• Journal of Korean Society of Steel Construction
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• v.16 no.6 s.73
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• pp.737-745
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• 2004

In general, most of the beam-to-column connections for steel structures are regarded as either rigid connections or pin connections. Recently, the concept of a semi-rigid connection was introduced for a correct analysis of steel structures. Several experimental and theoretical researches have been performed regarding the structural behaviors of frames and buildings with semi-rigid connections. The results are not well known, and structural frame/building has not been designed to introduce the concept of semi-rigid connections between a beam and column until this time. To resolve this, this research depends on design specifications prepared by other advanced countries for the design of buildings with semi-rigid connections. Such a specification, however, should incorporate domestic characteristics of steel material properties and load conditions. This paper deals with structural capacities and deformable behaviors for a split-T tensile connection with F10T high-strength bolts to investigate the structural characteristics of semi-rigid frames. The experimental parameters include the thickness of T-flanges, painted or not, preloaded or not, and load pushover pattern. A total of 20 specimens were fabricated and tested with a 300-ton UTM. The structural capacities and behavior for split-T tensile connections were evaluated on each research parameter.

• Journal of Korean Society of Steel Construction
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• v.17 no.5 s.78
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• pp.569-580
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• 2005

The postbeam joint connection of the existing steel structure moment flexible frame system did not produce sufficient seismic resistance during the earthquakes in Northridge and Kobe, and it sustained brittle fracturing on the joint connection. This study was performed to execute the high-tensile bolt share connection of H-beams web and the full-scale experiment as a parameter of the existing reinforcement of H-flange rib, by making the shape of the existing joint connection. This experiment was performed to determine the extent of the decrease of the number of high-tensile bolts and how to improve workability of the two-phase shear connection of web beam. In addition, this study was performed to enhance the seismic resistant capacity through the enforcement of rib plates. As a result of the experiment of two-phase shear connection of H-beam web and of joint connection to be reinforced by rib plates, the results of this study showed that the initial stiffness, energy-dissipation capacity, and rotational capacity of plasticity was higher than the existing joint connection. As to the rate of increasing the strength and deformation capacity, there were differences between the tension side and compression side because of the position of shear tap. However, as a whole, they have shown excellent seismic resistant capacity. Also, all the test subjects exceeded 4% (rate of delamination), about 0.029 rad (total plastic capacity), and about 130% (maximum strength of joint connection) of fully plastic moment for the original section. Accordingly, this study was considered as it would be available in the design more than the intermediate-level of moment flexible frame.

• Journal of Korean Society of Steel Construction
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• v.9 no.3 s.32
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• pp.363-375
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• 1997

This study encompasses the performance of static and fatigue test for the 8 large scale test specimens to clarify the fatigue behavior of coped stringer and the effect of the repair and strengthening on the damaged stringer of the floor system in steel railway bridges. For the purpose of the research, the actual stress wave for the existing bridge was measured, the basic stress range frequency histogram was made and the equivalent stress range was calculated. Using the result from the equivalent stress range made by adjusting the stress range, the static and fatigue test was carried out by identifying the previous rehabilitation and after. As the result of the static tests, it was revealed that the level of local stress under the S1 specimen test of the real equivalent stress range was similar to tensile strength of the test material, and it was consistent with the requirement of the initiation condition of the fatigue crack. Through the various rehabilitation methods to the damaged specimens, the effects of the repair and reinforcement were analyzed. According to the results of the repair of effect, bolting the high tension bolt over the stop hole was confirmed to be more adequate method than drilling only stop hole to delay the fatigue crack growth. Futhermore, in case of the stringer subjected by bending moment, the reinforcement over the upper flange side was determined to be a useful strengthening method, and the reinforcement to the web of the stringer was not appropriate to accomodate as a adequate strengthening method. Also it was confirmed that the category of the fatigue design for the coped stringer met with the category E specified on the fatigue design criteria of the Highway Standard Specification in Korea.