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This paper outlines the development process for cast components used in structural automotive applications. Typical design characteristics such as STRENGTH, STIFFNESS, CRASHWORTHINESS, FATIGUE and manufacturability for COST are discussed. Appropriate methods for material selection, part consolidation, development process and tools, product specification and nondestructive testing, prototype and product validation testing are covered in details. As aluminum alloys are the most commonly used lightweighting materials, the VRC/PRC process, invented by Alcoa, will be used in most of the case studies presented. This article constitutes a reference for design engineers and purchasing engineers to select material and manufacturing process that best suit their applications based on cost and performance.

The Hybrid Electric Vehicle Team of Virginia Tech (HEVT) is participating in the 2005 - 2007 Challenge X advanced technology vehicle competition series, sponsored by General Motors Corporation, the U.S. Department of Energy, and Argonne National Lab. This report documents the Equinox REVLSE (Renewable Energy Vehicle, the Larsen Special Edition) design and how it meets the Challenge X goals. The design process, Vehicle Technical Specifications (VTS), system components, control strategy, model validation, vehicle balance, and the Challenge X Vehicle Development Process (XVDP) are defined and explained. The selected Split Parallel Architecture (SPA) E85-fueled hybrid vehicle powertrain design can meet the performance, emissions and fuel economy goals of Challenge X, while reducing petroleum use by 80 %.

Notched bar Izod impact testing of zinc die cast Alloy 3, Alloy 5, ZA-8, and AcuZinc 5 was performed at five temperatures between -40 °C and room temperature in accordance with ASTM E23 for impact testing of metallic materials. A direct comparison between ASTM D256 for impact testing of plastics and ASTM E23 was performed using continuously cast zinc specimens of Alloy 5 and ZA-8 at -40 °C and room temperature. There are differences in sample sizes, impact velocity, and striker geometry between the two tests. Bulk zinc tested according to ASTM E23 resulted in higher impact energies at -40 °C and lower impact energies at room temperature then did the same alloys when tested according to ASTM D256.

Cast parts are traditionally inspected prior to initial production runs and subsequently in support of high volume production to ensure consistent quality and accurate dimensions that match the “as designed” part within specified tolerances. Classical methods for dimensional measurements are CMM systems using touch probes, laser sensors, or optical techniques. Flaw conditions such as cracks, porosity and inclusions can be detected with “real-time” x-ray inspection. These techniques are quite effective on simple parts with two dimensional geometry and non-complicated structures. Specialized x-ray inspection systems for alloy wheel production are examples of such systems. Complex three dimensional castings such as cylinder heads and engine blocks have functional internal structures with close tolerances and morphology that cannot be verified by CMM systems externally or by real-time x-ray.

Semi-solid processing (SSM) has many advantages in that the alloy is cast at lower temperatures (i.e., in the two-phase region) giving rise to reduced die wear, as well as giving rise to novel microstructures. The resultant SSM processed castings are dendrite-free and do not contain hot tears; rather, the SSM structure is globular, and the liquid phase surrounding the globules acts as a “lubricant” during processing. Moreover, the flow of the slurry into the die cavity is more laminar than turbulent, since the starting metal is in the mushy region. This concept of SSM processing was realized by the development of a continuous process titled: CRP - Continuous Rheo-conversion Process. In this process, one allows the incipient solidification of alloy melt(s) under the combined effects of forced convection and rapid cooling rates. In the CRP, two liquids held at particular level of superheat, are passively mixed within a reactor.

Lean Six Sigma is an approach that is gaining momentum both in manufacturing and service industries. Design for Lean Six Sigma (DFLSS) is an outgrowth of the DFSS and Lean Six Sigma approaches. The essence of DFLSS is to ensure design quality and predictability during the early design phases and the approach employs a structured integrated product development methodology and a comprehensive set of robust tools to drive product quality, innovation, faster time to market, and lower product costs. When it comes to automotive Product Development, applying lean principles and DFSS together becomes more of a challenge within the existing PD system. While the benefits of DFLSS present an attractive proposition in a fiercely competitive market it brings its own challenges as to how to deploy it for maximum benefits. This paper examines the challenges, potential and opportunities for DFLSS in the automotive industry and presents a vision for integrating it in to the Product Development System.

Determination of the solubility of a blowing agent, i.e. supercritical N2, in polypropylene (PP) and elastomer material is crucial for achieving high-quality thermoplastic polyolefin (TPO) foams in automotive industry. A magnetic suspension balance (MSB) was employed in the experiments to measure the apparent solubility, while the swollen volume predicted by the Sanchez-Lacombe (SL) equation of state (EOS) was used to account for the buoyancy effect. The volume swelling of the polymer/gas mixture and the gas solubilities for both PP and polyolefin elastomer were discussed.

The intention of this work is to illustrate a method used to overcome limitations of tire models developed during an evaluation study of an Empirical Dynamic™ (ED) damper model. A quarter vehicle test system was built to support the evaluation, and a model of the test system was also developed in ADAMS™. In the model, the damper was represented by a polynomial spline function and by an ED model separately. Vehicle level comparisons between the physical measurements and the model predictions were conducted. The actuator displacement signal from the physical test was used to drive the virtual test system. Spindle acceleration, spindle force, and other signals were collected for comparison. The tire model was identified as a significant source of error and as a result, the direct vehicle level correlation study did not illustrate any advantage of the ED damper model over a spline damper model.

This paper presents the fundamental principles of variation analysis and robust design for dimensional datum schemes. The kinematics equations for rigid body motions are simplified through linearization. The simplified formulations explicitly relate the dimensional deviations of a rigid part with its datum scheme configuration and dimensional variations at datum target points. This simplified approach can be used with either the first order Taylor series approximation or Monte Carlo simulation to study the statistical characteristics of datum scheme variations. A headlamp case study is presented that shows the application procedures and demonstrates that both Taylor series and Monte Carlo methods generate comparable results, but the former offers more efficiency and convenience due to its close form formulation. This approach has found many applications especially in on-site problem solving and fast what-if studies.

The Mahalanobis Taguchi System is a diagnosis and forecasting method for multivariate data. Mahalanobis distance is a measure based on correlations between the variables and different patterns that can be identified and analyzed with respect to a base or reference group. The issue of multicollinearity is not adequately addressed in the MTS method. In cases where strong relationships exist between variables, the correlation matrix becomes almost singular and the inverse matrix is not accurate. Multicollinearity can be handled by utilizing the adjoint matrix of the correlation matrix and Gram-Schmidt orthogonalization. This paper presents a case study of the MTS methodology with the application of the adjoint matrix to avoid some effects of multicollinearity.

There are several reasons why it can be daunting to apply Six Sigma to product creation. Foremost among them, the functional performance of new technologies is unknown prior to starting a project. Although, Design For Six Sigma (DFSS) was developed to overcome this difficulty, a lack of applicable in-class case studies makes it challenging to train the product creation community. The current paper describes an in-class project which illustrates how Six Sigma is applied to a simulated product creation environment. A toy construction set (TCS) project is used to instruct students how to meet customer expectations without violating cost, packaging volume and design-complexity constraints.

A nonlinear finite element passenger car radial-ply tire model was developed to investigate a tire's three-dimensional transmissibility in the X, Y, and Z directions. The reaction forces of the tire axle in longitudinal (X axis), lateral (Y axis), and vertical (Z axis) directions were recorded when the tire encountered a cleat, and then the FFT (Fast Fourier Transform) algorithm was applied to extract tire's transient response information in the frequency domain. The result showed that this passenger car tire has clear peaks at 47-51 and 91-92 Hz longitudinal, 41-45 Hz lateral, and 80-83Hz vertical. An analytical rigid ring model was also formulated, based on the dynamic equations of the rigid ring tire model. The characteristic equations were obtained and solved for eigenvalues and eigenvectors, which represent tire's free vibration natural frequencies and mode shapes.

A second law analysis of spark ignition (SI) engines has been conducted to identify areas in which work capability is presently lost due to either thermodynamic irreversibilities or undesirable work transfers. The impact of advanced combustion strategies on raising powertrain efficiency is assessed. The modeling study relies on two simulation codes: a one-dimensional gas-dynamic simulation code for air flow and heat transfer external to the cylinder, and a single-cylinder thermodynamic cycle simulation code modified to incorporate a second law (Availability) analysis. Modeling results are presented for a base case 3.0 liter, port fuel injection (PFI) gasoline engine with a 10.5 compression ratio (CR), operated homogeneously with a stoichiometric fuel/air ratio.

CAE tools are utilized within the automotive lighting industry to develop thermal models and thus predict temperature distributions for various lamp components. The ultimate goal of developing CAE models is to accurately predict temperatures for lamp systems at early stages in the design process. A major factor in developing a reliable CAE model is the accurate estimation of thermal parameters such as the convection coefficient. This study investigates the effects of six thermal parameters on automotive lamp temperature. A 2-level design of experimentations (DOE) methodology is utilized to determine the significance level of each parameter on the temperature change of the lens and the housing. A first-order linear response function is generated, using the most significant factors with a confidence level of 95%. It is found that a small alteration in the convection coefficient can change the hot spot temperature prediction of the lens and the reflector by 32% and 25%, respectively.

Bench fuel injection experiments were performed to investigate the levels of generated fuel vapor immediately after fuel injection into a closed vessel. A synthetic fuel mixture was used consisting of six individual fuel components that are representative of gasoline. Vessel (e.g. port) temperature and pressure were varied, as well as sample location and sample delay time after injection. Vessel vapor space samples were collected and processed in a gas chromatograph in order to quantify the contribution to the fuel vapor by the various fuel components. Companion modeling was performed in order to evaluate two fuel vapor mixture preparation models (Raoult's Law and NIST's SUPERTRAPP). Results indicate that approximately 1/6 to 1/3 of the injected fuel mass is in the vapor form immediately after fuel injection (as a function of temperature). SUPERTRAPP modeling indicates that the injected fuel mass is approximately in equilibrium with 6% of the available air.

Today, reducing the noise emitted from vehicles is of great concern in the vehicle design. Recent reports state that the noise level increases close to bump area in the streets. In this paper effect of bumps on the emitted noise from car is investigated experimentally. The experiments in this paper are performed using two various passenger cars and two different types of bump with a noise level analyzer (B&K 2060). Obtained results show that bumps increase the emitted noise level from car up to 19 dB (A).

Low and high beam design is strongly restricted by rules caused by legal conditions. Therefore position light styling attracts more and more attention of designers as well as marketing people [1]. They enjoy playing more freely with position light design to give the eyes of the car an unique styling, to let special version look like more valuable or to create a characteristic brand design. With the increase of variations in position lamp design the expectations in simulation and visualisation rise to enable a fast and as much as possible realistic impression of the expected appearance even in an early state of the developing process.

Most automotive lighting components must survive testing on the SAE J577 vibration testing machine. This test subjects the lamp to a periodic impact while attached to the testing apparatus. Failure to pass this test means that the lamp cannot be supplied to the customer. The intent of this document is to show how the vibration that occurs during this testing can be simulated using finite element analysis (FEA). FEA is a very efficient way of proving designs and concepts without building expensive prototypes. A method of characterizing the loads that are applied by the SAE J577 test machine will be presented. These loads can then be applied to a finite element model to simulate the actual test. As with all simulations, it is paramount to properly correlate the simulation to prove the methodology. Correlation method and data will be provided as part of proving the simulation methodology.

A field study to measure peripheral visual performance under various headlamp conditions typical of halogen and high intensity discharge (HID) headlamps and including functions that could be incorporated in advanced forward-lighting systems (AFS), was conducted. The study simulated an approach of left- and right-hand turns. Targets of varying size were located at different locations along the edges of the curves, and different headlamp illumination conditions were used. Reaction times and missed targets were measured. The results were consistent with previously published studies showing a benefit of increased peripheral illumination commonly found in HID headlamps and with AFS systems on peripheral target detection.

A clear understanding of Customer and User requirements is essential to successfully develop, design, build, test and produce components and systems for Customer Programs. Failure to thoroughly understand Customer Requirements can result in costly design and tooling changes, schedule delays and ultimately, Customer dissatisfaction. Statistics across all industries indicate that 25-50% of all projects that fail to meet their imperatives are due to poor requirements and lack of user involvement. A team was formed to develop and apply Six Sigma Green Belt methods and tools to address project requirements management. The hypothesis of this study was that a substantial opportunity exists to increase project efficiency while providing what the Customer wants by following a standardized work practice for managing requirements throughout the life of a project.