Steel beam-to-column RBS connections with European profiles: I. Static optimization

In this work we present an optimization procedure for achieving best beam-to-column reduced beam section connections in steel moment frames under static loading. The whole scheme is based on selecting European I-profiles for beams and columns, using the component method of Eurocode 3 for evaluating the design moment resistance of the joint, regression analysis to correlate the geometrical and inertial characteristics of the various components and elementary principles of Mechanics. In doing this, were are led to a constraint optimization problem, which is formed according to the design restrictions of European and North American Standards for RBS connections, regarding expected seismic behavior. Adopting advanced numerical procedures, optimum results are obtained, regarding either combinations of connection components or existing steel frames, a fact validating the flexibility and applicability of the proposed method. The calibration, verification and validation of the excellent seismic performance of the results obtained will be demonstrated in a companion paper, via FE analyses under cyclic loading. Hopefully, this work will contribute in adopting RBS connections in the design of steel moment frames in European engineering practice, as well as in the relevant codes.