Microcomputer‐Aided Optimal Plastic Design of Frames

Abstract

Using the kinematic approach with automatic generation of independent mechanisms, an efficient procedure and an interactive microcomputer BASIC program have been developed for optimal plastic design of low‐rise frames of general configuration. This procedure has been compared with a previous algorithm for optimal plastic design of frames based on the static approach without generating the independent mechanisms. It is concluded that the kinematic approach with automatic generation of mechanisms is more efficient than the static approach without generating the mechanisms. In order to display/plot the failure mechanism by microcomputer, an efficient scheme has been developed for calculating the displacements of the joints of the failure mechanism called the “tree” method. In addition to the failure mechanism, the interactive microcomputer program can also display/plot the frame configuration including the loading, and the bending moment diagram. Four examples are presented. This research demonstrates the effectiveness of inexpensive microcomputers for optimal plastic design of low‐rise frames of arbitrary configuration.