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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 1,459 records · Page 81
All sourcesNASA NTRSDOE OSTI
NASA NTRS1973

Bibliography of information on mechanics of structural failure

A bibliography of approximately 1500 reference citations related to six problem areas in the mechanics of failure in aerospace structures is presented. The bibliography represents a search of the literature published in the ten year period 1962-1972 and is largely limited to documents published in the United States. Listings are subdivided into the six problem areas: (1) life prediction of structural materials; (2) fracture toughness data; (3) fracture mechanics analysis; (4) hydrogen embrittlement; (5) protective coatings; and (6) composite materials. An author index is included.

Carpenter, J. L., Jr.↗
NASA NTRS1972

Constrained optimal design of columns against buckling.

The buckling loads of straight, simply supported columns, loaded by axial thrust are maximized, subject to the restriction that the available volume of structural material is specified. In addition, a constraint is placed upon the maximum allowable prebuckling stress. Analytic solutions are presented for a variety of different cross-sectional geometries.

Frauenthal, J. C.↗
NASA NTRS1972

Fastening on the F-14A for cost effective fatigue resistance

Cost effectiveness airframe considerations dictated a variable geometry wing design that requires weight optimization, maximum working stress resistance and minimum fatigue concentration factors. The extensive use of titanium structural materials employed electron beam welding methods and interference fit fastening techniques as principle mechanical joining means for economic F-14A production and reliability engineering.

Beal, B. H.↗
NASA NTRS1973

Systems design study of the Pioneer Venus spacecraft. Appendices to volume 1, sections 3-6 (part 1 of 3)

The design is described of the Venus probe windows, which are required to measure solar flux, infrared flux, aureole, and cloud particles. Window heating and structural materials for the probe window assemblies are discussed along with the magnetometer. The command lists for science, power and communication requirements, telemetry sign characteristics, mission profile summary, mass properties of payloads, and failure modes are presented.

Source record↗
NASA NTRS1973

Benefits of advanced propulsion technology for the advanced supersonic transport

Future supersonic transports will have to provide improvement in the areas of economics, range, and emissions relative to the present generation of supersonic transports, as well as meeting or improving upon FAR 36 noise goals. This paper covers the promising propulsion systems including variable-cycle engine concepts for long-range supersonic commercial transport application. The benefits of applying advanced propulsion technology to solve the economic and environmental problems are reviewed. The advanced propulsion technologies covered are in the areas of structures, materials, cooling techniques, aerodynamics, variable engine geometry, jet noise suppressors, acoustic treatment, and low-emission burners. The results of applying the advanced propulsion technology are presented in terms of improvement in overall system takeoff gross weight and return on investment.

Hines, R. W.↗
NASA NTRS1974

Composite materials inspection

Investigation of the application requirements, advantages, and limitations of nondestructive testing by a technique of ultrasonic-vibration holographic-interferometry readout used in a production control facility for the inspection of a single product such as composite compressor blades. It is shown that, for the detection and characterization of disbonds in composite material structures, this technique may represent the most inclusive test method.

Erf, R. K.↗
NASA NTRS1975

Fracture toughness testing data: A technology survey and bibliography

Announced survey includes reports covering fracture toughness testing for various structural materials including information on plane strain and developing areas of mixed mode and plane strain test conditions. Bibliography references cite work and conclusions in fracture toughness testing and application of fracture toughness test data, and in fracture mechanics analysis.

Stuhrke, W. F.↗
NASA NTRS1974

Earth Observatory Satellite system definition study. Report no. 3: Design/cost tradeoff studies. Appendix D: EOS configuration design data. Part 1: Spacecraft configuration

The results of structural studies of the Earth Observatory Satellite (EOS) which define the member sizes to meet the vehicle design requirements are presented. The most significant requirements in sizing the members are the stiffness required to meet the launch vehicle design frequencies both in the late al and in the longitudinal directions. The selected configurations, both baseline and preferred, for the Delta and Titan launch vehicles were evaluated for stiffness requirements. The structural idealization used to estimate the stiffness of each structural arrangement, was based on an evaluation of primary loads paths, effectivity of structural members, and estimated sizes for the preferred configurations. The study included an evaluation of the following structural materials: (1) aluminum alloys, (2) titanium alloys, (3) beryllium, (4) beryllium/aluminum alloy, and (5) composite materials.

Source record↗
NASA NTRS1975

Engine/airframe compatibility studies for supersonic cruise aircraft

Technology assessment studies were conducted to provide an updated technology base from which an advanced supersonic cruise aircraft can be produced with a high probability of success. An assessment of the gains available through the application of advanced technologies in aerodynamics, propulsion, acoustics, structures, materials, and active controls is developed. The potential market and range requirements as well as economic factors including payload, speed, airline operating costs, and airline profitability are analyzed. The conceptual design of the baseline aircraft to be used in assessing the technology requirements is described.

Source record↗
NASA NTRS1975

Fracture toughness testing data: A technology survey

Technical abstracts for about 90 significant documents relating to fracture toughness testing for various structural materials including information on plane strain and the developing areas of mixed mode and plane stress test conditions are presented. An overview of the state-of-the-art represented in the documents that have been abstracted is included. The abstracts in the report are mostly for publications in the period April 1962 through April 1974. The purpose of this report is to provide, in quick reference form, a dependable source for current information in the subject field.

Stuhrke, W. F.↗
NASA NTRS1975

Beryllium reflected cavity reactor for UF6 critical experiments

Experiments and theoretical studies are being conducted for NASA on critical assemblies with one-meter diam by one-meter long low-density cores surrounded by a thick beryllium reflector. These assemblies make extensive use of existing nuclear propulsion reactor components, facilities, and instrumentation. Due to excessive porosity in the reflector, the initial critical mass was 19 kg U(93.2). Addition of a 17-cm-thick by 89-cm-diam beryllium flux trap in the cavity reduced the critical mass to 7 kg when all the uranium was in the zone just outside the flux trap. A mockup aluminum UF6 container was placed inside the flux trap and fueled with uranium-graphite elements. Fission distributions and reactivity worths of fuel and structural materials are available. These results will be used to guide the design of a prototype plasma core reactor which will test energy removal by optical radiation.

Jarvis, G. A.↗
NASA NTRS1976

User's guide to computer program CIVM-JET 4B to calculate the transient structural responses of partial and/or complete structural rings to engine-rotor-fragment impact

A user-oriented computer program CIVM-JET 4B is described to predict the large-deflection elastic-plastic structural responses of fragment impacted single-layer: (a) partial-ring fragment containment or deflector structure or (b) complete-ring fragment containment structure. These two types of structures may be either free or supported in various ways. Supports accommodated include: (1) point supports such as pinned-fixed, ideally-clamped, or supported by a structural branch simulating mounting-bracket structure and (2) elastic foundation support distributed over selected regions of the structure. The initial geometry of each partial or complete ring may be circular or arbitrarily curved; uniform or variable thicknesses of the structure are accommodated. The structural material is assumed to be initially isotropic; strain hardening and strain rate effects are taken into account.

Stagliano, T. R.↗
NASA NTRS1976

YF-12 Lockalloy ventral fin program, volume 1

Results are presented of the YF-12 Lockalloy Ventral Fin Program which was carried out by Lockheed Aircraft Corporation - Advanced Development Projects for the joint NASA/USAF YF-12 Project. The primary purpose of the program was to redesign and fabricate the ventral fin of the YF-12 research airplane (to reduce flutter) using Lockalloy, and alloy of beryllium and aluminum, as a major structural material. A secondary purpose, was to make a material characterization study (thermodynamic properties, corrosion; fatigue tests, mechanical properties) of Lockalloy to validate the design of the ventral fin and expand the existing data base on this material. All significant information pertinent to the design and fabrication of the ventral fin is covered. Emphasis throughout is given to Lockalloy fabrication and machining techniques and attendant personnel safety precautions. Costs are also examined. Photographs of tested alloy specimens are shown along with the test equipment used.

Duba, R. J.↗
NASA NTRS1976

Design principles of a rotating medium speed mechanism

Design principles of a medium speed mechanism (MSM) are presented, including discussion on the relative merits of beryllium and aluminium as structural materials. Rotating at a speed of 60 rpm, the application envisaged for the MSM was as a despin bearing for the despun platform or despun antenna of a spin stabilized satellite. The MSM was built and tested to qualification level and is currently undergoing real time life testing.

Hostenkamp, R. G.↗
NASA NTRS1976

Improving aircraft energy efficiency

Investigations conducted by a NASA task force concerning the development of aeronautical fuel-conservation technology are considered. The task force estimated the fuel savings potential, prospects for implementation in the civil air-transport fleet, and the impact of the technology on air-transport fuel use. Propulsion advances are related to existing engines in the fleet, to new production of current engine types, and to new engine designs. Studies aimed at the evolutionary improvement of aerodynamic design and a laminar flow control program are discussed and possibilities concerning the use of composite structural materials are examined.

Povinelli, F. P.↗
NASA NTRS1976

The metallurgy of high temperature alloys

Nickel-base, cobalt-base, and high nickel and chromium iron-base alloys are dissected, and their microstructural and chemical components are assessed with respect to the various functions expected of high temperature structural materials. These functions include the maintenance of mechanical integrity over the strain-rate spectrum from creep resistance through fatigue crack growth resistance, and such alloy stability expectations as microstructural coarsening resistance, phase instability resistance and oxidation and corrosion resistance. Special attention will be given to the perennial conflict and trade-off between strength, ductility and corrosion and oxidation resistance. The newest developments in the constitution of high temperature alloys will also be discussed, including aspects relating to materials conservation.

Tien, J. K.↗
NASA NTRS1978

Computer program for determining mass properties of a rigid structure

A computer program was developed for the rapid computation of the mass properties of complex structural systems. The program uses rigid body analyses and permits differences in structural material throughout the total system. It is based on the premise that complex systems can be adequately described by a combination of basic elemental shapes. Simple geometric data describing size and location of each element and the respective material density or weight of each element were the only required input data. From this minimum input, the program yields system weight, center of gravity, moments of inertia and products of inertia with respect to mutually perpendicular axes through the system center of gravity. The program also yields mass properties of the individual shapes relative to component axes.

Hull, R. A.↗