383 research outputs found

    Computer-Aided Process Organization In Software Deslgn

    Get PDF
    As the complexity of systems increase, the need for computer-aided techniques in software system definition, design, ·and construction becomes apparent. It is the ultimate task of software engineering to develop tools and procedures which reduce the effort invol ved in production of effective software. Effective software must possess characteristics of correctness, reliability, efficiency, documentation, and flexibility. This paper deals with the devel opment of a computer-aid for one portion of the software system design probl em, namely, the determination of process organization in program modul e specification

    Product specification documentation standard and Data Item Descriptions (DID). Volume of the information system life-cycle and documentation standards, volume 3

    Get PDF
    This is the third of five volumes on Information System Life-Cycle and Documentation Standards which present a well organized, easily used standard for providing technical information needed for developing information systems, components, and related processes. This volume states the Software Management and Assurance Program documentation standard for a product specification document and for data item descriptions. The framework can be applied to any NASA information system, software, hardware, operational procedures components, and related processes

    Development of Integrated Programs for Aerospace-vehicle Design (IPAD): Product manufacture interactions with the design process

    Get PDF
    The product manufacturing interactions with the design process and the IPAD requirements to support the interactions are described. The data requirements supplied to manufacturing by design are identified and quantified. Trends in computer-aided manufacturing are discussed and the manufacturing process of the 1980's is anticipated

    Grid sensitivity capability for large scale structures

    Get PDF
    The considerations and the resultant approach used to implement design sensitivity capability for grids into a large scale, general purpose finite element system (MSC/NASTRAN) are presented. The design variables are grid perturbations with a rather general linking capability. Moreover, shape and sizing variables may be linked together. The design is general enough to facilitate geometric modeling techniques for generating design variable linking schemes in an easy and straightforward manner. Test cases have been run and validated by comparison with the overall finite difference method. The linking of a design sensitivity capability for shape variables in MSC/NASTRAN with an optimizer would give designers a powerful, automated tool to carry out practical optimization design of real life, complicated structures

    Evaluation of computer aided software as a space analysis tool for outfit unit design and planning

    Full text link
    http://deepblue.lib.umich.edu/bitstream/2027.42/1123/2/89009.0001.001.pd

    Feasibility study of an Integrated Program for Aerospace vehicle Design (IPAD). Volume 1B: Concise review

    Get PDF
    Reports on the design process, support of the design process, IPAD System design catalog of IPAD technical program elements, IPAD System development and operation, and IPAD benefits and impact are concisely reviewed. The approach used to define the design is described. Major activities performed during the product development cycle are identified. The computer system requirements necessary to support the design process are given as computational requirements of the host system, technical program elements and system features. The IPAD computer system design is presented as concepts, a functional description and an organizational diagram of its major components. The cost and schedules and a three phase plan for IPAD implementation are presented. The benefits and impact of IPAD technology are discussed

    Recent developments in structural sensitivity analysis

    Get PDF
    Recent developments are reviewed in two major areas of structural sensitivity analysis: sensitivity of static and transient response; and sensitivity of vibration and buckling eigenproblems. Recent developments from the standpoint of computational cost, accuracy, and ease of implementation are presented. In the area of static response, current interest is focused on sensitivity to shape variation and sensitivity of nonlinear response. Two general approaches are used for computing sensitivities: differentiation of the continuum equations followed by discretization, and the reverse approach of discretization followed by differentiation. It is shown that the choice of methods has important accuracy and implementation implications. In the area of eigenproblem sensitivity, there is a great deal of interest and significant progress in sensitivity of problems with repeated eigenvalues. In addition to reviewing recent contributions in this area, the paper raises the issue of differentiability and continuity associated with the occurrence of repeated eigenvalues

    Large scale prop-fan structural design study. Volume 1: Initial concepts

    Get PDF
    In recent years, considerable attention has been directed toward improving aircraft fuel consumption. Studies have shown that the inherent efficiency advantage that turboprop propulsion systems have demonstrated at lower cruise speeds may now be extended to the higher speeds of today's turbofan and turbojet-powered aircraft. To achieve this goal, new propeller designs will require features such as thin, high speed airfoils and aerodynamic sweep, features currently found only in wing designs for high speed aircraft. This is Volume 1 of a 2 volume study to establish structural concepts for such advanced propeller blades, to define their structural properties, to identify any new design, analysis, or fabrication techniques which were required, and to determine the structural tradeoffs involved with several blade shapes selected primarily on the basis of aero/acoustic design considerations. The feasibility of fabricating and testing dynamically scaled models of these blades for aeroelastic testing was also established. The preliminary design of a blade suitable for flight use in a testbed advanced turboprop was conducted and is described in Volume 2

    1992-1993 Louisiana Tech University Catalog

    Get PDF
    The Louisiana Tech University Catalog includes announcements and course descriptions for courses offered at Louisiana Tech University for the academic year of 1992-1993.https://digitalcommons.latech.edu/university-catalogs/1022/thumbnail.jp

    OEXP Analysis Tools Workshop

    Get PDF
    This publication summarizes the software needs and available analysis tools presented at the OEXP Analysis Tools Workshop held at the NASA Langley Research Center, Hampton, Virginia on June 21 to 22, 1988. The objective of the workshop was to identify available spacecraft system (and subsystem) analysis and engineering design tools, and mission planning and analysis software that could be used for various NASA Office of Exploration (code Z) studies, specifically lunar and Mars missions
    • …
    corecore