Cyclic loading tests of an earthquake-resilient prefabricated steel frame with open-web steel channel beams

Abstract

Based on the ideas of damage control and energy dissipation by sliding, this paper puts forward an earthquake-resilient prefabricated steel frame with two open-web steel channel beams (OWSCBs). To study its seismic performance and post-earthquake repair performance, the low frequency cyclic loading tests and low cyclic fatigue tests were carried out on five specimens, and several seismic behavior indicators such as the hysteretic curve, the slip curve, the strain analysis curve and the skeleton curve of frames were obtained. The influence of the thickness of the flange cover plate (FCP), the number of connecting bolts in the FCP and the residual deformation on seismic performance of prefabricated steel frames before and after restoration were mainly investigated. The results show that there are two main failure modes of the specimen, one is FCP friction sliding and the other is local buckling deformation of FCP dog-bone weakened section, while the main components such as beams and columns are still in the elastic stage. The repaired specimens have the same experimental phenomena and seismic performance as the initial specimen, which indicates that the functional restoration of prefabricated steel frame structures can be realized by repairing beam-column joint connecting devices. The repair process of the specimen with residual story drift went well, and this specimen still showed good mechanical and seismic performance after repaired. The overall bearing capability of the specimens decreases obviously with the thickness of the FCP decreasing. The decrease in the number of the connecting bolts in the FCP will reduce the critical sliding load of the FCP, which will lead to the slippage of the FCP in advance and reduce the overall bearing capability of the specimens.