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Tests to simulate rollovers are currently very often criticized because of the nonreproducibility of the tests and their results. There are test procedures that attempt to simulate vehicle rollovers, for example, rollovers initiated by a ramp, rollovers initiated by inertial movement of a vehicle positioned on a slope on a car which is stopped rapidly, drop test of upside-down vehicle, and static roof crush test. In addition, another test procedure is used by Volkswagen. A flat impact plate equal to the empty weight of the vehicle is dropped from a defined height onto the roof of the vehicle. The vehicle can be mounted on a bed at various angles relative to the impact plate. The results with this simple test method provide a comparative scale for roof rigidity rather than an absolute comparison with dynamic vehicle rollover roof rigidity.

A test facility and procedure have been developed for use in evaluating passenger car roof intrusion resistance strength in the laboratory. This facility and procedure produce reliable and repeatable data which permit numerical comparison of separate test bodies or vehicles and automatically indicate performance through the use of a X,Y,Y plotter. The test facility consists of three parts: an adjustable structural frame for supporting the test unit in position for test, a hydraulic loading system for applying the load, and instrumentation for lead and placement readout. A complete description of the facility is presented, with emphasis on the advantages of dual readout of data. The test procedure is also detailed, with description of sample preparation, mounting the test unit, and the graphical addition of curves.

A procedure has been developed for measuring the relative visibility of automotive instrument panel graphics and components. Through use of a Luckiesh-Moss Visibility Meter, discreet values of visibility can be assigned to visual targets and related to driver reaction time. Also, eyes off the road lapsed time boundaries may be established which will define visibility requirements necessary to serve the total driver population. These requirements can be translated into meaningful guidelines or standards for visibility attributes such as size, shape, color, contrast, and position of graphics, controls, and indicators. How visibility measurements are made and interpreted and the visibility measuring facility are discussed in this paper.

For the instrument panel designer, good visibility means providing clear, legible, and easy-to-understand instruments and controls free from obstructions, shadows, and inadequate lighting. Unfortunately, most of these provisions are subjective in nature and it is ultimately the designer or group of designers who must decide what is “good visibility.” In order to remove some of this subjectivity, a study was undertaken by Chrysler Corp. to find a more objective approach to measuring visibility. In particular, this study dealt with measuring in a quantitative manner the readability of letter patterns used on instruments, controls, and indicators. This report, which covers the main results of the study, deals with the effects of such diverse factors as driver age, illumination, and letter size on a driver's perception time-the time it takes for a driver to take his eyes off the road and read a target on his instrument panel.

Off-road vehicles, to negotiate snowcovered terrain reliably and economically, must comply with a narrow range of design parameters. The practical lessons of past experience are evaluated, indicating the superiority of the four-tracked vehicle configuration. The design details essential to achieve snowmobility are indicated. Engineering information and the current state-of-the-art indicate that a functional, low-cost ordnance vehicle can be designed for use during all seasons in the Arctic.

This paper describes analytical and experimental methods used to ensure a maximum amount of safety in the design of a high-speed snowmobile. Constructional features of the resultant record-breaking 140 mph snowmobile Pegasus are related to the various specifications considered essential to operator safety. Development of this vehicle involved investigation of crucial parameters such as yaw and drag on directional stability while operating at high speeds. These effects and other aerodynamic influences are explained as they affect single-track and dual-track vehicles. The final design of this snowmobile incorporated measures to counter adverse tendencies during high-speed operation, as well as backup devices such as a rollover bar, auxiliary braking system, fire protection, and an escape mechanism.

In the United States and Canada 1,600,000 snowmobiles have been manufactured, some of them capable of speeds up to 80 mph. Good legislation, safety training programs, and more safety features in the snowmobiles are essential to decrease the rising accident toll. For example, changes in the windshield construction which might reduce facial injuries are recommended. Hospital charts of snowmobile accidents are reviewed describing location of body injury, mechanism of the injury, time of day, age, sex, and cause of death.

The Motor Vehicle Safety Standard 302 becomes effective September 1, 1972, establishing a 4 ipm horizontal burn rate for materials used in the passenger compartment of motor vehicles. Limitations of the standard are touched upon. Conventional approaches to impart fire retardance to vinyls,polyolefins, urethane foams, ABS, polyester, and carpeting are reviewed. Potential problems associated with each of the approaches include fogging, dripping, staining, low-temperature flexibility, durability, effect on physical properties, and cost.

The Occupational Health and Safety Act of 1970 may have much importance to the truck cab designer. The levels of noise, heat, and carbon monoxide to which the truck operator is exposed may be a health and safety hazard. While current standards for these hazards have not been directly applied to commercial carriers, it is predicted that they will be in the near future. Some current research in the noise and carbon monoxide areas in particular is cited; legal standards for these are projected for the designer's use. The inclusion of air conditioning as standard equipment in large trucks may be a realistic way to meet new standards.

This paper describes the development of a hybrid-computer simulation of a recreational snowmobile. The vehicle has been mathematically represented by a displacement-driven, damped nonlinear spring-mass system with two degrees of freedom. The analog circuit and the logic level control system of the analog/hybrid computer is discussed. The use of a hybrid system using Hytran Operational Interpreter to perform OFF-LINE and ON-LINE checks is also discussed. Finally, a method to display a visual representation of the vehicle on an oscilloscope screen is presented. The simulation permits vehicle designers to vary at will the various design parameters and to observe immediately the effect of so doing.

Driver environment encompasses physical room, control placement, visibility, interior noise level, occupant protection, and temperature control. All of these factors have an effect on a driver's temperament and fatigue level. Reduction of adverse effects contribute to a driver's alertness. This paper outlines International Harvester's approach to total driver environment.

The data from five residual stress round robins run by the X-Ray Fatigue Division of the SAE Fatigue Design and Evaluation Committee have been studied. Many factors affecting precision have been isolated during 16 years of testing. Some of these relate to the sample?material hardness and geometry- while others, such as alignment, are instrumental or procedural. Laboratories using proper techniques can achieve an interlaboratory standard deviation of 2.5 ksi on a stressed, hardened steel cylinder.

Fuel-exhaust compositional relationships are derived for exhaust hydrocarbons and aldehydes using data obtained with 18 full-boiling-range gasolines used as fuel in a late model vehicle. The agreement found between the data from the present work and those obtained by others in similar studies indicates that the relationships should be sufficiently general to apply to a large segment of the current vehicle population. The present data indicate that aromatic hydrocarbon and aromatic aldehyde emissions are linearly related to fuel aromatic content, while exhaust olefin and aliphatic aldehyde emissions show an inverse relationship. Regression analysis of the aromatic hydrocarbon and aromatic aldehyde data, expressed as a function of fuel aromaticity, gives fuel aromatic coefficients of 0.49 and 0.41 for the hydrocarbon and aldehyde expressions, respectively.

The measurement of stress by x-ray diffraction techniques is considered from both the technical and practical viewpoints. Basic principles are discussed and the techniques and x-ray instrumentation presently in use here and abroad are described and compared from the standpoints of accuracy, precision, and time required for stress determination. Both diffractometer and film or camera techniques are covered. Other factors discussed are alignment requirements, selection of optimum instrumental conditions, required corrections to raw diffractometer data, specimen surface preparation, and stress constant evaluation methods. Step-by-step procedures for the novice with illustrations of typical data and calculations are finally presented for the two exposure and sin2ψ diffractometer techniques and for the two-exposure camera method.

Two applications of x-ray residual stress measurements in steel are reported. One application shows how residual stresses have a direct bearing on fatigue strength caused by varying material and heat treatment. The other application shows how x-ray diffraction measurements can help determine the cause of grinder cracking in carburized and hardened steel parts. Grinder cracking occurs by overheating the surface which produces tensile residual stresses that exceed the fracture strength of the steel. Also, there appears to be a relationship between retained austenite content and the grinder cracking phenomenon.

A detailed understanding of the surface phenomena associated with exhaust hydrocarbon (HC) emissions is required to be certain that all avenues of emission control, internal to the combustion chamber, have been exploited. This paper presents information obtained on a single-cylinder research engine, which supports the following hypotheses: there exists a critical piston top land-to-bore clearance above which HC emissions decrease sharply; the presence of an oxidatively active catalytic surface in the combustion chamber increases HC emissions; using a clean engine operating on a fuel containing 5% lubricating oil, HC emissions increase within minutes to a level comparable to that obtained with equilibrium deposits; the first parcel of gas to leave the exhaust valve contains an order of magnitude lower concentration of HCs than does the total mixed exhaust; and a cylinder bore tapered outward towards the top eliminates oil-droplet formation in a motored engine.

The effects of engine speed and load on nitric oxide emission were investigated with a single-cylinder engine operated at conditions representative of those found in the 7-mode, 7-cycle Federal Emissions Test Cycle. The fuel-air mixture was constant at 83% of stoichiometric and the spark settings were optimized. Nitric oxide emission increased as engine speed and load were increased. The effects were interdependent, in that, the effect of speed was greatest at low load and the effect of load was greatest at low speed. In addition, both speed and load effects were larger when valve overlap was higher. Engine speed and load affected exhaust nitric oxide concentration primarily via influences on charge dilution. This finding explains the interdependency of the speed and load effects, and also why they depended on valve overlap.

Laboratory and field tests were conducted to determine how changes in some gasoline compositional factors might affect atmospheric visibility and soiling caused by exhaust particulate matter emitted from late model automobiles. In the laboratory tests, measurements of light scattering, soiling index, and mass emission rates of air-suspendible particles were made on diluted exhaust from cars driven on a programmed chassis dynamometer. These tests showed that light scattering, and also soiling, were increased by increasing the aromatic content, removing lead antiknocks, or increasing the combined amounts of sulfur and phosphorus in gasoline. Field tests in a turnpike tunnel used two 4-car fleets operating on leaded and unleaded premium gasoline of high and average aromatic content. The air in the tunnel sampled during the tests with the cars using the unleaded gasolines soiled the filters 57% more than the air sampled during the tests with the cars using the leaded gasolines.

A proposed set of modifications, which, in combination with a mixture-Optimizer, enables a spark-ignition engine to accept air-fuel mixtures as lean as 22 - 23-1/2:1 without impairment of drivability, will permit the simultaneous reduction of all pollutant exhaust emissions, HC, CO, and NOx, to a very low level. Under such circumstances, the true best economy mixture largely coincides with the mixture ratio that minimizes the exhaust emissions. The mixture-Optimizer is a feedback type of electronic control device which automatically selects for a carburetor or fuel injection system the air-fuel ratio that yields the minimum fuel consumption for any given power output. For all driving conditions, other than idling and coasting, the minimum fuel consumption occurs at mixture ratios close to the borderline misfire limit. Therefore the mixture-Optimizer, by seeking these mixture ratios, tends to reduce all pollutant exhaust emissions that are under legal control.

The interactions of a marine propeller and its propulsion engine are surveyed, with particular concern for the interaction as seen from the engine end. It is pointed out that linking characteristics of engine and propeller should be considered together when marine engineers design a propulsion plant. Propeller characteristics and engine characteristics are reviewed, with a suggestion that, as a compromise between efficiency and vibration excitation, the designer choose from a number of blades, the area of the blades being a compromise between efficiency and having sufficient thrust area to avoid cavitation. Matching of engine and propeller in several situations is then discussed. Problems of off-design and margin allowance are included.