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Technical Paper

Wind Tunnel Investigation of an Inflatable Aerodynamic Boattail for Tractor-Trailers

1996-02-01
960908
The objective of this research was to initiate the development of a design procedure to optimize the shape of a drag reducing device to obtain a significant drag reduction on the rear end of a trailer of a tractor-trailer rig. To meet this objective, four wind tunnel experiments were conducted. An optimized shape has not been determined as of yet; however, it was found that the aerodynamic drag could be reduced as much as 17.4 percent, and that there are several important parameters that influence the drag reduction, such as: device length, device edge curvature, and the device-to-trailer attachment angles.
Technical Paper

Life Cycle Management - A Manageable Approach for Integrating Life Cycle Management into Manufacturing

1996-02-01
961028
Environmental issues have significantly impacted automotive operations worldwide. Countries are continuing to ratchet down their allowable emissions and to remain competitive, all industries must take Life Cycle Management (LCM) and implement it into everyday practice. Economic competitiveness as a part of economic development is central to the nation's social and financial well-being. America must catch-up to the rest of the world in how it views government and industry relationships as well as how to focus costs within the corporate structure. The adversarial relationships between government and industry must give way to stronger partnerships. For this concept to succeed a long term view of problems must be made by a corporation and both short and long term actions taken to resolve these problems. Industry must help create the market for recycled goods and must “walk the talk” by using recycled goods where possible.
Technical Paper

Automated Test Request and Data Acquisition System for Vehicle Emission Testing

1997-02-24
970273
Due to new regulations, emissions development and compliance testing have become more complex. The amount of data acquired, the number of test types, and the variety of test conditions have increased greatly. Due to this increase, managing test information from request to analysis of results has become a critical factor. Also, automated test result presentation and test storage increases the value and quality of each test. This paper describes a computer system developed to cope with the increasing complexity of vehicle emission testing.
Technical Paper

Advancements in RRIM Fascia Application Provide Cost Competitiveness While Meeting Performance Requirements

1997-02-24
970482
The commercial validation of a optimized RRIM polyurethane substrate with a novel barrier coat for fascia applications is reviewed which creates cost competitiveness to thermoplastic olefins (TPO), without sacrificing performance. Meeting fascia performance requirements with thinner and lighter RRIM materials containing recyclate and the subsequent application of a barrier coat eliminating the traditional primecoat cycle was investigated.
Technical Paper

Using Life Cycle Management to Evaluate Lead-Free Electrocoat‡

1997-02-24
970696
Environmental costs are a delayed financial burden that result from product decisions made early in the product life cycle--early material choices may create regulatory and waste management costs that were not factored into the acquisition cost. This paper outlines a step-wise approach to determine decision points; environmental, health, safety and recycling (EHS&R) cost drivers that affect decisions; and sources of information required to conduct a Life Cycle Management (LCM) review. Additionally, how LCM fits into the larger concurrent engineering framework is illustrated with an electrocoat primer example. Upstream and downstream supply chain processes are reviewed, as well as organizational challenges that affect the decision process.
Technical Paper

Panel Contribution Study: Results, Correlation and Optimal Bead Pattern for Powertrain Noise Reduction

1997-05-20
971953
To understand how the passenger compartment cavity interacts with the surrounding panels (roof, windshield, dash panel, etc) a numerical panel contribution analysis was performed using FEA and BEA techniques. An experimental panel contribution analysis was conducted by Reiter Automotive Systems. Test results showed good correlation with the simulation results. After gaining some insight into panel contributions for power train noise, an attempt was made to introduce beads in panels to reduce vibration levels. A fully trimmed body structural-acoustic FEA model was used in this analysis. A network of massless beam elements was created in the model. This full structural-acoustic FEA model was then used to determine the optimal location for the beads, using the added beams as optimization variables.
Technical Paper

Can the k-ε Model Withstand the Challenges Posed by Complex Industrial Flows?

1997-04-08
971516
The purpose of this paper is to present numerical solution for three-dimensional flow about rotating short cylinders using the computer program AIRFLO3D. The flow Reynolds number was kept at 106 for all computations. The drag forces on the cylinder were obtained for different rotational speeds. Predictions were obtained for both an isolated cylinder and a cylinder on a moving ground. The standard k-ε model was employed to model the turbulence. Computed drag coefficients agreed well with the previous experimental data up to a spin ratio (=rω/V) of 1.5.
Technical Paper

Life Cycle Management of Hydraulic Fluids and Lubricant Oils at Chrysler

1998-11-30
982221
A systematic life cycle management (LCM) approach has been used by Chrysler Corporation to compare existing and alternate hydraulic fluids and lubricating oils in thirteen classifications at a manufacturing facility. The presence of restricted or regulated chemicals, recyclability, and recycled content of the various products were also compared. For ten of the thirteen types of product, an alternate product was identified as more beneficial. This LCM study provided Chrysler personnel with a practical purchasing tool to identify the most cost effective hydraulic fluid or lubricant oil product available for a chosen application on an LCM basis.
Technical Paper

The Chrysler “Quick Shift Neon” Automanual Transmission Project

1998-11-16
983082
Formula One motorsport competition, ever seeking increases in powertrain responsiveness and efficiency, has utilized electronically-shifted manual transmissions for nearly a decade. With the advent of this technology for passenger car usage ( for example the Magneti Marelli “Selespeed” system), new levels of powertrain electronic control become possible. At the same time, world-wide emission and fuel economy standards have driven powertrain designers to seek transmissions that are multi-faceted; able to offer manual transmission levels of driveline efficiency while simultaneously offering the ability to be automatically controlled. This paper will document a 1995-1996 Chrysler advanced powertrain concept study that culminated in a fully driveable, fully automatic, manual 5 speed transmission Neon coupe.
Technical Paper

Cycle-by-Cycle Analysis of HC Emissions During Cold Start of Gasoline Engines

1995-10-01
952402
A cycle-by-cycle analysis of HC emissions from each cylinder of a four-stroke V-6, 3.3 L production engine was made during cold start. The HC emissions were measured in the exhaust port using a high frequency flame ionization detector (FID). The effect of the initial startup position of the piston and valves in the cycle on combustion and HC emissions from each cylinder was examined. The mass of fuel injected, burned and emitted was calculated for each cycle. The equivalence ratio of the charge in the firing cycles was determined. The analysis covered the first 120 cycles and included the effect of engine transients on HC emissions.
Technical Paper

The Behavior of Multiphase Fuel-Flow in the Intake Port

1994-03-01
940445
Most of the current fuel supply specifications, including the key parameters in the transient fuel control strategies, are experimentally determined since the complexity of multiphase fuel flow behavior inside the intake manifold is still not quantitatively understood. Optimizing these specifications, especially the parameters in transient fueling systems, is a key issue in improving fuel efficiency and reducing exhaust emissions. In this paper, a model of fuel spray, wall-film flow and wall-film vaporization has been developed to gain a better understanding of the multiphase fuel-flow behavior within the intake manifold which may help to determine the fuel supply specifications in a multi-point injection system.
Technical Paper

Comparison of Contributions to Energy Dissipation Produced with Safety Airbags

1995-02-01
950340
Safety restraint technology relies on woven fabrics as the principle material of construction. On impact, gases are generated instantaneously to inflate the bag. As the pressure within the bag increases during deployment and later from passenger contact, the airbag fabric stretches in a biaxial-manner. Passenger contact with the slowly deflating airbag accelerates the gaseous outflow through the fabric, airbag seams, and through specially constructed vents. A fraction of the impact energy can also be adsorbed by mechanical biaxial stretching of the fabric's fibers. However, the fabric's permeability and/ or vent system appear to be of primary importance to energy dissipation. A unique blister-inflation technique was developed and used to evaluate the fabric properties necessary for energy dissipation by these four mechanisms. The performance of fabrics woven from two traditional commercial polymeric fibers offered for airbag construction were considered.
Technical Paper

Modeling of Biaxial Deformation of Airbag Fabrics Using Artificial Neural Nets

1995-02-01
950343
Supplemental airbag safety restraint systems are an integral part of today's vehicle package. This inflatable restraint technology relies heavily on woven fabrics and particularly on knowledge pertaining to a fabric's permeability as a function of pressure drop, inflation temperature of the gas and fabric weave. While fabric permeability can be quantified by actual experimental measurements, the number and non-linearity of the variables involved make the experiments time and cost intensive. Moreover, interpolations within a given data set yield questionable results. For these reasons a feed-forward artificial neural network (ANN) technique was utilized to predict fabric permeability. This is an interpretive procedure. An ANN routine must first be trained. During this training the ANN is introduced to actual cause and effect patterns with adjustments being made by changes in weighting factors until the errors in the output variables are minimized.
Technical Paper

A Novel “Blister-Inflation” Technique for Evaluating the Thermal Aging of Airbag Fabrics During Deployment

1995-02-01
950341
Due to commercial television almost everyone is familiar ‘automotive inflatable restraint system,’ commonly referred to as airbag. Traditionally these bags were made of polyamide fabrics coated with polychloroprene, which made them essentially impermeable. Even though this restraint technology has been in use for more than fifteen years, there remain some features that still need to be improved; i.e., the high cost, the high package volume, the weight and the need for replacement of coated fabrics. In this paper special attention is given to uncoated fabrics. A novel blister-inflation technique was utilized to evaluate the permeability of test fabrics under biaxial stretching conditions. Further, the effect of inflation temperature and internal pressure drop across the fabric on the permeability of the fabrics can be evaluated by this technique.
Technical Paper

Analysis of the Pelvis-Chest Interactions in Hybrid III

1995-02-01
950663
The interaction ILLEGIBLEf the chest of the Hybrid III dummy with the air bag restrILLEGIBLEt system during a crash is complex. Forces applied to one ILLEGIBLEmponent of the dummy can generate an unexpected response in a distal part. Motion, both linear and angular, of the pelvis during impact can create an enigmatic spike in the acceleration of the chest. Because significant changes in the chest acceleration response can affect the development of an airbag system, this pelvis-chest interaction is cause for concern. The factors that appear to affect the chest acceleration spike as a result of the pelvis-chest interaction are: the mass moment of inertia of the pelvis, the interaction of the pelvis with the femur, the characteristic of the lumbar spine, and the differential velocity of the pelvis with respect to the chest.
Technical Paper

Changes in Reliability During the Design and Development Process of a Vehicle's Electrical/Electronic Systems

1995-02-01
950826
The changes in reliability of the Electrical/Electronic Systems of a vehicle-line during its early design and development engineering processes have been studied. A computerized vehicle failure tracking system was used to provide results from several stages of early development vehicle testing at the proving grounds. The data were analyzed using a software program that assumes that failures in a repairable system, such as a car, occur as a nonhomogeneous Poisson process. Results suggest that, under normal circumstances, a significant and quantitative improvement in reliability is achievable as the system or component design progresses through the early design and development processes. This also provides a means of predicting future system(s) reliability when the system(s) is in production.
Technical Paper

Hydrogen Embrittlement in Automotive Fastener Applications

1996-02-01
960312
Fastener failure due to hydrogen embrittlement is of significant concern in the automotive industry. These types of failures occur unexpectedly. They may be very costly to the automotive company and fastener supplier, not only monetarily, but also in terms of customer satisfaction and safety. This paper is an overview of a program which one automotive company initiated to minimize hydrogen embrittlement in fasteners. The objectives of the program were two-fold. One was to obtain a better understanding of the hydrogen embrittlement phenomena as it relates to automotive fastener materials and processes. The second and most important objective, was to eliminate hydrogen embrittlement failures in vehicles. Early program efforts concentrated on a review of fastener applications and corrosion protection systems to optimize coated fasteners for hydrogen embrittlement resistance.
Technical Paper

Environment, Health and Safety: A Decision Model for Product Development

1996-02-01
960407
Environmental issues continue to emerge as a significant concern of the public today. End-of-pipe controls have proven to be costly solutions and have not addressed the root causes of environmental issues. Pollution prevention programs better address concerns and produce more cost-effective solutions. Additionally, regulations can no longer be addressed in isolation. Industry must view regulatory requirements as other business matters are addressed. The integration of regulatory requirements into the business plan focuses the cost of compliance on appropriate products or processes and exposes formerly hidden costs. For highly outsourced OEM's, supplier participation is critical to the success of any program. The bounds of Early Supplier Involvement (ESI) are extended through an integrated global raw material strategy that encompasses regulated substance control, material selection and rationalization, and design for recyclability/separability.
Technical Paper

Extending the Enterprise: The Supplier Role in Product Stewardship

1995-12-01
952785
The bounds of Early Supplier Involvement (ESI) are extended through an integrated global raw material strategy which encompasses regulated substance control, material selection and rationalization, and design for recyclability/separability. A life cycle management (LCM) model is used to evaluate environmental, health, safety and recycling (EHS&R) issues in a systematic business decision framework.
Technical Paper

Achieving Dent Resistance Improvements and Weight Reduction Through Stamping Process Optimization and Steel Substitution

1996-02-01
960025
Resistance to dents and dings, caused by plant handling and in-service use, is generally recognized as an important performance requirement for automotive outer body panels. This paper examines the dent resistance improvements that can be achieved by maximizing surface stretch, through adjustments to the press settings, and substitution of a higher strength steel grade. Initially, the stamping process was optimized using the steel supplied for production: a Ti/Nb-stabilized, ultra low carbon (ULC) grade. The stamping process was subsequently optimized with a Nb-stabilized, rephosphorized ULC steel, at various thicknesses. The formed panels were evaluated for percent surface stretch, percent thinning, in-panel yield strength after forming, and dent performance. The results showed that dent resistance can be significantly improved, even at a reduced steel thickness, thus demonstrating a potential for weight savings.
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