Design optimization of semi-rigid plane steel frames with semi-rigid bases using biogeography-based optimization and genetic algorithms

Abstract

This paper performs optimization for plane steel frames with semi-rigid beam-to-column connections, in a company with fixed, semi-rigid and hinged base connections using a biogeography-based optimization algorithm (BBO), along with a genetic algorithm (GA). In this paper, Kanvinde and Grilli [1] nonlinear model is used for simulating semi-rigid base connections, where this model considers all deformations in different base connection components under the applied loads to determine the relative spring rotation for the sake of getting accurate base rotational stiffness value. In addition, Frye and Morris [2] nonlinear model is used for simulating semi-rigid beam-to-column connections. The P-∆ effect and geometric nonlinearity are considered. The stress and displacement constraints of AISC-LRFD [3] specifications, together with size adjustment constraints, are considered in the design procedure.