Replaceable Prefabricated Concrete-Filled Steel Tubular Node

Abstract

A replaceable prefabricated Concrete-filled Steel Tubular (CFST) frame structure is proposed in this paper. The structure has excellent advantages in its construction technology, mechanical behaviour, material application, and post-earthquake recovery and is a green structural system. To explore the seismic performance of the structure, ABAQUS is used to study the influence of different variables on the seismic performance of the node. The hysteretic curve, skeleton curve, stiffness degradation, displacement ductility, and energy dissipation capacity of the node were analysed. The results show that the ductility of this node is basically in a range of 2.02 -5.75, which is generally higher than 3.0 and has optimal deformation. Furthermore, this node's equivalent viscous damping coefficient is higher than 0.35. In addition, increasing the bolt preload can significantly improve the energy dissipation capacity of the structure in a particular range, and an excessive bolt preload has little effect. Moreover, the high-strength concrete can effectively improve the energy dissipation capacity of the structure. As the axial compression ratio increases, the equivalent viscous damping coefficient has an obvious upward trend. Finally, the stress mechanism of this node was comprehensively analysed according to the theory of oblique bars, the unified theory of concrete-filled steel tubes, and the Kupfer-Gerstle yield criterion, considering the influence of steel tubes on the core concrete.