Browsing by Author "Anderson, Henriette"

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    An expert system for the design of single-storey steel portal frames using the plastic design method
    (Stellenbosch : Stellenbosch University, 1994) Anderson, Henriette; Dunaiski, P. E.; Stellenbosch University. Faculty of Engineering. Department of Civil Engineering.
    ENGLISH ABSTRACT: The purpose of this study project is to develop an expert system, PFEXPERT, for the design of single-storey steel portal frames with the plastic design method according to the SABS 0162-1:1993. The development tool LEVEL5/OBJECT, an expert system shell, was selected for the development of PFEXPERT. PFEXPERT consists of two basic parts, an inference engine and a knowledge base. The inference engine, (reasoning mechanism), searches through the knowledge base looking for answers and solutions. The knowledge is expressed in the form of rules and explanatory text in the knowledge base. A menu-driven user interface, that consists of different screens which allow the user to interact with the knowledge base, has been developed and is supplemented by warning messages, explanations and recommendations. The knowledge base cf PFEXPERT consists of an input phase, an analysis phase and a design phase. The input phase requires structural data, material section properties and load-case data. PFEXPERT interfaces with a steel section properties data base file for the selection of properties. The analysis phase consists of the elastic analysis and the plastic analysis of the structure for different load-case combinations. The elastic analysis is done on the structure subjected to nominal loads. The plastic analysis is done on the structure subjected to factored loads. PFEXPERT interfaces with an analysis program or these analyses. In the design phase, PFEXPERT checks all SABS 0162-1:1993 code requirements for serviceability and ultimate limit state design. The expert system, PFEXPERT, is a useful tool for the design engineer for the plastic design of portal frames because it can be maintained and updated to reflect any future code revisions without too much difficulty.