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This report defines humanlike quasi-static bending response characteristics of the lower torso. Six volunteers were subjected to a total of 72 tests to define response characteristics for sagittal flexion and extension bending. The effects of muscle tensing and knee bend on the response are evaluated. Sixteen loading corridors of moment of applied force about the H-point axis versus thorax-pelvis and pelvis-femur angles are suggested. The significant differences between the relaxed and tensed muscles results illustrate the need for a philosophical decision regarding which of these conditions should be adopted to define lower torso bending response for the human surrogate used in automotive safety studies.

Results from longitudinal impact tests on the knees of nine seated cadavers are reported. Typical impact velocities, impact force histories and femur strain histories are presented. The importance of femur bending is revealed by strain readings on the medial, lateral, anterior and posterior surfaces. The effects of impactor padding, leg tissue and oblique impacts are illustrated. The average fracture force level was found to be 10.04 kN and the impact energy to be 549J. The fracture patterns and possible mechanisms are discussed.

This paper presents the results of direct impact tests and driving point impedance tests on the legs of seated unembalmed human cadavers. Variables studied in the program included impactor energy and impact direction (axial and oblique). Multiple strain gage rosettes were applied to the bone to determine the strain distribution in the bone. The test results indicate that the unembalmed skeletal system of the lower extremities is capable of carrying significantly greater loads than those determined in tests with embalmed subjects (the only similar data reported in the present literature). The strain analysis indicated that significant bending moments are generated in the femur with axial knee impact. The results of the impedance tests are used to characterize the load transmission behavior of the knee-femur-pelvis complex, and the impact test results are combined with this information to produce suggested response characteristics for dummy simulation of knee impact response.

A review of the existing mathematical models of a car occupant in a rear-end crash reveals that existing models inadequately describe the kinematics of the occupant and cannot demonstrate the injury mechanisms involved. Most models concentrate on head and neck motion and have neglected to study the interaction of the occupant with the seat back, seat cushion, and restraint systems. Major deficiencies are the inability to simulate the torso sliding up the seat back and the absence of the thoracic and lumbar spine as deformable, load transmitting members. The paper shows the results of a 78 degree-of-freedom model of the spine, head, and pelvis which has already been validated in +Gz and -Gx acceleration directions. It considers automotive-type restraint systems, seat back, and seat cushions, and the torso is free to slide up the seat back.

The overall objective of this experimental investigation of pedestrian/vehicle impacts was to conduct representative impacts of unembalmed cadavers in order to (1) pioneer the establishment of impact tolerance levels for the pelvis and legs of a standing pedestrian and (2) explore the ability of a few selected geometry and compliance modifications to the impacting vehicle to increase the impact velocities that can be tolerated. A series of 15 experimental impacts were conducted which covered a speed range from 10 to 30 mph. Dynamic data obtained included high-speed films and time histories of (1) bumper and hood edge forces, (2) horizontal and vertical ground reaction forces, and (3) pelvic acceleration. The resulting injuries were determined from examination of pre- and post-impact X-rays and detailed pathological dissections, and were assessed as to probable temporary total and permanent partial disabilities.

Pedestrian-vehicle accidents have become a peculiar urban problem that has to be solved in the future. This demands a better knowledge about the performance of pedestrian accidents. Tests using dummies to simulate real world accidents are very important to study the mechanism of impacts. Since only the dummy has been fitted with measuring devices like accelerometers, it is highly difficult to estimate the interaction between the dummy and the car to a fair degree of accuracy. Therefore, it is necessary to measure the body forces in addition to the dummy accelerations in order to explain the impact mechanism more precisely. For this purpose, a body force measuring test vehicle has been developed at the Institute of Automotive Engineering, Berlin. A deformable unit which simulates the stiffness and geometrical measurements of a vehicle front is supported by load cells.

Several types of energy absorbers were tested on a sled simulating a crash deceleration using instrumented, seated erect dummies and cadavers. The energy absorbers were mechanical load limiting devices which attenuated the impact by yielding or tearing of metal. Their principal effects were to reduce the peak deceleration sustained by the occupant with the expected reduction in restraint forces. Constant load level energy absorbers were found to be unattractive because they can easily “bottom out” causing forces and body strains which could be much higher than those without absorbers. Head accelerations were significantly reduced by the energy absorbers as well as some body strain. However, spinal strains in the cadaver were not significantly reduced. They appear to be not only a function of the peak deceleration level but also of the duration of the pulse.

Collisions between vehicles and pedestrians are analyzed, in conjunction with a bidisciplinary “pedestrian” investigation, by simulating accidents using adult and child dummies. A series of experimental collisions were carried out at varying impact speeds with a sample of vehicles representative of the various front-end profiles of vehicles at present running on the roads, the purpose being to study how these profiles affect the kinematics of the adult and child and to define the risks of injury during the different phases of the accident. The degrees of severity of the impact against the vehicle and the ground are compared and head impact speeds analyzed. Countermeasures are proposed and an initial evaluation made using a cadaver.

The use of a high efficiency, continuously variable transmission (CVT) with a wide ratio range is required in order to operate an automotive engine at minimum brake specific fuel consumption (bsfc). Such operation will increase fuel economy from 20-40% over conventional practice. This paper describes a 12:1 ratio range CVT, and shows a simplified control system capable of allowing a vehicle to operate with the engine at or very near minimum bsfc under all demand power conditions for optimized fuel economy. Also described is the effect such a transmission has on vehicle performance and raises the possibility of reducing engine size to maintain normal performance, and further increase fuel economy.

Since the pneumatic farm tire was developed, the basic carcass construction has been bias or diagonal plies. As tractor manufacturers continue to produce models with higher and higher horsepower, it has become evident that the conventional design changes--lug shape, lug angle, aspect ratio, etc.--are no longer sufficient to achieve significant improvements in tractor drive wheel tire performance. After investigating various alternatives, B.F.Goodrich determined that a radial construction offered distinct performance advantages over a bias construction without requiring any redesigning of the tractor. These include: increased traction, reduced fuel consumption, longer wear and improved ride. This paper will present comparative performance results of radial and bias drive wheel tractor tires, and discuss the basic radial tire mechanics which make the performance improvements possible.

Chrysler Corporation used a mini-systems approach in the design and manufacture of a new generation of small cars, not merely new models. These cars are the Plymouth Volare and Dodge Aspen. A new generation of cars is defined as a full line of vehicles - 2-door coupe, 4-door sedan, and 4-door station wagon - which offer customers new values for this size car, especially in the areas of rideability, handling, fuel efficiency, visibility, roominess, comfort, quietness and amenities. In addition, a new generation of cars means an adaptable and cost-efficient product that, because of its design and manufacturing flexibility, can serve as a model for the resizing and redesign of the corporation's complete line of cars in the last half of this decade.

The emission control of small naturally aspirated diesels has posed severe problems and it has been generally thought that their acceptability in pollution sensitive areas would decline. The investigation described attempts to reverse this view. The exhaust quality of engines of this type can be improved by reducing the combustion temperatures and/or reducing the initial heat release rate: a range of methods of achieving this were examined and found commercially unacceptable. A qualitative review of the problem led to the evolution of a modified cycle characterized by high turbulence leading to higher air/fuel mixing rates and faster diffusion burning. This “Squish Lip” combustion system allowed CARB 1977 projected emission levels to be met on development engines without performance deterioration. Bench and field trials are in hand and a second generation system for truck applications is being evaluated.

Experimental insight derived from the measurement of heat transfer rates is useful in a number of engine-related activities-ranging from developing simulations for predicting engine performance to defining cooling requirements for insuring the integrity of engine materials. Consequently, a device for measuring steady-state heat-transfer rates in a solid was designed after an extensive heat-transfer analysis. Subsequent experimentation and development has led to an accurate miniature sensor which can be installed directly into a parent material with little thermal disturbance. An analytical model of the sensor, installed in the combustion chamber wall of an engine, predicted this disturbance error to be 3% or less over a wide range of parent material properties and engine operating conditions. Experimentation at four heat-transfer rates confirmed this predicted performance.

Three different types of temperature measurement on the automobile and the development of suitable controls are discussed. High temperature probe controls for emission catalysts; small, fast response thermostats for engine blocks; and PTC ceramic sensors for a variety of uses are developed.

Crushed samples of Engelhard PTX (II-B) catalyst were calcined at temperatures between 900-2700°F. When the temperature exceeds about 1100°F in air, the crystallites of precious metals (platinum-palladium) grow larger, exposing less surface for catalysis. When the catalyst is exposed to temperatures on the order of 1500-1800°F for extended periods of time (16 h or more), the wash-coat tends to lose a substantial percentage of its surface area. Finally, above about 2300°F, the cordierite of the ceramic becomes converted to mullite and amorphous material. The intrinsic rate constant for the oxidation of pure propylene is inversely related to Pt-Pd crystallite size. Thus, in the absence of poisoning, changes in intrinsic oxidation rate constant can be accounted for by changes in degree of dispersion of precious metal.

Experimental results with a 25-hp charge-cooled rotary combustion engine are presented for a variety of lubricant base stocks and additive packages. A rating method which combines endurance and deposition level is described. Lubricant performance is evaluated based upon this rating scheme, and contribution of base stock and additive package components is analyzed.

The mechanism of reduction of nitric oxide by hydrogen and carbon monoxide was studied on base metal catalysts under simulated automobile exhaust conditions. The catalysts were low copper-nickel alloys supported on an all-metal open-mesh substrate. Space velocity and concentrations of inlet and outlet NO, H2, CO, and O2 were used as study parameters. Dependence of ammonia formation on the hydrogen content in the gas was established. It was found that the dependence of ammonia formation on the oxygen content could be accounted for by the reaction of oxygen with the hydrogen produced by the water-gas reaction. In general, indications were obtained that under the conditions studied, the reduction of NO on base metal catalysts proceeds by a mechanism in which ammonia is an intermediate.

Platinum resistance sensors are currently used for continuous service from -260°C to +800°C and up to 1200°C for short term use. The historical development of resistance sensors is discussed and the advantages of using platinum resistance sensors over thermocouples is described. Parameters used in the evaluation of platinum sensors and signal conditioners are enumerated. Errors encountered in temperature measuring schemes and methods to reduce these errors are summarized.

A monolithic integrated circuit has been developed that is a sensor, a voltage reference, and an operational amplifier, all in a simple four-lead package. Although the circuit is designed to sense absolute temperature as a physical parameter, certain application techniques allow other inputs to be handled. Differential temperature, position, and air velocity can be converted to analog, on-off, or frequency outputs as desired. Specific examples are provided.

A radiometric method has been developed to measure apex seal wear in rotary engines. Seal wear rates are measured in ranges of μg/min without engine disassembly, and at various speed and load conditions using a dynamometer. The method incorporates radioactive apex seals in the front rotor of a Mazda 10A engine. Neutron irradiation of commercial carbon-aluminum apex seals produced radioisotopes of iron and chromium. Experimental carbon-aluminum seals, containing terbium oxide as an additive to improve the nuclear properties of the seals, were also used. The radiometric method involves the following steps: 1.operation of a rotary engine at any desired engine condition with radioactive apex seals, 2.collection of the seal wear debris by filtering the exhaust gas, and 3.the quantitative determination of the resulting radioactivity on the filter medium.