Cyclic loading tests of earthquake-resilient prefabricated cross joint with single flange cover plate

Abstract

Earthquake-resilient functions have become a frontier hot direction in the field of seismic engineering. Based on the concept of damage control, a new type of earthquake-resilient prefabricated cross joint (ERPCJ) with single flange cover plate (FCP) has been proposed. The ERPCJ is composed of a circular tubular steel column with a cantilever beam, a common beam, and a connection device. The plastic hinge will be transferred to the connection device, when the cantilever beam has been strengthened and the FCPs have been reduced. This design only requires replacement of the connection device to achieve recovery after an earthquake. In this study, seven low frequency cyclic loading tests were carried out on six specimens. The failure mode, hysteresis curve, skeleton curve, and other seismic performance indices of the joint were obtained. The influences of the weakened form, thickness and material property of the FCPs, and the gap between the beams on the seismic performance of the joint were mainly investigated. The experiments showed that the ERPCJ with reasonable parameter settings possessed good bearing capacity and hysteresis characteristics. The repair program of replacing the connection device was feasible and the requirements of earthquake resilience could be met. The ERPCJ utilizes the plastic deformation of the FCPs to dissipate the seismic energy and improve its ductility and rotation ability. In addition, thickness and material property of the FCPs, and a gap between the beams significantly affect the seismic performance of the joint. Therefore, the values of these parameters should be designed reasonably.