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2015-06-15
Technical Paper
2015-01-2197
Stijn Vercammen, Fabio Bianciardi, Peter Kindt, Wim Desmet, Paul Sas
In the context of the reduction of traffic-related noise the research reported in this paper contributes to the development of low noise tyres. Two measurement techniques have been analyzed for exterior noise radiation characterization of a loaded rotating slick tyre on a rough road surface. On one hand sound pressure measurements at low spatial resolution with strategically placed microphones on a half-hemisphere around the tyre/road contact point have been performed. This technique provides a robust solution to compute the (overall) sound power level. On the other hand sound intensity measurements at high spatial resolution by means of a scanning intensity probe, LMS Soundbrush, have been performed. This technique allows a more detailed spatial visualization of the noise radiation and helps in getting more insight and better understanding of the acoustical phenomena.
2015-06-15
Technical Paper
2015-01-2353
Jan Bunthoff, Frank Gauterin, Christoph Boehm
In an automotive suspension, the shock absorber plays a significant role to enable the vehicle performances, especially in ride, handling and Noise-Vibration-Harshness (NVH). Understanding its physical characteristics is of great importance, as it has a main influence on the overall vehicle performance. Within this research project simulation models for different passive monotube shock absorber systems have been created in a 1-D system simulation software. The simulation models are designed and parameterized physically. To validate the simulation models measurements on different hydropulse-shaker with specially designed control signals to investigate the response during high frequency excitation, have been done. A detailed discussion of the several models and results of a simulation to measurement comparison is given. After detailed investigation the shock absorber simulation models are now adaptable to the multi body simulation.
2015-06-15
Technical Paper
2015-01-2233
Hudson P. V, V Shivaraj, Sukumar T, Suresh Gaikwad
Generally the brake system products are mounted on chassis with brackets which are subjected to dynamic loads due to road undulations. Exhaust brake is used to restrict the engine exhaust flow passage and thereby creates a back pressure in the engine for reducing the engine speed. This in turn reduces the vehicle speed. This is widely used in the vehicles operating in the hilly areas. This product is mounted on the exhaust passage and the air cylinder sub-assembly which actuates the exhaust brake is mounted on a bracket. Automotive industries perform durability tests on vehicles to reduce the failure on end-user environment. An assembly which has cleared the durability test got failed on addition of a spring into the assembly. The inclusion of spring is for enhancing the performance of the overall assembly. This paper deals with investigations carried out using finite element method (FEM) to study the effect of spring on the assembly and to propose a design solution for the failure.
2015-06-15
Technical Paper
2015-01-2354
Xiao-Ang Liu, Zhaoping Lv, Wenbin Shangguan
Since the balances of 3-cylinder engine is worse than 4- or 6- cylinder engine, design of powertrain mounting system for engine with three cylinders is much more significant to engine vibration isolation. Inline 3-cylinder engine vibrations are caused by imbalance forces from reciprocate inertial forces of pistons, the rotation inertia forces from the crank and connecting road and the gas combustion forces. The excitation of a 3-cylinder engine is heavier than 3-cylinder engine, so the new design method of mounting system for isolation engine vibration should be developed. The purpose of this paper is to analyze the balance method for 3-cylinder engine, and the optimization method for its mounting system. Firstly the calculation method for obtaining the forces and moments applied to the engine block is presented.
2015-06-15
Technical Paper
2015-01-2351
Hongyu Shu, Shuang Luo, Li Wang
Recently auto shock absorbers have caused automobile users in China a lot of complaints that they have abnormal noise. In order to measure the noise of auto shock absorbers, a test bench which detect piston-rod vibration response of shock absorber excited by oscillating crankshaft mechanism, and measuring analyzer named as SANTS-Ⅰ,which included specialized signal process and analysis software have been developed. A lot of tests of auto shock absorbers of the abnormal noise have been carried out with the test bench and the piston-rod vibration response data have been collected. It has been showed that there are violent peaks with high frequency in the sine curve of piston-rod oscillating with relative low frequency, signal processed by SANTS-Ⅰmeasuring analyzer.
2015-06-15
Technical Paper
2015-01-2368
Babitha Kalla, Sanjeevgouda Patil, Mansinh Kumbhar
Idle NVH is one of the major quality parameters that customer looks into while buying the vehicle. Idle shake is undesirable vibrations generated from Engine while it is in idling condition. These low frequency vibrations affects both driver and passenger comfort. Vibrations are perceived by customer through the interfaces such as the seats, floor, and steering wheel. The frequencies of vibration felt by customer ranges between 10-30 Hz and varies based on engine configurations. There are two factors that are critical to the vehicle idle NVH quality, 1. Engine excitation force and 2. Vehicle sensitivity to excitation forces (Transfer function). Even though the engine excitation forces are governed by cylinder combustion process inside the cylinder and engine mass, it is also largely affected by how well the engine and transmission are supported on vehicle through isolators.
2015-06-15
Journal Article
2015-01-2193
Masami Matsubara, Daiki Tajiri, Makoto Horiuchi, Shozo Kawamura
Generally as change of vibration characteristics of a tire, natural frequency of a load and rolling tire is lower than that of an unrolling tire. This phenomena is considered to be due to the change of tire stiffness. Early studies described the reason why the change was caused by property of rubber material. One of the evaluation tire stiffness is sidewall stiffness. This stiffness, which have an influence on tire vibration characteristics, is also important design parameter for carry the vehicle body. Tire sidewall is parts of resisting the tension due to inflation pressure. Hence, it is considered that tire sidewall stiffness is decided by tension of inflation pressure and structural dynamic characteristics including property of rubber material. It is necessary to reveal the dynamic characteristic of tire sidewall stiffness. This study describes tire sidewall stiffness as difference of inflation pressure.
2015-06-15
Technical Paper
2015-01-2198
Masami Matsubara, Nobutaka Tsujiuchi, Takayuki Koizumi, Akihito Ito, Kensuke Bito
Tires of passenger cars greatly influence the performance of NVH (Noise, Vibration and harshness). Especially, it is important to reveal the tire vibration characteristics because there is a strong correlativity between the tire vibration and the interior noise of passenger cars as against road noise, one of the NVH performance. Early studies on the tire vibration characteristics for road noise focused on tire vibration of radial direction, circumferential mode is known, because this mode is dominant in vertical spindle force. However, recent studies of NVH prediction with development, including tires as car substructure, found that not only the circumferential mode, but also the lateral bending mode affect interior noise. Tire vibration mode making noise and vibration problem differs depending on axle vibration direction, and it is demand a comprehensive approach for this problem. This paper presents a new approach for evaluation of natural frequency of tire.
2015-06-15
Journal Article
2015-01-2355
Luke Fredette, Jason Dreyer, Rajendra Singh
Hydraulic bushings with amplitude sensitive and spectrally varying properties are commonly used in automotive suspension. However, scientific investigation of their dynamic properties has been mostly limited to linear system based theory, which cannot capture the significant amplitude dependence exhibited by the devices. This paper extends prior literature by introducing a nonlinear fluid compliance term for reduced-order bushing models. Quasi-linear models developed from step sine tests on an elastomeric test machine can predict amplitude dependence trends, but offer limited insight into the physics of the system. A bench experiment focusing on the compliance parameter isolated from other system properties yields additional understanding and a more precise characterization. Computational analysis of the bench experiment offers general agreement with both bench experiment and step sine test results.
2015-06-15
Technical Paper
2015-01-2194
Giorgio Bartolozzi, Marco Danti, Guido Nierop, Andrea Camia
Abstract Within the automotive industry, a typical way to account for tires in a roadnoise mission simulation is to use the “modal model” supplied by tire manufacturers. Even though this kind of models is certified by the suppliers and is very simple to use, it has the drawback to be disconnected from the physical description of the tire. This reflects in limiting the carmaker company to be able only to request certain modal characteristics to the supplier. The aim of this paper is to present an accurate, yet easy to use, methodology to develop an FE model of a tire, to be used in a full-vehicle simulation. The determined model must be connected to the tire physical properties. These properties are not measured directly, but determined by tuning a properly created geometric FE model to the measured point inertances of the inflated tire. This allows creating the model only by using an optimization algorithm to tune such properties.
2015-06-15
Journal Article
2015-01-2199
Rui Cao, J Stuart Bolton
Abstract Experimental measurements of tire tread band vibration have provided direct evidence that higher order structural-acoustic modes exist in tires, not just the well-known fundamental acoustical mode. These modes display both circumferential and radial pressure variations within the tire's air cavity. The theory governing these modes has thus been investigated. A brief recapitulation of the previously-presented coupled structural-acoustical model based on a tensioned string approach will be given, and then an improved tire-acoustical model with a ring-like shape will be introduced. In the latter model, the effects of flexural and circumferential stiffness are considered. This improved model accounts for propagating in-plane vibration in addition to the essentially structure-borne flexural wave and the essentially airborne longitudinal wave accounted for in the previous model. The longitudinal structure-borne wave “cuts on” at the tire's circumferential ring frequency.
2015-06-15
Journal Article
2015-01-2196
Farokh Kavarana, Scott Fritz, John DeYoung
Abstract Recent trends in vehicle light-weighting and tire design requirements have created an increased awareness to tire flat-spotting. Tire flat-spotting occurs when tires remain in a loaded condition without rolling for an extended period of time. Tire flat-spotting can either be temporary or permanent depending on the length of storage and other environmental factors. Tire non-uniformity caused due to flat-spots often induces shake and shimmy (back and forth oscillation of steering wheel) vibration in vehicles due to increased tire-wheel force variation input into the chassis. This can result in increased warranty costs for OEMs (Original Equipment Manufacturers) as well as customer dissatisfaction exhibited in third party quality surveys like the annual J. D. Power IQS (Initial Quality Survey).
2015-05-20
Article
A custom tractor-trailer technology demonstrator built by Alcoa is outfitted with various current and “soon-to-be-available” aluminum solutions that altogether can reduce the weight of a tractor-trailer by up to 2500 lb (1135 kg) compared to traditional steel components.
2015-05-14
WIP Standard
J294
This SAE Recommended Practice establishes a method of testing the structural integrity of the brake system of all new trucks, buses, and combination vehicles designed for roadway use and falling in the following classifications: a. Trucks and Bus— Over 4500 kg (10 000 lb) GVWR b. Combination of vehicle—Towing vehicle over 4500 kg 10 000 lb) GVWR The test consists of two parts: a Structural EnduranceTest followed by a Structural Ultimate Strength Test.
2015-05-12
Standard
J694_201505
This SAE Recommended Practice contains dimensions and their tolerances concerning disc wheel to hub or drum interface areas for truck and bus applications. Disc wheels designed only for single wheel applications (not dual wheels) for light trucks and special or less common applications are not covered in this document.
2015-05-12
Standard
J1939DA_201505
This document is intended to supplement the J1939 documents by offering the J1939 information in a form that can be sorted and search for easier use. 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. It also includes the supporting descriptions and figures previously published in the SAE J1939-71 document.
2015-05-07
Article
Researchers from Tsinghua University propose a new type of EHPS system suitable for heavy-duty commercial vehicles, with the purpose of reducing the power demand of an electric motor while guaranteeing sufficient power assist. The motor is only activated on-demand, which also helps to improve fuel economy.
2015-05-07
Standard
ARP597E
This document recommends supplementary design criteria to enhance endurance and reliability of transport aircraft wheels and brakes.
2015-05-07
Standard
J2975_201505
This procedure describes a method for generating, preparing and analyzing samples of new and unused brake friction materials for their chemical constituents.
2015-05-05
Magazine
Democratizing hybrid technologies Engineers continue to wring efficiency and mass out of their latest electrified propulsion systems with the aim of mainstreaming the technology. Automakers see possibilities, limits for gesture controls Recent concepts have shown the possibilities of gesture for controlling infotainment functions but the need for industry standards and control simplification complicate development. Ferrari massages 458 to create 488 GTB Ferrari engineers have further refined the 458 Italia model with a new turbocharged and downsized engine and revised aerodynamics to create the 488 GTB.
2015-05-05
Journal Article
2015-01-9107
Zhiyun Zhang, Miaohua Huang, Meixia Ji, Shuanglong Zhu
Abstract In the field of active safety, the active four-wheel-steering (4WS) system seems to be an attractive alternative and an effective tool to improve the vehicles' handling stability in lane-keeping control performance. Under normal using condition, the vehicle's lateral acceleration is comparatively small, and the mathematic relationship between the small side force excitation and the small slip angle of the tire is in the linear region. Furthermore, the effects of roll, heave, and pitch motions are neglected as well as the dynamic characteristics of the tires and suspension system in this work. Therefore, the linear quadratic control (LQC) theory is used to ensure that the output of the 4WS control system can keep track of the desired yaw rate and zero-sideslip-angle response can also be realized at the same time.
2015-05-01
Journal Article
2015-01-9141
Selim Oleksowicz, Keith Burnham, Navneesh Phillip, Phil Barber, Eddie Curry, Witold Grzegozek
Hybrid and electric vehicle (H/EV) technology is already well established in the automotive industry and a great majority of car manufacturers offer vehicles with alternative propulsion systems (hybrid or electric - H/E). This advancement, however, does not mean that all technical aspects of H/E propulsion systems have already been encapsulated or even fully understood. This statement is specifically valid for regenerative braking technology. In order to regenerate the maximum possible energy, which may be limited in real applications (e.g. by the charging ratio of the energy storage device(s)), the interaction of regenerative braking and the active driving safety systems (ADSSs) such as the anti-lock braking system (ABS) needs to be taken in to account. For maximum recaptured energy via electric motor (E-Motor) braking, the use of regenerative braking, which generates decelerations greater than 0.1g, should be deployed.
2015-05-01
Journal Article
2015-01-9106
Magnus Löfdahl, Arne Nykänen, Roger Johnsson
Abstract In the automotive industry, tire noise is an important factor for the perceived quality of a product. A useful method to address such NVH problems is to combine recordings with measurements and/or simulations into auralizations. An example of a method to create structure-borne tire noise auralizations is to filter recordings of hub forces and moments through binaural transfer functions experimentally measured from the hub of the car to an artificial head in the car cabin. To create authentic auralizations of structure-borne sound, all six degrees of freedom (DOFs) of hub forces and moments and transfer functions should be included. However, rotational DOFs are often omitted due to measurement difficulty, complexity, time, and cost. The objective was to find which DOF (or DOFs) is perceived as most prominent in structure-borne tire noise. An auralization model of interior structure-borne tire noise was used.
2015-05-01
Journal Article
2015-01-9109
Dzmitry Savitski, Valentin Ivanov, Barys Shyrokau, Jasper De Smet, Johan Theunissen
Anti-lock braking functions of electric vehicles with individual wheel drive can be effectively realized through the operation of in-wheel or on-board motors in the pure regenerative mode or in the blending mode with conventional electro-hydraulic anti-lock braking system (ABS). The regenerative ABS has an advantage in simultaneous improvement of active safety, energy efficiency, and driving comfort. In scope of this topic, the presented work introduces results of experimental investigations on a pure electric ABS installed on an electric powered sport utility vehicle (SUV) test platform with individual switch reluctance on-board electric motors transferring torque to the each wheel through the single-speed gearbox and half-shaft. The study presents test results of the vehicle braking on inhomogeneous low-friction surface for the case of ABS operation with front electric motors.
2015-04-22
WIP Standard
AS1145C
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.
2015-04-21
Standard
ARP4834B
This SAE Aerospace Recommended Practice (ARP) sets forth criteria for the selection, inspection, retread and repair of worn civil aircraft tires, and the means to verify that the retreaded tire is suitable for continued service. This document is applicable to both bias ply and radial aircraft tires qualified subsequent to the adoption of this document.
2015-04-14
Collection
Topics of this technical paper collection include (but are not limited to) nonlinear behavior of tires and wheels, static/dynamic stress analysis, nonlinear material modeling, contact stress, impact, noise, vibration, traction, hydroplaning, effect of tires on vehicle performance, rolling resistance, and durability.
2015-04-14
Technical Paper
2015-01-1120
Siddhartha Singh, Sudha Ramaswamy
Abstract 1 The modern engine is capable of producing high torque and horsepower. Now the customer wants state of the art comfort and ergonomics.Thus the manufacturers are focusing on reducing the clutch pedal effort and providing a pleasurable driving experience. In heavy traffic conditions where the clutch is used frequently, the pedal effort required to disengage the clutch should be in comfortable range. Often drivers who drive HCV complain about knee pain which is caused due to high pedal effort, this occurs when ergonomics of ABC (accelerator, brake and clutch) pedals is not designed properly. Thus there is a need to reduce the driving fatigue by optimizing the clutch system. Latest technologies like turbo charging and pressure injection have increased the engine power and torque but have also led to increase the clamp load of clutch. Thus the release load required to disengage the clutch has also increased.
2015-04-14
Technical Paper
2015-01-1363
Charles Yuan, Niat Mahmud Rahman
Abstract For a CAE model of the park pawl dynamic system, the engagement speed calculation is done by controlling the input rotational velocity of the vehicle. Usually, it requires multiple adjustment of the input rotational velocity to get the engagement speed and that demands time, effort and file management skill of an analyst. The current objective of this paper is to demonstrate how software Isight, working with ABAQUS Explicit as the solver, can be used to automate the engagement speed calculation procedure and thus reduce the time and effort required of a CAE analyst. The automated system is developed in a way such that the accuracy of the results can be controlled by the end user. It is observed that the automated system significantly saves an analyst's effort. The system design can be optimized easily for modifiable design features such as the torsional spring and the actuator spring stiffness values using the proposed procedure.
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