32 research outputs found

    STORESIM : an integrated system for multi-body cfd simulations using unstructured, adaptive grids /

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    "This report documents the effort conducted at the Computational Mechanics Company, Inc., Austin, Texas.""62201F-2404-10-B8.""Final Report for Period September 1990-August 1996.""December 1996."Includes bibliographical references (pages 77-78)Print reproduction.Air Force Contract No.Mode of access: Internet

    Horizontal shear testing of woven fiberglass/epoxy composites /

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    In this program horizontal (apparent) shear data from a number of quality control efforts were compiled and augmented by additional tests. The data were used to show the effects of test parameters, cure conditions, and material age on the apparent shear. Failure modes were recorded. Findings include: (1) Based on the horizontal shear test, CE 9000 (Ferro Corp.) should not be postcured above 370 F, and the desirability and effects of a postcure between 350F and 370F should be explored before committing to this postcure condition. (2) Autoclave cure of CE 9000 will increase its resin dominated shear properties 50% or more, compared to vacuum-bag, oven-cured parts. An appreciable drop in apparent shear using the short beam method occurs as S/t6 is increased. Data should be normalized to a consistent S/t for comparison. (3) The predominant damage pattern for woven glass coupons is related to S/t and the degree of cure. (4) Certain woven glass composites require an S/t well below 5 to achieve shear failure. (5) Short beam specimens of the type investigated should be fabricated with peel plies or porous release cloth on both sides.Research supported by the United States Air Force Wright Aeronautical Laboratories."Final Report for Period January 1979 - April 1982.""October 1983."Includes bibliographical references (page 42).In this program horizontal (apparent) shear data from a number of quality control efforts were compiled and augmented by additional tests. The data were used to show the effects of test parameters, cure conditions, and material age on the apparent shear. Failure modes were recorded. Findings include: (1) Based on the horizontal shear test, CE 9000 (Ferro Corp.) should not be postcured above 370 F, and the desirability and effects of a postcure between 350F and 370F should be explored before committing to this postcure condition. (2) Autoclave cure of CE 9000 will increase its resin dominated shear properties 50% or more, compared to vacuum-bag, oven-cured parts. An appreciable drop in apparent shear using the short beam method occurs as S/t6 is increased. Data should be normalized to a consistent S/t for comparison. (3) The predominant damage pattern for woven glass coupons is related to S/t and the degree of cure. (4) Certain woven glass composites require an S/t well below 5 to achieve shear failure. (5) Short beam specimens of the type investigated should be fabricated with peel plies or porous release cloth on both sides.Mode of access: Internet

    Aerodynamic testing in a free-flight spark range /

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    "Final report for the period June 1990-March 1997.""62602F-2502-67-03.""April 1997."Includes bibliographical references.Mode of access: Internet

    FORMAT : Fortran matrix abstraction technique.

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    The FORMAT System has been augmented with highly efficient and reliable procedures for structural analysis via an alternate solution approach which combines the rigorous generation features of the existing force method with a few new equation solving process characteristic of the current displacement methods. As a result, a tenfold increase in potential problem size to in excess of 10000 elastic degrees of freedom is the minimum currently anticipated as attainable on present major digital computers, and the linear behavioral characteristics can take immediate advantage of any advance in hardware capabilities. In making these provisions considerable emphasis was placed on the control of both physical and numerical error throughout the total solution process. To actual aerospace structures with up to 6500 degrees of freedom have been successfully processed as single entities on a production basis, that is, within the confines of a production schedule with maximum reliability at minimum cost.Research supported by the Air Force Flight Dynamics Laboratory, Air Force Systems Command, United States Air Force, and performed by the Douglas Aircraft Company."April 1973."Includes bibliographical references (pages 131-132).The FORMAT System has been augmented with highly efficient and reliable procedures for structural analysis via an alternate solution approach which combines the rigorous generation features of the existing force method with a few new equation solving process characteristic of the current displacement methods. As a result, a tenfold increase in potential problem size to in excess of 10000 elastic degrees of freedom is the minimum currently anticipated as attainable on present major digital computers, and the linear behavioral characteristics can take immediate advantage of any advance in hardware capabilities. In making these provisions considerable emphasis was placed on the control of both physical and numerical error throughout the total solution process. To actual aerospace structures with up to 6500 degrees of freedom have been successfully processed as single entities on a production basis, that is, within the confines of a production schedule with maximum reliability at minimum cost.Air Force Contract No.Mode of access: Internet

    Quantitative feedback theory (QFT) : technique for designing multivariable control systems /

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    "Based upon the technical articles and the unpublished lecture notes of Professor Isaac M. Horowitz and the thesis of AFIT MS students"--Preface."January 1987."Cover title.Includes bibliographical references.Mode of access: Internet

    FORMAT : Fortran matrix abstraction technique.

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    FORMAT (Fortran Matrix Abstraction Technique) is a digital computer program system consisting of three distinct programs written entirely in Fortran IV. The system provides for generation, manipulating, printing, and plotting of large order (i.e., 2000) matrices commonly used in state-of-the-art structural analyses. Phase I of the system automatically generates matrices required in the thermomechanical analysis of structures by the Force or Displacement Methods including those necessary in joining, symmetric/antisymmetric r reaction disconnect, vibration, and stability analyses. Modules for converting continuous-to-discrete loads, and analytic-to-discrete geometry and for maintenance of a master case data file are also provided to minimize input data requirements. Phase II provides an abstraction capability to effect basic matrix algebra via the standard matrix operations (e.g., add, multiply, etc.), and several control operations (e.g., save and print matrices, etc.). The sequence of operations is user designated. Phase III provides for self-explanatory report form printing of matrix data resulting from Force or Displacement Method analyses, and a nominal graphical display capability for matrix and geometry data."Research supported by the Air Force Flight Dynamics Laboratory, Research and Technology Division, Air Force Systems Command, United States Air Force, and performed by the Douglas Aircraft Company, Aircraft Division."AD0683261 (from http://www.dtic.mil)."December 1968."Includes bibliographical references (pages 687-688).FORMAT (Fortran Matrix Abstraction Technique) is a digital computer program system consisting of three distinct programs written entirely in Fortran IV. The system provides for generation, manipulating, printing, and plotting of large order (i.e., 2000) matrices commonly used in state-of-the-art structural analyses. Phase I of the system automatically generates matrices required in the thermomechanical analysis of structures by the Force or Displacement Methods including those necessary in joining, symmetric/antisymmetric r reaction disconnect, vibration, and stability analyses. Modules for converting continuous-to-discrete loads, and analytic-to-discrete geometry and for maintenance of a master case data file are also provided to minimize input data requirements. Phase II provides an abstraction capability to effect basic matrix algebra via the standard matrix operations (e.g., add, multiply, etc.), and several control operations (e.g., save and print matrices, etc.). The sequence of operations is user designated. Phase III provides for self-explanatory report form printing of matrix data resulting from Force or Displacement Method analyses, and a nominal graphical display capability for matrix and geometry data.Air Force Contract No.Mode of access: Internet
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