Nonlinear Numerical Analyses of a Fabricated Connection of Concrete-Filled Steel Column to Steel Beam Under Low-Reversed Cyclic Loading

Introduction: Based on FEM program ABAQUS, three-dimensional numerical models of a fabricated connection of concrete-filled steel column to steel beam under low-reversed cyclic loading were established by considering both nonlinearity of material and geometry. Effects of stiffen ring plate, axial compression ratio and backing plate on the hysteresis curves, skeleton curves, ductility coefficient and energy dissipation coefficient were analyzed respectively. Methods: Furthermore, parametric analyses with comparison were also conducted to discuss the mechanical characteristics and damage mechanism of the fabricated connection. Results: The results show that there are clear stress concentrations near the area of bolt holes in beam flange. The increase in width of ring plate and the shape change of ring plate from square to circle can both improve the ductility and the characteristics of hysteretic behavior. Besides, the backing plates have positive effects on the hysteretic characteristics, ductility and energy dissipation of the CFST column connections. Oppositely, the increase in axial compression ratio contributes negatively to both the bearing capacity and deformation performance of the connection specimens. Conclucion: It can be concluded that the fabricated connection displays good working performance relating to hysteretic characteristics, energy dissipation and ductility, which can be hopefully applied and provide reference to engineering practice.