Experimental Research on Seismic Performance of Modular Prefabricated Steel- Reinforced Concrete Column to Steel Beam Composite Joints

A modular composite joint suitable for the industrialization of buildings was proposed. Three basic specimens were designed with the concept of beam-column-joint core area separation and modular prefabrication. Through the quasi-static test, the failure process and failure characteristics of each joint with different beam-to-column liner stiffness ratios (k_i) were obtained. The seismic performance of joints such as hysteresis curve, skeleton curve, ductility, energy consumption, and stiffness degradation were analyzed. The results showed that with the increase of k_i value, the failure mode of the joints developed from beam-end bending to joint shear and column-end compression bending, and had experienced three stages of elasticity, elastoplasticity, and failure. The hysteresis curve of the joints was full, and the skeleton curve was in the shape of 'S’. The overall stiffness degradation performance of the joints was stable, the mean ductility coefficients were in the range of 3.71-4.25, the limit rotation angles were in the range of 0.064 6-0.076 0 rad, and the mean equivalent viscous damping coefficients were in the range of 0.32-0.33, and the joints showed good mechanical and hysteretic properties. The beam-to-column linear stiffness ratio had a greater impact on the strain of longitudinal reinforcement and concrete but had a smaller impact on the strain of H-shaped steel skeleton, steel beam webs, and flange connecting plates. The shear mechanism of the joint core area was consistent with that of the 'oblique strut’.