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2017-06-05
Technical Paper
2017-01-1804
Chulwoo Jung, Hyeon Seok Kim, Hyuckjin Oh, Kwang Hyeon Hwang, Hun Park
An efficient method to determine bush stiffness of passenger cars for satisfying requirement of noise and vibration is developed. In general, a passenger vehicle includes various types of bush to connect systems and control forces (loads) transferred between systems which affect characteristics of noise and vibration of the vehicle. Noise and vibration of a vehicle are mainly caused by forces from power train (engine and transmission) and road excitation. While a vehicle is in operation, road excitation is applied to the vehicle through bushes. If a bush transfers less force to the body structure, levels of noise and vibration will be decreased. In other words, it is necessary to well determine characteristics of bushes when developing passenger vehicles. Bush stiffness is one of key factors to affect the performance of noise and vibration of the vehicle.
2017-06-05
Technical Paper
2017-01-1851
Taewook Yoo, Ronald W. Gerdes, Seungkyu Lee, Daniel Stanley, Thomas Herdtle, Georg Eichhorn
Several methods for evaluating damping material performance are commonly used, such as Oberst beam test, power injection method and the long bar test. Among these test methods, the Oberst beam test method has been widely used in the automotive industry and elsewhere as a standard method, allowing for slight bar dimension differences. However, questions have arisen as to whether this Oberst test result reflect real applications. Therefore, the long bar test method has been introduced and has been used in the aerospace industry for some time. In addition to the larger size bar in the long bar test, there are a few differences between Oberst (cantilever) and long bar test (center-driven) methods. In this paper, the differences between Oberst and long bar test methods will be discussed both experimentally and numerically using Finite Element Analysis. Furthermore, guidelines for a long bar test method will be provided.
2017-06-05
Technical Paper
2017-01-1904
Tan Li, Ricardo Burdisso, Corina Sandu
Tire-pavement interaction noise (TPIN) is a dominant source for passenger cars and trucks above 40 km/h and 70 km/h, respectively. TPIN is mainly generated from the interaction between the tire and the pavement. In this paper, twenty-two tires of the same size (16 in. radius) but with different tread patterns were tested on a non-porous asphalt pavement. For each tire, the noise data were collected using an on-board sound intensity (OBSI) system at five speeds in the range from 45 to 65 mph. The OBSI system used an optical sensor to record a once-per-revolution signal to monitor the vehicle speed. This signal was also used to perform order tracking analysis to break down the total tire noise into two components: tread pattern-related noise and non-tread pattern-related noise.
2017-06-05
Technical Paper
2017-01-1879
Pranab Saha
Traditionally, the damping performance of a visco-elastic material is measured using Oberst bar damping test, where a steel bar is excited using a non-contacting transducer. However, in an effort to lightweight the vehicles, serious effort is put in to change the body panels from steel to aluminum and composite panels in many cases. These panels cannot be excited using a non contacting transducer, although in some cases a very thin steel panel (shim) is glued to the vibrating bar to introduce ferrous properties to the bar so it can be excited. In the off highway vehicles, although the panels are made of steel, they are very thick and are difficult to excite using the Oberst bar test method. This paper discusses a measurement methodology based on mechanical impedance measurements and has the potential to be a viable/alternate test method to the Oberst bar testing. In the impedance method, the test bar is mounted to a shaker at the center (Center Point method).
2017-06-05
Technical Paper
2017-01-1901
Christian Glandier, Stefanie Grollius
With the reduction of engine noise in internal combustion engines and the advent of alternative propulsion systems, road noise has become the major source of interior noise in urban and suburban driving in the low frequency range. The challenges of weight reduction, performance improvement and reduced development time call for stronger support of the development process by numerical methods. The long and complex transfer paths from the road surface to the occupants’ ears through tire, chassis, bushings, body, trim and air cavity make such a prediction a non-trivial task. This starts with the tire. Tire manufacturers have a thorough knowledge of their product and the physics involved in its behavior and deploy refined simulation techniques. However, interfacing difficulties between tire simulation and vehicle simulation very often lead to unnecessary losses in accuracy.
2017-06-05
Technical Paper
2017-01-1836
Fangfang Wang, Peter Johnson, Hugh Davies, Bronson Du
Introduction Whole-body vibration (WBV) is associated with several adverse health and safety outcomes including low-back pain and driver fatigue. Recently introduced active suspension truck seats have been shown to reduce WBV exposures up to 50% relative to industry standard air-suspension seats, but drivers do not universally prefer these active suspension seats and their higher costs concern some companies. The objective of this study was to evaluate the efficacy of three commercially-available air-suspension truck seats for reducing truck drivers’ exposures to WBV. Methods Seventeen truck drivers operating over a standardized route were recruited for this study and three commercially available air suspension seats were evaluated. The predominant, z-axis average weighted vibration (Aw) and Vibration Dose Values (VDV) were calculated and normalized to represent eight hours of truck operation.
2017-06-05
Technical Paper
2017-01-1805
Krzysztof Prażnowski, Jaroslaw Mamala
The vibrations of the sprung mass of a passenger car, traveling on a road surface, are random and are its main source but not the only one. The resulting force ratio is further confounded by other factors occurring at the interface of the pneumatic tire with the road surface, such as non-uniformity of tires, errors shape and imbalances. The resulting the additional inertia force acts on the previously brought kinematic force acting on the car body. Occurring at the time of the sprung mass vibrations of the car body can be treated as a potential source of diagnostic information, but their direct identification is difficult. Moreover, all basic identification is complicated by force derived from random interference unevenness in the road. Then the ratio defined as SNR accepts negative values. Due to the lack of description in the literature conclusive research to identify the unbalance the whole pneumatic wheel real conditions, conducted its own experimental research.
2017-06-05
Technical Paper
2017-01-1857
Joshua R. Goossens, William Mars, Guy Smith, Paul Heil, Scott Braddock, Jeanette Pilarski
Tenneco is using fe-safe/rubber to implement fatigue analysis capabilities and workflows that offer unprecedented control over durability issues in development programs.  The implementation includes a new materials testing facility that can measure the parameters governing elastomer fatigue behavior.  Our lab measures the fatigue crack growth rate curve, crack precursor size, strain crystallization function, and cyclic stress-strain curves.  The measurement and computational capabilities are demonstrated here for a series of uniaxial, biaxial and triaxial load cases on a Front Lower Control Arm vertical ride bushing.  Abaqus was used to obtain the strain history for each load case, and fe-safe/rubber has been used to compute fatigue life and failure mode.  For each case, we present the results of fe-safe/rubber’s Critical Plane Analysis, illustrating the insights that the analysis provides in tracing the development of damage in the bushing.
2017-06-05
Technical Paper
2017-01-1778
Enrico Galvagno, Antonio Tota, Mauro Velardocchia, Alessandro Vigliani
This paper explores the potentiality of reducing noise and vibration of a vehicle transmission thanks to powertrain control integration with active braking system. The torsional backlashes between transmission rotating components (gears, synchronizers, splines, CV joints), in the presence of external disturbances, coming from the driver, e.g. during tip-in / tip-out maneuvers, or from the road, e.g. crossing a speed bump or driving on a rough road, may lead to NVH issues known as clonk. In this study, first of all the positive effect of a brake torque application at the driving wheels during such maneuvers on transmission NVH performance is shown. After that, a powertrain/brake integrated control strategy is proposed. The braking system is activated in advance with respect to the perturbation and it is deactivated immediately after to minimize the energy loss.
2017-06-05
Technical Paper
2017-01-1829
Guillaume Loussert
The new fuel efficiency and emission standards have forced OEMs to put emphasis on different strategies such as engine downsizing, cylinder deactivation... Unfortunately these new technologies may lead to increased powertrain vibrations generated by the engine and transmitted to the chassis and the car cabin, such that their reduction or elimination has become a key topic for the automotive industry. The use of active engine mounts, acting directly on the fluid of an hydromount, or active vibration dampers, acting as an inertial mass-spring system, are very effective solutions, particularly when using electromagnetic based actuators. Nevertheless, all electromagnetic actuators technologies are not equals and the choice of such actuators must be considered carefully by taking into account the full performances and the overall cost of the solutions. This paper presents an electromagnetic actuator technology, that can be considered as the best tradeoff between performances and cost.
2017-06-05
Technical Paper
2017-01-1833
Bonan Qin, Jue Yang, Xinxin Zhao
Articulated engineering vehicle travels on complex road, its working condition is bad and because of the non-rigid connection between the front and rear body, additional degrees of freedom is brought in and the transverse stiffness is relatively weak. When the articulated vehicle run in a high speed along a straight line, it is easy to cause the transverse swing and the poor manipulation stability. If it is serious enough, it will lead to "snake shape" instability phenomena. This kind of instability will increase driving resistance and tire wear, the lateral dynamic load and aggravate the damage of the parts. When steering, the center of gravity will offset laterally which will lead a higher probability of rollover accident. A mathematical model for a 35t articulated dump truck with four motor-driven wheels is established in this paper, to study the condition for its stable driving and the effects of the vehicle structural parameters.
2017-06-05
Technical Paper
2017-01-1837
Paul R. Donavan, Carrie Janello
Acoustic beamforming was used to localize noise sources on heavy trucks operating on highways in California and North Carolina at a total of 20 sites. Over 1,200 trucks were measured under a variety of operating conditions including cruise on level highways, on upgrades, down degrades, low speed acceleration, and for various speeds and pavements. The contours produced by the beamforming measurements were used to identify specific source contributions under these conditions and for a variety of heavy trucks. Consistently, the highest noise levels were seen the tire-pavement interface with lessor additional noise radiated from the engine compartment. Noise from elevated exhaust stacks was only documented for less than 5% of the trucks measured. The results were further reduced to produce vertical profiles of noise levels versus height above the roadway. The profiles were normalized to the highest noise level at ground level.
2017-06-05
Technical Paper
2017-01-1890
Xingyu Zhang, Bo Yang, Manchuang Zhang, Sanbao Hu
H-Bahn ("hanging railway") refers to the suspended, unmanned urban railway transportation system. Through the reasonable platform layout, H-Bahn can be easily integrated into the existing urban transit system. With the development of urban roads, the associated rail facilities can be conveniently disassembled, moved and expanded. The track beam, circuits, communication equipment, and sound insulation screen are all installed in a box-type track beam so that the system can achieve a high level of integration and intelligence. The carriage of the modern H-banh vehicle is connected with the bogies by two hanging devices. The vehicle is always running in the box-type track beam; therefore there are less possibilities of derailment. Consequently, the key work focuses on the running stability evaluation and curve negotiation performance analysis.
2017-06-05
Technical Paper
2017-01-1752
Kapil Gupta, Arun Choudhary, Rakesh Bidre
At present, a Dual Mass Flywheel (DMF) system is widely known to provide benefits on driveline induced noise, vibration and drivability over a Single Mass Flywheel (SMF). A well-tuned DMF provides nice isolation of torsional vibrations generated in periodic combustion process of automobile IC engines. Similarly, a torsional vibration damper mounted on driveline component reduces the torsional excitation and results a lower torsional vibration at driveline components. Noise and vibration issues like boom noise and high vibrations at low engine rpm range drive are often resulted due to high engine firing order torsional excitation input to the driveline. More often, this becomes one of the most objectionable noise and vibration issues in vehicle and should be eliminated or reduced for better NVH performance. A 4 cylinder, 4 stroke small diesel engine equipped with SMF is found to have high engine firing order torsional excitation.
2017-06-05
Technical Paper
2017-01-1819
Cyril Nerubenko, George Nerubenko
The results of dynamical study of new patented Torsional Vibration Dampers mounted on a crankshaft in V8 engines are presented. Design and structure of Torsional Vibration Damper is based on author’s US Patent 7,438,165 having the control system with instantaneous frequencies tuner for all frequencies of running engine. Analysis and disadvantages of conventional rubber and viscous Crank Dampers are shown. The focus of the study is on Torsional Vibration Damper having the mechanical self-tuning structure applicable for V8 engines. Mathematical model based on the system of ordinary differential equations describing the rotation and vibration of mechanical components has been used for the analysis of the dynamic behavior of V8 engine crankshaft system having proposed Torsional Vibration Damper. Attention is paid to composition and selection of optimal parameters of a proposed device for solving the problems of effective mitigation of crankshaft torsional vibrations in V6 engines.
2017-06-05
Technical Paper
2017-01-1855
Ramakanta Routaray
The basic function of a motorcycle frame is somewhat similar to that of the skeleton in the human body, i.e. to hold together the different parts in one rigid structure. One of the major benefits (for a motorcycle enthusiast) of using an advanced frame design lies in the sporty handling characteristics of the bike. A well designed frame can add to the joy of riding a motorcycle as the bike would feel more stable, effortless, and confident around corners, in straight lines and while braking. A well approved modeling techniques or adequate guide line principles have to be followed while designing the body and chassis in order to achieve the vibration within control. This paper depicts a methodological right approach to model the body and chassis of a two wheeler in order to control noise and vibration of the body and chassis.
2017-06-05
Technical Paper
2017-01-1903
Masami Matsubara, Nobutaka Tsujiuchi, Tomohiko Ise, Shozo Kawamura
The tire is one of the most important parts, which influence the noise, vibration, and harshness of the passenger cars. It is well known that effect of rotation influences tire vibration characteristics, and earlier studies presented formulas of tire vibration behavior. However, there is no studies of tire vibration including lateral vibration on effect of rotation. In this paper, we present new formulas of tire vibration on effect of rotation using a three-dimensional flexible ring model. The model consists of the cylindrical ring represents the tread and the springs represent the sidewall stiffness. The equation of motion of lateral, longitudinal, and radial vibration on the tread are derived based on the assumption of inextensional deformation. Many of the associated numerical parameters are identified from experimental tests.
2017-06-05
Technical Paper
2017-01-1905
Kiran Patil, Javad Baqersad, Jennifer Bastiaan
Tires are one of the major sources of noise and vibrations in vehicles. The vibration characteristic of a tire depends on its resonant frequencies and mode shapes. Hence, it is desirable to study how different parameters affect the characteristics of tires. In the current paper, experimental modal tests are performed on a tire in free-free and fixed conditions. To obtain the mode shapes and the natural frequencies, the tire is excited using a mechanical shaker and the response is measured using three roving tri-axial accelerometers. The mode shapes and resonant frequencies of the tire are extracted using LMS POLYMAX modal analysis. The extracted mode shapes in the two configurations are compared using Modal Assurance Criterion (MAC) to show how mode shapes of tires change when the tire is moved from a free-free configuration to a fixed configuration.
2017-06-05
Technical Paper
2017-01-1755
Frank C. Valeri, James T. Lagodzinski, Scott M. Reilly, John P. Miller
Hybrid powertrain vehicles inherently create discontinuous sounds during operation. The discontinuous noise created from the electrical motors during transition states are undesirable since they can create tones that do not correlate with the dynamics of the vehicle. The audible level of these motor whines and discontinuous tones can be reduced via common noise abatement techniques or reducing the amount of regeneration braking. One electronic solution which does not affect mass or fuel economy is Masking Sound Enhancement (MSE). MSE is an algorithm that uses the infotainment system to mask the naturally occurring discontinuous hybrid drive unit and driveline tones. MSE enables a variety of benefits, such as more aggressive regenerative braking strategies which yield higher levels of fuel economy and an overall more pleasing interior vehicle powertrain sound. This paper will discuss the techniques and signals used to implement MSE in a hybrid powertrain equipped vehicle.
2017-04-30
Book
Eduardo Galindo, David Blanco, Chris J. Brace, Edward Chappell, Richard Burke
The use of the chassis dynamometer test cells has been an integral part of the vehicle development and validation process for several decades, involving specialists from different fields, not all of them necessarily experts in automotive engineering. CHASSIS DYNAMOMETER TESTING: Addressing the Challenges of New Global Legislation (WLTP and RDE) sets out to gather knowledge from multiple groups of specialists to better understand the testing challenges associated with the vehicle chassis dynamometer test cells, and enable informed design and use of these facilities.
CURRENT
2017-04-27
Standard
J2743_201704
This SAE Recommended Practice is intended to describe a procedure for rating the size of single-stage reciprocating air compressors. It describes the conditions that can be used for testing and it defines a standardized rating expressed in SLPM (SCFM).
2017-04-27
WIP Standard
J2494/2
This SAE Standard covers general dimensional specifications for non-metallic body reusable push to connect tube fittings for use in the piping of air brake systems on automotive vehicles. This type of fitting is intended for use with nylon tubing per SAE J844. It is not intended to restrict or preclude other designs of a tube fitting for use with SAE J844. Performance requirements for SAE J844 are covered in SAE J1131. See SAE J2494-3 for the performance requirements of Reusable (push-to-connect) fittings intended for use in Automotive Air Brake Systems and U.S. Department of Transportation FMVSS 571.106.
2017-04-27
WIP Standard
J2494/1
This SAE Standard covers general and dimensional specifications for brass bodied reusable Push to Connect tube fittings for use in the piping of vehicular air brake systems. This type of fitting is intended for use with nylon tubing per SAE J844. See SAE J2494-3 for the Performance Requirements of Reusable (Push to Connect) Fittings Intended for Use in Automotive Air Brake Systems and U.S. Department of Transportation, National Highway Traffic Safety Administration (NHTSA) Federal Motor Vehicle Safety Standards (FMVSS) 571.
2017-04-27
WIP Standard
J512
This SAE Standard covers complete general and dimensional specifications for the various types of tube fittings intended for general application in the automotive, appliance, and allied fields. See SAE J1131 for the performance requirements of reusable (push to connect) fittings intended for use in automotive air brake systems.
2017-04-26
WIP Standard
AS1145D
This specification covers minimum requirements for brake temperature monitoring equipment whenever used on any type and model of civil aircraft. It shall be the responsibility of the purchaser to determine the compatibility of these requirements with the application aircraft and to specify requirements in excess of these minimums as necessary.
2017-04-25
WIP Standard
J1462
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.
2017-04-17
Article
More on-board processing power is needed to enable the next generation of vehicle systems, said Dr. Holger Klein, ZF's Head of Car Chassis Technology.
2017-04-14
WIP Standard
J2684
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.
2017-04-11
Journal Article
2017-01-9177
N. Obuli Karthikeyan, R. Dinesh Kumar, V. Srinivasa Chandra, Vela Murali
Abstract In the modern automotive sector, durability and reliability are the most common terms. Customers are expecting a highly reliable product but at low cost. Any product that fails within its useful life leads to customer dissatisfaction and affects the reputation of the OEM. To eradicate this, all automotive components undergo stringent validation protocol, either in proving ground or in lab. This paper details on developing an accelerated lab test methodology for steering gearbox bracket using fatigue damage and reliability correlation by simulating field failure. Initially, potential failure causes for steering gearbox bracket were analyzed. Road load data was then acquired at proving ground and customer site to evaluate the cumulative fatigue damage on the steering gearbox bracket. To simulate the field failure, lab test facility was developed, reproducing similar boundary conditions as in vehicle.
2017-04-06
WIP Standard
J2848/1
This SAE recommended practice defines the system and component functions, measurement metrics, testing methodologies for evaluating the functionality and performance of tire pressure systems, and recommended maintenance practices within the known operating environments. This document is applicable to all axle and all wheel combinations for single unit powered vehicles exceeding 7257 kg (16 000 US lb) gross vehicle weight rating (GVWR), and multi-unit vehicle combinations, up to three (3) towed units, which use an SAE J560 connector for power and/or communication, or equivalent successor connector technology, or which use a suitable capacity wireless solution. Examples of included single chassis vehicles would be – utility and delivery vans, tow trucks, rack trucks, buses, recreational vehicles, fuel trucks, trash trucks, dump trucks, cement trucks, and tractors.
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