Practical analysis for PR frame design

In conventional frame analysis, the behavior of beam-to-column connections are assumed to have either pinned or rigid joints. For simplicity, AISC/ASD methods of analysis assume pinned connections under gravity loads, as rigid joints under wind loading. In recent years, extensive theoretical and experimental work has produced accurate connection models and good design methods. In general, however, these methods are complex and their application is cumbersome. Thus, practical design of semi-rigid frames (Type PR Construction as specified in the AISC-LRFD Specification, 1994) is seldom made use of in engineering practice, even though it can offer a more realistic and rational design approach. The aim of the work described in this thesis is to provide a practical method for the design of Type PR construction used in the design office using popular structural software. A set of useful design tables is provided based on the AISC/LRFD Specification for the selection of top- and seat-angle with double web-angle connections for given beam sections and applied loads. Three computer programs are developed for PR frame design using C++. The design tables enable the engineer to rapidly select proper angle sizes and configurations as well as to determine its moment-rotation curve. The three-parameter power model is used here to represent the moment-rotation relationship of these connections. To this end, extensive studies have been made to confirm the suitability of the semi-rigid connection model proposed by Richard (1961) and of the design method presented by Barakat (1989). The connection model and design method have been further developed and refined to achieve both simplicity of use and, as far as possible, a realistic representation of actual behavior. Herein, detailed design procedures are provided and two comprehensive case studies are carried out and compared with results based on second-order refined plastic hinge analysis. The later provides the final confirmation of the validity of the proposed method. Since the proposed method is practical, it is recommended for general design office use