This document defines the Level 1 tests required for qualifying an artificial bird for certification testing of aircraft and aircraft engines. Level 1 refers to the lowest level of the test pyramid associated with the building block approach defined in the CMH-17 Composite Materials Handbook. The test pyramid consists of a sequence of 5 levels of testing, ranging from the most basic at the lowest level of the pyramid to the most complex at the apex. Typically the number of tests performed has an inverse relationship to the complexity of the tests. The building block approach is used for defining the tests required to qualify an artificial bird that would be accepted by regulatory agencies for certification testing of aircraft, including rotorcraft, fixed wing fuselages and engines, where bird strike testing is currently required. This document only describes the tests required for Level 1 of the test pyramid. Separate documents define the tests required at higher levels.
A finite element model of the human lower extremity has been developed in this study to simulate lower extremity behavior in frontal car crashes. Precise geometry of the human lower extremity and material properties of the hard and soft tissues were introduced to the model. The performance of the model was evaluated by comparing with dynamic loading test data using post mortem human subjects (PMHS). The comparison proved its ability to estimate dynamic responses of the human lower extremity. A study was conducted using the model to investigate possible factors of loading to the ankle and tibia. Force and moment were calculated with different time history profiles of footwell intrusion and pelvis motion. The results suggested that timing of maximum intrusion was important as well as its magnitude. It was also found that loading to the tibia could be affected not only by intrusion but also by pelvis motion.
TWO distinct phases of the subject are the physical and the economic, both of which are included in the conclusions stated in the paper, based on investigations made by the Bureau of Public Roads. It is as pertinent to inquire what effect the highways have on the motor-vehicle as to inquire what effect the motor-vehicle has on the highways. Mutual adjustment must be made if real economy is to result. Two general conclusions that may be drawn from the observations presented are that the six-wheel vehicle offers a desirable and effective answer to (a) the problem of the load in excess of the normal desirable limit of weight for the four-wheel truck, and (b) the problem of the load equal to the heavier four-wheel truck in areas where road conditions do not permit the maximum wheel-load concentration.
Benefits gained by distributing truck weights and loads among six wheels rather than four, include less liability to cause road destruction, greater carrying capacity and more economical operation. The author classifies the causes of road destruction under headings of excessive loads on tires, impacts between road and tires, traction effects of wheels, and braking effects and says that the remedy is to reduce load or to correct improper weight-distribution. Impacts probably contribute most destructive effects.
In investigating the forces that tend to break up and destroy roads, the most destructive of these being that of impact, the United States Bureau of Public Roads devised a method of receiving the impact of a truck on a small copper cylinder and determining its amount by measuring the deformation of the cylinder. The impact values are largely dependent upon the type and construction of the truck. Unsprung weights have a great influence upon the impact value of the blow on the road surface and a reverse influence upon the body of the truck; these effects are in two different directions. The present aim of the Bureau is to investigate this impact and the effect of the unsprung weight on the road. Most of the tests have been made on solid tires, a few have been made on worn solid tires and some on pneumatic tires. The Bureau intends to elaborate all of these tests, including different types of pneumatic tire, different unsprung weights and special wheels, such as cushion or spring wheels.
THE author believes that the flexible bladder-cell tank may be a good, practical solution to the fuel tank crash fire problem. He reports further that this type of tank need not carry with it an unreasonably high weight penalty. These tanks have successfully withstood some simulated crash tests corresponding to approximately 20g, so they are undergoing further tests to determine their ultimate crash strength. The opinions expressed in this paper are those of the author and do not necessarily represent the opinions of the Civil Aeronautics Administration.
The Cadillac Company has used S.A.E. 3250 steel for at least 8 years. This is medium nickel-chromium steel. Many other kinds have also been tried. Experience has shown that transmission gears made of carburized steel are not within 30 per cent as accurate as those made of oil-treated steel. This may be because of the fact that more attention has been paid to oil-hardened than to carburized steel gears. Efforts to control the distortion of carburized gears were unsuccessful. The hardening was done in salt pots, lead pots and open furnaces, heated by gas, oil and electricity. The same thing applies to spur gears. Oil-treated steel for rear axles has not been tried. When transmission gears were made from drop-forged blanks made by the conventional pegged-out process from flat stock they became oval. Upset gear forgings are used as fast as the forging suppliers can become equipped for the work.
The author discusses the different types of material used in the production of the Liberty engine, the physical properties of the finished parts and the heat-treatments used in making them, applying the information as set forth to the automobile, truck and tractor industries. Under their several heads the different engine pans are discussed with close attention to details. Chemical analyses are given for each part and approved heat-treating temperatures are indicated. Quenching, direct and indirect, water and oil cooling, hard spots, warpage, scaling and hair-line seams are treated. The advantages and disadvantages of the Izod impact test are stated briefly.
This title carries the papers developed for the 2014 Stapp Car Crash Conference, the premier forum for the presentation of research in impact biomechanics, human injury tolerance, and related fields, advancing the knowledge of land-vehicle crash injury protection. The conference provides an opportunity to participate in open discussion the causes and mechanisms of injury, experimental methods and tools for use in impact biomechanics research, and the development of new concepts for reducing injuries and fatalities in automobile crashes. The topics covered this year include: • Head/brain biomechanics • Thorax, spine, and pelvis biomechanics • Overlap/angled frontal crash testing and real-world performance • Pedestrian and cyclist injury factors and testing • Rollover and side-impact crashes and computational modeling
This book is an internationally oriented discussion on how to evaluate products, processes, services and systems. The authors identify key generic safety principles an discuss their applications. Decision-making criteria are also explained, and in-depth information on human simulation, human error control and driver distractions is provided. The book details reconstruction techniques and methods of crash testing, and looks at future vehicle safety and universal design.
An H-25A Piasecki helicopter has been employed in recreating a “typical” accident occurring with both longitudinal and vertical velocity components at impact. Acceleration patterns at various stations in the aircraft and in the dummy occupants have been found to be incomparable with the results of similar tests conducted for fixed-wing aircraft by NACA. For the helicopter, large magnitude, short duration, accelerations have been observed. By contrast, accelerations of smaller magnitude but with relatively longer duration were found for transport type aircraft by NACA. When the acceleration environment for the H-25 is compared with known tolerance limits for human subjects, the need for modification in crew and passenger seats to provide better crash protection for the aircraft’s occupants becomes apparent.
A description is given of the technique used by FIAT, where three simple and economical methods for testing the complete car have been set up, namely, a static compression test, a dynamic test on catapult, and collision road tests of radio guided cars (controlled from other cars or from helicopters). The results are reciprocally integrating so as to give a thorough understanding of the behavior of several car models in collisions occurring in different ways and at different speeds. About 200 full-scale tests have been run so far and the results are in fair agreement with findings from actual road accidents. The information obtained has permitted progressive design refinements, and has shown the way towards constructional improvements likely to increase car safety.
A program of research was conducted to examine the validity of a digital computer simulation of an automobile occupant during a frontal, head-on collision. The simulation is designed to permit a detailed study of the effects of several types of restraint systems on occupant responses in a confined compartment, where injury-producing contact forces occur. The effects on occupant responses produced by the positions, orientations, and load-deflection properties of contacted interior surfaces are also simulated. This progress report covers one phase of a CAL long-range program of development of simulation techniques for study of occupant/vehicle and vehicle/obstacle collision responses. Detailed comparisons are presented of responses from instrumented sled tests and corresponding computed responses from the simulation. The comparisons include forces in restraint belts and on contacted surfaces, accelerations of the dummy, and the detailed kinematics of the dummy itself.
Accident statistics indicate that postcrash fire is one of the most serious threats to human life in aircraft crashes. It is also a serious threat in automotive crashes. Several methods are available to reduce this hazard. The simplest and most effective method is through control of the fuel spillage. Aircraft crash testing has shown that fuel systems incorporating tough, flexible fuel tanks that are smooth in contour, free from rigid attachments, and mated with flexible fluid lines are capable of preventing fuel spillage during crashes involving decelerative loading above the human survival range.
This paper describes the usage of an exponential weighting factor for appraising deceleration or force impulses registered on dummies or impacting hammers in safety testing. The proposed impulse-integration procedure, it is shown, takes into account in a more rational way, and in better conformity with published injury tolerance data, the relative importance of time and intensity of the pulse than do the “peak g” or impulse-area criteria. Use of the new Severity Index for assessment of head impact pulses is illustrated. It is shown to be of special value in comparing the relative severity of pulses which differ markedly in shape (because of structural differences in the component being struck) and it is pointed out that without a weighting factor of this nature, laboratory impact tests can yield incorrect ranking of the relative safety merit of alternative designs. Automated methods for quick calculation of the Severity Index are possible.
In the crash tests performed in 1960-61 by Automotive Safety Research Project in the Mechanical Engineering Department of the University of Minnesota, the test data for the forces on a human being held by a seat belt was based upon the effectiveness of the hydraulic shock-absorbing bumper, a 50-cycle per second natural frequency seat belt and a seat belt tightener without release. The present paper presents an analytical study of the same system with the seat belt tightener connected directly to the hydraulic bumper; the tightener cylinder being thus loaded and unloaded with the bumper. Under this system, a seat-belt force is held to ¼ the force otherwise produced on a seat belt without a bumper and retraction. This condition was suggested on page 82 in the original paper, “Reduction in Crash Forces, ” James J.
The Impact Sled, a full-scale laboratory facility which simulates vehicle accidents, has been in use at the General Motors Proving Ground since late 1962. This paper describes the facility and supporting instrumentation, and reviews some of the many types of tests that were run in the first year of operation. These range from tests of complete vehicles loaded with passenger dummies to tests of single components such as seat belts, seat adjusters, door locks, and windshields. This new research tool, which produces results comparable to those of the classical barrier impact test, has proved to be a valuable and versatile addition to the automotive testing facilities at the Proving Ground.
High-intensity discharge (HID) headlamps are increasingly being employed in place of incandescent headlamps for automotive forward light systems. While the post-impact analysis of incandescent bulbs and filaments to determine the power state at impact is a mature field, there is little information currently available in the literature that can be used to determine if an HID headlamp was powered at the time of impact. HID headlamps differ significantly both in architecture and operation compared to incandescent headlamps; the light is produced by passing electrical current through a gas and generating a luminous arc, rather than by resistive heating of an incandescent filament. Though the filament examination techniques often used by accident investigators cannot be directly applied to HID lamps, the unique features of these lamps provide opportunities for new methods. This paper presents the results of stationary impact tests performed on a representative HID lamp.
The purpose of this study was to develop a numerical analytical model of collinear low-speed bumper-to-bumper crashes and use the model to perform parametric studies of low-speed crashes and to estimate the severity of low-speed crashes that have already occurred. The model treats the car body as a rigid structure and the bumper as a deformable structure attached to the vehicle. The theory used in the model is based on Newton's Laws. The model uses an Impact Force-Deformation (IF-D) function to determine the impact force for a given amount of crush. The IF-D function used in the simulation of a crash that has already occurred can be theoretical or based on the measured force-deflection characteristics of the bumpers of the vehicles that were involved in the actual crash. The restitution of the bumpers is accounted for in a simulated crash through the rebound characteristics of the bumper system in the IF-D function.