Experimental and numerical study on the seismic performance of rocking steel frames with different joints under earthquake excitation

Abstract

A rocking steel frame is proposed in this paper, which can reduce the plastic deformation of the main structural components under strong earthquake actions and can be easily repaired after earthquakes. Three 1:2 testing steel frames (buckling-restrained braced steel frame, rocking steel frame with rigid beam-column joint and rocking steel frame with semi-rigid beam-column joint) are designed and manufactured. The pseudo-static tests on the three specimens are carried out respectively. The hysteretic curves, skeleton curves, stiffness degradation rules and other parameters of the three specimens are compared and analyzed to study the seismic performance and damage characteristics of the rocking steel frame. The effect of beam-column joint form on the seismic performance of the rocking steel frame is investigated. In addition, the corresponding numerical analysis and modelling methods are introduced. The results indicate that the rocking structure can effectively reduce the damage of beams and columns. The RBS (rigid beam-column joint with reduced beam section) on the beam end can effectively transfer plastic hinge to the beam end, thus protecting the beam-column joints. It can be also concluded from the results that compared with rigid beam-column joint, semi-rigid beam-column joint has greater superiority and better seismic performance, which can protect the main components more effectively.