Simplified Computational Procedure for the Design of Special Moment Resisting Steel Connections

A simplified computational procedure for determining the optimal design of special moment resisting steel connections is proposed. The connection, recently patented by the authors, is the so-called Limited Resistance Plastic Device (LRPD); it appertains to the class of the Reduced Beam Sections (RBS) which mainly constitute appropriate beam portions devoted to receiving plastic deformations, but it also possesses additional and innovative features related with its resistance and stiffness. The optimal design of the LRPD usually requires the solution of a strongly nonlinear minimum volume problem. On the grounds of the known expected LRPD mechanical features, a simplified computational procedure is defined. Reference will be made to the device applied to I-shaped steel beam elements subjected to a plane force system. Some numerical applications are presented, regarding the comparison between the results obtained by means of the proposed simplified strategy and those obtained by the solution to the optimal design problem. Furthermore, a larger application devoted to a plane frame proves the reliability of the devices as receptors of plastic deformations.