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Technical Paper

Simulors, An Innovative Tool for Molds Development

1996-04-01
91A117
Mold designers and foundrymen spend a lot of time in developing molds without knowing exactly the phenomena which take place inside. Simulor, which has been used in an industrial environment for two years, offers the solution to make foundrymen understand what happens during the filling of the mold and the solidification of the part. Based on navier-stokes and heat transfer equations, simulor provides speed distribution and metal front evolution in the cavity and thermal map in the mold and the part. Some examples with different metals (cast iron, aluminum alloy) cast with various processes (sand or die casting, low pressure or gravity casting) will be given. This new tool will given foundrymen the opportunity to test the mold before having it machined and will also allow reduction in development delays.
Technical Paper

The Development of Plastic Lenses for Vehicle Headlamps

1996-04-01
91A111
The pending changes in European law enabling the use of plastic lenses on vehicle headlamps provide an opportunity for further advancement of vehicle styling, lighting performance and aerodynamic efficiency. Plastic lenses can also provide a useful weight saving and contribute to energy savings during the lifetime of the vehicle. This paper discusses the current requirements, technologies and solutions for plastic lenses, and indicates the way this advance can impact on the evolution of lighting products.
Technical Paper

Evaluation of Advanced Aluminum Alloys and Mmc Obtained By Means of a Spray Depositon Approach

1996-04-01
91A112
The paper review some recent efforts, made by the aluminum industry, towards the development of new advanced alloys for aerospace applications; unconventional production technologies and MMC occupy an outstanding position in this context. Raid solidification processes are currently used for obtaining advanced alloys and, among them, the powder metallurgy route is one of the most commonly applied, since it has reached a considerable level of maturity. Experimental results of PM materials are shown and discussed in order to appreciate the potentialities of this class of materials and some recent further progress is shown: the spray deposition approach (osprey process). After having described the main features of the osprey process, some results obtained at the Department of Aerospace Engineering of Pisa about the development of high strength Al-alloy and MMC obtained by means of the osprey process are shown.
Technical Paper

Practical Applications of Composite Exotic Hybrids and Their Structural Use in Vehicles

1996-04-01
91A098
An overview of high strength thermoset and thermoplastic composites will provide a basis of comparison with exotic hybrid composites. A specific theoretical application for a very high strength unibody application will be presented and test results evaluated. A critical overview of immediate applications will be presented and evaluated. In conclusion, it will be suggested that a uniform standard of performance be established for the practical application's requirements for these materials
Technical Paper

U.S. and California Vehicle Emissions Control Programs Effectiveness and Application of Experience

1988-03-01
871148
Many areas of the world are in various stages of development which frequently includes a rapid increase in the motor vehicle population. As a result, some areas are beginning to show the effect of increased motor vehicle use on air pollution. The vehicle's contribution to California's air pollution has long been recognized and studied, and measures have been implemented to reduce emissions from motor vehicles. The history of light duty vehicle emission control in the South Coast Air Basin of California is reviewed. Emission reductions achieved, current levels, projected future emissions and the need for further emissions reductions from light duty vehicles are discussed. For other areas of the world where motor vehicles contribute to air pollution, suggestions are made which can improve the effectiveness of emission control efforts; which should be consistent with political and economic realities, and efforts to achieve international harmonization of standards.
Technical Paper

Modeling and Measurement of Occupied Car Seats

1999-05-17
1999-01-1690
An overview of model development for seated occupants is presented. Two approaches have been investigated for modeling the vertical response of a seated dummy: finite element and simplified mass-spring-damper methods. The construction and implementation of these models are described, and the various successes and drawbacks of each modeling approach are discussed. To evaluate the performance of the models, emphasis was also placed on producing accurate, repeatable measurements of the static and dynamic characteristics of a seated dummy.
Technical Paper

Case History: Engine Timing Gear Noise Reduction

1999-05-17
1999-01-1716
This paper describes the procedures used to reduce the tonal noise of a class eight truck engine timing gear train that was initially found to be objectionable under idle operating conditions. Initial measurements showed that the objectionable sounds were related to the fundamental gear mesh frequency, and its second and third harmonics. Experimental and computational procedures used to study and trouble-shoot the problem include vibration and sound measurements, transmission error analysis of the gears under light load condition, and a dynamic analysis of the drive system. Detail applications of these techniques are described in this paper.
Technical Paper

Application of a Lean Cellular Design Decomposition to Automotive Component Manufacturing System Design

1999-05-10
1999-01-1620
A design framework based on the principles of lean manufacturing and axiomatic design was used as a guideline for designing an automotive component manufacturing system. A brief overview of this design decomposition is given to review its structure and usefulness. Examples are examined to demonstrate how this design framework was applied to the design of a gear manufacturing system. These examples demonstrate the impact that low-level design decisions can have on high-level system objectives and the need for a systems-thinking approach in manufacturing system design. Results are presented to show the estimated performance improvements resulting from the new system design.
Technical Paper

Durability, Acoustic Performance and Process Efficiencies of Absorbent Fibers for Muffler Filling

1999-05-17
1999-01-1655
Silencers are very often filled with absorbent fibers to optimize the acoustic performance, particularly when the volume is limited. The fibers have to meet several specifications concerning (1) acoustic damping as a function of frequency, (2) temperature stability, (3) processing, and (4) blow-out resistance. This paper will review the characteristic properties for continuous fibers including Advantex™ versus standard E Glass as well as discontinuous fibers such as basalt wool. The failure mechanism of the various fibers will be explored in detail. Thermal shock testing, single filament tensile strengths, and weight loss measurements will be used to contrast the failure mechanism of these fibers. Additionally, the acoustic performance of silencers filled with different fibers will be analyzed and compared. The selection of different filling materials is closely linked to the production process utilized.
Technical Paper

Graduate Education in Manufacturing Engineering for the Automotive Industry of the Future

1999-05-10
1999-01-1638
This paper discusses the evolution of graduate education in manufacturing engineering and the curriculum needed to educate manufacturing engineers in the automotive industry. This paper examines the master's and doctoral curriculum in manufacturing engineering at the University of Michigan-Dearborn. Finally, it proposes future direction for graduate education in manufacturing that will be needed for the automotive industry of the future.
Technical Paper

Evaluation of Oil Performance Using the TU High Temperature Engine Test with a View to Extending Oil Drain Intervals

2000-06-19
2000-01-1822
The extension of engine oil drain intervals leads vehicle manufacturers to demand ever greater oil oxydation stability. These demands are evaluated by various tests, and particularly with the help of the ASTM III E and the CEC TU3 High Temperature engine test, which allow: the evolution of the viscosity during test to be observed the aptitude of the oil to avoid ring sticking to evaluated the merit rating of piston cleanliness to established (absence of deposits) This article aims to establish a correlation between the degradation of the engine oil in vehicle endurance and during theCEC TU3 High Temperature engine test on the test bench, and in high temperature laboratory tests. The results obtained on three types of oil (mineral, semi-synthetic and synthetic) while extending the oil drain intervals to 20 or 30000 km. As well as the oil thickening, the evolution of piston cleanliness during the vehicle endurance runs will be presented.
Technical Paper

Advanced Lithium Solid State Battery Developments

2000-04-02
2000-01-1588
This paper presents a summary of a recent conference entitled Advanced Lithium Solid State Batteries Workshop that was held on July 13–15, 1999. The conference was sponsored by the Department of Energy's Office of Advanced Automotive Technologies, and the Office of Basic Energy Sciences' (BES) Division of Chemical Sciences. This paper presents a summary of the results and recommendations from the conference, including: A review of current research on solid state electrolytes and their interfaces with an emphasis on both applied and basic studies. The research includes theoretical studies of solid polymer electrolytes (SPEs), lithium ion transport in SPEs, and simulations of the electrolyte–cathode interface. Experimental results are presented on ion transport phenomena in SPEs (NMR and X–ray) and mechanical stresses on electrodes, among other topics.
Technical Paper

An Architecture for Autonomous Agents in a Driving Simulator

2000-04-02
2000-01-1596
The addition of synthetic traffic to a driving simulation greatly enhances the realism of the virtual world. Giving this traffic human-like behavior is likewise desirable, and has been the focus of some research over the past few years. This paper presents a modular architecture for including autonomous traffic in a driving simulation, and describes the first steps taken toward the application of this architecture to the DaimlerChrysler Auburn Hills Simulator. By separating the planning part of the agent from the low-level control and vehicle dynamics systems, the described architecture permits the inclusion of powerful, previously developed components in a straightforward way; in the present application, agents use Soar to reason about their actions. This paper gives an overview of the structures of the agents, and of the entire system, describes the components and their implementations, and discusses the current state of the project and plans for the future.
Technical Paper

A Stochastic Approach for Occupant Crash Simulation

2000-04-02
2000-01-1597
Stochastic simulation is used to account for the uncertainties inherent to the system and enables the study of crash phenomenon. For analytical purposes, random variables such as material crash properties, angle of impact, human response and the like can be characterized using statistical models. The methodology outlined in this approach is based on using the information about the probability of random variables along with structural behavior in order to quantify the scatter in the structural response. Thus the analysis gives a more complete picture of the actual simulation. Practical examples for the use of this technique are demonstrated and an overview of this approach is presented.
Technical Paper

Review of Organic Friction Modifiers - Contribution to Fuel Efficiency?

2000-06-19
2000-01-1792
Friction modifiers have been around for many years. Originally, the application was for limited slip gear oils, automatic transmission fluids and multipurpose tractor fluids. Since fuel economy became an international issue, initially to reduce crude oil consumption, friction modifiers have been introduced into automotive crankcase lubricants as well. The current emphasis is to improve the fuel efficiency through the engine lubricant and to reduce emissions to the environment. This paper describes the chemistry of the various organic friction modifiers as well as the non-organic types. A basic understanding is given on the mechanisms how and why these products work as friction modifiers and what is known about structure - activity relationships. Definitions are given about the various lubrication regimes as well as figures to what extend these regimes are present in current engine tests measuring fuel economy.
Technical Paper

Experimental and Numerical Approach to Productionizing a GDI-2 Stroke Spark Ignited Small Displacement Engine Design

1999-09-28
1999-01-3290
The first part of the paper gives an overview of the environmental conditions with which a future two stroke powered vehicle must comply and explains the reasons for which a direct gasoline injection into the combustion chamber offers a potential solution. The paper continues with a description of the fuel/air mixture injection used in the F.A.S.T. concept and gives a detailed overview of the layout of the 125 cc engine to which it is applied. The structure of its electronic engine management system, mandatory for the necessary control precision, is presented. Hereafter is made a short introduction to the visualization and numerical computation tools used for the engine design optimization. The paper concludes with a detailed presentation and discussion of the experimental results obtained with the engine operated, either in steady state and transient conditions on an engine test rig, and mounted in a classic small dimension two-wheel vehicle submitted to road tests.
Technical Paper

Experimental Investigation on the Characteristics and on the Reproducibility of the Flow issuing from a High-Pressure Direct-Injection Nozzle

1999-10-25
1999-01-3655
This paper presents an investigation on the experimental determination of some characteristics of the flow issuing from a swirl injector dedicated to direct-injection spark-ignited engines. The reproducibility, from one injection to another, of the temporal evolution of the liquid flow characteristics during the opening of the injector was investigated. This was achieved by using a high-speed film camera set at 8,000 images/s. The resulting visualizations allowed us to measure the evolution of the penetration length and velocity as well as of the liquid cone angle. It was found that the spray produced is a low momentum spray whose penetration length and velocity are small. The good reproducibility of the temporal evolution of the liquid flow characteristics has been obtained, except for the liquid cone angle during the opening stage. A fast-shutter video camera was also used to make images of the early development of the issuing liquid flow.
Technical Paper

Differential Torque Steering for Future Combat Vehicles

1999-11-15
1999-01-3740
This paper discusses the evolution of skid steer systems, and takes a new look at the advantages and implications of designing future ground combat vehicles with all non-steerable wheels. The traditional “skid steer” designation of such vehicles is dropped in favor of the more descriptive phrase “differential torque steer” vehicle. The possible advantages of such systems for combat vehicle application are presented along with a synopsis of various past modeling, simulation, and vehicle hardware efforts to evaluate skid steer systems. A comprehensive vehicle modeling effort for a differential torque steer system is then presented. Two independent implementations of the model are presented along with model verification and validation results. Finally the model is used to evaluate potential turning performance for a 4×4 vehicle with differential torque steer.
Technical Paper

New Traction-Optimized Front Axle Limited-Slip Differential for AWD All-Terrain-Vehicle

2000-03-06
2000-01-1155
An advancement in All-Terrain-Vehicle (ATV) traction control has entered the market place with the debut of the 1999 Bombardier Traxter. The basis for this is the progressive front axle limited-slip differential. The Visco Lok‚ differential provides a speed-sensing progressive traction-optimized characteristic for maximum off-road performance. This paper includes an overview of the vehicle driveline system, functional characteristics of the differential, and torque transfer requirements.
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