Comparative Study of CFRP‐Confined CFST Stub Columns under Axial Compression

Abstract

is paper presented a comparative study of concrete-filled steel tubular (CFST) stub columns with three different confinement types from carbon fiber reinforced polymer (CFRP): outer circular CFRP, inner circular CFRP, and outer square CFRP. e compressive mechanism and physical properties of the composite column were analyzed firstly aiming at investigating the confinement effect of CFRP. Ultimate axial bearing capacity of these three CFRP-confined CFST columns was calculated based on Unified eory of CFSTand elastoplastic limit equilibrium theory, respectively. Meanwhile, the corresponding tests are adopted to validate the feasibility of the two calculation models. rough data analysis, the study confirmed the ultimate strength calculation results of the limit equilibrium method were found to be more reliable and approximate to the test results than those of Unified eory of CFST. en axial bearing capacity of the pure CFSTcolumn was predicted to evaluate the bearing capacity enhancement ratio of the three types of composite columns. It was demonstrated that the averaged enhancement ratio is 16.4 percent, showing that CFRP-confined CFST columns had a broad engineering applicability. rough a comparative analysis, this study also confirmed that outer circular CFRP had the best confinement effect and outer square CFRP did better than inner circular CFRP. e confinement effect of CFRP increased with the decrease of concrete strength, and it was proportional with relative proportions of CFRP and steel under the same concrete strength.

Behavior of an Innovative Square Composite Column Made of Four Steel Tubes at the Corners and Corrugated Steel Batten Plates on all Sides

“…e eight-node reduced integration linear solid elements with three translation degrees of freedom (C3D8R) were utilised for modelling the steel tube, corrugated steel plate, concrete and loading plates [1][2][3][4]. Obviously, the thin-walled steel tube used in the ISSCC column buckles locally outwards with the extrusion provided by the filled concrete.…”

“…e damageplasticity model was used in the FE model to simulate the concrete, and the value of dilation Angle (ψ) was 35°, which was determined by using equation (1). e flow potential eccentricity was taken as the default value of 0.1.…”

“…e CFST column composes of an empty steel tube filled with concrete, at which both materials sustain together the applied axial load. In recent years, CFST column has widely been used in various building structures and bridges due to good mechanical properties and construction performance [1][2][3][4].…”

Axial Cyclic Testing of Concrete‐Filled Steel Tube Columns in Diagrid Structures

“…For the components, Zhou et al [5], Kim et al [6], and Han et al [7] conducted pseudostatic tests on intersecting nodes in the diagrid structure and analysed the force mechanism and hysteresis performance under axial cyclic loads; however, the relevant research on inclined CFST columns in diagrid structures is still in the initial stage. Currently, the studies on CFST columns mainly focus on the monotonic behaviour of vertical bearing members and the seismic performance of lateral force-resistance components [8][9][10][11][12][13][14][15], while minimal research has focused the mechanical behaviour under cyclic loads of components such as lateral braces [16,17], and few studies have been conducted on the mechanical behaviour of the inclined CFST columns under cyclic axial loads, which are the major components of the diagrid structure.…”

Tests of Inclined Concrete‐Filled Steel Tubular Stub Columns under Vertical Cyclic Loading

“…With the advancement in materials, the effect of high material strength was investigated by Liu et al [6] and Zhou et al [7]. Using of carbon fiber reinforced polymer (CFRP) to confine the CFST columns was investigated by Guo and Zhang [8]. e study indicated the increase of confinement using the outer CFRP especially for the square column.…”