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A new six-speed transaxle has been introduced by the Chrysler Group of DaimlerChrysler AG. Along with the six forward ratios in the normal upshift sequence, this transaxle features a seventh forward ratio used primarily in a specific downshift sequence. A significant technical challenge in this design was the control of so-called double-swap shifts, the exchange of two shift elements for two other shift elements. In the case at hand, one of the elements is a freewheel. A unique solution is discussed for successful control of double-swap shifts. The new design replaces a four-speed transaxle but makes use of a large percentage of parts and processes from the four-speed design. This approach enabled the new transaxle to reach production in three years from concept. The new transaxle, referred to as the 62TE, has substantially improved performance and passing maneuvers coupled with a new 4.0L high output engine for which the 62TE was developed.

Once the design of a door sheetmetal and accessories is confirmed, the acoustics of the door system depends on the sound package assembly. This essentially consists of a watershield which acts as a barrier and a porous material which acts as an absorber. The acoustical performance of the watershield and the reverberant sound build-up in the door cavity control the performance. This paper discusses the findings of a design study that was developed based on design of experiments (DOE) concepts to determine which parameters of the door sound package assembly are important to the door acoustics. The study was based on conducting a minimum number of tests on a five factor - two level design that covered over 16 different design configurations. In addition, other measurements were made that aided in developing a SEA model which is also compared with the findings of the results of the design study.

Laser lap welding quality is a non-linear response based on a host of categorical and numeric material and process variables. This paper describes a Grammatical Evolution approach to the structure identification of the laser lap welding process and compares its performance with linear regression and a neuro-fuzzy inference system.

With the increasing emphasis on Systems Engineering, there is a need to ensure that Electrical/Electronic (E/E) Systems Endurance Testing of vehicles, in a real world environment, prior to Production Launch, is performed in a manner and at a technological level that is commensurate with the high level of electronics and computers in contemporary vehicles. Additionally, validating the design and performance of individual standalone electronic systems and modules “on the bench” does not guarantee that all the permutations and combinations of real-world hardware, software, and driving conditions are taken into account. Traditional Proving Ground (PG) vehicle testing focuses mainly on powertrain durability testing, with only a simple checklist being used by the PG drivers as a reminder to cycle some of the electrical components such as the power window switches, turn signals, etc.

We are the first to report about a micromachined flow sensor directly integrated in the Common Rail injection nozzle body between the double guidance and the tip of the nozzle. The thermal measurement principle is chosen, because it enables a very precise and fast detection of gaseous and liquid mass flows. Additionally, the velocity field in the nozzle is only slightly influenced by the integration of the sensor in the nozzle body due to the negligible height of the sensitive layer. For a hot film anemometer, a high pressure stable ceramic substrate can be used, fabricated in a low cost batch process. The technology, to fabricate the sensor, as well as the first flow measurements, carried out at a high pressure test set up, are presented.

This paper will provide an overview of the need, requirements, and constraints governing the development and application of polymer composites in automotive body components. It will discuss the efforts underway to lead and support the technology developments required for the cost-effective application of these new materials in mass-produced vehicles. The requirements and constraints of customer-driven, mass-produced, energy-efficient vehicles with uncompromised cost, capacity and performance, drive careful consideration of an injection-molded thermoplastic approach to a composite automotive body. Recent progress with this approach will be reported and some next steps examined.

Detail parts are approved during several different phases of the prototype build cycle. There is much pressure at all stages to meet strategic body quality targets. Parts stamped for assembly must meet a process capability requirement of Cpk>1.33. For final PSO (process sign off), as called out in the PPAP (Production Part Approval Process) manual, the requirement can be increased to meeting a Cpk>1.67. During the 2000 Neon part approval process, the PPAP requirements provided the guideline necessary for consistent buy-offs. However, on some critical parts the Cpk requirement made part approvals difficult to accomplish. Occasionally this caused resources to be focused in the wrong place. This paper will discuss how a requirement of Cpk>1.33 can make part approvals more difficult to achieve and change the entire application of a tolerance.

Thixomolding (1) is a relatively new process in which the metallic slurry is injected into a die cavity tool at semi-solid or liquid temperatures to form near net-shape products from the solid feedstock. As part of on-going research into Thixomolding technology, this study continues the work of a previous study, that concentrated on magnesium alloys AZ91D and AM60B. The test samples were made with high, low and zero percent fraction solid. The test results of the thixomolded samples of the various percent fraction solid are compared to conventional high pressure die casting samples and there is a discussion of the why the Thixomolding process produces superior properties. In addition, a comprehensive corrosion resistance study was completed utilizing uncoated corrosion plates in an salt spray environment (ASTM B117).

The launching of direct injection gasoline engines is currently one of the major challenges for the automotive industry in the European Union. Besides its potential for a notable reduction of fuel consumption, the engine with direct gasoline injection also offers increased power during stoichiometric and stratified operation. These advantages will most probably lead to a significant market potential of the direct injection concept in the near future. In order to meet the increasingly more stringent European emission levels (EURO IV), new strategies for the exhaust gas aftertreatment are required. The most promising technique developed in recent years, especially for NOx conversion in lean exhaust gases, is the so-called NOx storage catalyst.

This paper deals with the multi-parameter and boundary mannequin techniques in creating human models in automotive applications. The concepts and applications of single-parameter, multiple parameter and boundary mannequin method are discussed respectively to clarify certain confusion. Emphasis is put on how to create boundary mannequins for a specific application, which may have been puzzling many engineers in practical applications. The authors would like to share their experience in using the digital human modeling software and make discussions on some common issues. A number of case studies from typical automotive manufacturing assembly operations are also presented to demonstrate the usage of the multi-parameter and boundary mannequin techniques.

Computer applications have been widely used to assist product design. The successes and sophistication of computer aided engineering (CAE) techniques are respectfully recognized in this field. CAE applications in the manufacturing area however are still developing, although the manufacturing community is increasingly starting to pay attentions to computer simulations in its daily workings. This paper will briefly introduce some of these applications and promote awareness of computer simulations in manufacturing area. It contains four main sections: finite element analysis (FEA) in machining fixture design, FEA applications in component assembly, machining process simulations and machining vibrations in the milling operation. Each section comes with a practical case study, potential benefits are identified and conclusions are presented by using an integrated design and analysis approach.

Vehicle design and packaging is a repetitive and tedious process that involves frequent engineering and design changes. To improve design efficiency, a standard naming vehicle design methodology is proposed in this paper. For the geometric or the functional object used in the vehicle context, a standard name is assigned and also used as a unique object feature through its life cycle. With the proposed standard naming design methodology, the engineering knowledge can be efficiently embedded into the CAD design, and hence, vehicle design can be executed in a more automated fashion. Work case of the standard naming design methodology is illustrated by a vehicle design and packaging application using CATIA V5.

The use of composite materials in the automotive industry has become increasingly widespread. With this increase in use, techniques for non-destructive testing (NDT) have become more and more important. Various optical NDT inspective methods such as holography, moiré techniques, and shearography have been used for material testing. Among these methods, shearography appears to be most practical. Shearography has a simple optical setup due to its “self-referencing” system, and it is relatively insensitive against rigid-body motions. Measurements of displacement derivatives, and thus strain directly, rather than the displacement itself is achieved through this method. Therefore shearography detects defects in objects by correlating anomalies of strain which are usually easier than correlating the anomalies of the displacement itself, as in holography. To date shearography has shown potential as a NDT tool for identifying defects in small structures.

In a vehicle NVH development and refinement phase, it is necessary to understand the source of the noise and vibration from various powertrain and drivetrain mechanisms. The noise and vibration generated by a drivetrain in a vehicle is a complicate but significant source of physical mechanism, which might become important issues in early or later phase of the vehicle development. For the diagnostic purpose of the drivetrain, a rear-wheel drive (RWD) vehicle in early development phase has been used to measure the bending and torsional vibration of the drivetrain, as well as the vehicle interior noise simultaneously, while the vehicle is running up and down under quasi-steady state on a chassis dynamometer. The lower frequency resonances of torsional and bending vibrations from the drivetrain are correlated with the vehicle interior boom or overall loudness.

The effect of forming strains on the fatigue behavior of an automotive mild steel, interstitial free steel, was studied after being prestrained by balanced biaxial stretch and plane strain. In the long life region, higher than 5×105 reversals, prestrain improves fatigue resistance. In the short life region, prestrain reduces fatigue resistance. At even shorter fatigue lives, the detrimental effect of prestrain diminishes. For plane strains, the fatigue behavior is anisotropic. In the direction perpendicular to the major strain, the steel exhibits much better fatigue resistance than in the direction parallel to the major strain.

Vehicle evaluations and model calculations were conducted on a vacuum-insulated catalytic converter (VICC). This converter uses vacuum and a eutectic PCM (phase-change material) to prolong the temperature cool-down time and hence, may keep the converter above catalyst light-off between starts. Tailpipe emissions from a 1992 Tier 0 5.2L van were evaluated after 3hr, 12hr, and 24hr soak periods. After a 12hr soak the HC emissions were reduced by about 55% over the baseline HC emissions; after a 24hr soak the device did not exhibit any benefit in light-off compared to a conventional converter. Cool-down characteristics of this VICC indicated that the catalyst mid-bed temperature was about 180°C after 24hrs. Model calculations of the temperature warm-up were conducted on a VICC converter. Different warm-up profiles within the converter were predicted depending on the initial temperature of the device.

The problem of predicting the quality of weld is critical to manufacturing. A great deal of data is collected under multiple conditions to predict the quality. The data generated at Daimler Chrysler has been used to develop a model based on grammatical evolution. Grammatical Evolution Technique is based on Genetic Algorithms and generates rules from the data which fit the data. This paper describes the development of a software tool that enables the user to choose input variables such as the metal types of top and bottom layers and their thickness, intensity and speed of laser beam, to generate a three dimensional map showing weld quality. A 3D weld quality surface can be generated in response to any of the two input variables picked from the set of defining input parameters. This tool will enable the user to pick the right set of input conditions to get an optimal weld quality. The tool is developed in Matlab with Graphical User Interface for the ease of operation.

A new multi-layer co-extruded in-color Ionomer film is developed to provide an alternative decoration process to replace paint on Dodge Neon Fascias. The Ionomer film provides a high-gloss “class-A” surface in both non-metallic and metallic colors that match the car body paint finish. Using the Ionomer film to decorate fascias reduces cost; eliminates VOCs; increases manufacturing flexibility and improves performance (weatherability and durability). The molding process consists of thermoforming a film blank and injection molding Polypropylene or TPO behind the film. The paper will include the background, the benefits, the technology development objectives, the film materials development, tooling optimization, film fascia processing (co-extrusion; thermoforming and injection molding) and validation testing of the film.

Laminated steel sheets sandwiched with a polymer core are increasingly used for automotive applications due to their vibration and sound damping properties. However, it has become a major challenge in finite element modeling of laminated steel structures and forming processes due to the extremely large differences in mechanical properties and in the gauges of the polymer core and the steel skins. In this study, circular cup deep drawing and V-bending experiments using laminated steels were conducted in order to develop a modeling technique for laminate forming processes. The effectiveness of several finite element modeling techniques was investigated using the commercial FEM code LS-Dyna. Furthermore, two production parts were selected to verify the modeling techniques in real world applications.

Different methodologies to test transfer case imbalance were investigated in this study. One method utilized traditional standard single plane and two plane methods to measure the imbalance of the transfer case when running it on a dynamic balance machine at steady RPM, while a second method utilized accelerometers and a laser vibrometer to measure vertical vibration on the transfer case when running it on a dynamic balance machine in 4 Hi open mode during a run up from 1000 to 4000 RPM with a 40 RPM difference between the input and output shaft speeds. A comparison of all of the measurements for repeatability and accuracy was done with the goal of determining an appropriate and efficient method that generates the most consistent results. By using the traditional method, the test results were not repeatable. This may be due to the internal complexity of transfer cases. With the second method, good correlation between the measurements was obtained.