Optimal girder bridge study via CASE: Computer-Augmented Structural Engineering methodology
Abstract
Fabrication of steel member sections from plate components is becoming much more economical than at any time previously. This dissertation presents the development of a design methodology that includes the structural synthesis process as an integrated component of a Computer-Aided Design and Draft (CADD) system for girder bridge design. The sythesis is based upon minimum cost of the superstructure using unit price values. The constraints are imposed according to the American Association of State Highway and Transportation Officials (AASHTO) specifications with the option of using either the Working Stress Design method or Load Factor Design method. Both the concrete roadway deck and steel girders are considered in the synthesis process. The process allows the steel girders to be fabricated with either stiffened or unstiffened webs, but restricts the synthesis to evaluation of a single depth girder throughout the bridge superstructure. The effect of utilizing fabricated girder sections composed of various plate thicknesses, widths, and depths causes a variation in section properties throughout the girder. This nonprismatic member effect is included in the analysis and synthesis processes. The nonprismatic element stiffness matrices are derived based upon a classical formulation and employing numeric guadrature techniques. An extremely efficient analytical approach has been developed to perform the complex analysis which results from the traversing vehicle loading. This CADD methodology has been developed so as to allow extension into a Computer-Aided Manufacturing (CAM) environment. The key factor in the ability to extend this methodology to encompass CAM is based upon the use of fabricated components. This unique formulation, exclusive to CASE, is possible due to the relational database architecture developed for the CASE methodology. The database holds specifically that information required by the fabricator to order material for the manufacturing process, schedule plant operations, operate numeric control machinery, and control shipping and inventory.
Degree
Ph.D.
Advisors
Yener, Purdue University.
Subject Area
Civil engineering
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