Search NASA⌕ Search

SEARCH · Search NASA

Results for “Box”

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 19 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1982

High-Density Terminal Box for Testing Wire Harness

Compact terminal box provides access to complex wiring harnesses for testing. Box accommodates more than twice as many wires as previous boxes. Box takes in wires via cable connectors and distributes them to contacts on box face. Instead of separate insulated jacks in metal face panel, box uses pairs of small military-standard metal sockets in precision-drilled plastic panel. Shorting plug provides continuity for wires when not being tested.

Pierce, W. B.↗
NASA NTRS1944

Secondary Stresses in Open Box Beams Subjected to Torsion

In open box beams subjected to torsion, secondary stresses arise owing to lateral bending of the spar caps. The present paper outlines a simple method for estimating the magnitude of these stresses and gives the results of tests of an open box beam in the neighborhood of a discontinuity where the cover changed from the top to the bottom of the box.

BULKHEADS-STRESSES↗
NASA NTRS1948

Shear Lag in a Plywood Sheet-stringer Combination Used for the Chord Member of a Box Beam

Theoretical and experimental investigations were made of the distribution of strains in a plywood sheet-stringer combination used as the chord member of a box beam acted upon by bending loads. The theoretical solution was obtained with the help of the principle of minimum potential energy and certain simplifying assumptions. Strain measurements were made on a build-up box beam by means of electrical-resistance strain gages connected with strain indicators. A very satisfactory agreement between the theoretical and experimental strains was obtained.

LOADS - BEAMS, BOX↗
NASA NTRS1971

CDL description of the CDC 6600 stunt box

The CDC 6600 central memory control (stunt box) is described utilizing CDL (Computer Design Language), block diagrams, and text. The stunt box is a clearing house for all central memory references from the 6600 central and peripheral processors. Since memory requests can be issued simultaneously, the stunt box must be capable of assigning priorities to requests, of labeling requests so that the data will be distributed correctly, and of remembering rejected addresses due to memory conflicts.

Hertzog, J. B.↗
NASA NTRS1971

The vibration of a box-type structure. II - Response to a travelling pressure wave.

A finite element method is formulated for determining the transient response of a box-type structure to a traveling, arbitrarily shaped pressure wave. The method is illustrated by considering an example of practical concern - the sonic boom. The acceleration-time histories of a closed box are compared with those obtained experimentally from a simulated boom. Satisfactory agreement is obtained with only four rectangular elements per individual face and a simplified loading of the box.

Popplewell, N.↗
NASA NTRS1973

Modeling a particular class of multiple-input/multiple-output black boxes with stochastic integral equations and identifying the required parameters

A method is given for obtaining a mathematical model of a class of black boxes having multiple inputs and multiple outputs in terms of Ito stochastic integral equations. This method is applicable to the class of black boxes having ergodic correlation functions when there is zero applied input. The point of view adopted in this paper is phenomenological in that it is desired that calculations made using the mathematical model should be close to what is actually observed at the output of the black box. How close is defined in the problem statement.

Eyman, E. D.↗
NASA NTRS1976

An investigation of drag reduction on box-shaped ground vehicles

A wind tunnel investigation was conducted to determine the reduction in drag which could be obtained by making various configuration changes to a box-shaped ground vehicle. Tests were conducted at yaw (relative wind) angles of 0, 5, 10, 20, and 30 degrees and Reynolds numbers of 300,000 to 850,000. The power required to overcome the aerodynamic drag was reduced by a maximum of 73% for a head wind for the best configuration relative to the smooth bottom box-shape, or 75% relative to the rough bottom box-shape. The reduction for a 20 MPH wind at 30 deg to the vehicle path was, respectively, 77% and 79%.

Muirhead, V. U.↗
NASA NTRS1939

Compressive Tests of a Monocoque Box

A monocoque box specimen of aluminum alloy was subjected to end compression and the strains in the stringers were measured up to loads at which permanent set became noticeable. The stringer strains at low loads agreed closely with those computed from the assumption of uniform stress distribution. Buckling of the 0.026-inch sheet between stringers and of the 0.075-inch shear web took place at stresses in accord with theoretical values. Permanent set became noticeable at a load of 115,200 pounds, corresponding to an average stringer stress of about 16,000 pounds per square inch. The measured average strain above the first buckling load was within 2 percent of the theoretical strain as calculated from the dimensions of the box and effective width formulas due to Marguerre and to Cox.

BOXES, MONOCOQUE - STRENGTH, COMPRESSIVE↗
NASA NTRS1965

Double gloves reduce contamination of dry box atmosphere

Pair of encased low permeability hand gloves between which an inert gas circulates reduces dry box contamination. This innovation is applicable to dry boxes using radioactive and alkali metal compounds, submicron powders, and liquid metals.

Herbell, T. P.↗
NASA NTRS1967

Gas purged dry box glove Patent

Gas purged dry box glove reducing permeation of air or moisture into dry box or isolator by diffusion through glove

Herbell, T. P.↗
NASA NTRS1972

Development and fabrication of a graphite polyimide box beam

The state-of-the-art of graphite/polyimide structures was evaluated and key design and fabrication issues to be considered in future hardware programs are defined. The fabrication and testing at 500 F of a graphite/polyimide center wing box beam using OV-10A aircraft criteria was accomplished. The baseline design of this box was developed in a series of studies of other advanced composite materials: glass/epoxy, boron/epoxy, and boron/polyimide. The use of this basic design permits ready comparison of the performance of graphite/polyimide with these materials. Modifications to the baseline composite design were made only in those areas effected by the change of materials. Processing studies of graphite fiber polyimide resins systems resulted in the selection of a Modmor II/Gemon L material.

Nadler, M. A.↗
NASA NTRS1973

Computer based analyses of the response of box type structures to random pressures.

Analysis of the vibration of the internal structure of a relatively simple flight vehicle structural model consisting of a multicellular box in which two parallel outer face plates (skins) are connected together by several internal plates (ribs) which are parallel to each other and normal to the face plates. Such a box is representative of a wing or stabilizer structure. Three representations of the structure were considered in the computation. The simplest model which can account for the coupling between the face plates and the ribs is a two-dimensional assembly of beams. A more realistic, yet still simple, three-dimensional model has been developed using the Rayleigh-Ritz method. The third computational method employed was the NASTRAN finite-element displacement method. The computational results are compared with experimental data.

Clarkson, B. L.↗
NASA NTRS1973

Flexible bulb large storage box hydrogen maser

The principal limitation on the accuracy of the hydrogen maser as a primary frequency standard has been the irreproducibility of the frequency shift caused by collisions of the radiating atoms with the walls of the vessel containing them. The flexible bulb-large storage box hydrogen maser allows correction for this wall shift within a single device, sidestepping the reproducibility problem, and reducing the frequency error from the wall shift to the level imposed by the device's stability. The principles of the device are discussed including the flexible bulb technique and the complications caused by a multiple region storage bulb. The stability of the device is discussed including a comparison with an ordinary hydrogen maser. Data is presented from a working flexible bulb-large storage box hydrogen maser demonstrating the feasibility of the device and showing some of its operating characteristics. The flexibility of the device is demonstrated by showing how the device's added degrees of freedom allow measurement of parameters unmeasurable in an ordinary hydrogen maser.

Reinhardt, V.↗
NASA NTRS1974

Box for working with lunar samples in nitrogen atmosphere

The design and equipment of a box specially built for working with lunar surface material is described. The box is intended for preliminary investigations, packing of samples, and carrying out a large number of operations necessary for this stage in the study of samples.

Stakheyev, Y. I.↗
NASA NTRS1977

A fourth-order box method for solving the boundary layer equations

A fourth order box method for calculating high accuracy numerical solutions to parabolic, partial differential equations in two variables or ordinary differential equations is presented. The method is the natural extension of the second order Keller Box scheme to fourth order and is demonstrated with application to the incompressible, laminar and turbulent boundary layer equations. Numerical results for high accuracy test cases show the method to be significantly faster than other higher order and second order methods.

Wornom, S. F.↗