Abstract

Abstract In this paper, Artificial Bee Colony (ABC) algorithm, fuzzy logic and Simple Genetics (GA) are used for stiffness optimization of steel frames with rigid or semi-rigid connections. In the genetic algorithm, uniform crossover operator is employed and also, binary coding is used to achieve better convergence. Behavior of steel frames depends highly on beam to column connections. Here, beam to column connections are assumed to be semi-rigid or rigid. Linear analysis and design has been used for steel frame structures. Matlab program has been utilized for the process of optimization in combination with OpenSees software for frame analysis. Beams and columns sections are selected from a standard set of steel sections such as American Institute of Steel Construction (AISC) wideflange (W) shapes. Displacement and stress constraints are imposed on the frame. Frye and Morris polynomial model is used for semi-rigid connection. Also, the proposed algorithm considers a fitness function using appropriate balancing factors which leads to a faster convergence. Three different design examples with various types of connections are presented to demonstrate the efficiency and robustness of the proposed approach. The results show that the fuzzy genetic algorithm and artificial bee colony results in lighter structures consuming less computation time compared to simple genetic algorithm. Keywords: weight optimization. semi-rigid connection, genetic algorithm, fuzzy logic, Artificial Bee Colony