• Title/Summary/Keyword: Tension Structure

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Design and Evaluation of the Tension Sensor for Surgical Steel Wires (수술용 강선에 대한 인장력 측정센서의 설계 및 특성평가)

  • Joo, Jin-W;Lee, Bong-S
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.21 no.2
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    • pp.261-271
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    • 1997
  • This paper presents the design process and characteristic test results of tension sensors for measuring the ultimate tension forces of surgical wires. Three types of sensor were designed and tested for calibration. The first two types which transfer the wire tension to the sensing element by direct contact have too much hysterisis errors due to the firctional effect. This error can be considerably reduced in the modified structure, where a cover and a loading button is used to transfer force and moment to the sensing element. The strains predicted by theoretical equations agree well with those by finite element calculations neglecting friction and the strains by finite element analysis considering friction are in good agreement with those measured by four strain gages. The modified ring type tension sensor developed in this paper is expected to be useful for measuring the tension of surgical wires with nonlinearity of 1.31%FS, hysterisis of 5.74%FS and repeatability of 0.19%FS.

A Study on the Stabilization Process of Truss Structure Stabilized by Cable Tension (장력안정트러스 구조물의 안정화기법에 관한 연구)

  • 권택진;한상을;김충한;최옥훈
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1996.10a
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    • pp.330-339
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    • 1996
  • The primary objective of this paper is to grasp characteristics of unit system, for the stabilization of stablized truss structure that is an assemblage of unit system by prestress. This unit system is composed of a central post and eight cables, and is connected by hinge joints, and stabilized by the self-equilibrated stress system. As this unit structures itself is a statically closed and stabilized system individually, it can be employed to assemble a structure with a variety of configuration. In this paper, for the stabilization of truss structure stabilized by cable tension, it is proposed the self-equilibrated axial mode equation and the range of the various geometrical parameter about unit system.

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THE INFLUENCE OF CATCH VOLUME ON TRAWLER WARP TENSION (어류가 대량으로 입강했을 때의 선미 trawl의 warp 장력)

  • Kim Cha Dol
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.2 no.2
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    • pp.173-178
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    • 1969
  • Few reports have been written regarding the measurement of stern trawler warp tension under conditions of a full catch. This report compares the tension imposed on the warps at the time the boat begins to tow the net and the tension at the time the cod end is filled with a large quantity of fish. The structure of the otter boards and trawl net used for the experiment was the same types as used by Koyama, Sakurai, and Sumikawa (1968). The warp tension was measured with a load cell tension meter. 3) This meter continuously records the tension on a pen oscillograph. The net towing speed was measured with the CM-lA type current meter, Toho Dentan Co. Ltd., Japan. The data collected in the experiment are shown in Table 1. This table indicates that shooting No. 2 and No. 11 show a large catch volume, and the types of fish caught are shown in Table 2. The tension meter recordings when the boat began to tow the net and when the cod end was filled with a large quantity are shown in Fig. 1 and Fig. 2. It is indicated that the barracouta Thyrsites atun (EUPHRASEN) causes little tension difference between the time before they enter the net and the time after they enter the net before hauling. Other types of fish influence tension similarly. According to these results, the warp tension measurements as recorded on a big stern trawler are more influenced by rough sea wave action than by the volume of fish caught.

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Meso-Scale Approach for Prediction of Mechanical Property and Degradation of Concrete

  • Ueda, Tamon
    • Corrosion Science and Technology
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    • v.3 no.3
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    • pp.87-97
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    • 2004
  • This paper presents a new approach with meso scale structure models to express mechanical property, such as stress - strain relationships, of concrete. This approach is successful to represent both uniaxial tension and uniaxial compression stress - strain relationship, which is in macro scale. The meso scale approach is also applied to predict degraded mechanical properties of frost-damaged concrete. The degradation of mechanical properties with frost-damaged concrete was carefully observed. Strength and stiffness in both tension and compression decrease with freezing and thawing cycles (FTC), while stress-free crack opening in tension softening increases. First attempt shows that the numerical simulation can express the experimentally observed degradation by introducing changes in the meso scale structure in concrete, which are assumed based on observed damages in the concrete subjected to FTC. At the end applicability of the meso scale approach to prediction of the degradation by combined effects of salt attack and FTC is discussed. It is shown that clarification of effects of frost damage in concrete on corrosion progress and on crack development in the damaged cover concrete due to corrosion is one of the issues for which the meso scale approach is useful.

Influence of Tether Length in the Response Behavior of Square Tension Leg Platform in Regular Waves

  • El-gamal, Amr R.;Essa, Ashraf
    • International Journal of Ocean System Engineering
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    • v.4 no.1
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    • pp.19-28
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    • 2014
  • The tension leg platform (TLP) is a vertically moored structure with excess buoyancy. The TLP is regarded as moored structure in horizontal plan, while inherit stiffness of fixed platform in vertical plane. In this paper, a numerical study using modified Morison equation was carried out in the time domain to investigate the influence of nonlinearities due to hydrodynamic forces and the coupling effect between surge, sway, heave, roll, pitch and yaw degrees of freedom on the dynamic behavior of TLP's. The stiffness of the TLP was derived from a combination of hydrostatic restoring forces and restoring forces due to cables and the nonlinear equations of motion were solved utilizing Newmark's beta integration scheme. The effect of tethers length and wave characteristics such as wave period and wave height on the response of TLP's was evaluated. Only uni-directional waves in the surge direction was considered in the analysis. It was found that for short wave periods (i.e. 10 sec.), the surge response consisted of small amplitude oscillations about a displaced position that is significantly dependent on tether length, wave height; whereas for longer wave periods, the surge response showed high amplitude oscillations about that is significantly dependent on tether length.

Shear and tensile behaviors of headed stud connectors in double skin composite shear wall

  • Yan, Jia-Bao;Wang, Zhe;Wang, Tao;Wang, Xiao-Ting
    • Steel and Composite Structures
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    • v.26 no.6
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    • pp.759-769
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    • 2018
  • This paper studies shear and tensile behaviors of headed stud connectors in double skin composite (DSC) structure. Firstly, 11 push-out tests and 11 tensile tests were performed to investigate the ultimate shear and tensile behaviors of headed stud in DSC shear wall, respectively. The main parameters investigated in this test program were height and layout of headed stud connectors. The test results reported the representative failure modes of headed studs in DSC structures subjected to shear and tension. The shear-slip and tension-elongation behaviors of headed studs in DSC structures were also reported. Influences of different parameters on these shear-slip and tension-elongation behaviors of headed studs were discussed and analyzed. Analytical models were also developed to predict the ultimate shear and tensile resistances of headed stud connectors in DSC shear walls. The developed analytical model incorporated the influence of the dense layout of headed studs in DSC shear walls. The validations of analytical predictions against 22 test results confirmed the accuracy of developed analytical models.

FSI(Fluid-Structure Interaction) Analysis for Harmonious Operation of High-Speed Printing Machine

  • Kim, Jin-Ho;Lee, Jae-Woo;Park, Soo-Hyung;Byun, Do-Young;Byun, Yung-Hwan;Lee, Chang-Jin
    • International Journal of Aeronautical and Space Sciences
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    • v.9 no.1
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    • pp.137-146
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    • 2008
  • Proper amount of entrained air and nip force should be also considered to minimize ballooning phenomenon since tight contact between a roller and web is required. In this paper, various web materials, PET(Polyester) and OPP(Oriented Poly Propylene) have been selected and investigated to satisfy high-speed printing requirement. Several web speeds, web tensions, and temperature conditions are imposed on each web materials and the pressure and gap profiles as well as nip force have been calculated. Increase of both the winding roller radius and the incoming wrap angle is considered under proper taper tension at 500 m/min of rewinding roller. By solving coupled Reynolds equation and web deflection equation simultaneously, the fluid-structure interaction process has been developed and is applied to the rewinding roller to investigate the ballooning phenomenon which causes guiding problems in high-speed printing performance conditions. By adjusting the linear taper tension, stress distribution between rewinding webs can be remarkably reduced and stable pressure and gap profile with ignorable ballooning phenomenon have been found.

Construction of Roof Structure for Pusan Main Stadium (부산종합운동장 주경기장 지붕구조물의 시공)

  • Lee Ju-Young;Ryu Sang-Hyon
    • Proceedings of the Korean Institute Of Construction Engineering and Management
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    • autumn
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    • pp.228-231
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    • 2001
  • Construction of roof structure, cable suspended structure, for Pusan main stadium is adapted a lifting method that is VSL lifting system. 5 precesses are practiced for erection of the roof structure including the first lifting process for erection of upper cables and the second lifting process for erection of lower cables. Since all cables of this roof structure with two open speller sockets are determined their length, some cable were wrong length, the roof structure would be unstable. But At complete of erection for the roof structure each cab3e is attained to theoretical tension force with average $4\%$ errors.

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Study on stress transition mechanism by tensile and fracture characteristics of membrane material at bolting part in clamping part of membrane Structures (막구조 정착부의 볼트접합부 막재료의 신장 및 파단상태를 통한 응력전달체계에 관한 연구)

  • Kim, Hee-Kyun;Shim, Chun-Bo;Kim, Jae-Yeol
    • Journal of Korean Association for Spatial Structures
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    • v.23 no.4
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    • pp.97-105
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    • 2023
  • The membrane structure should maintain the membrane materials in tension for structural stability guaranty. The anchoring part in the membrane structure is an important part. It has the function to introduce tension into membrane materials and function to transmit stress which membrane materials receives to boundary structure such as steel frames. In this paper, it grasps anchoring system of the anchoring part in the membrane structure concerning the fracturing characteristic condition of membrane structure, and the influence which is caused to yield it designates the stress state when breaking the membrane structure which includes the anchoring part and that stress transition mechanism is elucidated as purpose. This paper follows to previous paper, does 1 axial tensile test concerning the bolting part specimen, grasp of fracturing progress of the bolting part and the edge rope and hardness of the rubber, does the appraisal in addition with the difference of bolt tightening torque. As a result, the influence which the bolt anchoring exerts on the fracturing characteristics of the membrane material in the membrane structure anchoring part is examined.

Empirical formulas to estimate cable tension by cable fundamental frequency

  • Ren, Wei-Xin;Chen, Gang;Hu, Wei-Hua
    • Structural Engineering and Mechanics
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    • v.20 no.3
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    • pp.363-380
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    • 2005
  • The cable tension plays an important role in the construction, assessment and long-term health monitoring of cable structures. The cable vibration equation is nonlinear if cable sag and bending stiffness are included. The engineering implementation of a vibration-based cable tension evaluation is mostly carried out by the simple taut string theory. However, the simple theory may cause unacceptable errors in many applications since the cable sag and bending stiffness are ignored. From the practical point of view, it is necessary to have empirical formulas if they are simple and yet accurate. Based on the solutions by means of energy method and fitting the exact solutions of cable vibration equations where the cable sag and bending stiffness are respectively taken into account, the empirical formulas are proposed in the paper to estimate cable tension based on the cable fundamental frequency only. The applicability of the proposed formulas is verified by comparing the results with those reported in the literatures and with the experimental results carried out on the stay cables in the laboratory. The proposed formulas are straightforward and they are convenient for practical engineers to fast estimate the cable tension by the cable fundamental frequency.