EXPERIMENTAL STUDY OF HYSTERETIC BEHAVIOR OF RESILIENT PREFABRICATED STEEL FRAMES WITH AND WITHOUT INTERMEDIATE COLUMNS

The research innovatively proposed a seismic resilient structural system including a prefabricated self-centering steel frame (PSC) and an intermediate column with a friction damper (CD). The CD, installed in the mid-span beam of the PSC, was expected to provide additional stiffness and damping, The seismic performance of the newly-developed resilient structural system thus can be greatly improved. This paper stated the experimental study on the hysteretic behaviors of the newly -developed system. Comparative pseudo-dynamic tests were conducted for the validation where two systems, a PSC with CD and a PSC without CD, were tested respectively. The testing results indicated that a PSC with CD has better seismic performance for long-span structures under catastrophic earthquakes' attack. The CD overall provided additional stiffness for requirements of earthquake fortification criteria. The friction damper, part of CD greatly improves the damping effect together with the energy-dissipation bolts. The small residual rotations of beam-column connections on the PSC subsystem provides a satisfactory self-centering mechanism. Moreover, the steel strands of the resilient structural system can maintain the elasticity even after the highest-intensity earthquake. In turn, the satisfactory seismic performance of the proposed PSC with CD structural system validated. This research developed a series of design formula for the T-plate and L-plate friction damper in the CD to guarantee the designed seismic performance of the proposed seismic resilient structural system. The theoretical hysteresis curve of the system was proposed for the future design specification.