• Title/Summary/Keyword: Rope

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Shear Capacity of Reinforced Concrete Continuous T-Beams Externally Strengthened with Wire Rope Units (와이어로프로 외부 보강된 철근콘크리트 연속 T형 보의 전단내력)

  • Yang, Keun-Hyeok;Sim, Jae-Il;Byun, Hang-Yong
    • Journal of the Korea Concrete Institute
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    • v.19 no.6
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    • pp.773-783
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    • 2007
  • A simple unbonded-type shear strengthening technique for reinforced concrete beams using wire rope units is developed. Six two-span continuous T-beams externally strengthened with wire rope units and an unstrengthened control beam were tested. The main variables investigated were the amount and prestressing force of wire rope units. All specimens had the same geometrical dimension and arrangement of internal reinforcement. Influence of the distribution of vertical stresses in beam web owing to the prestressing force of wire rope units on the diagonal shear cracking load and the ultimate shear capacity of beams tested is presented. Based on the current study, it can be concluded that the amount and initial prestress of wire rope should be limited to be above 2.5 times the minimum shear reinforcement ratio specified in ACI 318-05 and below 0.6 times its own tensile strength, respectively, to ensure the enhancement of shear capacity and ductile failure mode of the strengthened beams. A numerical analysis based on the upper-bound theorem is developed to assess the shear capacity of continuous T-beams strengthened with wire rope units. From the comparisons of measured and predicted shear capacities, a better agreement is achieved in the proposed numerical analysis than in empirical equations recommended by ACI 318-05.

Arthroscopic Stabilization of Acromioclavicular Joint Dislocation using TightRope® (TightRope®를 이용한 내시경하 급성견봉쇄골관절 탈구의 고정술 메리놀병원 정형외과)

  • Choi, Sun-Jin;Park, Jong-Hoon;Lee, Hyeong-Seok
    • Clinics in Shoulder and Elbow
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    • v.11 no.2
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    • pp.172-176
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    • 2008
  • Purpose: The proper surgical methods for treating acromioclavicular joint dislocation is still controversial. New methods should provide better early motion with sufficient strength. Materials and Methods: We performed arthroscopic stabilization using TightRope$^{(R)}$ (Arthrex, Inc, Naples, FL) in 10 cases of acromioclavicular joint dislocation between April, 2007, and December, 2007, and followup for a minimum of 10 months. We performed radiologic evaluation by comparing the clavicle anteroposterior radiograph with the contralateral one. Clinical evaluation was made for pain, function, and range of joint motion by Imatani's methods. Results: In clinical evaluation, 6 cases were excellent, 3 cases were good, and 1 case was poor. In radiologic evaluation, 9 cases were excellent and 1 case was poor. Redislocation occurred in 1 case. Conclusion: During short-term followup, 9 of 10 patients who underwent arthroscopic stabilization using TightRope$^{(R)}$ had excellent results in Imatini tests and radiologic evaluation, except 1 patient with redislocation.

Dynamic Modeling and Simulation of a Towing Rope using Multiple Finite Element Method (다물체 요소이론을 이용한 예인줄 동역학의 모델링 및 시뮬레이션)

  • Yoon, Hyeon-Kyu;Lee, Hong-Seok;Park, Jong-Kyu;Kim, Yeon-Gyu
    • Journal of Navigation and Port Research
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    • v.36 no.5
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    • pp.339-347
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    • 2012
  • After towing rope connecting a barge to a tug was subdivided into multiple finite elements, then those dynamic models was established using Newton's second law and considering the external force and moment such as tension, drag, Coriolis force, gravity, buoyancy, and impact due to free surface acting on each element. While the previous research on the model of towing rope considered only translation, five-degree-of-freedom equations of motion except roll based on the body-fixed frame were established in this paper. All elements are connected by a spring and a damper, and the stiffness of the spring was set as the equivalent value of the real rope. In order to confirm the established multiple finite element model, various scenarios such as freely falling of towing rope in the air and above the free surface, accelerating of a tug which tows a barge connected by towing rope, and sinusoidal moving of a tug were set up and simulated. As the results, the trajectories of the tug, the barge, and the towing rope showed good tendencies to the ones of real expected situations.

Coil Sensors for Wire Rope Inspection using Magnetic Flux Leakage Instrument

  • Go, Hyun-Min;Takayama, Junya;Ohyama, Shinji;Kobayashi, Akira
    • 제어로봇시스템학회:학술대회논문집
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    • 2002.10a
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    • pp.79.5-79
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    • 2002
  • $\textbullet$ Introduction $\textbullet$ Deterioration of wire rope $\textbullet$ Magnetic flux leakage Instrument $\textbullet$ Experiment setup $\textbullet$ Performance of the instrument $\textbullet$ Conclusions

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Study on the Shear Strengthening of Concrete Beams with Wire Rope Clamped by Bolts (볼트 체결된 와이어 로프를 이용한 RC 보의 전단보강에 대한 연구)

  • Kim, Sun-Young;Song, Jin-Gyu;Lee, Young-Uk;Byun, Hang-Yong
    • Journal of the Korea Concrete Institute
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    • v.18 no.2 s.92
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    • pp.283-290
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    • 2006
  • The paper describes m experimental study on the shear strengthening of concrete beams with exposed wire rope. The strengthening method is using the mechanical bolting of wire rope tensioned on the exterior of beam section. There are two shear strengthening types. The first is closed type wrapped beam section with wire rope like as closed stirrup. The second is U type tensioned at the anchor located in the side of beam section. The main parameters of specimens are strengthening spacings of wire rope with 150, 200, and 250mm for the closed and U type respectively. The shear span ratio of specimens applied by 3-point loading is 4. The results showed that the ultimate shear strength and ductility of strengthened beams increased significantly compared with non-strengthened beams. Especially, the strengthening effect of closed type was very preferable to U type. Therefore, the shear strengthening method with wire rope is very reasonable in view of repair and rehabilitation of beams.

Mechanization of Fishing Operation on the Sea Eel Pots - 3 . Automatic Loop Catcher and Recoiling System of the Main Line - (장어 통발어업의 자동기계화에 관한 연구 - 3 . 모릿줄과 고달이채기의 자동화 -)

  • 하정식
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.26 no.2
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    • pp.118-124
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    • 1990
  • The rope winder in addition to the line hauler was used for recoiling of the main line to the rope pond at the stern, however, catching the loops, evenly revoiling and arrangements of the loops were done manually by two men. The automatic loop catcher under the rope winder was consisted with the rotary lever, semicircle guide plates, transfer belt and swing rope receiver for arrangements of the loops and evenly recoiling. The obtained results are as follows: 1. The minor diameter of a loop and the diameter of the coiling pile in a lead core PP rope(ø 10mm) are about 14cm and 60cm while the rope is piled on the bottom. 2. Distribution ratio of the loops within upper or lower 10cm from the transfer belt is 93% with a lead sinker and 98% without sinker using by the smaller loop catcher. 3. The relationship between revolutions of the rotary lever N sub(1) (rpm) and the hauling pulley N sub(p) (rpm) by gear ratio 3:1 in the smaller loop catcher is as follows: N sub(p) =2.86 N sub(1) +23.74 and optimum ratio of horizontal speed of the loops by the rotary lever to hauling speed is about 70%. 4. The rope receiver is swung front and rear for the evenly recoiling and its period can be controlled by gear ratio or hydraulic circuit in accordance with the interval of the loops.

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