanwhile, Ford has engineered its latest F-450 with half the GCVW capability of a Class-8 tractor-trailer.
Article
2014-07-15
Opel recently broke ground on a €210 million expansion of its Rüsselsheim International Technical Development center (ITDC) that will be used to develop and test engines. The 36,000-m² (400,000-ft²) expansion will be completed in 2017.
Article
2014-07-15
Northrop Grumman Corp. broke ground on a new $20 million Maryland Space Assembly and Test (M-SAT) facility on its Baltimore campus adjacent to Baltimore Washington International Thurgood Marshall Airport.
Article
2014-07-15
VPT Inc. has added a comprehensive radiation laboratory and test services facility to its Chelmsford, MA, facility. The 5000-ft² VPT Rad facility, which will serve the radiation and related test needs of aerospace electronics manufacturers, provides specialized environments and equipment for evaluating electronics used in applications where ionizing radiation can degrade device performance.
Magazine
2014-07-10
Off-highway engines advance beyond Tier 4 With Tier 4 Final/Stage IV needs met, engine OEMs direct their focus and competitive energies toward optimizing competitive solutions. At the same time, they need to keep a weather eye out for future regulations, which many expect. Autonomous vehicle challenges span many fields Many of the challenges faced by military and commercial design teams are similar. Racket busters With a quiet cab at the top of many tractor buyers' wish lists, agricultural equipment manufacturers are pursuing every opportunity possible to shed decibels.
Article
2014-07-07
Recently, with increased vehicle safety requirements, vehicle manufacturers are installing cutting-edge testing equipment in their own crash test facilities.Chrysler Group LLC partnered with Messring Systembau GmbH to upgrade Chelsea Proving Grounds, the central testing facility in Chelsea, MI.
Standard
2014-07-01
This SAE Aerospace Information Report (AIR) provides Nuclear, Biological and Chemical (NBC) protection considerations for environmental control system (ECS) design. It is intended to familiarize the ECS designer with the subject in order to know what information will be required to do an ECS design where NBC protection is a requirement. This is not intended to be a thorough discussion of NBC protection. Such a document would be large and would be classified. Topics of NBC protection that are more pertinent to the ECS designer are discussed in more detail. Those of peripheral interest, but of which the ECS designer should be aware are briefly discussed. Only radiological aspects of nuclear blast are discussed. The term CBR (Chemical, Biological, and Radiological) has been used to contrast with NBC to indicate that only the radiological aspects of a nuclear blast are being discussed. This is actually a more accurate term to describe the subject of this paper, but NBC has become more widely used in the aircraft industry.
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