Optimal Design of Beam-Column Connections of Plane Steel Frames Using the Component Method

Abstract

This paper presents a methodology for optimization of beam-column connections of plane steel frames. The objective is to obtain beam-column connections mechanically more efficient and with minimum cost by determination of the optimal dimensions for the components of the connection; satisfying mechanical constraints associated with the bending moment and the rotational stiffness of the connection, without compromising its safety and integrity. Minimum and maximum limits of geometric parameters are considered, according to current regulations. Algorithms were developed to calculate the bending moment and the rotational stiffness of the connection using the "Method of Components" of Eurocode 3. Initially, it was developed a digital database with structural profiles, steel plates and commercial bolts obtained from catalogs of manufacturers, with automatic access of the data by the computational modules of structural analysis and optimization. In the optimization model, it is adopted the connection with extended end plate without stiffeners, the design variables are the dimensions and the thickness of the end plate, the diameter and the location of the bolts. In the optimization process, we use genetic algorithms with continuous and discrete variables, with the discrete variables being associated to the database. In this way, this paper presents a computational tool fully developed in MATLAB® environment for analysis and optimal design of beam-column connections for plane steel frames. Applications that show quite satisfactory results when compared with results available in the literature are presented.