• Journal of the Korea institute for structural maintenance and inspection
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• v.6 no.2
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• pp.127-133
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• 2002

Most structures are constantly influenced by repeated weathering phenomena and load action during a period of its utilization, and their component materials become superannuated and their design performance becomes slowly lost. Therefore, it is thought that it is necessary to develop the online monitoring system that can make a great contribution to the maintenance management and disaster prevention of the building structure by sensing any slight change of the entire structure regardless of its inside and outside. Especially, this study was intended to explain the entire system of the online structure by interpreting welded built-up H-beams, of structural steel members having many advantages in terms of the qualities of structural materials, through limit state design, and presenting the basic plan to apply it to the structure.

• Journal of Korean Society of Steel Construction
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• v.17 no.4 s.77
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• pp.459-467
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• 2005

This study focuses on the development of a new method of H-shaped beam-to-square column connection with an outer diaphragm and a field welding. The specific type of beam-to-column connection with an external stiffener, using field welding, is proposed. The structural behavior of this connection was examined experimentally. Two loading type tests were conducted under the experimental parameters given as details. First described was the symmetrical loading test, which supported both ends or a beam simply and applied a load from the column to the pend (What does this mean?) to investigate a fundamental characteristic of this connection. Further described was the anti-symmetrical loading test, which carried out simple support of the column'stop end and the column base, and applied a load from both ends of a beam to investigate the structural performance of this connection. From the results, it is clear that the external- stiffener-type connection proposed in this paper is the reliable connection method.

• 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.15 no.5 s.66
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• pp.531-539
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• 2003

Unlike field-welded moment frames damaged during the Northridge earthquake, a column-tree moment frame has a tool to control and reduce its seismic behavior. The tool is the girder splice. Girder splices could be designed to be sufficiently ductile and to have a prescribed bending moment capacity. In such a design, during earthquakes, the girder splices would act as ductile "fuses" and limit the magnitude of forces including the bending moment that could be developed in the frame. In Korea, most moment frames arc composed of a column-tree moment frame. Therefore, the elasto-plastic behavior of steel beams with high strength bolted friction splice should be clarified. Furthermore, structural capacities, including energy absorption capacity, must be quantitatively found. This paper discusses an experimental study to clarify elasto-plastic behavior of steel beams with high strength bolted friction splices. A total of 5 specimens were tested. A specimen was fabricated to have a beam splice designed by a full strength method. Other specimens were fabricated to have beam splices with 75%, 50% and 0% capacities compared with the specimen.

• Journal of Korean Society of Steel Construction
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• v.15 no.6 s.67
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• pp.701-709
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• 2003

The paper presented the seismic performance of T-stiffener moment connections for use in steel moment-resisting frames. The connections were strengthened by welding the vertical and horizontal clement of the T-stiffener to the beam flange and column f1ange. Finite clement analysis and experiments were conducted to determine the behavior of T-stiffener-reinforced connections. The results of the finite element analysis confirmed the effectiveness of the T-stiffener, whose horizontal element lengthened to mitigate local stress concentrations of the beam flange on the horizontal stiffener. Full-scale specimens were also tested cyclically to study hysteresis behavior. The main parameters used were the ratio of the T-stiffener to beam strength and the shape of the horizontal element. As the length of the horizontal element increased, the deformation capacity of the connections enhanced. Likewise, all specimens behaved according to the Ramberg-Osgood curve and showed stable hysteresis behavior.