Your Selections

SAE 2011 World Congress & Exhibition
Show Only

Collections

File Formats

Content Types

Dates

Sectors

Topics

Authors

Publishers

Affiliations

Events

 

Ground Clearance Simulation at GM Europe using Hyperworks/MotionView

Adam Opel AG - General Motors Company-Dr. Peter Riede, Mark Beer, Peter Erb, Christoph Halfmann
Published 2011-04-12 by SAE International in United States
The early evaluation of vehicle and subsystem concepts, the reduction of the number of necessary test runs, the verification of multiple variants and the possibilities to do quick parameter studies are critical issues in modern engineering where sophisticated simulation methods are used to improve and to fasten the engineering process. Given the future legal requirements for CO2 emissions and the correlated measures to improve the aerodynamics of the vehicle the evaluation of ground clearance is one of the most important topics for the development of future passenger cars.This paper describes how the multi-body simulation environment at GM Europe (GME) - consisting of the Hyperworks/MotionView pre-processing, the Virtual Modeling Components (ViMC) library and the Adams solver - is used to simulate ground clearance load cases (e.g. driving over curbs, ramps and speed humps with distinct speed and with distinct steering angles). Since it is important to use a high-performance tire model that models the deflection of the tire when driving over curbs or edges, the FTire tire model is used. A multi-body simulation with a full…
Annotation icon
 

Programmable Diesel Injector Transducer Test Results

Great Plains Diesel Technologies, L.C.-Charles B. Bright
Iowa State Univ.-LeAnn Faidley, Adam Witthauer, Evan Rickels, Theodore Donlin
Published 2011-04-12 by SAE International in United States
In order to approach the Carnot efficiency in modern diesel engines that see variable loads and high speeds, programmable electrically controlled fuel injections are required. Traditional solenoid based transducers are binary and cannot achieve this programmability while newer piezoelectric transducers are susceptible to performance degradation due to high pressures and temperatures. This paper presents the experimental characterization of a programmable diesel fuel injector transducer designed by Great Plains Diesel Technologies, L.C. to address the limitations of existing technology. This transducer employs a little-known magnetostrictive alloy to position its needle. In contrast to piezoelectric ceramics, quantum mechanics endows this alloy with the indestructible property of magnetostriction, the ability to strain proportional to a magnetic field. This allows it to be fast and infinitely adjustable (or, “programmable”) without degradation. A fuel injector based on this alloy has the inherent durability to survive on an engine while maximizing performance. In the tested prototype, the magnetostrictive rod is surrounded by a coil excited by a current pulse to energize the alloy. The prestress needed to achieve maximum performance is…
Annotation icon
 

Small Amplitude Torsional Steering Column Dynamics on Smooth Roads: In-Vehicle Effects and Internal Sources

General Motors Company-Kenneth L. Oblizajek, John D. Sopoci
Published 2011-04-12 by SAE International in United States
Internally excited torsional steering wheel vibrations at frequencies near 8-22 Hz on smooth roads can produce driver disturbances, commonly described as “SHAKE”. These vibrations are primarily excited by the rotating front suspension corners and are periodic in the rotational frequencies of the tire-wheel assemblies. The combination of vehicular dynamic amplification originating in dominant suspension and steering system vibratory modes, and a sufficiently large 1st harmonic non-uniformity excitation of the rotating corner components, can result in periodic vibrations exceeding thresholds of disturbance. Controlling the periodic non-uniformity excitation through individual component requirements (e.g., wheel imbalance, tire force variation, wheel runout, concentric piloting of wheel on hub) is difficult since the desired upper limits of individual component requirements for vibration-free performance are typically beyond industry capability. Alternative approaches include de-sensitizing the vehicle, or the vehicle subsystems, at the critical frequency bands, which yield a lower overall vibration level for statistically relevant amplitudes of periodic excitation. One vehicle subsystem, the steering column assembly in a rack-mounted assisted steering system, may have a torsional dynamic response that can produce unwanted…
Annotation icon
 

Development of a Control Strategy for a Suspension System with an Active Variable Kinematics

Ferrari S.p.A.-Franco Cimatti
Politecnico di Milano-Edoardo Sabbioni, Federico Cheli, Francesco braghin
Published 2011-04-12 by SAE International in United States
Active and semi-active suspension systems are widely diffused into the automotive industry. Most of the proposed devices try to achieve a better compromise between handling and comfort requirements by replacing traditional springs, shock absorbers and antiroll bars with active or semi-active actuators allowing to change suspension stiffness and damping according to a suitable control strategy. An alternative way for controlling passenger car suspensions is proposed in this paper. Traditional passive springs and dampers are maintained, while the geometry of the suspension and thus its kinematics is actively varied. By changing the suspension geometry, spring and damper rates are in fact varied, this modifying the vertical load on the tire and/or the vehicle height from the ground. Among the advantages concerned with this device, the most significant ones are that antiroll bars can be avoided (thus increasing the vehicle interior spaciousness), vehicle aerodynamics can be improved by regulating the vehicle height and vertical loads distribution can be modified during turns. The layout of a double wishbone suspension has thus been adapted and optimized in order to…
Annotation icon
 

An Examination of Snapshot Data in Caterpillar Electronic Control Modules

SAE International Journal of Passenger Cars - Mechanical Systems

Fox Valley Technical College-Michael J. Farrell
Wisconsin State Patrol-Timothy P. Austin
  • Journal Article
  • 2011-01-0807
Published 2011-04-12 by SAE International in United States
It has been recognized that Event Data Recorder (EDR) technology incorporated into the Electronic Control Modules (ECMs) of on-highway heavy truck engines can be a benefit to motor vehicle collision investigation and reconstruction [1,2,3,4,5,6,7]. Such beneficial features include the snapshots recorded by many Caterpillar engines. These snapshots, which are triggered by engine faults, operator input, or by what is called a “Quick Stop,” record engine operation and parameters surrounding the event. Past research has reported that while snapshot data are accurate, the documented event time may be off by 24 hours in some ECMs, notwithstanding the module's clock settings being correct [7]. Furthermore, other research has suggested that some modules may report the time interval between data points at approximately two times the actual duration [6]. In these cases, without a formal detailed study of snapshot records, the validity of the data may be brought into question should a snapshot be shown to have occurred on a different date, or should the timing of data be off.This study performed a detailed examination of the data…
Annotation icon
 

Structural Evaluation of an Experimental Aluminum/Magnesium Decklid

SAE International Journal of Materials and Manufacturing

General Motors Company-Jon T. Carter, Andres R. Melo, Vesna Savic, Louis Gerard Hector, Paul E. Krajewski
  • Journal Article
  • 2011-01-0075
Published 2011-04-12 by SAE International in United States
Experimental decklids for the Cadillac STS sedan were made with Al AA5083 sheet outer panels and Mg AZ31B sheet inner panels using regular-production forming processes and hardware. Joining and coating processes were developed to accommodate the unique properties of Mg. Assembled decklids were evaluated for dimensional accuracy, slam durability, and impact response. The assemblies performed very well in these tests. Explicit and implicit finite element simulations of decklids were conducted, and showed that the Al/Mg decklids have good stiffness and strength characteristics. These results suggest the feasibility of using Mg sheet closure panels from a structural perspective.
Annotation icon
 

Hydroplaning Behavior during Steady- State Cornering Maneuvers

SAE International Journal of Materials and Manufacturing

Metz Engineering & Raciing, LLC-L. Daniel Metz
  • Journal Article
  • 2011-01-0986
Published 2011-04-12 by SAE International in United States
Vehicles running in wet conditions may experience hydroplaning of one or more tires. Hydroplaning can, and often does, change vehicle braking, acceleration and handling characteristics dramatically. Proper analysis of this behavior requires accommodating the clearing of paths for the rear tires that may result from the front tires engaging the water-coated surface first. In this work, a hydroplaning analysis is presented that examines steady-state cornering under potential hydroplaning situations and includes lateral weight transfer, tire load sensitivity and path clearing potential. The sensitivity of vehicle understeer/oversteer characteristics to path clearing and vehicle dimensional characteristics is also examined.
Datasets icon
Annotation icon
 

Combustion Behavior of Leaking Hydrogen and Effects of Ceiling Variations

SAE International Journal of Passenger Cars - Mechanical Systems

Japan Automobile Research Institute-Yohsuke Tamura, MASARU TAKABAYASHI, Jinji Suzuki
Nohmi Bosai LTD.-Takashi Nohmi, Maya Maekawa
  • Journal Article
  • 2011-01-0254
Published 2011-04-12 by SAE International in United States
Hydrogen concentration during combustion in a confined space with a ceiling was investigated. The results indicated that steady-state hydrogen concentration was highest at the ceiling surface for all hydrogen flow rates. When hydrogen concentration was 10-20%, weak flame propagation occurred at the ceiling surface, with the most easily burnable spots being dented areas such as seams, pores and creases on the ceiling surface. The unstable and limited nature of flame propagation at the ceiling surface was attributed to the relationship between temperature and hydrogen concentration in a confined space.
Annotation icon
 

On-System Engine Cooling Fan Measurement as a Tool for Optimizing Cooling System Airflow Performance and Noise

SAE International Journal of Materials and Manufacturing

Robert Bosch LLC-Michael Sortor
  • Journal Article
  • 2011-01-1169
Published 2011-04-12 by SAE International in United States
When designing the vehicle cooling system, accurate knowledge of the required airflow through the heat exchangers is necessary for proper specification of the cooling fan, the heat exchangers, and the associated electrical loads. The simplest method of expressing the engine cooling fan performance requirement is based on the “open air” performance curve measured on the airflow test chamber, excluding effects of the heat exchangers and vehicle environment. However, the difference between open air and on-system airflow performance and noise (installed on the heat exchangers) can be significant due to the influence of the heat exchangers, fan shroud, and downstream blockage on the airflow through the fan. If these factors are neglected in the evaluation of the cooling fan, incorrect specification of the fan performance can result.In this paper, two case studies are presented in which different fan modules, designed for the same vehicle applications, are compared both in open air and installed on the heat exchangers. In both cases, open air test results lead to erroneous conclusions concerning power consumption and noise for a given…
Annotation icon
 

Development of the Chevrolet Volt Portable EVSE

General Motors Company-Tony Argote, Gery Kissel
Published 2011-04-12 by SAE International in United States
The plug-in vehicles developed in the 1990's ushered in the first standards for electrified vehicles. These standards included requirements for Electric Vehicle Supply Equipment or EVSEs. EVSE is a general term for all the non vehicle components needed to charge a plug-in vehicle. These components include cabling, connectors and shock safety equipment. EVSEs are used to charge vehicles at home, work and in commercial settings.Many people identify EVSEs with public charge stations. While public charge stations are iconic with plug-in vehicles, these are just one type of EVSE. Until public EVSEs become readily available, plug-in vehicle drivers will need to partially rely on portable versions of EVSE.Portable EVSEs are required to provide the identical function and safety protection as their stationary cousins but their portability brings unique challenges and design considerations.Thermal, vibration, ergonomic and vehicle storage are just a few of the challenges facing design of portable EVSEs that stationary EVSEs are completely or partially immune to. This paper will explore the development of the portable EVSE for the Chevrolet Volt. Aspects of the portable…
Annotation icon