Search NASA⌕ Search

SEARCH · Search NASA

Results for “attachment”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 289 records · Page 16
All sourcesNASA NTRSDOE OSTI
NASA NTRS1980

Design, fabrication and test of graphite/polyimide composite joints and attachments for advanced aerospace vehicles

Bonded and bolted designs are presented for each of four major attachment types. Prepreg processing problems are discussed and quality control data are given for lots 2W4604, 2W4632 and 2W4643. Preliminary design allowables test results for tension tests and compression tests of laminates are included. The final small specimen test matrix is defined and the configuration of symmetric step-lap joint specimens are shown. Finite element modeling studies of a double lap joint were performed to evaluate the number of elements required through the adhesive thickness to assess effects of various joint parameters on stress distributions. Results of finite element analyses assessing the effect of an adhesive fillet on the stress distribution in a double lap joint are examined.

Skoumal, D. E.↗
NASA NTRS1982

Lathe Attachment Finishes Inner Surface of Tubes

Extremely smooth finishes are machined on inside surfaces of tubes by new attachment for a lathe. The relatively inexpensive accessory, called a "microhone," holds a honing stone against workpiece by rigid tangs instead of springs as in conventional honing tools. Inner rod permits adjustment of microhoning stone, while outer tube supports assembly. Outer tube is held between split blocks on lathe toolpost. Microhoning can be done with either microhone or workpiece moving and other member stationary.

Lancki, A. J.↗
NASA NTRS1980

Design, fabrication and test of graphite/polyimide composite joints and attachments for advanced aerospace vehicles

Principal program activities dealt with the literature survey, design of joint concepts, assessment of GR/PI material quality, fabrication of test panels and specimens, and small specimen testing. Bonded and bolted designs are presented for each of the four major attachment types. Quality control data are presented for prepreg Lots 2W4651 and 3W2020. Preliminary design allowables test results for tension tests and compression tests of laminates are also presented.

Source record↗
NASA NTRS1980

Design, fabrication and test of graphite/polyimide composite joints and attachments for advanced aerospace vehicles

Results of an experimental program to develop several types of graphite/polyimide (GR/PI) bonded and bolted joints for lightly loaded flight components for advanced space transportation systems and high speed aircraft are presented. Tasks accomplished include: a literature survey; design of static discriminator specimens; design allowables testing; fabrication of test panels and specimens; small specimen testing; and standard joint testing. Detail designs of static discriminator specimens for each of the four major attachment types are presented. Test results are given for the following: (1) transverse tension of Celion 3000/PMR-15 laminate; (2) net tension of a laminate for both a loaded and unloaded bolt hole; (3) comparative testing of bonded and co-cured doublers along with pull-off tests of single and double bonded angles; (4) single lap shear tests, transverse tension and coefficient of thermal expansion tests of A7F (LARC-13 amide-imide modified) adhesive; and (5) tension tests of standard single lap, double lap, and symmetric step lap bonded joints. Also, included are results of a finite element analysis of a single lap bonded composite joint.

Barclay, D. L.↗
NASA NTRS1981

Design, Fabrication and Test of Graphite/Polyimide Composite Joints and Attachments for Advanced Aerospace Vehicles

Standard and advanced bonded joint concepts were evaluated to develop a data base for the design and analysis of advanced composite joints for use at elevated temperatures (561K (550F)). Design concepts for specific joint applications and the fundamental parameters controlling the static strength characteristics of such joints were identified. Test results are presented for rail shear and sandwich beam compression tests and tension tests of moisture conditioned specimens and bonded on "T" sections. Coefficients of thermal expansion data are presented for A7F (LARC 13 Amide-imide modified) adhesion. Static discriminator test results for type 1 and type 2 bonded and bolted preliminary attachment concepts are presented and discussed.

Cushman, J. B.↗
NASA NTRS1981

Design, fabrication and test of graphite/polyimide composite joints and attachments for advanced aerospace vehicles

The development of several types of graphite/polyimide (GR/PI) bonded and bolted joints is reported. The program consists of two concurrent tasks: (1) design and test of specific built up attachments; and (2) evaluation of standard advanced bonded joint concepts. A data base for the design and analysis of advanced composite joints for use at elevated temperatures (561K (550 deg F)) to design concepts for specific joining applications, and the fundamental parameters controlling the static strength characteristics of such joints are evaluated. Data for design and build GR/PI of lightly loaded flight components for advanced space transportation systems and high speed aircraft are presented. Results for compression and interlaminar shear strengths of Celion 6000/PMR-15 laminates are given. Static discriminator test results for type 3 and type 4 bonded and bolted joints and final joint designs for TASK 1.4 scale up fabrication and testing are presented.

Source record↗
NASA NTRS1982

On the instability of shock waves attached to wedges and cones

A numerical study is made of the stability of weak and strong shocks attached to wedges and cones. The stability is shown to depend on the boundary conditions imposed, in good agreement with the experimental observations and the principle of minimum entropy. The behavior of the solutions is explained by quasi-static considerations.

Salas, M. D.↗
NASA NTRS1982

Mission analysis techniques for attached Shuttle payloads

Visibility times, i.e., times which desired targets are visible to a payload, are examined for attached Shuttle payloads. These times are affected by a number of constraints. Some constraints are examined along with mathematical or computer modeling techniques used to determine their effects. The constraints include: occultation of the earth, moon, and sun, and limb avoidance angles of each; orbit parameters such as inclination and ascending node, along with sensitivity to changes in each; TDRSS acquisition; South Atlantic Anomaly (SAA) avoidance, nighttime viewing only; bright earth avoidance angles; the field of view; Shuttle attitude, and Orbiter operational constraints. All of this information is integrated and, with computer programs, a schedule of observations and Shuttle attitudes is obtained.

Lambros, S.↗
NASA NTRS1984

Attaching Strain Gages to Composite Materials

Polyurethane adhesive bonds strain gages reliably to graphite/epoxy composites. Adhesive easy to apply, used over wide temperature range (ambient to cryogenic), and applied in short time. Tests on gages bonded to composite with adhesive demonstrated reliability of attachment.

Penn, B.↗
NASA NTRS1982

Edge attachment study for fire-resistant canopies

Twenty-two resin systems were evaluated in laminate form for possible use as edge attachment material for fire-resistant canopies. The evaluation uncovered an unexpected development when the laminates were subjected to an intense flame: (1) the high-heat-resistant materials could withstand the flame test quite well, but experienced rapid heat transfer through the test specimen; (2) the laminates which exhibited a low rate of heat transfer were materials which lost strength rapidly in the presence of the flame by decomposition, delamination, and blistering.

Wintermute, G. E.↗
NASA NTRS1983

A supersonic maneuver wing designed for nonlinear attached flow

A wing designed using the concept of attached supercritical crossflow for supersonic maneuvering aircraft wings has been built and tested. The detailed wing shape was determined using nonlinear potential flow computational aerodynamics methods to obtain a specified target pressure distribution. The test results showed that the target pressures were essentially obtained and that the drag-due-to-lift values at maneuver lift coefficients were considerably less than those expected using linear theory design procedures. The paper provides a detailed description of the wing design and test, and an analysis of the results.

Mason, W. H.↗
NASA NTRS1982

Calculation of SF6-/SF6 and Cl-/CFCl3 electron attachment cross sections in the energy range 0-100 meV

Electron attachment cross sections for the processes SF6-/SF6 and Cl-/CFCl3 are calculated in a local theory using a model in which diatomic-like potential energy curves for the normal modes are constructed from available spectroscopic data. Thermally populated vibrational and rotational levels are included. Good agreement is found with experimental cross sections in the energy range 5-100 meV for a particular choice of potential energy curve parameters.

Chutjian, A.↗
NASA NTRS1983

Iterative PNS method for attached flows with upstream influence

A stable global-iteration procedure is developed by utilizing successive sweeps, from inflow to outflow boundaries, of a parabolized Navier-Stokes code for attached, steady supersonic flow. It is shown that the procedure converges in about ten or fewer iterations, and allows for the upstream influence within the subsonic region of a supersonic boundary layer. An implicit forward difference is employed in the subsonic region to evaluate the pressure-gradient term in the streamwise momentum equation. The pressure-gradient term is normally approximated in standard single-sweep parabolized methods, suppressing the upstream influence. The iterative results obtained demonstrate the validity of the single-sweep method for weak interactions. For hypersonic viscous interaction on a flat plate at a Mach number of 5.8, it is found that the single-sweep method has a small error that vanishes as the Reynolds number of the flow is increased. However, the skin friction has an error of about 10 percent for low Reynolds numbers and for hot wall conditions. The application of this method to laminar two-dimensional flow over weak expansion and compression corners shows that the pressure and skin friction results in the vicinity of the expansion corner compare favorably with a time-dependent Navier-Stokes numerical solution.

Rakich, J. V.↗
NASA NTRS1985

Electron-Attachment Profiles

Report available that describes technique of photoelectron spectroscopy to measure shapes of threshold electron-attachment cross sections of various gases.

Chutjian, A.↗
NASA NTRS1983

A Definition of STS Accommodations for Attached Payloads

An input to a study conducted to define a set of carrier avionics for supporting large structures experiments attached to the Space Shuttle Orbiter is reported. The "baseline" Orbier interface used in developing the avionics concept for the Space Technology Experiments Platform, STEP, which Langley Research Center has proposed for supporting experiments of this sort is defined. Primarily, flight operations capabilities and considerations and the avionics systems capabilities that are available to a payload as a "mixed cargo" user of the Space Transportation System are addressed. Ground operations for payload integration at Kennedy Space Center, and ground operations for payload support during the mission are also discussed.

Echols, F. L.↗
NASA NTRS1983

Supersonic loads due to shuttle-orbiter/external-tank attachment structures

A large variety of tests were conducted during development of the Space Shuttle to determine the strength, fatigue, and thermal characteristics of the thermal-protection system of the orbiter. The research and analysis carried out to accurately define and simulate the flow characteristics immediately ahead of the external tank attachment structures are described. The highest known acoustic pressure loads occur in these regions and tests to insure the ability of the titles to withstand these acoustic loads, plus those due to pressure gradient, were thought necessary. First flight-critical wind tunnel tests were therefore conducted in the Langley 8-Foot Transonic Pressure Tunnel (8-Ft. TPT), which simulated the time histories of Shuttle ascent loads on tile arrays bonded to structures which accurately duplicated those of the Shuttle. The time-varying free stream conditions were provided by controlling the deflection angle history of diffuser spoiler flaps in an automated way. Time histories of the critical load parameters imposed on the tile arrays in the tunnel are compared with those expected in flight.

Edwards, C. L. W.↗
NASA NTRS1983

An Attached Payload Operations Center (APOC) at the Goddard Space Flight Center (GSFC), volume 1

A management overview of the Attached Payload Operations Center (APOC) functional requirements and design are presented. The rationale for developing the APOC concept and the assumptions utilized are presented. A summary of the concept complete with major functional areas and associated data flows is provided. The attributes of this concept are formalized and the necessary resources needed for its development and operation presented.

Source record↗