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The current practice of gear design is based on the Lewis bending and Hertzian contact models. The former provides the maximum stress on the gear base, while the latter calculates pressure at the contact point between gear and pinion. Both calculations are obtained at the reference configuration and ideal condition; i.e., zero tolerances. The first purpose of this paper is to compare these two analytical models with the numerical results, in particular, using finite element analysis. It turns out that the estimations from the two analytical equations are closely matched with that from the numerical analysis. The numerical analysis also estimates the variation of contact pressure and bending stress according to the change in the relative position between gear and pinion. It has been shown that both the maximum bending stress and contact pressure occur at non-reference configuration, which should be considered in the calculation of safety factor.

Described in this paper is a component test methodology to evaluate the door trim armrest performance in an Insurance Institute for Highway Safety (IIHS) side impact test and to predict the SID-IIs abdomen injury metrics (rib deflection, deflection rate and V*C). The test methodology consisted of a sub-assembly of two SID-IIs abdomen ribs with spine box, mounted on a linear bearing and allowed to translate in the direction of impact. The spine box with the assembly of two abdominal ribs was rigidly attached to the sliding test fixture, and is stationary at the start of the test. The door trim armrest was mounted on the impactor, which was prescribed the door velocity profile obtained from full-vehicle test. The location and orientation of the armrest relative to the dummy abdomen ribs was maintained the same as in the full-vehicle test.

The Piston assembly friction loss contributes for larger part in the engine frictional loss. In order to reduce the frictional loss due to piston assembly motion, a complete model describing the dynamics of assembly is necessary. This paper presents a model to study the primary and secondary motion of piston and also a model for determination of frictional losses in the piston assembly of an automotive Internal Combustion Engine. A mixed lubrication model based on a two-dimensional Reynolds equation is presented to use in conjunction with a piston secondary motion analysis.

As part of an ongoing technical collaboration between Ford and Rouge Steel Company, a comprehensive study of door slam event was undertaken. The experimental phase of the project involved measurements of accelerations at eight locations on the outer panel and strains on six locations of the inner panel. Although slam tests were conducted with window up and window down, results of only one test is presented in this paper. The CAE phase of the project involved the development of suitable “math” model of the door assembly and analysis methodology to capture the dynamics of the event. The predictability of the CAE method is examined through detailed comparison of accelerations and strains. While excellent agreement between CAE and test results of accelerations on the outer panel is obtained, the analysis predicts higher strains on the inner panel than the test. In addition, the tendency of outer panel to elastically buckle is examined.

This paper discusses the development, test case simulation and preliminary sensitivity study of a computer model designated SCORES (Steering Column and Occupant REsponse Simulation). The model was developed to simulate an occupant impacting a steering assembly in a frontal collision. The interactions of various body regions with steering assembly contact surfaces are modeled by defining the force deflection properties. During the impact event, the program describes the rotation and deformation of the wheel about the column, rotation, displacement and stroke of the column due to occupant loading and intrusion. Applications of the model could be: To reconstruct actual accident cases. To assess safety performance of steering assemblies. To predict improved performance of steering assemblies.

Used ATs (automatic transmissions) in the market were analyzed using a remanufacturing process, and causes of troubles/defects were investigated. By providing specific parts of an AT with sufficiently ample working-stress levels at the design stage, the remanufacturing cycle can be better controlled and managed, while still maintaining the quality of ATs at the highest levels. Scheduled part changes performed as part of this process successfully make an AT returnable to new-car assembly lines for reinstallation. This fully recycled AT enables reductions in steel and aluminum consumption, and thus contributes substantially to environmental protection efforts.

This paper introduces for the first time a fully connectorized passive optical star for use with plastic optical fiber that addresses all automotive application requirements. A unique mixing element is presented that offers linear expandability, uniformity of insertion loss, and packaging flexibility. The star is constructed of all plastic molded components to make it low cost and produceable in high volume and is single-ended to facilitate vehicle integration. The star is connectorized to facilitate assembly into the vehicle power and signal distribution system.

A correlation of aerodynamic wind tunnels was initiated between Chrysler, Ford and General Motors under the umbrella of the United States Council for Automotive Research (USCAR). The wind tunnels used in this correlation were the open jet tunnel at Chrysler's Aero Acoustic Wind Tunnel (AAWT), the open jet tunnel at the Jacobs Drivability Test Facility (DTF) that Ford uses, and the closed jet tunnel at General Motors Aerodynamics Laboratory (GMAL). Initially, existing non-competitive aerodynamic data was compared to determine the feasibility of facility correlation. Once feasibility was established, a series of standardized tests with six vehicles were conducted at the three wind tunnels. The size and body styles of the six vehicles were selected to cover the spectrum of production vehicles produced by the three companies. All vehicles were tested at EPA loading conditions. Despite the significant differences between the three facilities, the correlation results were very good.

This paper compares the desirable and undesirable characteristics of the rotary engine as an automobile powerplant. It is pointed out that in order for the engine to become an inexpensive automobile powerplant, certain seal design parameters should be changed to reduce tolerances required and to eliminate the costly, difficult-to-machine coatings on the trochoid and end-housing running surfaces. An analysis of the loads on the apex seal has been made and design parameters set up for a material to eliminate, or greatly reduce, the well-known chatter problem. The authors have analyzed the geometry of the side compression and oil seals and propose changes in geometry and design of the seals to allow for automated assembly procedures.

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.

Today, many automakers are using LED lamp sources in exterior lamps to establish brand awareness and introduce specialized lamp designs. These eye-catching LED lamp source solutions require many control functions as the lamp functions are diversified and advanced, and accordingly the requirements for standardization and optimization of controllers are increasing. In particular, our LED rear combination lamps have a variety of LED loads according to the design of the lamp model, the installation position, and the diagnostic regulations, so that the design complexity and the number of specifications of the controller are increased [4]. In recent years, more and more aesthetic designs and new technologies are used by various automakers to optimize their controllers in cooperation with global partners to optimize costs [1].

The driving behaviors of young drivers under the influence of anger are analyzed by driving simulator in this paper. A total of 12 subjects are enrolled during the experiment. Standardized videos are utilized to induce the driver's anger emotion. And the driver's electrocardiogram (ECG) signal is collected synchronously and compared before and after emotional trigger, which prove the validity of emotional trigger. Based on the result, the driver's driving performance under the straight road and the curve under normal state and angry state are compared and analyzed. The results of independent sample t-test show that there are significant differences in the running time of straight sections and the standard deviation of steering wheel angle in curves between normal and angry states. In conclusion, the longitudinal and lateral operation of drivers is unstable in angry state and the driver will be more destructive to the regular driving behavior.

The most time-consuming step in an external aerodynamics or underhood CFD process is that of generating a usable mesh from CAD data. Conventional mesh generators require a water-tight surface mesh before they can generate the volume mesh. Typical CAD surface data available for mesh generation is far from satisfactory for volume mesh creation: no node-to-node matching between mating parts, minute gaps, overlapping surfaces, overlapping parts, etc. To clean up this kind of data to a level that can be used for volume mesh creation requires a lot of manual work that could take a couple of weeks or more to accomplish. This paper presents a fast and fully automated, Cartesian cell dominated projected mesh generation algorithm used in CFD-VisCART that eliminates the need for CAD data cleaning, thus shaving off weeks worth of time off the design cycle.

Virtual design validation of an air induction system (AIS) requires a proper finite element (FE) assembly model for various simulation based design tasks. The effect of the urethane air filter seal within an AIS assembly, however, still poses a technical challenge to the modeling of structural dynamic behaviors of the AIS product. In this paper, a filter seal model and its modeling approach for AIS assemblies are introduced, by utilizing the feature finite elements and empiric test data. A bushing element is used to model the unique nonlinear stiffness and damping properties of the urethane seal, as a function of seal orientation, preloading, temperature and excitation frequency, which are quantified based on the test data and empiric formula. Point mobility is used to character dynamic behaviors of an AIS structure under given loadings, as a transfer function in frequency domain.

Federal Motor Vehicle Safety Standard (FMVSS) 121 has introduced many new and varied problems for vehicle manufacturers, component manufacturers, and vehicle operators. An area of great concern to vehicle operators, particularly fleets, is the question of compatibility associated with antilock system intermix, old and new vehicle intermix, and control standardization. This paper discusses the compatibility related problems observed during limited fleet tests and evaluation of FMVSS 121 braking systems. Test data, observations, and possible solutions are presented with emphasis on the need for more extensive investigation in this area to ensure that the goal of FMVSS 121-increased truck safety-is achieved.

ALTHOUGH the enormous demand for automobiles has been met with continual improvement in performance, economy, comfort, and appearance of the vehicle, the development of the transmission has lagged badly for more than a decade. Car-ability has been handicapped by the limitations of the three-ratio gearbox. Notwithstanding that the added car-flexibility, economy and smoothness that result from increasing the number of ratios between the engine and the axle have long been appreciated by engineers, the short-comings of conventional four-speed transmissions, friction drives and two-speed rear-axles having double ring-gears and pinions are many, and the first cost and lack of over-all efficiency of the gasoline-electric drive have prevented their greater use in passenger-car and truck service.

Repetitive movements have been found to affect assembly operations in many ways such as increasing the risk of injuries, increasing the cost of production, and reduction in the quality of products. This has been a big problem for industries. The method adopted by these studies seems to pose more injuries to workers as workers need to perform a task to the extreme level of pain to determine if repetitive injuries will occur or not. The method of modeling and simulation of human operations is a valid technique that is effective, but could be complex. Some of the modeling and simulation software packages make use of such guidelines as NIOSH, Snook and Ciriello, RULA, REBA, and Biomechanics single action analysis. However, various applications of these tools in actual ergonomic studies tend to be very time consuming and trivial due to the lack of a valid framework to guide the process.

One phase of the broad General Motors program to improve fuel economy has been the design of an integral 4-speed automatic transmission that improves mileage in light trucks. This new overdrive unit features wide ratio gearing with 4-speeds and reverse from 2 planetary gear sets, a cpnverterclutch assembly, a variable capacity oil pump and extensive use of aluminum. Unique construction of several components produces a compact transmission that weighs only two pounds more than the 3-speed unit it replaces.

This paper describes a fuzzy model that is designed to diagnose automotive engineering faults. The fuzzy model has two modes, L-mode, which is the fuzzy learning mode and T-mode, which is the test mode. In the L-mode, the system learns two types of engineering diagnostic knowledge, expert knowledge, and the knowledge acquired from training data using machine learning techniques. A fuzzy diagnostic system for engine vacuum leak detection has been implemented based on this fuzzy model. The system has been tested on the data downloaded directly from the test sites of assembly plants of the Ford Motor Company, and its performance is excellent.

In previous Life Cycle Assessment (LCA) methods, environmental burden items to be analyzed, prior to a life cycle inventory analysis, were assumed as the main factors of environmental problems regardless of the product category. Next, the life cycle inventory analysis, in which the total amount of environmental burden items emitted during the life cycle of a product was calculated, and an environmental impact assessment were performed. The environmental impact assessment was based on the initially assumed environmental burden items. The process, in other words, was a particular solution based on this assumption. A general solution unconstrained by this assumption was necessary. The purpose of this study was to develop a general method of LCA that did not require such initially assumed environmental burden items, and to make it possible to perform a comprehensive environmental impact assessment and strategically reduce environmental burden of a product.