Computer aided plastic design of unbraced frameworks

A computer program for the plastic design of two-dimensional unbraced steel frameworks is described. The program is an extension of a set of programs developed at Lehigh University, and uses the subassemblage method of analysis to analyse each story of the framework. In the program described, member sizes are determined firstly on the basis of strength alone, and then an optimal set of increments in the member sizes is determined to satisfy suitable constraints on sway deflections under working load conditions. Mathematical programming procedures are involved in this incrementing process. Some design examples are presented, and the program is compared with other approaches reported in the literature.