• Journal of Korean Society of Steel Construction
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• v.12 no.1 s.44
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• pp.55-63
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• 2000

This paper is a study on the behavior of Concrete-Filled Square Tubular(CFST) column to H-beam connections reinforced with external stiffeners and reinforcing bar. The cyclic loading tests of 5 test specimens were carried out. The main Parameters are as follows; 1)the length of the stiffener: 200mm, 250mm, 2)the diameter of reinforcing bar: HD16, 19. The results of the researches demonstrate that the increase of the stiffener length was more effective than the increase of the area of reinforcing bar in the point of both strength and stiffness. By reinforcing external stiffeners, stable hysteretic behavior was shown and plastic hinge was formed on the beam flange. Cold-formed tube sections should be used carefully to avoid the welding fracture at the round corners of section, and the proposed welding methods are suitable for this connections.

• Journal of Korean Society of Steel Construction
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• v.10 no.4 s.37
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• pp.641-655
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• 1998

It researched several jointing-methods of frame consisting of a concrete-filled steel tubular column and H-shaped beam. These beam-to-column connections is parameters to following: columns of square shape pipe infilled with or without concrete, joints assembled two types of diaphragm, outside-type and through-type. And it is testing that cyclically lateral loadings used hydraulic ram. In testing. we'll be on purposed to estimate the hysteretic behavior, strength and stiffness, energy absorption capacity, deformation capacity and failure configuration of each specimen. It is concluded that the frame specimens with outside-type are more stable and exhibit more energy absorption capacity compared with the through-type, in column of filled with concrete.

• Steel and Composite Structures
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• v.38 no.5
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• pp.547-562
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• 2021

This paper aims to explore the mechanical behavior and moment-rotation model of blind bolted joints between concrete-filled double skin steel tubular columns and steel-concrete composite beams. For this type of joint, the inner tube and sandwiched concrete were additionally identified as basic components compared with CFST blind bolted joint. A modified moment-rotation model for this type of connection was developed, of which the compatibility condition and mechanical equilibrium were employed to determine the internal forces of basic components and neutral axis. Following this, load transfer mechanism among the inner tube, sandwiched concrete and outer tube was discussed to assert the action area of the components. Subsequently, assembly processes of basic coefficients in terms of their stiffness and resistances based on the component method by simplifying them as assemblages of springs in series or in parallel. Finally, an experimental investigation on four substructure joints with CFDST columns for validation purposes was carried out to capture the connection details. The predicted results derived from the mechanical models coincided well with the experimental results. It is demonstrated that the proposed mechanical model is capable of evaluating the complete moment-rotation relationships of blind bolted CFDST column composite connections.