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Eight full-scale collision experiments were conducted and 73 collision fire case studies were investigated to provide data relating to fuel system failure modes and susceptibility of fuel system designs to collision fires. Data regarding impact speeds, nature of injuries, and climatic conditions are included. Results of extensive laboratory experiments provide specific ignition conditions for common fuels and define ignition hazards of exhaust systems and electrical and lighting circuitry. The physics of crash fire atmospheres is described, including air quality, radiant and convective heat transfers, and the relationship between burn physiology and occupant escape time. Design concepts are suggested for limiting fuel spillages, ignition sources, and thermal stress to motorists.

Human volunteers were exposed to increasing levels of sled acceleration and velocity during simulated barrier crashes while seated in a padded, bucket automobile seat and restrained by an advanced, passive, three-point belt which contained energy-absorbing fibers and was integral with the seat structure. By muscular tensing, bracing, and riding with the head flexed, two of the subjects were exposed to crash velocities as high as 30.0 mph (over 33 mph, total velocity change), without suffering significant pain or injury.

This paper describes the results of 13 tests simulating a frontal impact against a fixed barrier at 50 km/h and 25 g. The results showed a marked increase in the severity of injuries with increasing age and more frequent chest injuries than head and spinal injuries. The tests were made with two types of restraint systems, both of which seemed equal in occupant protection.

Longitudinal impact tests were conducted on the knees of four seated embalmed cadavers using an impact pendulum. Impact force and femur strain histories were recorded, and peak force at fracture was determined. The results show that femur stiffness (average = 3.29 MN) for impacts is nearly the same as for static loads. Peak fracture loads varied from 8731-11570 N, all above the fracture criterion proposed by King, Fan and Vargovick. Strain histories and fracture patterns suggest that bending effects play a major role in determining the response of embalmed cadaver femurs to longitudinal impact.

Biomechanical guidelines for the development of an anthropometric dummy knee have been lacking. Quasi-static tests were performed on adult male volunteers and embalmed cadavers to define the force-penetration characteristics of the knee when loaded by a rigid, crushable foam of known crush properties. The test subject was seated erect with the thigh horizontal and lower leg unrestrained. Axial thigh (femur) force and knee penetration were recorded as a block of foam was pressed against the knee. The test was conducted incrementally with increasing peak load, and a new foam block was used for each increment. This enabled evaluation of the foam indent volume as a function of peak load. Pertinent anthropometric data are presented for each subject, and normal distribution theory is used to develop percentile scaling rules for the knee response. Loading corridors for biomechanically sound 50th percentile performance are suggested.

The chest impact data of Kroell, et al., and Stalnaker, et al., were examined to determine the relationships that might exist between the physical characteristics of cadavers, impact conditions, and responses. It was found that while the Kroell male, Kroell female, and Stalnaker data had similar physical characteristics, their responses were not related to their physical characteristics and impact conditions in the same manner. Regression equations were found that fit the Kroell male data extremely well. Based on a regression analysis of the Kroell male data, scaling rules were developed that allowed performance requirements for chest response to be defined for 5th, 50th, and 95th percentile dummies. Previous response requirements were for 50th percentile dummies only and were based on averaged responses from subjects whose average characteristics differed widely from 50th percentile characteristics.

Previous studies of human thoracic injury tolerance and mechanical response to blunt, midsternal, anteroposterior impact loading were reported by the authors at the 1970 SAE International Automobile Safety Conference and at the Fifteenth Stapp Car Crash Conference. The present paper documents additional studies from this continuing research program and provides an expansion and refinement of the data base established by the earlier work. Twenty-three additional unembalmed cadavers were tested using basically the same equipment and procedures reported previously, but for which new combinations of impactor mass and velocity were used in addition to supplementing other data already presented. Specifically, the 43 lb/11 mph (19.5 kg/4.9m/s) and 51 lb/16 mph (23.1 kg/7.2 m/s) conditions were intercrossed and data obtained at 43 lb/16 mph (19.5 kg/7.2 m/s) and 51 lb/11 mph (23.1 kg/4.9 m/s).

For investigating the safety of passengers impacting windshields, above all in test series in the development of new glass constructions, the phantom test is practically indispensable. But since the evaluation values for internal safety-head acceleration and lacerations-can only be properly measured when the movement carried out at impact is realistic, the tests must be carried out at the impact angles occurring in motor vehicles. The results of the phantom test depend largely on the construction of the phantom head. Due to the use of phantom heads of varying construction (because of lack of test regulations), the results of the individual testing installations frequently deviate from one another.

Crash test dummies serve as human surrogates in automotive crash simulations, and accelerations monitored in the heads of these dummies are used for assessment of human head injury hazard. For these acceleration measurements to be meaningful indicators of head injury, the impact response of the human head must be a part of dummy head design. This paper describes the conception, design, and development of a crash test dummy head. Geometric, inertial, and performance requirements based on biomechanical information are presented and discussed. The head design concept is compatible with current head injury assessment procedures, and the configuration is based on the GM Research skull and head geometry models. The manufacture and development are described, and the test procedures and results are presented and discussed with reference to the biomechanical and functional requirements. The resulting dummy head is shown to comply with these requirements.

In order to understand better the head injury mechanism and to clarify the unsettled question as to whether the shear strain or the reduced pressure is the primary injury etiology during a given impact, a realistic model capable of predicting both the shear strain and the reduced pressure effects should be devised. The approach to such a realistic but complicated boundary value problem in biomechanics is achieved through the application of the finite element method. By use of the finite element displacement formulation, the human head is modeled as a viscoelastic core bonded to a thin viscoelastic shell, which simulates the brain and the skull, respectively. For purpose of comparison, two configurations-a spherical shape and a prolate ellipsoid-have been used to describe the geometry of the human head.

The intensive search for an alternative low-emission powerplant for passenger cars has led to a re-evaluation of the gas turbine for this type of service. The GT-225 engine was designed as a research tool to aid in making such an evaluation. Factors which received special consideration in making design decisions included exhaust emissions, fuel economy and drivability. An extensive combustor development effort was undertaken to achieve low emissions. The engine has been installed in a test-bed vehicle to permit evaluation of emissions and other factors under actual driving conditions. Vehicle tests of the engine fitted with a low-emission combustor demonstrated the following emissions: 0.11 g/km (0.18 g/mile) HC; 1.2 g/km (2.0 g/mile) CO; and 0.23 g/km (0.38 g/mile) NOx.

This paper describes a mathematical model for head injury prediction based on the hypothesis that injury results from a combination of displacement and rotation of the brain inside the skull. The model is a 12-degrees-of-freedom mechanical system consisting of masses, dashpots, and springs. The classical Lagrange's method is used informulating the equations of motion. Numerical integration is used to obtain their solution. Constants for the elements of the model are obtained from published experimental measurements. Other lumped parameters which have not yet been measured are determined by adjusting them until a satisfactory agreement is obtained between the model's response and equivalent measured responses. The frequency and time responses of the model, for a variety of loading conditions, are studied. Results show a good agreement between experimentally observed and mathematically generated responses.

A technique for evaluating ride quality as a function of cab isolation parameters is presented. The technique is applied to a cab over engine tractor to demonstrate limits of ride quality improvements.

The feasibility of converting a conventional unthrottled 2-stroke diesel engine to gaseous fuel was investigated. The development work was performed in two phases. In phase 1 the conversion concepts were built and tested on a single-cylinder engine. In phase 2 one of these was put into effect in a 6-cyl (DDA 6V-71) engine. The design concept with the most promise includes a divided combustion chamber utilizing a gas inlet valve in each chamber and a spark plug ignition source located in the prechamber. The concept has the potential of reducing the exhaust emissions well below the levels now existing in commercial diesels without exhaust smoke and odor and with equivalent fuel consumption and horsepower, as demonstrated in the single-cylinder conversion. Further development work remains to be done to perfect the concept for the multi-cylinder engine.

An experimental technique to estimate the contributed noise levels of diesel engine components is presented. The technique predicts the contributed noise level in a reverberant acoustic environment from vibration measurements made on the surfaces of the engine components and the use of simple acoustic radiation theory. An experimentally determined value of the radiation efficiency is used in calculating the contributed noise levels. Experimental results are presented for a high speed Vee form engine. Also discussed are other techniques used to assess contributed noise levels of diesel engine components.

In the automotive industry today, weight reduction on the automobile has become a critical design priority. The purpose of this paper is to describe the significance of weight reduction on the automobile, to show the properties and economies of several thermoplastic resins, and to report the fit that these properties of the engineering thermoplastics have for the current design priorities calling for weight reduction on the automobile.

One of the prime requisites for automobile radar systems is obstacle hazard evaluation, the extent needed being dependent upon the particular system application. Much of the information necessary for a radar system to assess the degree of hazard of a target must come from characteristics which can be measured by the radar itself. While the hazard evaluation capacity has not yet been developed for automobile radar systems, research to provide this capability is in progress. Continuous wave (CW) scattering measurements have been made in a manner which is consistent with automobile radar operation. Various aspects of simple targets and of an automobile were measured in a microwave anechoic chamber. Both horizontal and vertical linear polarizations were transmitted and their co-linear and cross polarizations received. These data have been used to confirm the existence of and to understand certain scattering mechanisms.

The antenna configuration of a radar crash sensor determines in large part the kinematic measuring capabilities of such a sensor. Simple monostatic and bistatic antennas have limited collision estimation abilities which can potentially be overcome by a binaural system. The theoretical characteristics of a binaural radar have been used to optimize the collision estimation abilities for point target obstacles. Measurements with obstacles of small lateral extent are in good agreement with theory. Measurements with obstacles of large lateral extent do not agree with simple point target theory due to detection of different scattering centers by the two bistatic arrays of the binaural radar. Methods of minimizing this problem are discussed.

The National Highway Traffic Safety Administration has been involved in an investigation into the economic and technical feasibility of applying radar devices as sensors for automatic braking systems. Several different system application philosophies have been defined and discussed with consideration being given to the expected economic and safety benefits afforded by each. The technical feasibility study, performed for NHTSA by the Institute for Telecommunication Sciences of the U. S. Department of Commerce, included such topics as radiation hazards, intersystem blinding effects, performance restrictions imposed by common highway geometries, effects of precipitation on signal propagation, and analysis of vehicular radar cross sections.

A dual-mode (cooperative and non-cooperative) collision avoidance radar is proposed. The cooperative mode of the radar is based on tagging cooperating vehicles and other potential highway hazards with modulated fundamental frequency reflectors. The range of the radar when looking at tagged targets is approximately 100 metres. Targets that do not carry tags are also recognized by the radar. However, in order to minimize the “false target” problem, the range of the non-cooperating mode of the radar is restricted to a few metres.