Showing papers on "Design tool published in 1977"

Automated logical data base design: concepts and applications

Abstract: This paper describes the design effort for an integrated data base and then develops techniques for automating significant portions of the labor. These techniques have been incorporated in a program to provide an effective data base design tool (Data Base Design Aid) in current use. The processes involved with this aid are discussed.

The application of simplified, fundamental design procedures for flexible pavements

Abstract: Prior to acceptance in practice of complete analytically based pavement design procedures, engineers have to be introduced to the basic concepts involved and this can best be achieved by use of a simplified approach. The Simplified Design Method has been successfully used for such educational purposes and is described in detail. It makes use of charts and equations but has also been programmed onto a computer of modest size. The Analytical Design Method is a more versatile, but still somewhat approximate, design tool in the form of a computer program. The immediate use which can be made of a design package of this kind is demonstrated by investigating the effects of mix variables on layer thickness. /Author/

Conceptual design of single turbofan engine powered light aircraft

Abstract: The conceptual design of a four place single turbofan engine powered light aircraft was accomplished utilizing contemporary light aircraft conventional design techniques as a means of evaluating the NASA-Ames General Aviation Synthesis Program (GASP) as a preliminary design tool. In certain areas, disagreement or exclusion were found to exist between the results of the conventional design and GASP processes. Detail discussion of these points along with the associated contemporary design methodology are presented.

Analysis of an operational rigid-pavement system for continuously reinforced concrete pavements

Abstract: A diagnostic study of four, in-service, continuously reinforced concrete pavements in Texas was prepared by using computerized performance models in the rigid-pavement design system. The performance models were developed by the American Association of State Highway Officials, and the rigid-pavement design system was developed by the Center for Highways Research of the University of Texas at Austin, the Texas Transportation Institute at Texas A&M University, and the Texas State Department of Highways and Public Transportation. The study shows that use of performance models in the rigid-pavement design system reliably predicts the change in serviceability for continuously reinforced concrete pavements. Data gathered and used for the diagnostic study show that the number of 8165-kg (18-kip) equivalent axle loads had a great influence on the condition of the pavements and the predictions made by the design program. The results indicate that not only does the design program reliably predict service life, but that the designs produced by the program, in light of the performance of the four pavement sections, are reasonable for these in-service sections. Information is also presented that begins to establish the correct level of confidence that should be used in the design of Interstate-type continuously reinforced concrete pavements. The conclusions include the belief that the capabilities of the program as a design further studied so that the ultimate goal of program implementation can be achieved. Future modification of the system should include a simplification of program input by deleting those variables that are insensitive to the design. Thus, the program can be used as a design tool because of its economic capability that allows for ranking various designs based on the costs of construction, traffic delay, maintenance, and overlay strategies. /Author/