ABSTRACT
During the last ten years, extensive research has been carried out on self-centering (SC) steel moment resisting frames (MRFs) in several countries. As an alternative to welded beam-to-column connection construction, the authors developed a post-tensioned friction damped connection (PFDC) for use in seismic resistant steel MRFs. The connection utilizes high strength steel strands (Fig. 1(a)) that are post-tensioned after the friction devices are installed. The post-tensioning strands run through the column, and are anchored outside the connection region (Fig. 1(b)). A properly designed PFDC has several advantages: (1) field welding is not required; (2) the connection is made with conventional materials and skills; (3) the connection has an initial stiffness similar to that of a typical welded connection; (4) the connection is self-centering without residual deformation, thus the MRF will not have residual drift after an earthquake if significant residual deformation does not occur at the base of the ground floor columns; and (5) the beams and columns remain essentially elastic while the friction devices provide energy dissipation.
