Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “Matrix”

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 1,153 records · Page 64
All sourcesNASA NTRSDOE OSTI
NASA NTRS1971

Evaluation of metal matrix composites

The results of an evaluation of candidate metal-matrix composite materials for shuttle space radiators mounted to external structure are presented. The evaluation was specifically applicable to considerations of the manufacturing and properties of a potential space radiator. Two candidates, boron/aluminum and graphite/aluminum were obtained or made in various forms and tested in sufficient depth to allow selection of one of the two for future scale-up programs. The effort accomplished on this program verified that aluminum reinforced with boron was within the state-of-the-art in industry and possessed properties usable in the external skin areas available for shuttle radiators where re-entry temperatures will not exceed 800 F. It further demonstrated that graphite/aluminum has an apparently attractive future for space applications but requires extension development prior to scale-up.

Okelly, K. P.↗
NASA NTRS1972

The BANDIT computer program for the reduction of matrix bandwidth for NASTRAN

A computer program, BANDIT, is described which was developed for use as a preprocessor to NASTRAN to automatically resequence the grid point numbers for reduced matrix bandwidth. The BANDIT program accepts a standard NASTRAN data deck as input, resequences the grid point numbers for reduced bandwidth, and generates a set of SEQGP cards for insertion into the NASTRAN bulk data deck. BANDIT uses the Cuthill-McKee strategy for resequencing grid points. The program is operational on the CDC 6000 series of computers, the IBM 360, and the Univac 1108.

Everstine, G. C.↗
NASA NTRS1971

Jones's matrix representation of optical instruments. II - Fourier interferometers /spectrometers and spectropolarimeters/.

Our method of matrix synthesis of optical components and instruments is applied to the derivation of Jones's matrices appropriate for Fourier interferometers (spectrometers and spectropolarimeters). These matrices are obtained for both the source beam and the detector beam. In the course of synthesis, Jones's matrices of the various reflectors (plane mirrors; retroreflectors: roofed mirror, trihedral and prism cube corner, cat's eye) used by these interferometers are also obtained.

Fymat, A. L.↗
NASA NTRS1972

A numerical algorithm suggested by problems of transport in periodic media - The matrix case.

Extension of Allen and Wing's (1970) previous work on problems of transport in periodic media to the matrix case. A method in the form of a complete set of equations is presented that may be used without any further analytical work by investigators interested in computing solutions to problems of the type the method is designed to handle. All the formulas have been checked out numerically, and their effectiveness is demonstrated by numerical examples.

Allen, R. C., Jr.↗
NASA NTRS1972

Study of X-ray diffraction on aging alloys with different degrees of volume discrepancy between the precipitation phase and the matrix

Study of the diffraction patterns of X rays diffracted by dispersion-hardened alloys with various degrees of difference between the specific atomic volumes of their precipitation phases and matrices. Experiments were performed on aging alloys KhN77TIuR (nimonic) and KhN67VMTIuO, which have the same types of gamma solid solutions and precipitating gamma prime phases, but differ considerably with respect to the volume factor. It is found that in the decay of supersaturated solid solutions for which the difference between the specific atomic volumes of the precipitation phase and the matrix is small (alloy KhN67VMTIuO) the nature of the intensity distribution of the diffraction lines remains practically unchanged regardless of the aging, while in cases where the volume discrepancy is large (alloy KhN77TIuR) significant changes in the appearance of the diffraction lines are recorded.-

Gitgarts, M. I.↗
NASA NTRS1972

Fracture of boron filaments in an aluminum matrix.

The B-Al composite specimens tested in this study were fabricated by diffusion bonding of 1230 aluminum foil and boron filaments placed in alternate layers, using an acrylic resin solution to maintain filament spacing. The specimens were put under tensile stresses parallel to the filaments, and filament fracture was monitored acoustically under loads. Fracture of specimens under loads was caused by break propagation with a characteristic wedge-type fragmentation pattern indicating its direction. The aluminum foil matrix of the specimens failed by ductile shear type fracture after the break of the filaments.

Steele, J. H.↗
NASA NTRS1973

Fiber composite materials: A survey of fiber matrix interface mechanics

Report is described which discusses mechanism of load transfer from matrix to fiber through interface and effects of interface on composite structural integrity. Theoretical considerations are supplemented with experimental data. General trends and significant points are illustrated graphically.

Chamis, C. C.↗
NASA NTRS1972

The location of the poles of the scattering matrix

A number of recent results bearing on the direct problem are described. The results deal with exterior problems and relate geometric properties of the scattering obstacles to analytic properties of the associated scattering matrix.

Lax, P. D.↗