A MICROCAD system for design of steel connections—I. Program structure and graphic algorithms

Abstract

A microcomputer-aided design (MICROCAD) system is presented for interactive design of connections in steel buildings made of standard rolled I-sections. Design of different types of connections is based on the American Institute of Steel Construction Specification. Connecting elements may be plates, angles, or T-sections. Connectors may be bolts or welds. The MICROCAD system can display/plot any isometric view of the connection plus three orthographic views, i.e. front, side, and top views. Program structure, face frame representation, and graphic algorithms are presented. An efficient priority list algorithm with back-face elimination is developed for the orthographic views. The painter's algorithm is used to remove hidden lines. A five-test algorithm is developed for efficient drawing of the isometric views. Application of the MICROCAD system for practical design of steel connections is presented in an accompanying paper.