Nonlinear Finite Element Analysis on Long Columns of High-Strength Concrete-Filled Square Steel Tube With Inner CFRP Circular Tube Under Axial Load

Abstract

ABSTRACT:The concrete-filled square steel tubular structure has been applied wildly in the practical projects around the world. To install CFRP into the column is beneficial not only to overcome the disadvantages of the high-strength concrete, but also to improve the bearing capacity and the stability of the concrete-filled square steel tube. This paper adopts finite element analysis software ABAQUS 6.7 to make nonlinear finite element analysis on a large number of long columns of high-strength concrete-filled square steel tube with inner CFRP circular tube subjected to axial compression. The analysis results are verified by the tests. In addition, the load-axial strain curves in the whole process are calculated and analyzed, and they are divided into 4 segments: elastic phase, plastic phase, descending phase and rebound phase. Based on the curves of load-axial strain, the stresses analysis on the core concrete, CFRP tube and square steel tube are conducted. The results of finite element simulation analysis show the destruction of long columns subjected to axial compression are all buckling failure. It indicates that slenderness ratios are the key to decide the type of buckling failure for long columns under axial compressive loading. The boundary slenderness ratio between elastic buckling and plastic buckling is discussed.

Seismic Optimization Analysis of Vertical Stiffener Connection to L-CFST Column

“…where T is the torque of the cross section at the column flange, and Wt is the torsion resistant cross-sectional modulus of the L-CFST column in Eqs. (6) and 7, respectively, where e is the vertical distance from the centroid centre to the shear centre; Ip is the polar moment of inertia of the L-CFST column section; ρmax is the distance from the column flange corner to the shear centre of the L-CFST column.…”

“…Because of the weak seismic behaviour of the frame structure system with the special-shaped reinforced concrete column, the height of this structure system has strict limitations in earthquake-prone areas [1]. Meanwhile, the concrete-filled steel tubular column has been studied by many scholars because of its beneficial seismic behaviour, high bearing capacity, fireproofing qualities and economic benefits [2][3][4][5][6][7]. The research background of this paper is the frame structure system of a special-shaped column composed of concrete-filled steel tubes (S-CFST column), which can be applied to high-rise steel residential buildings particularly with braces or shear walls.…”

Study on axial compression bearing capacity of in-sulated sandwich concrete wall with embedded columns

“…Then, after introducing the initial defects to the model, in the finite element simulation, 0.001 of specimen height was introduced as initial defect, nonlinear analysis was performed considering material nonlinearity and geometric nonlinearity. The elastic modulus of steel Es is 206 × 10 3 N/mm 2 while Poisson ratio as 0.3 (Li et al, 2013). The damaged plasticity of concrete (CDP) model in ABAQUS is used to simulate the mechanical properties of concrete (Qiao et al, 2020c).…”

Study on Moment-Rotation Relationship of Steel Sleeve Beam-Column Joint With Interference Fit

“…In the model, Chinese grade Q235 was used for steel. The elastic modulus of steel Es is 206 × 10 3 N/mm 2 while Poisson ratio as 0.3 [17]. The constitutive model of steel suggested in reference [18] is adopted.…”