Inclined concrete-filled SHS steel column to steel beam joints under monotonic and cyclic loading: Experiments

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.

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Performance of parking steel column damaged by fire

Journal of Structural Fire Engineering ◽

10.1108/jsfe-03-2018-0006 ◽

2019 ◽

Vol 10 (2) ◽

pp. 138-154

Author(s):

Farshid Masoumi ◽

Ebrahim Farajpourbonab

Keyword(s):

Cyclic Loading ◽

Seismic Performance ◽

Numerical Study ◽

Mechanical Analysis ◽

Content Type ◽

Steel Columns ◽

Fire Engineering ◽

Steel Column ◽

Concrete Coating ◽

Fire Loading

Purpose The primary purpose of this research was to expand the knowledge base regarding the behavior of steel columns during exposure to fire. This paper presents the numerical study of the effect of heat on the performance of parking steel column in a seven-story steel building under cyclic loading. Design/methodology/approach In this research, the forces and deformations developed during a fire are estimated by using detailed 3D finite-element models. The analyses are in the form of a coupled thermo-mechanical analysis in two types of loading: concurrent loading (fire and cyclic loading) and non-concurrent loading (first fire and then cyclically), and the analyses have been conducted in both states of the fire loading with cooling and without cooling using the ABAQUS software. Further, it was investigated whether, during the fire loading, the specimen was protected by a 3-cm-thick concrete coating and how much it changes the seismic performance. After verification of the specimen with the experimental test results, the column model was investigated under different loading conditions. Findings The result of analyses indicates that the effect of thermal damage on the performance of steel columns, when cooling is happening late, is more than the state in which cooling occurs immediately after the fire. In this paper, thermal–seismic performance of parking steel columns has been specified and the effect of the fire damage has been investigated for the protected steel by concrete coating and to the non-protected steel, under both cooling and non-cooling states. Originality/value This study led to recommendations based on the findings and suggestions for additional work to support performance-based fire engineering. It is clear that predicting force and deformation on steel column during fire is complex and it is affected by many variables. Here in this paper, those variables are examined and proper results have been achieved.

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Collapse and Buckling Behavior of Octagonal Concrete Filled Steel Column Connected to a Beam Under Cyclic Loading

Lecture Notes in Civil Engineering - Proceedings of SECON 2020 ◽

10.1007/978-3-030-55115-5_60 ◽

2020 ◽

pp. 657-666

Author(s):

Silia Mary Silbi ◽

Sajan Jose

Keyword(s):

Cyclic Loading ◽

Buckling Behavior ◽

Steel Column

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Improvement of bearing performance on exterior steel beam-reinforced concrete column joints with steel column

Proceedings 12th international conference on Advances in Steel-Concrete Composite Structures - ASCCS 2018 ◽

10.4995/asccs2018.2018.7077 ◽

2018 ◽

Author(s):

Shinya Nakaue ◽

Yasushi Nishimura

Keyword(s):

Reinforced Concrete ◽

Shear Failure ◽

Maximum Strength ◽

Punching Shear ◽

Steel Beam ◽

Transverse Reinforcement ◽

Concrete Column ◽

Bearing Failure ◽

Reinforced Concrete Column ◽

Steel Column

To improve the bearing failure behavior of the exterior steel beam-reinforced concrete column joints composed of reinforced concrete columns, joint details using steel column was proposed. Steel column was attached to the lower flanges at right angles to the steel flange. The objective of this study is to clarify the effectiveness of proposed joint details experimentally and theoretically. To clarify the influence of steel column on the bearing failure of the joint, seven T-shaped subassemblages were tested under reversed cyclic loading. All specimens had the same cross sections of the steel beam. The experimental variables were the embedded length of the steel column, whether there is the end plate at the tip of the embedded steel column, and, the arrangement of transverse reinforcement ratio surrounding the steel column. The following remarks can be drawn from the test results. 1) In case of the specimen with a short embedded length of the steel column, the punching shear failure on the upper surface of the steel beam flange was remarkable when the maximum strength was reached. However, in the specimen with long embedded length of steel column, it was not observed the punching shear failure. 2) The maximum strength increased with the embedded length of the steel column. Further, the maximum strength of the specimen with the embedded length of three times of the steel column depths is subjected to bending yield strength of the steel column. 3) It was shown that the transverse reinforcement to surround the steel column and the end plate were necessary to improve the bearing failure of the joint.

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