An Investigation on Ductility of RBS Connection, in Dual System of Moment Frame and Eccentric Braced Frame

In the Eccentric braced frames (EBFs), which one end of the link beam is connected to a column, the safety of the link-to-column connection is a requirement for the ductile and safe performance of the EBF. But among of the tests that have been implemented on this connection yet, because of the intensity of forces on vulnerable region of the link-to-column connection, the tested specimens were confronted with brittle and sudden failures. So it seems that the reduced beam section (RBS) can be a suitable solution for raising this problem, by concentrating flexural stresses at a location away from the connection, in flexural yielding link beams. Therefore in this paper, the possibility of keeping the plastic hinge away from the location of link-to-column connection, in the meanwhile achieving the required plastic rotation of link beam, by using the RBS connection, were investigated. This evaluation was done by using a finite element program ETABS and with nonlinear static analysis (pushover) for a dual system of special moment frame and special eccentric braced frame. According to the present work, the models with RBS by earlier developing the hinge at the RBS region, delay yielding occurrence of link at the column face. So the yielding does not occur at the column face, at least prior to achieving the moment at the location of RBS region to 1.1 times of its expected plastic moment capacity.