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DISPARITY between the factors of automobile and highway design that are far advanced and the factors that lag far behind constitutes the cause of many of our transportation difficulties, according to the author. The paper therefore aims to show the demand for safety and its economic advantage to the automotive industry and to indicate some of the principles necessary for its accomplishment. After stating that the automobile manufacturers should take a far-sighted view of the situation, take positive steps toward safety and cash in on the demand that is growing and that cannot be stopped by denying its existence, the author considers and comments upon some of the characteristics of automobiles that undoubtedly are partly responsible for accident potentialities. Visibility from the driver's seat is considered in detail, together with devices that assist visibility. The other driver's viewpoint also is considered.

With rising customer expectations, driver comfort will become more and more important for car manufacturers in distinguishing themselves from others. This creates a design challenge, since it is difficult to predict comfort, especially in early design stages. Today, comfort can only be assessed and tested very late during design and construction efforts (mostly using prototypes). Potentially, anthropometric and biomechanical human modeling systems, provide a solution for early comfort testing. Hence, the application of these systems will decrease costs, lead-time and testing time. However, before one is able to create such a software solution, one must have insight in the relationship between mechanical parameters and comfort. This relationship was investigated through a series of experiments in a driving simulator. Both mechanical parameters and postural comfort were measured.

An understanding of the relationship between user acceptance and system effectiveness is necessary for designing collision warning systems for cars and for accurately estimating their safety benefits. To better understand this relationship, an exploration was conducted into the results of a recent naturalistic field operational test of an integrated vehicle-based safety system installed into a fleet of passenger vehicles. Correlation analyses were conducted for system effectiveness, which was measured in terms of near-crash reduction, and for user acceptance, which was measured using responses to a questionnaire that drivers filled out after completing the study. The key findings were as follows: (1) although remaining generally positive overall, user acceptance decreased slightly for drivers as system effectiveness increased.

As the key part of automobile chassis system, friction material, brake pads are viewed from many aspects. Although more and more strict requirements are put out, wear is still one of the most important assessment index for friction materials. It's influenced by many factors, friction performance level, friction stability, material hardness, even including drivers' driving ways and habits. During driving and braking, pads temperature and rotor temperature go up and down for many cycles. When the temperature is high enough, there are kinds of chemical and physical reactions. Friction film forms and then frictioned out. Among the process, there is a friction interface which is crucial. In this paper, relationship between driving distance, friction interface morphology and wear amount was discussed. Based on a low-metallic formulation, fixed the tested pads on dyno, take out the pads for test when the driving distance is 1000km,2000km,3000km,4000km,5000km.

Four wheel steering vehicle applied SATO's rear control logic is studied and compared with conventional vehicle via theoretical methods. Specially, the topic is discussed through eigenvalue sensitivity, frequency response and notion time history using simple model which has yaw and lateral motion freedom, and complicated model which is applied suspension derivatives, steering system flexibility and the non-linearity of tyre. Simulation studies are employed to test the validity of rear steer control logic which was designed on the basis of linear vehicle.

A large number of production balance limits have been collected from various automotive related fields, ranging from electric motors to heavy duty truck assemblies. The production balance limits when normalized will be shown to have very similar ISO balance limits classification. They have been related to two sets of standards: balance limits for machinery and limits for human perception. The change of tolerances for some components over the last several decades will be considered, and it will be shown that these production balance limits now are closely related to limits for human perception.

The job of an engineering department is defined in terms of its relationship to the business enterprise. This establishes the perspective between the engineering department and the parent enterprise. Two basic assumptions are made: that the business requires product engineering and that the business is not a research institute or contract engineering organization. The author then takes his premises through incorrect concepts of engineering, the engineering job, design or synthesis, paperwork, level of confidence, and costs.

The dioiefin content of unstable gasolines has been implicated in the restriction of multi-port fuel injectors by deposits. Vehicle tests of the effect of adding a diolefin mixture to a stable (olefinic) gasoline indicated that a deposit-producing gasoline resulted. Laboratory oxidation tests showed that addition of a “dienophile” to an unstable gasoline significantly reduced deposit formation, increased oxidation stability, and reduced gum formation. Additional vehicle tests with a dienophile-treated fuel showed that some injector deposits were reduced, but new deposits occurred in other areas of the fuel system. Apparently, diolefins can be a factor in producing plugged fuel injectors, but other fuel factors are also likely to play important roles whether diolefins are present or not.

A relationship of selected hemodynamic functions to subjective's seating comfort evaluations has been observed. Studies were conducted using rating scales, subjective probabilities, adjective check lists and concurrent measures of hemodynamics variations with a representative driver population to develop reliable psychophysiological indices of comfort. Thirty-two variables constituted the data bank subjected to multivariate canonical correlation analyses. Subjective data were composed with physiological data and SAE Seat dimensions. Significant relationships among subjective and physiologic measures were found.

A high speed road test procedure was developed to demonstrate performance of multigrade engine oils in journal bearing wear protection. High shear viscosities of test oils were approximated through use of a pump loop. A reasonable first approximation of critical viscosity for bearing failure is estimated by measurements at 149°C and about 5Xl05 sec -1 with the pass/fail limit being about 3.5 cSt.

An analysis of oil pumpability reveals that engine oil pumping failures may occur because either the oil cannot flow under its own head to the oil screen inlet, or the oil is too viscous to flow through the screen and inlet tube fast enough to satisfy pump demands. To determine which factor is controlling, the behavior of commercial, multigraded oils was observed visually at temperatures from -40 to 0°F (-40 to - 17.8°C) in a laboratory oil pumpability test apparatus. Test results revealed that pumping failures occur by the first alternative: a hole is formed in the oil, and the surrounding oil is unable to flow into the hole fast enough to satisfy the pump. Of 14 oils tested, 7 failed to be pumped because of air binding or cavitation which developed in this manner. A model, which explains these failures in terms of yield point considerations and the low shear apparent viscosity of the oils, is proposed.

This paper will concern itself with the reliability aspects of the ABRES feasibility programs. A specific example of the Athena program will address booster and data acquisition system reliability improvement. In addition to typical reliability practices, strong management control and examination of the hardware, procedures and design compromises resulted in a continuous reliability growth during the course of the program. The criticality of payloads obtaining good payload test data from very few and expensive flights requires an entirely different approach for the reliability aspects of these systems. Finally, some specific thoughts and techniques employed to achieve the enviable record for this program will be described.

The internal combustion engine cylinder head gasket is the most complex of all gasket applications. This is due to the variety of seals and sealing conditions which must be achieved in a single gasket. Some of the physical characteristics studied for such gaskets include spring rate, stress relaxation, torque loss, and permeability of current materials and elements used in these constructions. The effects of temperature, sealing stress, thickness, geometry, and engine operation on the properties of gaskets are discussed. In one of the theoretical derivations given, a mathematical model of a viscoelastic material is used to explain the results of certain experimental testing. Major emphasis is placed on spring rate and stress relaxation, which are directly related to fluctuations of sealing pressure and loss of torque which must be controlled in order to achieve satisfactory sealing.

In order to meet common fuel specifications such as cetane number and volatility, a refinery must blend a number of refinery stocks derived from various process units in the refinery. Fuel chemistry can be significantly altered in meeting fuel specifications. Additionally, fuel specifications are seldom changed in isolation, and the drive to meet one specification may alter other specifications. Homogeneous charge compression ignition (HCCI) engines depend on the kinetic behavior of a fuel to achieve reliable ignition and are expected to be more dependent on fuel specifications and chemistry than today's conventional engines. Regression analysis can help in determining the underlying relationships between fuel specifications, chemistry, and engine performance. Principal Component Analysis (PCA) is used as an adjunct to regression analysis in this work, because of its ability to deal with co-linear variables and potential to uncover ‘hidden’ relationships between the variables.

The proliferation of Unibody construction, for vehicle weight reduction, and the expanded use of precoated steel, for improvement in outer body rust-through protection, has significantly increased the number of bimetallic and crevice unions on U.S. manufactured vehicles. Cyclic corrosion and proving ground testing has shown that these unions are highly active electrochemically, resulting in extensive anodic corrosion and cathodic de-lamination of the paint film. This work examines the individual contribution of each layer of the applied protective coatings package, with respect to applied film thickness, to the reduction of permeation by water, oxygen, and NaCl and resultant corrosion.

It has been shown that the concentration of V.I. improver polymer required to give a predicted residual viscosity lift in a given base oil, after a shear stability test related to over-the-road performance, is relatively independent of the Shear Stability Index of the polymer over a wide range of shear stability level. Evidence is included which indicates that the high-temperature diesel engine performance of polymethacrylate V.I. improvers is related to the concentration of polymer in the lubricant and independent of the dispersancy capabilities of the polymer. These findings have demonstrated that the use of a predicted in-service viscosity instead of a point-of-sale viscosity as a specification target has a significant effect on the selection of the V.I. improver for use in a lubricant. In particular, it becomes practicable to use more shear stable V.I. improvers than were formerly used.

The ignition delay time for direct injection compression ignition engines is determined by complex physical and chemical phenomena that prepare the injected liquid fuel for gas phase ignition. In this work, Computational Fluid Dynamics (CFD) simulations of a reacting spray within a constant volume spray chamber are conducted to investigate the relative importance of liquid fuel physical properties and oxidation chemistry on the ignition delay time. The simulations use multi-component surrogates that emulate the physical and chemical properties of petroleum-derived (Jet-A) and natural-gas-derived (S-8) jet fuels. Results from numerical experiments isolating the fuel physical property and chemistry effects show that fuel chemistry is significantly more important to ignition delay than fuel physical properties under the conditions studied.

This study evaluated the relative effects of horizontal and vertical misaim of low-beam headlamps. The approach involved analyzing light-output matrices of 150 production low beams, manufactured for sale in the U.S., Europe, and Japan. The specific analysis involved computing, for 225 locations in the central part of each beam pattern, the ratios of nominal intensity and intensity for vertical and horizontal misaim of up to 1.5°. The ratios greater than 1 log unit were considered to be of practical significance in terms of changes in visual performance and discomfort glare, and those greater than 0.5 log unit of likely significance. Only changes relative to visual performance and glare under nominal aim were considered; absolute levels were not examined. Furthermore, simultaneous horizontal and vertical misaims were not considered.

Driver distraction, defined here as engaging in a secondary task or activity that is not central to the primary task of driving, has been shown to be a contributing factor for many crashes. The secondary tasks and other activities in which drivers choose to engage while driving is also known to be highly varied, including very complex activities(e.g., text messaging on a cellular device) to very simple activities (e.g., selecting a radio preset). Several important distinctions affect the relative risk of engaging in these tasks. Recent data from large-scale instrumented vehicle studies (i.e., “naturalistic” driving studies like the recently released “100 car study” (1)) have begun to provide data where the relative risk, in terms of crash and near crash involvement, can be directly assessed for differing secondary tasks. These data have provided some important insights into the features that create risk.