• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.153-156
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• 2008

The objective of the present study is to evaluate the flexural behavior of reinforced concrete columns externally strengthened with wire rope and T-shape steel plate units. Three strengened columns and a control unstrengthened column were tested under cyclic lateral load simultaneously subjected to a constant axial load. All columns had same section size, and the arrangement of longitudinal reinforcement and internal hoop. The spacing of wire rope range from 40 ${\sim}$ 80mm, which corresponds from 1.0 ${\sim}$ 0.5, respectively, times the minium amount of hoop specified in seismic design of ACI 318-05. Test results showed that the proposed unbonded-type strengthening procedure is very effective for improving the flexural ductility of reinforced concrete columns.

• Journal of Ocean Engineering and Technology
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• v.23 no.1
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• pp.89-95
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• 2009

The purpose of the present study was to evaluate the safety under extreme environmental conditions and the dynamic safety under service environment conditions, of oceanographic buoy mooring systems consisting of a variety of materials, including chain, wire rope, nylon rope, and polypropylene rope. For the static safety assessment of a mooring system, after the calculation of external forces and the division of a mooring system into finite elements, the numerical integral was conducted to yield the elemental static tension until satisfying the geometrical convergence condition. To evaluate the dynamic safety, various processes were considered, including data collection about the anticipated areas for mooring, a determination of the parameters for the interpretation, the interpretation of the dynamic characteristics based on an analytic equation that takes into account the heave motion effect of a buoy hull and a mooring system, and a fatigue analysis of the linear cumulative damage. Based on the analysis results, a supplementary proposal for a wire rope that has a fracture in an actual mooring area was established.

• Journal of Korean Society of Steel Construction
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• v.22 no.2
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• pp.151-160
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• 2010

The number of cases of collapsed plastic greenhouses in farmlands has increased due to the heavy local snowfall caused by extraordinary atmospheric phenomena. Consequently, the economic losses of farmers have also increased. However the government policy in relation to damage pretension is insufficient and collapse case is repeated every year. The main reason for frame collapse is that the moment capacity of a steel pipe is not sufficient to resist a heavy snowload. In this study, experiments were conducted on the current frame system of a greenhouse with a tension tie. The frame consisted of two sections(${\phi}25.4{\times}1.5$, ${\phi}31.8{\times}1.5$), and its span length was 6.5 m. A temporary tension tie using a steel wire and a fabric rope was connected to the two joints, to which a curved beam and a straight column were connected. The pretension force was applied at the tension tie, and a vertical force simulating snowfall was applied until failure. The fabric rope frame increased the load-carrying capacity by 10-45% compared to the normal frame without a tension tie, and the steel wire frame increased the load-carrying capacity by 58-73% compared to the normal frame without a tension tie. Steel wire was found to be more effective as far as strength is concerned, but its connection details and pretension application are more difficult and complicated than those of the fabric rope. The test results thus show that the fabric rope is more preferable.

• Fire Science and Engineering
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• v.26 no.6
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• pp.78-84
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• 2012

In this study, we have conducted a fire resistance experiment under loading condition on standard fire to evaluate the fire resistance performance according to applying reinforcement of methods for reinforcing the lateral confinement of reinforced bars (Wire Rope) and fire resistance reinforcement (Fiber-Cocktail) for 100 MPa high strength concrete column. In the result of the experiment, in case of the test objects applied by hoop, it has been shown as not possible to be applied as the fire resistance structure after satisfying the fire resistance performance for 43 minutes. In case of applying the wire rope as lateral confinement of reinforced bar, instead of hoop in identical volume ratio, it has been shown as possible to apply it to the buildings with under 4 floors after satisfying the fire resistance performance fro 69 minutes with any separate fire resistance process. Also, in case of applying with mixing wire rope method, instead of hoop, and Fiber-Cocktail mix method to prevent spall, it has been shown as possible to apply to the buildings with over 12 floors after satisfying the fire resistance performance for 180 minutes.

• Tribology and Lubricants
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• v.19 no.4
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• pp.223-229
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• 2003

The sliding wear characteristics of the crane sheave were investigated using a pin-on-disk rig tester. The experiment was conducted using a high carbon steel wire that was upper material, also carbon steel castings that was disk material. There are various operating conditions in this work. At the room temperature, we carried out the wear test under a grease lubrication and dry condition. The results of wear test showed that an annealed-casted have lower, also the wear curves are linearly increased with increasing of sliding distance. For the specific wear rate of annealed-casted, the wear resistance was increased with decreasing diameter of wire. The wear of a wire and a disk have a different mechanism, the one is the abrasive wear due to fatigue wear under lubrication, another is the adhesion wear under dry condition.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2001.06a
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• pp.319-326
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• 2001

The sliding wear characteristics of carbon steel castings were Investigated using a ball on disk type tester. The experiment was conducted using high carbon steel wire rods as ball material and carbon steel castings as disk material and different operating conditions, at room temperature under a lubrication and dry conditions. The results showed that the carbon steel castings appeared average wear volume Is lowed after annealing under a lubrication conditions and wear curve linear Increased. The specific wear rate of carbon steel castings Increased with wire diameter lubrication and dry also Increased 125 times In Ory. The sliding wear mechanism were Investigated due to fatigue wear lubrications and abrasive wear dries also wire Included fatigue and abrasive wear by plastic flow.

• Journal of the Korean GEO-environmental Society
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• v.6 no.3
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• pp.35-45
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• 2005

The rockfall protection fence is one of the most common rockfall protection methods in Korea. The typical rockfall protection fence consists mainly of three parts ; H-beam supports, wire meshes, and wire ropes. The design of the rockfall protection fence is made such that the total energy absorbing capacity of the fence. Therefore, resulting from the combined energy absorbing capacity of the three parts is larger than the falling energy of rocks. In present study, a new rockfall protection fence, constructed using expanded metals instead of the existing wire rope and wire mesh for the typical type of rockfall protection fence, was evaluated on its performance by conducting both laboratory and field tests. Also, for a comparison, the same tests were performed on the typical rockfall protection fence. The test results revealed that the expanded material is an economic alternative to the existing protection materials and the expanded metal rockfall protection fence exhibits the higher energy absorbing capacity compared to that of the typical rockfall protection fence.

• Journal of the Korean GEO-environmental Society
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• v.10 no.6
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• pp.49-60
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• 2009

In order to develop a new rockfall protection fence using high carbon steel wire rod (HSWR) material instead of the conventional wire rope material, the author has conducted the laboratory strength tests of both materials and their connections, and carried out evaluation of absorbing rockfall energy through the vertical field rockfall tests. The vertical filed rockfall tests showed that the new rockfall protection fence with 12 rows of the HSWR could absorb more rockfall energy than 50 kJ which stands for the typical design criteria. In addition, when the quantity of HSWR was increased up to the 16 rows, the capacity of absorbing energy was greatly improved. The new rockfall protection fence was successfully applied to the highway rock-cut slope. As a result of the filed application, its constructability was similar to the conventional fence, but its total image was improved as simple and clean. The total construction cost was saved up to 20% in comparison with the conventional one.

• Journal of the Korean GEO-environmental Society
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• v.24 no.2
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• pp.25-30
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• 2023

The high-strength rockfall net developed in this study is to replace the fallout prevention net method using PVC coating net made of core wire thickness 3.2 mm and tensile strength 290-540 MPa class steel wire. General PVC coating net have low performance, and in the event of falling rocks or surface loss, they cannot withstand the load and are torn, which rather adds to the damage. Developed rockfall net was manufactured using steel wires with a core wire thickness of 2.8 to 3.2 mm and a tensile strength of 1,000 to 2,000 MPa. Test method was referred to the international standard Steel wire rope net panels and rolls-Definitions and specifications (ISO 17746:2016), and was conducted in accordance with the provisions of the punching test. Through indoor punching tests, the load-displacement curves of the general PVC coating network and the developed high-strength capture net (1,000 and 2,000 MPa) were compared, and the maximum Pull-out load was analyzed to be improved by 324.47% (2,000 MPa high-strength net).

• Smart Structures and Systems
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• v.18 no.6
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• pp.1203-1215
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• 2016

When strain sensing cables are under long-term stress and cyclic loading, creep may occur in the jacket material and each layer of the cable structure may slide relative to other layers, causing fatigue in the cables. This study proposes a device for testing the fatigue characteristics of three types of cables operating under different conditions to establish a decay model for observing the patterns of strain decay. The fatigue characteristics of cables encased in polyurethane (PU), GFRP-reinforced, and wire rope-reinforced jackets were compared. The findings are outlined as follows. The cable strain decayed exponentially, and the decay process involved quick decay, slow decay, and stabilization stages. Moreover, the strain decay increased with the initial strain and tensile frequency. The shorter the unstrained period was, the more similar the initial strain levels of the strain decay curves were to the stabilized strain levels of the first cyclic elongation. As the unstrained period increased, the initial strain levels of the strain decay curves approached those of the first cyclic elongation. The tested sensing cables differed in the amount and rate of strain decay. The wire rope-reinforced cable exhibited the smallest amount and rate of decay, whereas the GFRP-reinforced cable demonstrated the largest.