Recursive Optimization for Seismic Steel Frames

Abstract

The theoretical derivations and numerical procedures used in the computer program ODSEWS‐2D‐II for the analysis and optimum design of two‐dimensional regular and irregular steel frames subjected to static, earthquake, and wind forces are presented. The seismic input can be interacting ground motions of actual earthquake records, various response spectra, and different building provisions of the Uniform Building Code (UBC), ATC‐03 in the United States, and TJ‐11 in China. Included are the mathematical formulation based on the consistent mass and the displacement method with consideration of geometric nonlinearity, three levels of recursive optimization procedures, the objective function of minimum construction and damage costs, and the constraints of stresses, displacements, frequencies as well as the upper and lower bounds of the design variables. Several design examples are provided to show the efficiency of the proposed algorithms, the versatility of the computer program, and the effect of the various code requirements on the optimum solutions.