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Tests run at high pressure indicate that various polymer materials used show inverse relationship between thickness and impact sensitivity. Several materials tested exhibited greater impact sensitivity in gaseous oxygen than in liquid oxygen. Materials tested in gaseous oxygen showed enhanced impact sensitivity with higher pressure.
On November 9, 2022, the National Aeronautics and Space Administration (NASA) conducted a full-scale crash test of the NASA Lift+Cruise (LPC) reference vehicle at the NASA Langley Research Center Landing and Impact Research Facility (LandIR) under combined vertical and horizontal impact conditions to simulate a severe but survivable crash. The LPC test article is a carbon-composite skin/frame structure design, developed and fabricated for the cabin section only. The test utilized various configurations of seats and Anthropomorphic Test Devices (ATDs, a.k.a. crash test dummies) intended to encompass a variety of occupant conditions. In addition, an in-house developed energy absorbing subfloor was utilized for the evaluation of load attenuation. Overhead mass was simulated using attached lifting hardware and other systems were simulated using ballast mass. The test article impacted the ground with velocities of 38.1 ft/s horizontal and 31.4 ft/s vertical. During the first approximately 38 milliseconds (ms), the cabin section experienced a large amount of acceleration on the belly which was attenuated by the subfloor structures and seats. Over the next approximately 160 ms, the test article experienced failure in the a-, b- and c-pillars, leading to a partial collapse of the overhead structure. Test data was collected on the belly, floors, seats, overhead mass, and tail. In addition, there was high speed full-field digital image correlation analysis data collected on the port side skin surface. Collected ATD data showed that the ATDs seated in the energy absorbing seats experienced loads at limits below the those in current regulations. Even without an energy absorbing seat, the energy absorbing subfloors crushed as intended, and limited the load on the large 95 th percentile ATD to 10% over suggested limits. The collapse of the roof did affect the 95 th percentile ATD, which showed high neck loading values due to head contact, whereas survivable volume was maintained for the other ATDs. While the energy absorbing subfloor and energy absorbing seats both contributed to occupant load attenuation, further optimization is suggested to increase their robustness.
On November 9, 2022, the National Aeronautics and Space Administration (NASA) conducted a full-scale crash test of the NASA Lift+Cruise (LPC) reference vehicle at the NASA Langley Research Center Landing and Impact Research Facility (LandIR) under combined vertical and horizontal impact conditions to simulate a severe but survivable crash. The LPC test article is a carbon-composite skin/frame structure design, developed and fabricated for the cabin section only. The test utilized various configurations of seats and Anthropomorphic Test Devices (ATDs, a.k.a. crash test dummies) intended to encompass a variety of occupant conditions. In addition, an in-house developed energy absorbing subfloor was utilized for the evaluation of load attenuation. Overhead mass was simulated using attached lifting hardware and other systems were simulated using ballast mass. The test article impacted the ground with velocities of 38.1 ft/s horizontal and 31.4 ft/s vertical. During the first approximately 38 milliseconds (ms), the cabin section experienced a large amount of acceleration on the belly which was attenuated by the subfloor structures and seats. Over the next approximately 160 ms, the test article experienced failure in the a-, b- and c-pillars, leading to a partial collapse of the overhead structure. Test data was collected on the belly, floors, seats, overhead mass, and tail. In addition, there was high speed full-field digital image correlation analysis data collected on the port side skin surface. Collected ATD data showed that the ATDs seated in the energy absorbing seats experienced loads at limits below the those in current regulations. Even without an energy absorbing seat, the energy absorbing subfloors crushed as intended, and limited the load on the large 95 th percentile ATD to 10% over suggested limits. The collapse of the roof did affect the 95 th percentile ATD, which showed high neck loading values due to head contact, whereas survivable volume was maintained for the other ATDs. While the energy absorbing subfloor and energy absorbing seats both contributed to occupant load attenuation, further optimization is suggested to increase their robustness.
The Revolutionary Vertical Lift Technology (RVLT) Project is one of six projects in the Advanced Air Vehicles Program (AAVP) of the NASA Aeronautics Research Mission Directorate. The overarching goal of the RVLT Project is to develop and validate tools, technologies, and concepts to overcome key barriers for vertical lift vehicles. The project vision is to enable the next generation of vertical lift vehicles with aggressive goals for efficiency, noise, and emissions, to expand current capabilities and develop new commercial markets. The RVLT Project invests in technologies that support conventional, non-conventional, and emerging vertical-lift aircraft in the very light to heavy vehicle classes. Research areas include acoustic, aeromechanics, drive systems, engines, icing, hybrid-electric systems, impact dynamics, experimental techniques, computational methods, and conceptual design. The project research is executed at NASA Ames, Glenn, and Langley Research Centers; the research extensively leverages partnerships with the US Army, the Federal Aviation Administration, industry, and academia. The primary facilities used by the project for testing of vertical-lift technologies include the 14- by 22-Ft Wind Tunnel, Icing Research Tunnel, National Full-Scale Aerodynamics Complex, 7- by 10-Ft Wind Tunnel, Rotor Test Cell, Landing and Impact Research facility, Compressor Test Facility, Drive System Test Facilities, Transonic Turbine Blade Cascade Facility, Vertical Motion Simulator, Mobile Acoustic Facility, Exterior Effects Synthesis and Simulation Lab, and the NASA Advanced Supercomputing Complex. To learn more about the RVLT Project, please stop by booth #1004 or visit their website at https://www.nasa.gov/aeroresearch/programs/aavp/rvlt.
Chemical flare for analysis of chemical composition and physical structure of lunar surface - spectroscopic, combustion, impact, and compatibility tests
Method for estimating accelerations of shipping containers and contents on impacting railroad car
Slingshot device for high-velocity shock testing analyzed for impact delivery, shock pulse, and g-level
Work providing a firm basis for building an engineering model thrust subsystem (TSS) is described. A 1500-hr functional demonstration test revealed the impact of each element on TSS integration, operation, and future development. The primary conclusions are: accurate and specific definition of interfaces is essential to a timely system integration program. In addition to normal operating requirements, this definition must include requirements for preflight checkout, self-protection of all interfaces, capability expansion, failure modes, maximum input power, interelement power losses, noise and transient sensitivity and production, packaging for vacuum, thermal control, electrical grounding, cabling, mounting, and handling. In any future design, each phase of the TSS operation (startup, throttling, switching, etc.) should be considered in detail to anticipate and account for possible in-flight variations in element characteristics and performance.
The mechanical properties of type 431 stainless steel in two conditions: annealed bar and hardened and tempered bar are presented. Test specimens, manufactured from approximately 1.0 inch (2.54 cm) diameter bar stock, were tested at temperatures of 80 F (+26.7 C), 0 F (-17.8 C), -100 F (-73 C), and -200 F (-129 C). The test data indicated excellent tensile strength, notched/unnotched tensile ratio, ductility, shear, and impact properties at all testing temperatures. Results of the alternate immersion stress corrosion tests on stressed and unstressed longitudinal tensile specimens 0.1250 inch (0.3175 cm) diameter and transverse C-ring specimens, machined from 1.0 inch (2.54 cm) diameter bar stock, indicated that the material is not susceptible to stress corrosion cracking when tested in a 3.5 percent NaCl solution for 180 days.
Photogeologic analysis was attempted on a strip of Apollo 16 metric photographs; the superior quality and stereographic properties of the photography permitted this reevaluation. Geologic contacts, as redrawn closely resemble those of earlier maps, but some differences resulted because of improved photographic quality and a conscious attempt to test fully the impact hypothesis. All or most of the nonmare material of the region of the northern Nectaris Basin rim can be explained by the formation of impact basins. This interpretation seems strained only for some irregular and clustered craters north of Mare Nectaris and for the southern facies of the Descartes material. If the latter material is shown to have been sampled and to be of impact origin, then extensive hill and crater-forming volcanic material of Imbrian or younger age probably does not exist on the lunar terra.
The development of a wind energy system is outlined that supplies reliable energy at a cost competitive with other energy systems. A government directed industry program with strong university support is recommended that includes meteorological studies to estimate wind energy potentials and determines favorable regions and sites for wind power installations. Key phases of the overall program are wind energy conversion systems, meteorological wind studies, energy storage systems, and environmental impact studies. Performance testing with a prototype wind energy conversion and storage system is projected for Fiscal 1977.
Proceedings from a conference on engineering advances are presented, including materials science, fracture mechanics, and impact and vibration testing. The tensile strength and moisture transport of laminates are also discussed.
The results of dynamic digital blade row compressor model studies of a J85-13 engine are reported. The initial portion of the study was concerned with the calculation of the circumferential redistribution effects in the blade-free volumes forward and aft of the compression component. Although blade-free redistribution effects were estimated, no significant improvement over the parallel-compressor type solution in the prediction of total-pressure inlet distortion stability limit was obtained for the J85-13 engine. Further analysis was directed to identifying the rotor dynamic response to spatial circumferential distortions. Inclusion of the rotor dynamic response led to a considerable gain in the ability of the model to match the test data. The impact of variable stator loss on the prediction of the stability limit was evaluated. An assessment of measurement error on the derivation of the stage characteristics and predicted stability limit of the compressor was also performed.
An analysis and description is presented for the proposed Airport Solar Photovoltaic Concentrator Project. The environmental effects and potential impacts of the test facilities are discussed.
This paper is concerned with the optical portion of the Voyager spacecraft imaging science subsystem (ISS). After a brief description of the Voyager mission and its photographic aspects, the functional requirements for the television optics are outlined. Environmental considerations that constrained the design are summarized. One section of the paper is devoted to radiation testing and its impact on the design of the wide-angle optics. The main portion of this report, however, is devoted to a description of the Voyager television optics. Finally, Voyager imagery results that are current with the preparation of this paper are presented.
A study was carried out of 112 impact survivable jet transport aircraft accidents (world wide) of 27,700 kg (60,000 lb.) aircraft and up extending over the last 20 years. This study centered on the effect of impact and the follow-on events on aircraft structures and was confined to the approach, landing and takeoff segments of the flight. The significant characteristics, frequency of occurrence and the effect on the occupants of the above data base were studied and categorized with a view to establishing typical impact scenarios for use as a basis of verifying the effectiveness of potential safety concepts. Studies were also carried out of related subjects such as: (1) assessment of advanced materials; (2) human tolerance to impact; (3) merit functions for safety concepts; and (4) impact analysis and test methods.
A 20 ft vertical spin tunnel, a 30 by 60 ft tunnel, a 7 by 10 ft high speed tunnel, a 4 by 7 meter tunnel, an 8 ft transonic pressure tunnel, a transonic dynamics tunnel, a 16 ft transonic tunnel, a national transonic facility, a 0.3 meter transonic cryogenic tunnel, a unitary plan wind tunnel, a hypersonic facilities complex, an 8 ft high temperature tunnel, an aircraft noise reduction lab, an avionics integration research lab, a DC9 full workload simulator, a transport simulator, a general aviation simulator, an advanced concepts simulator, a mission oriented terminal area simulation (MOTAS), a differential maneuvering simulator, a visual/motion simulator, a vehicle antenna test facility, an impact dynamics research facility, and a flight research facility are all reviewed.
A series hydraulic, active loads control main landing gear from a light, twin-engine civil aircraft was investigated. Tests included landing impact and traversal of simulated runway roughness. It is shown that the active gear is feasible and very effective in reducing the force transmitted to the airframe. Preliminary validation of a multidegree of freedom active gear flexible airframe takeoff and landing analysis computer program, which may be used as a design tool for active gear systems, is accomplished by comparing experimental and computed data for the passive and active gears.