High-temperature superconducting (HTS) tape and wire are promising for high power density shipboard motor and generator applications. There is a need, however, for improving the performance and stability of these materials in high magnetic fields in order to fully exploit this technology. The Naval Research Laboratory, with our extensive expertise and sophisticated capabilities for microstructural analysis, has been approached by and is working closely with several HTS wire processing groups,...

Topics: DTIC Archive, NAVAL RESEARCH LAB WASHINGTON DC MATERIAL SCIENCE AND TECHNOLOGY DIV, *ELECTRICAL...

The level 12 NASTRAN was used to support the NASA/LaRC advanced transport technology study, a predesign, short response time effort. Aeroelastic analyses were performed. NASTRAN calculated the vibration modes for the supported airfoil components and the entire unsupported vehicle. Other procedures were then used for the aeroelastic analysis, with procedure interfacing accomplished through use of the NASTRAN-produced restart tape. Stiffness matrices were used in static aeroelastic analyses;...

Topics: NASA Technical Reports Server (NTRS), AEROELASTICITY, FLIGHT CONTROL, FLUTTER, VIBRATION MODE,...

The objectives of the hot section technology (HOST) burner liner cyclic rig test program are basically threefold: (1) to assist in developing predictive tools needed to improve design analyses and procedures for the efficient and accurate prediction of burner liner structural response; (2) to calibrate, evaluate and validate these predictive tools by comparing the predicted results with the experimental data generated in the tests; and (3) to evaluate existing as well as advanced temperature...

Topics: NASA Technical Reports Server (NTRS), BURNERS, COMBUSTION CHAMBERS, FATIGUE LIFE, LININGS, METAL...

An overview of the design methodology for designing structural components from fiber composites is presented. In particular, the need for new conceptual structural designs for the future is discussed and the evolution of conceptual design is illustrated. Sources of design data, analysis and design procedures, and the basic components of structural fiber composites are cited and described. Examples of tradeoff studies and optimum designs are discussed and a simple structure is described in some...

Topics: NASA Technical Reports Server (NTRS), COMPOSITE MATERIALS, FIBERS, STRUCTURAL MEMBERS, MECHANICAL...

A computational methodology is described to probabilistically simulate the stress concentration factors (SCF's) in composite laminates. This new approach consists of coupling probabilistic composite mechanics with probabilistic finite element structural analysis. The composite mechanics is used to probabilistically describe all the uncertainties inherent in composite material properties, whereas the finite element is used to probabilistically describe the uncertainties associated with methods...

Topics: NASA Technical Reports Server (NTRS), DISTRIBUTION FUNCTIONS, FINITE ELEMENT METHOD, LAMINATES,...

The use of continuum models for the analysis of discrete built-up complex aerospace structures is an attractive idea especially at the conceptual and preliminary design stages. But the diversity of available continuum models and hard-to-use qualities of these models have prevented them from finding wide applications. In this regard, Artificial Neural Networks (ANN or NN) may have a great potential as these networks are universal approximators that can realize any continuous mapping, and can...

Topics: NASA Technical Reports Server (NTRS), NEURAL NETS, STRUCTURAL ENGINEERING, AEROSPACE ENGINEERING,...

This plan describes the Structural Mathematical Model of the METSAT AMSU-A2 instrument. The model is used to verify the structural adequacy of the AMSU-A2 instrument for the specified loading environments.

Topics: NASA Technical Reports Server (NTRS), MATHEMATICAL MODELS, MICROWAVE SOUNDING, RELIABILITY...

The influence of inelastic material models on computed stress-strain states, and therefore predicted lives, was studied for thermomechanically loaded structures. Nonlinear structural analyses were performed on a fatigue specimen which was subjected to thermal cycling in fluidized beds and on a mechanically load cycled benchmark notch specimen. Four incremental plasticity creep models (isotropic, kinematic, combined isotropic-kinematic, combined plus transient creep) were exercised. Of the...

Topics: NASA Technical Reports Server (NTRS), FATIGUE (MATERIALS), GAS TURBINE ENGINES, MATHEMATICAL...

Four Negro children's (two average and two slow readers) oral reading was taped at eight regular intervals during their second and third year of reading instruction in order to analyze their oral reading miscues and to discover any developmental changes. Retelling of stories read was also taped to measure comprehension. The miscues were analyzed using the Goodman Taxonomy of Reading Miscues. Attention was paid to phenomena of dialect and development on various levels of language. All subjects...

Topics: ERIC Archive, Black Dialects, Error Patterns, Grade 2, Grade 3, Oral Reading, Phonetic Analysis,...

This viewgraph presentation describes residual strength analysis of integral structures fabricated using different manufacturing procedures. The topics include: 1) Built-up and Integral Structures; 2) Development of Prediction Methodology for Integral Structures Fabricated using different Manufacturing Procedures; 3) Testing Facility; 4) Fracture Parameters Definition; 5) Crack Branching in Integral Structures; 6) Results and Discussion; and 7) Concluding Remarks.

Topics: NASA Technical Reports Server (NTRS), MANUFACTURING, RESIDUAL STRENGTH, STRUCTURAL ANALYSIS,...

The results of a 10-month research and development program for nonlinear structural modeling with advanced time-temperature constitutive relationships are presented. The implementation of the theory in the MARC nonlinear finite element code is discussed, and instructions for the computational application of the theory are provided.

Topics: NASA Technical Reports Server (NTRS), CONSTITUTIVE EQUATIONS, CREEP PROPERTIES, GAS TURBINE...

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Topics: Radio Program, Payment systems, Business law, Lie detection, Structural analysis, Tea, Taxation,...

The main features of the theory of line groups, and their irreducible representations are briefly discussed, as well as the most important applications of them. A new approach in the general symmetry analysis of the modulated systems is presented. It is shown, that the line group formalism could be a very effective tool in the examination of the structural phase transitions in High Temperature SUperconductors. As an example, the material YBa2Cu3O(7-x) is discussed briefly.

Topics: NASA Technical Reports Server (NTRS), GROUP THEORY, PHASE TRANSFORMATIONS, STRUCTURAL ANALYSIS,...

The use of prefabricated pultruded carbon-epoxy rods has reduced the manufacturing complexity and costs of stiffened composite panels while increasing the damage tolerance of the panels. However, repairability of these highly efficient discrete stiffeners has been a concern. Design, analysis, and test results are presented in this paper for a bolted-joint repair for the pultruded rod concept that is capable of efficiently transferring axial loads in a hat-section stiffener on the upper skin...

Topics: NASA Technical Reports Server (NTRS), EPOXY MATRIX COMPOSITES, BOLTED JOINTS, AIRCRAFT STRUCTURES,...

Results of a trade study addressing the issues and benefits in using carbon fiber reinforced composites for the Magnetosphere Imager (MI) spacecraft are presented. The MI mission is now part of the Sun/Earth Connection Program. To qualify for this category, new technology and innovative methods to reduce the cost and size have to be considered. Topics addressed cover: (1) what is a composite, including advantages and disadvantages of composites and carbon/graphite fibers; and (2) structural...

Topics: NASA Technical Reports Server (NTRS), CARBON FIBER REINFORCED PLASTICS, COMPOSITE STRUCTURES, SMALL...

Aerospace structural applications demand a weight efficient design to perform in a cost effective manner. This is particularly true for launch vehicle structures, where weight is the dominant design driver. The design process typically requires many iterations to ensure that a satisfactory minimum weight has been obtained. Although metallic structures can be weight efficient, composite structures can provide additional weight savings due to their lower density and additional design flexibility....

Topics: NASA Technical Reports Server (NTRS), STRUCTURAL DESIGN, FIBER COMPOSITES, FINITE ELEMENT METHOD,...

The main proposed tasks of Cooperative Agreement NCC1-382 were: (1) developing MSC/NASTRAN DMAP language scripts to implement the Soize fuzzy structures approach for modeling the dynamics of complex structures; (2) benchmarking the results of the new code to those for a cantilevered beam in the literature; and (3) testing and validating the new code by comparing the fuzzy structures results to NASA Langley experimental and conventional finite element results for two model test structures...

Topics: NASA Technical Reports Server (NTRS), DYNAMIC STRUCTURAL ANALYSIS, COMPUTERIZED SIMULATION, FUZZY...

Reusable space propulsion hot gas-path components are required to operate under severe thermal and mechanical loading conditions. These operating conditions produce elevated temperature and thermal transients which results in significant thermally induced inelastic strains, particularly, in the turbopump turbine blades. An inelastic analysis for this component may therefore be necessary. Anisotropic alloys such as MAR M-247 or PWA-1480 are being considered to meet the safety and durability...

Topics: NASA Technical Reports Server (NTRS), GAS TURBINES, LIFE (DURABILITY), MATHEMATICAL MODELS, SPACE...

An analysis of the MOD-1 2000 kW horizontal axis wind turbine was given. The MOD-1 design was briefly described, and the analysis used to evaluate the dynamic loads and structural interactions is discussed. The resonant frequency placement, the treatment of unsteady wind loading, and the dynamic load sensitivity to frequency shifts were reviewed for the design.

Topics: NASA Technical Reports Server (NTRS), AERODYNAMIC LOADS, DYNAMIC STRUCTURAL ANALYSIS, HORIZONTAL...

Elastic-plastic analytic capabilities were incorporated into the NASTRAN program. The present implementation includes a general rigid format and additional bulk data cards as well as to two new modules. The modules are specialized to include only perfect plasticity of the CTRMEN and CROD elements but can easily be expanded to include other plasticity theories and elements. The practical problem of an elastic-plastic analysis of a ship's bracket connection is demonstrated and compared to an...

Topics: NASA Technical Reports Server (NTRS), ELASTOPLASTICITY, FINITE ELEMENT METHOD, NASTRAN, STRUCTURAL...

Procedures for improving the modal modeling of structures using test data and to determine appropriate analytical models based on substructure experimental data were explored. Two related research topics were considered in modal modeling: using several independently acquired columns of frequency response data, and modal modeling using simultaneous multi-point excitation. In component mode synthesis modeling, the emphasis is on determining the best way to employ complex modes and residuals.

Topics: NASA Technical Reports Server (NTRS), DAMPING, DYNAMIC RESPONSE, EXCITATION, MODAL RESPONSE,...

The NASTRAN TRAPRG and TRAPAX finite elements are very restrictive as to shape and grid point numbering. The elements must be trapezoidal with two sides parallel to the radial axis. In addition, the ordering of the grid points on the element connection card must follow strict rules. The paper describes the generalization of these elements so that these restrictions no longer apply.

Topics: NASA Technical Reports Server (NTRS), COEFFICIENTS, COMPUTER PROGRAMS, FINITE ELEMENT METHOD,...

A Workstation has been designed and constructed for rapidly simulating motions of rigid and elastic multibody systems. We examine the Workstation from the point of view of analysts who use the machine in an industrial setting. Two aspects of the device distinguish it from other simulation programs. First, one uses a series of windows and menus on a computer terminal, together with a keyboard and mouse, to provide a mathematical and geometrical description of the system under consideration. The...

Topics: NASA Technical Reports Server (NTRS), BODY KINEMATICS, COMPUTER ANIMATION, DYNAMIC STRUCTURAL...

An objective of the High Performance Computing and Communication Program at the NASA Langley Research Center is to demonstrate multidisciplinary shape and sizing optimization of a complete aerospace vehicle configuration by using high-fidelity, finite-element structural analysis and computational fluid dynamics aerodynamic analysis. In a previous study, a multi-disciplinary analysis system for a high-speed civil transport was formulated to integrate a set of existing discipline analysis codes,...

Topics: NASA Technical Reports Server (NTRS), AERODYNAMIC CHARACTERISTICS, AEROELASTICITY, AEROSPACE...

Aerospace vehicle structures must be optimized for mass to maximize the mission payload. During the conceptual design phase, structures must be optimized to accurately predict the mass of the design. Analysis methods that are used in sizing members should allow for the selection of a variety of metallic and composite materials and user-defined geometry constraints. Rapid vehicle structural analysis is often necessary to improve the fidelity and the results that are obtained during the...

Topics: NASA Technical Reports Server (NTRS), STRUCTURAL ANALYSIS, AEROSPACE VEHICLES, COMPOSITE MATERIALS,...

While analyzing a rocket engine component, it is often necessary to account for any effects that adjacent fluids (e.g., liquid fuels or oxidizers) might have on the structural dynamics of the component. To better characterize the fully coupled fluid-structure system responses, an analytical approach that models the system as a coupled expansion of rigid wall acoustic modes and in vacuo structural modes has been proposed. The present work seeks to experimentally validate this approach. To...

Topics: NASA Technical Reports Server (NTRS), DYNAMIC STRUCTURAL ANALYSIS, LIQUID FUELS, OXIDIZERS, ROCKET...

Structural-efficiency analyses are used to determine the minimum-mass proportions of some panel configurations loaded in uniaxial compression. Five panel constructions, four of which incorporate circular-arc elements and the other a beaded-web corrugation, are shown to have improved structural efficiencies over conventional configurations. In addition to the structural-efficiency equations, which give the mass equivalent flat-plate thickness of the panel necessary to carry a given load, related...

Topics: NASA Technical Reports Server (NTRS), COMPRESSION LOADS, CURVED PANELS, STRUCTURAL ANALYSIS,...

Scale model tests to determine optimum configuration and characteristics of large jet transport aircraft during ditching

Topics: NASA Technical Reports Server (NTRS), AIRFRAMES, CRASH LANDING, DITCHING (LANDING), SCALE MODELS,...

The equations of motion for large structures with rotating flexible components are derived by regarding the structure as an assemblage of substructures. Based on a stationarity principle for rotating structures, it is shown that each continuous or discrete substructure can be simulated by a suitable set of admissible functions or admissible vectors. This substructure synthesis approach provides a rational basis for truncating the number of degrees of freedom both of each substructure and of the...

Topics: NASA Technical Reports Server (NTRS), DYNAMIC STRUCTURAL ANALYSIS, FLEXIBILITY, ROTATING BODIES,...

A verbatim transcript of the discussion by panel members is presented.

Topics: NASA Technical Reports Server (NTRS), COMPUTER PROGRAMS, CONFERENCES, MAINTENANCE, STANDARDIZATION,...

Results of kinematic analyses of Hurricane Frederick (1979) performed using satellite wind vectors, aircraft measurements and rawinsonde data are presented. The data were gathered, reduced, preliminarily integrated and used to analyze the structure of the storm in the inflow and outflow layers. The mean structure at large radii is in good agreement with composite analyses of tropical cyclones. Changes in the storm structure from 11 to 12 Sep. 1979 suggests that remote sensing techniques may be...

Topics: NASA Technical Reports Server (NTRS), HURRICANES, KINEMATICS, KINETIC ENERGY, REMOTE SENSING,...

This is the second part of a two-part report that describes the AJ10-221, a high performance iridium-coated rhenium (Ir-Re) 110 lbf (490N) welded rocket chamber with 286:1 area ratio nozzle. This engine was designed, built, and hot fired for over 6 hours on this program. It demonstrated an I(s) of 321.8 sec, which is 10 sec higher than conventional 110 lbf silicide coated Cb chambers now in use. The approach used in this portion of the program was to demonstrate the performance improvement that...

Topics: NASA Technical Reports Server (NTRS), COMBUSTION CHAMBERS, COMPUTER AIDED DESIGN, DESIGN ANALYSIS,...

NASTRAN contains two techniques to solve the differential stiffness problems. One is incorporated in a new static analysis rigid format and the other is contained in a new normal modes analysis rigid format. The two techniques relative to computational accuracy and time of execution are compared.

Topics: NASA Technical Reports Server (NTRS), NASTRAN, STIFFNESS MATRIX, STRUCTURAL ANALYSIS, COMPUTER...

Random decrement signatures of structures vibrating in a random environment are studied through use of computer-generated and experimental data. Statistical properties obtained indicate that these signatures are stable in form and scale and hence, should have wide application in one-line failure detection and damping measurement. On-line procedures are described and equations for estimating record-length requirements to obtain signatures of a prescribed precision are given.

Topics: NASA Technical Reports Server (NTRS), RANDOM VIBRATION, STRUCTURAL ANALYSIS, STRUCTURAL VIBRATION,...

From the beginning of the Shuttle Program to its end, integrated loads and dynamics analyses and tests have been critical in shaping the vehicle design and operational decisions for NASA and its customers. Starting with scaled models and simple mathematical simulations of the structural dynamics, engineers defined the required structural stiffness and predicted the limit loads for each element of the system. Early structural tests provided reasonable confidence that the models and predictions...

Topics: NASA Technical Reports Server (NTRS), SPACE SHUTTLES, LOADS (FORCES), DYNAMIC STRUCTURAL ANALYSIS,...

As a basis for this research program, Morrison and Goldberg (1982) presented a model of the memory structure which underlies procedural task performance. The model assumed that memory for a procedure is hierarchically organized around task goals. In the present study, this model was tested by a proximity analysis of soldier's recall. Proximity analysis is based on the assumption that items grouped together in memory tend to cluster together at recall. To perform this analysis, estimates of...

Topics: DTIC Archive, Morrison, John E, ARMY RESEARCH INST FIELD UNIT FORT KNOX KY, *ARMOR, *JOB ANALYSIS,...

This is the result of a study conducted by the Structural Dynamics Division of the Marshall Space Flight Center concerning the combination of low- and high-frequency dynamic loads for spacecraft design. Low-frequency transient loads are combined with high frequency acoustically induced loads to arrive at a limit load, for design purposes. Different methods are used for combining the loads which can lead to considerable variation in limit loads, depending on which NASA Center did the...

Topics: NASA Technical Reports Server (NTRS), TRANSIENT LOADS, RANDOM LOADS, DYNAMIC STRUCTURAL ANALYSIS,...

A finite element hydroelastic analysis formulation is developed on the basis of Toupin's complementary variational principle. Emphasis is placed on the special case of an incompressible fluid model which is applicable to propellant tank hydroelastic analysis. A concise fluid inertia representation results from the assumption of incompressibility and the hydroelastic equations reduce to a simplified form associated with the structure alone. The efficiency of the incompressible hydroelastic...

Topics: NASA Technical Reports Server (NTRS), FINITE ELEMENT METHOD, HYDROELASTICITY, NASTRAN, STRUCTURAL...

The syntactic relationship between the quantifier and the noun phrase (NP) and the function of the quantifier in the sentence are studied. In the first part of the paper, the theories of several linguists concerning the structure of the NP that includes a quantifier are reviewed. In parts 2 and 3 a syntactic description of the quantifier is presented, in which the quantifier is introduced in the deep structure as part of a noun phrase. Examples from French, English, Japanese, Chinese, and Thai...

Topics: ERIC Archive, Deep Structure, Generative Grammar, Grammar, Linguistic Theory, Nouns, Sentence...

The poor quality of most university courses in film history is due to several factors, among them the fact that there is insufficient analytical documentation and direct cinematic illustration in existent written film histories. These histories examine films on a thematic level, offering noncinematic interpretation such as literary meaning, social significance, philosophical connotation, and the historical paraphernalia surrounding films. To partially resolve this problem, serious film research...

Topics: ERIC Archive, Colleges, Content Analysis, Course Content, Film Libraries, Film Study, Films,...

The atomic and electronic structures of several Ca-Mg-TM amorphous alloys (TM is Cu or Zn) have been analyzed using ab initio molecular dynamics simulation and neutron diffraction. Partial pair distribution functions have been produced and the pair bond distances and partial coordination numbers have been reported for these alloys. Similarities and differences in the amorphous structures of the Ca-Mg-Cu and Ca-Mg-Zn alloys have been discussed. Strong interactions between Ca-Cu, Mg-Cu and Ca-Zn...

Topics: DTIC Archive, UES INC DAYTON OH, *METALLIC GLASS, *MOLECULAR DYNAMICS, ALLOYS, AMORPHOUS MATERIALS,...

In the past, models of deployable structures were limited largely to small scale models which could be readily deployed by suspending the model on several soft shock cords. The scale of the deployable truss used in the present investigation precluded the use of this test technique as the gravity forces and moments are of the same order of magnitude as the deployment forces and moments. For these tests, the truss was deployed during free-fall in the LaRC 55' vacuum facility. Appreciably larger...

Topics: NASA Technical Reports Server (NTRS), DEPLOYMENT, FREE FALL, LARGE SPACE STRUCTURES, TRUSSES,...

Teachers need to be proficient in the application of word analysis skills in order to insure their ability to provide adequate instruction to others. This study reports on the development of a word analysis test which evaluates potential teachers' ability to apply nine structural analysis generalizations before and after instruction in word analysis. The tests were administered to 83 students enrolled in teacher education courses in basic reading skills before instruction in syllabication was...

Topics: ERIC Archive, Diagnostic Teaching, Postsecondary Education, Reading Instruction, Reading Research,...

Micro air vehicles (MAVs) are intended for future intelligence, surveillance, and reconnaissance use. To adequately fulfill a clandestine capacity, MAVs must operate in close proximity to their intended target without eliciting counter-observation. This objective, along with DARPA's constraint of a sub-15 centimeter span, requires future MAVs to mimic insect appearance and flight characteristics. This thesis describes an experimental method for conducting a structural analysis of a Manduca...

Topics: DTIC Archive, AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH GRADUATE SCHOOL OF ENGINEERING AND...

LANGUAGE PROGRAMS FOR THE MENTALLY RETARDED ARE SUGGESTED FOR FIVE LEVELS FROM PREPRIMARY TO SENIOR HIGH. THE RECEPTIVE AND EXPRESSIVE LANGUAGE SKILLS ARE IDENTIFIED AND APPROPRIATE ACTIVITIES ARE SUGGESTED. IN AN ANNOTATED SECTION, 75 SOURCE MATERIALS ARE CLASSIFIED ACCORDING TO RECEPTIVE OR EXPRESSIVE SKILL AND BY AGE LEVEL. (MR)

Topics: ERIC Archive, Curriculum Guides, Instructional Materials, Language Instruction, Language Skills,...

The results of a study to define criteria and techniques of design, analysis and test which permit the use of a single major structural test article for performing dynamic, fatigue, and static testing are presented. The criteria developed is applicable to both space vehicles and aircraft structures operating in the subsonic or supersonic regime. The feasibility of such an approach was demonstrated by defining test interactions, compatibilities and incompatibilities between the three different...

Topics: NASA Technical Reports Server (NTRS), DYNAMIC STRUCTURAL ANALYSIS, FATIGUE TESTS, MATERIALS TESTS,...

Eight alternative modeling techniques to specify prescribed temperature at grid or scalar points for transient thermal analyses are presented. Four cases are for constant temperatures, and the others are time varying temperature functions. Theoretical explications and detailed listing of input data cards used for illustrating different modelings are given. It is shown that the NTA is exploited to extend beyond its normal capabilities through innovative modeling techniques. In addition, the...

Topics: NASA Technical Reports Server (NTRS), FINITE ELEMENT METHOD, NASTRAN, PREDICTION ANALYSIS...

A general summary of the MOD-1 wind turbine generator control system and simulation is presented. Mechanical and speed stabilization control means to add drive train damping were mentioned and MOD-1 simulation results showing the effects of speed stabilization are displayed.

Topics: NASA Technical Reports Server (NTRS), CONTROL SIMULATION, DYNAMIC STRUCTURAL ANALYSIS, PERFORMANCE...

The Objectives, Expected Results, Approach, and Fiscal Year FY 1984 Milestones for the Structures and Dynamics Division's research programs are examined. The FY 1983 Accomplishments are presented where applicable.

Topics: NASA Technical Reports Server (NTRS), AIRCRAFT SAFETY, COMPUTER AIDED DESIGN, CRASHWORTHINESS,...

The results of the Large Space Systems Technology special emphasis task are presented. The task was an analysis of structural requirements deriving from the initial Phase A Operational Geostationary Platform study.

Topics: NASA Technical Reports Server (NTRS), DYNAMIC LOADS, LARGE SPACE STRUCTURES, SPACE PLATFORMS,...