• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2003.10a
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• pp.387-390
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• 2003

Direct tensile tests were carried out for the tensile members of steel-reinforced polymer concrete with different steel diameters and steel ratios to figure out the effect of tensile strength of polymer concrete. In the experiments, polymer concrete with $1000kgf/cm^2$ of compressive strength, steel with $5200kgf/cm^2$ of tensile strength, and the tensile members with 100 cm of constant length were used. Experimental results showed that, regardless of steel diameters and steel content, the strain energy exerted by concrete till the initial crack was 14-15% of the total energy till the point of yield: The energy was much larger than the one of high-strength cement concrete. The behaviors of tensile members of steel-reinforced polymer concrete were in relatively good agreement with the model suggested by Gupta-Maestrini (1990), which was idealized by the effective tensile stress-strain relationship of concrete and the load-strain relationship of members, while those showed a big difference from CEB-FIP model and ACI-224 equation suggested for the load-displacement relationship that was defined as the cross sectional stiffness of effective axis. Modified ACI-224 model code about the load-displacement relationship for the tensile members of steel-reinforced polymer concrete and theoretical equation for the polymer concrete tensile stiffness of polymer concrete suggested through the results of this study are expected to be used in an accurate structural analysis and design for the polymer concrete structural members.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.11a
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• pp.197-200
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• 2005

This paper presents an analytical model for evaluation of Tension Stiffening Effect by actual Bond-Slip relationships between the reinforcement and the surrounding concrete. The presence of longitudinal splitting cracks was found to significantly after the tension stiffening. The model is applied to the longitudinal splittings cracks and derived to Tension stiffening model. The predicted values are shown to be in good agreement with the experimentally measured data.

• 한국공간정보시스템학회:학술대회논문집
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• 2004.05a
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• pp.131-138
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• 2004

The cable structure is a kind of ductile structural system using the tension cable and compression column as a main element. From mechanical characteristics of the structural material, it is profitable to be subjected to the axial forces than bending moment or shear forces. And we haweto consider the local buckling when it is subjected to compression forces, but tension member can be used until the failure strength. So we can say that the tension member is the most excellent structural member. Cable dome structures are made up of only the tension cable and compression column considering these mechanical efficiency and a kind of structural system. In this system, the compression members are connected by using tension members, not connected directly each other. Also, this system is lightweight and easy to construct. But, the cable dome structural system has a danger of global buckling as external load increases. That is, as the axisymmetric structure is subjected to the axisymmetric load, the unsymmetric deformation mode is happened at some critical point and the capacity of the structure is rapidly lowered by this reason. This phenomenon Is the bifurcation and we have to reflect this in the design process of the large space structures. In this study, We investigated the nonlinear unstable phenomenon of the Geiger, Zetlin and Flower-type cable dome.

• Journal of the Korea Concrete Institute
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• v.26 no.5
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• pp.581-589
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• 2014

This paper presents the tension stiffening behavior from experimental results of each 6 amorphous steel fibers and normal steel fibers reinforced direct tensile specimens with the main variables such as cover thickness to bar diameter ratio. A tension stiffening effect for steel fiber reinforced RC tension members improve on the increase in cover thickness, and also amorphous steel fiber is usually superior to normal steel fiber. The reinforcement of steel fibers controlled the splitting cracks and led to significant increase in the tension stiffening effect. In particular, if cover thickness is more than twice the bar diameter, the amorphous steel fiber reinforced specimen is controlled the splitting crack and increased the tension stiffening effect. And, the tension stiffening effect of amorphous steel fiber reinforced concrete tension members is different to current structural design code provision.

• Computers and Concrete
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• v.18 no.1
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• pp.139-154
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• 2016

Since the concrete strength around the reinforcement rebar affects the tension stiffening, the tension stiffening effect of ultra high performance concrete on the concrete members reinforced by steel rebar is examined by testing the specimens with circular cross section with the length 850 mm reinforced by a steel rebar at the center of a specimen's cross section in this research. Conducting a tensile test on the specimens, the cracking behavior is evaluated and a curve with an exponential descending branch is obtained to explain the post-cracking zone. In addition, this paper proposes an equation for this branch and parameters of equation is obtained based on the ratio of cover thickness to rebar diameter (c/d) and reinforcement percentage (${\rho}$).

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.461-467
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• 2007

Exact application of the tensile force is critical to high-tension members in civil engineering structures, and thus actual tensile forces have often been estimated in field. To date, a few methodologies have been presented utilizing static and/or dynamic responses of tension members. Each of these methods has its disadvantages as well as advantages in its procedures, accuracy, and equipment requirements. In this paper, the feasibility of a sensitivity based methodology, based on the relationship between the natural frequencies and the applied tensile force, developed by the authors, is verified using the measured data from a cable-stayed bridge structure. From the results, it is shown that the proposed method can be utilized in estimating the tensile force in tension member of a real structure.

• Journal of Korean Society of Steel Construction
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• v.22 no.4
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• pp.345-354
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• 2010

This paper presents an experimental investigation of the structural performance of a large-span girder bridge with an under-tension system. Typical long-span structures with beam and girder members have greater structural member depths and sizes to carry the moment and deflection. An under-tension system can be an effective structural system, as it allows the cables to resist some portions of the vertical loadings and deflections. To evaluate the serviceability and ultimate strength of the under-tension system, two $10m{\times}2.4m$ experimental under-tension systems were built and tested. One was developed with an H-beam section, and the other was made with a PF500 section that had the advantages of fast construction and lower construction cost. In the test, the maximum deflections at the mid-point of both beams were effectively reduced using under-tension systems. Also, the increased tension forces in the cable reduced the deflections. The PF500 members, which had a new shape and were developed using the module systems, performed better than the typical H-beam sections in terms of the deflections and ultimate strength.

• Journal of Power System Engineering
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• v.14 no.2
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• pp.48-54
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• 2010

An improved numerical scheme, to which the hydroelastic method is adapted, is introduced for predicting the motion and structural responses of tension leg platforms(TLPs) in regular waves. The numerical approach in this work is based on a combination of the three dimensional source distribution method and the finite element method. The hydrodynamic interactions among TLP members, such as columns and pontoons, are included in the motion and structural response analysis. The drag forces on the submerged slender members, which are proportional to the square of relative velocity, are included in order to estimate the responses of members with better accuracy. Comparisons with other results verify the works in this paper.

• International Journal of High-Rise Buildings
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• v.6 no.3
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• pp.285-296
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• 2017

It's been a decade since post-tension system began to be applied in earnest to buildings in Korea. In the meantime, post-tension system has been used in various buildings as main structural system including tall buildings. And post-tension system plays a role to overcome architectural limit of regular RC tall buildings particularly in the realization of long span with shallower depth than other structural system. The post-tensioned building market of Korea has been steadily grown in recent years with such advantage. Recently, post-tension technology is adapted for special structural members like belt walls. In this paper, the authors would like to explain design and construction of tall buildings in Korea using post-tension technology.

• 한국공간정보시스템학회:학술대회논문집
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• 2004.05a
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• pp.222-229
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• 2004

This study purports to analyze equally stressed surfaces in tension-membrane structures through a geometrically nonlinear approach. It adopts the formulation of a 4-node quadrilateral isoparametric plane stress element considering the orthotropic characteristic of membrane textures. Tension structures, which include cables and tension membranes, such as a cable dome initially exhibit unstable conditions because no initial internal stiffness such as bending stiffness is present. Such a structural system requires prestressing to the tension members to attain a stable state. A tension-membrane structure retains a stable three dimensional curved surface as a structural shape. This analytical process for finding the geometry is referred to as Shape Finding Analysis. In order to assess the validity of this study, we examine equally stressed surfaces of saddle and catenary shape shell structures and carry out pertinent stress analyses