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Viewing 164461 to 164490 of 183198
1967-02-01
Technical Paper
670911
V. R. Hodgson, E. S. Gurdjian, L. M. Thomas
Certain physical characteristics such as apparent mass and stiffness influence the dynamic response of the head and thereby the degree of trauma suffered from impact with another body. These characteristics are a function of frequency and can be determined by mechanical impedance measurement techniques. A force generator was attached directly to the skull and the force input and resulting motion at the point of attachment were measured respectively by a force and acceleration transducer. The magnitude as well as phase angle between these two vectors were measured over the frequency range from 5 to 5,000 Hz. A plot of the ratio of force and acceleration vs. frequency and phase angle vs. frequency on a nomograph reveal that both the apparent mass and stiffness of the head vary markedly from static values, and with location.
1967-02-01
Technical Paper
670910
G. Murray Mackay, C. P. de Fonseka
Some aspects of an on-the-spot study of 425 urban road accidents in Birmingham, England are presented. Injury patterns to pedestrians, motorcyclists and front seat car occupants are summarized. The origins of these injuries in relation to road and vehicular impacts are discussed. Vehicle components causing injury to pedestrians and to car occupants are analysed. Crash helmet effectiveness in motorcycle impacts is discussed and some comment is made on seat belt fitting and use.
1967-02-01
Technical Paper
670913
L. M. Patrick, H. J. Mertz, C. K. Kroell
Human tolerance to knee, chest, and head impacts based upon skeletal fracture of cadavers is reported. The results are based upon unrestrained cadaver impacts in a normal seated position in simulated frontal force accidents at velocities between 10 and 20 mph and stopping distances of 6-8 in. The head target was covered with 15/16 in. of padding. No skull or facial fractures were observed at loads up to 2640 lb. Extensive facial fractures and a linear skull fracture occurred during the application of the maximum head force of 4350 lb. The chest target was 6 in. in diameter with 15/16 in.of padding. The padding was rolled over the edge of the target to minimize localized high force areas on the ribs. A 1/8 in. diameter rod was inserted through the chest and fastened through a ball joint and flange to the soft tissue at the sternum.
1967-02-01
Technical Paper
670912
R. G. Rieser, J. Chabal
Impact performance of a large variety of interlayer combinations laminated with annealed plate, heat strengthened, and fully tempered glasses has been analyzed for acceleration pulses, “severity index,” and penetration. These tests, conducted at 0, 70, and 120 F, indicate that small interlayer thickness changes are most effective in upgrading performance. Severity index numbers well below 1000 were calculated for laminated safety glass with interlayer thickness as high as 0.120 in. Highly localized bending of glass panels during impact with the 22 lb headform has been recorded through high-speed photography as reflected grid board distortion. Lacerative potential of laminated safety glass is being evaluated by using a simulated tissue developed through studies of human tissue.
1967-02-01
Technical Paper
670915
J. L. Nickerson, Milana Drazic, R. Johnson, H. Udesen, K. Turner
An X-ray experimental method for observing the motion of body visceral regions subject to whole-body impact has been developed. The observations demonstrate the movement of internal areas relative to the spinal column and to the impact cradle. Calculation of displacement from the rest position, including the lag on free fall, and velocities and accelerations generated are presented. In these series of experiments the maximum drop height was 84 inches so that the trauma produced was minimal.
1967-02-01
Technical Paper
670914
J. Banshoya, H. Okoshi, S. Asano, K. Okamoto
Mainly intended for small passenger cars which have more dimentional restrictions than large ones do, a new energy-absorbing column is developed utilizing frictional and plastic deformation resistance as absorbing means. This paper presents its design details, test results on various specifications and conditions, discussions on various factors which affect the performance, analysis of column compression both statically and dynamically, testing methods and equipments for components and complete assembly, confirming that its intended features of relatively low peak load and reasonable compression length has been achieved.
1967-02-01
Technical Paper
670917
Paul Richter
Velocities, momenta, and energy distribution after impact can be calculated by a simple method. This technique can be used only when two bodies are involved that represent a closed system. One of the bodies is assumed to be at rest with respect to the chosen frame of reference before impact. Very simple geometric figures are used with the method. For the central impact, for example, the distribution of velocity and momentum after impact is found from the point of intersection of two straight lines. One of these represents the ratio of masses of the interacting bodies, and the other represents the degree of elasticity (thus depending only on the ratio of the actual loss of translatory kinetic energy - resulting from impact - to the highest possible loss of translatory kinetic energy - resulting from a non-elastic impact between two bodies of the same mass and velocity.)
1967-02-01
Technical Paper
670916
Jeffry S. Life, Bruce W. Pince
Embalmed cadavers have been used extensively to study impact dynamics, but the results seem inconclusive to us. To collect statistically valid data eventually allowing extrapolation to human beings, squirrel and rhesus monkeys (both alive and anesthetized and dead and embalmed) were impacted using a linear accelerator. The embalming procedures were standardized and the impacts were targeted, precisely controlled, and proportional. Necropsy showed that in both small- and medium-sized primates, embalmed bone is more susceptible to damage than live bone. The converse is true for the soft tissues impacted. The intraspecies differences are statistically significant, and further, the interspecies comparisons show positive correlation in most cases. Our results suggest that embalmed tissue response is not representative of live tissue response. This conclusion is at variance with others' findings. Embalming procedures and experimental design account for some of the discrepancies.
1967-02-01
Technical Paper
670869
William B. Engel, Richard F. Hazelton
DC-8 aircraft fuel tank sump drainings and soil, air, and fuel-water samples from fuel distribution facilities were analyzed for microbial contamination. The data were evaluated to determine the fuel tank contamination, its sources, and its effect upon the aircraft so that corrosion prevention methods could be developed. Sampling plans and microbial examination techniques are presented. Principal contaminants were Hormodendrum resinae, Candida sp., and yeastlike cells. They appeared together in many aircraft. Most of the microorganisms found in aircraft samples were also found in samples from fuel distribution facilities, but only in very low frequency in aircraft dispensed fuel. The fuel facilities could serve as an important microbial source when the final barrier is breached or not effective.
1967-02-01
Technical Paper
670871
A. J. Kasak, L. R. Last
Jet engine malfunctions can be detected by acoustic and vibration measurement. A means of detecting engine malfunctions, or functional variations, with a high confidence level is being investigated using digital computer techniques. Operation of the analyzer is based on subjecting incoming “real time” data to predetermined tests and categorizing the data based on these tests. Using this method, several different types of possible malfunctions could be checked at one time in less than 10 sec. Acoustic and vibration designdata, required to form the malfunction decision rule, were tape recorded in test programs of actual known malfunctions in jet engines. Both normal engine data and malfunction data with several degrees of failure were used to establish each predicted-malfunction detection mode. This paper presents the status of this activity.
1967-02-01
Technical Paper
670873
S. Rubin, F. A. Biehl
The paper demonstrates a mechanical impedance approach to an aircraft vibration problem. The desire is to reduce cabin noise resulting from fuselage vibration generated by engine rotor unbalance disturbances. A simplified analytical model is used in combination with experimental impedance data to investigate the effectiveness of several schemes applied to the engine/airframe interface. Airframe vibration absorbers are found to be the most effective. Qualitative correlation is achieved with the results of the installation of absorbers on the Douglas DC-9 aircraft. A more comprehensive analytical model is generated to account for three-dimensional effects; data acquistion for this model is discussed.
1967-02-01
Technical Paper
670872
L R. Hulls, J. R. Welch
This paper discusses, in a general way, the techniques that can be used for diagnosing engine malfunctions from vibration signals. The various kinds of signals which can be obtained by instrumenting an engine are considered with reference to the various analytical techniques available for abstracting useful diagnostic information. The results of two experiments are presented to provide a practical illustration of some of the methods propounded in this paper. One experiment shows how an oversized rod bearing can be detected, and the other demonstrates a technique which provides a method for pinpointing malfunctions in the valves.
1967-02-01
Technical Paper
670878
John M. Swihart
The variable-geometry features of the United States supersonic transport are described. Particular attention is given to the hardware development of those variable-geometry features unique to the supersonic transport. The design, development, and current status of a direct lift control sys tern, the supersonic internal-external compression inlet, and the full-scale wing pivot are described.
1967-02-01
Technical Paper
670879
Major Robert K. Parsons
This paper discusses some of the more significant factors which affect the design and flying qualities of a variable geometry aircraft. These comments were prepared by a test pilot currently involved in testing a variable geometry aircraft and are not as detailed as one might expect from a design engineer's viewpoint. The selection of a wing pivot location is discussed along with longitudinal stability characteristics. The comments on flying qualities of a variable wing aircraft include trim changes and buffet boundary limits with wing sweeps, performance gains, operational flexibility, and cockpit controls. In addition, some suggestions for future application of the variable geometry principles are made.
1967-02-01
Technical Paper
670880
S. K. Landgraf, R. N. Herring
Aircraft designs have been characterized by an increasing utilization of variable geometry features as aircraft capabilities expand into new flight regimes. The trend seems likely to continue as requirements for new aircraft become continually more demanding. The successful application of variable geometry depends on several things: the understanding of the aerodynamic principles involved, efficient structure, and whether an overall worthwhile improvementin performance, maneuverability, or flying qualities is gained; since it certainly will cost more, be less reliable, and more difficult to maintain. The application of some existing and proposed variable geometry schemes to aircraft is discussed. The aerodynamic factors affecting low and high speed performance, maneuverability, and stability and control characteristics indicate some of the desirable and troublesome aspects of these concepts.
1967-02-01
Technical Paper
670881
J. W. Harvey
Pivot point concepts for fighter type aircraft with variable sweep wings are reviewed. Structural and aerodynamic considerations involved in sweep pivot location, a summary of endurance testing of Teflon lined journal bearings, and variation of fatigue life of the aircraft versus wing sweep position are discussed.
1967-02-01
Technical Paper
670882
F. M. Paget
The use of variable sweep wings creates a special set ofaircraft mechanical design considerations. This paper con-tains some of the philosophy and design that grew from thedevelopment of the variable sweep feature on the F-111 aircraft.
1967-02-01
Technical Paper
670883
L. J. Onewein
The Boeing SST design incorporates a variable-geometry wing. Some of the wing-pivot-joint and actuation-system configurations considered during the development of the SST variable-geometry design are discussed herein. In addition, the selected SST design is described, and detailed maintainability and maintenance requirements are reviewed.
1967-02-01
Technical Paper
670884
G. C. Newell, F. E. Marsh
The United States SST must be capable of equaling or exceeding the reliability of today's subsonic jets to be profitable in scheduled revenue passenger service. This paper describes reliability aspects of the wing-sweep actuation system for the Boeing SST in terms of (a) the hardware interfaces, functional purposes, and basic design concepts; (b) the basic requirements and design criteria established by Federal Air Regulations, Tentative Airworthiness Standards, FAA-established numeric goals, and Boeing-evaluated airline economic goals; and (c) reliability analyses relating the hardware design to specific requirements.
1967-02-01
Technical Paper
670889
A. G. Tokarcik
A wide range of threaded fasteners for structural applications is available to fulfill the ever-increasing demands of the aerospace industry. Each of the basic designs was developed to fulfill a need and, consequently, possesses certain characteristic features defining that need such as extended fatigue performance, superior notch toughness, exceptional corrosion resistance, and new wrenching configuration. These characteristic features, in combination with the dimensional and mechanical property characteristics, define a product having a potential performance capability. The objective is to define the basic parameters considered mandatory for utilizing this performance capability in a structure.
1967-02-01
Technical Paper
670891
M. J. Church
Aircraft and accessory builders can cut airline operating costs by more careful selection of fasteners and fastening methods. Fastener performance, reliability, standardization, availability, ease-of-use, interchangeability, tooling, corrosion control, safety, re-useability, and identification are all important factors that must be considered. For optimum cost performance, keep fastener designs simple and “standardize on the best.”
1967-02-01
Technical Paper
670894
Bruce W. Pince
A physical model capable of credible simulation of human trauma is badly needed in automobile safety research. Development of such a model has been limited, not only by lack of biological and engineering data, but by lack of a coherent, sequential plan of attack on the problem. Such a plan, based upon the systems approach, is offered. The plan has two major phases. The first phase includes qualitative analysis, hypothetic modelling, and program planning; the second provides for emperic research, system modlling, and design, fabrication, and test of a physical model.
1967-02-01
Technical Paper
670895
R. J. Melosh, D. M. Kelley
The potential for rapid and precise predictions of car crash response lies in recent developments of computer-augmented structural analysis techniques. The essential step required is to develop and validate a mathematical and numerical simulation. This step is impeded by the complexity of the car structure and equation solution, the extensive calculations, and inadequacies in basic data. Test data indicate that no major technical advances are required. An economical analysis capability could be developed in less than 6 months.
1967-02-01
Technical Paper
670982
B. B. Turner
The Environmental Control System of the SST must keep the passengers safe and comfortable under all operating conditions. This requires not only an excellent system design, but a system that can be maintained and operated by typical airline personnel under all airline conditions of time and place. The airlines are working toward these objectives with the airframe manufacturer through SST specialist teams composed of engineering personnel from the airlines purchasing the 2707 or the Concorde. This paper discusses the objectives and considerations of the Environmental Control System specialist team in working toward minimizing the airlines problems on the SST.
1967-02-01
Technical Paper
670968
Thomas R. Wheaton
The free turbine type of gas turbine engine, because of its light weight, compactness, and inherent torque characteristics, permits the design of a new type of passenger train with light weight, high performance, and good economy. Conversely, the inherent advantages of the turbine can be realized only in a vehicle designed as a system. The United Aircraft TurboTrain is such a system design. In addition to turbine powerplants, it incorporates high strength lightweight structure, a lightweight banking suspension system, aerodynamic streamlining, and modern conveniences.
1967-02-01
Technical Paper
670963
W. A. Cox, J. K. Lock
In Western Europe, there is a large and growing number of diesel engines used in commercial vehicles, agricultural tractors, and industrial and marine applications. The paper reviews these engines and their lubricant requirements. Consideration is given to the relevance of internationally ac -cepted lubricant specifications in fulfilling these requirements and the inadequacies of these specifications are discussed. An attempt is made to forecast future trends in lubricant quality.
1967-02-01
Technical Paper
670966
George C. Best
Development of a 600 hp twin-shaft gas turbine with plate-fin recuperators has been proceeding successfully through the component and engine factory test phases. Since there has been no prior field experience with this type of engine, the need for prototype engine operation in representative installations is greater than usual. Experience to date with the design, assembly, and initial operation of the turbine in Army experimental tracked vehicles, a minesweeper, and a highway tractor are described.
1967-02-01
Technical Paper
670984
R. Trebosc
Discussed are the followed components of the Concorde's air conditioning system: dual pressure reduction/shutoff valve, mass flow control valve, primary heat exchanger bypass temperature control loop, cold air unit, temperature control valve, water extractor, and water extractor actuator controller. Functional and mechanical descriptions are given for each. The system is basically a bootstrap air cycle in which fuel and ram air cooling are provided in the intercooler loop.
1967-02-01
Technical Paper
670920
I. D. Neilson
Scientific research in the field of road safety has been in progress at the British Road Research Laboratory for more than 20 years. For the past 10 years, studies have been made of the ways of protecting vehicle occupants. Detailed accident and injury investigations showed that the greatest need was to provide protection against injuries produced in frontal collisions. Data from American impact studies and from the Laboratory's own controlled impact tests provided the basic information on which protective measures should be based. Theoretical and experimental work showed that safety belts which also afford restraint to the upper part of the body were likely to be by far the most effective way of providing protection; this work is described. The development of standards and of testing methods is briefly discussed. An assessment of the value of safety belts in use in protecting car occupants in Great Britain is given.
1967-02-01
Technical Paper
670921
Derwyn M. Severy, Harrison M. Brink, Jack D. Baird
Abstract Scientific methodology and engineering techniques were applied to the initial 4 of a series of 12 automobile rear-end collision experiments to provide data relating to seat and head support design. Two speeds of impact, three seatback heights, and two seatback strength values were studied. This is a study to evaluate the relative protective merits and the practicality of various seat designs with respect to the many variables common to rear-end collisions. This basic research data will provide a standard reference system for determining collision performance of seat and head support designs with respect to occupant size, posture, and proximity to injury-producing structures. IN THIS SERIES OF FOUR COLLISION EXPERIMENTS, a stationary 1967 4-door sedan was rear-ended by an identical striking car for each experiment. In the first experiment, the striking car was traveling at 30 mph; in the second experiment, at 20 mph; and in the remaining two experiments, at 30 mph.

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