• 제목/요약/키워드: Tension

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불연성 복합재의 기계적 접합부 설계 허용치 도출을 위한 실험적 절차 (Experimental Procedure for Design Allowances of Mechanical Joint in Non-flammable Composites)

  • 이창훈;김진봉;박지상;황병선
    • 한국복합재료학회:학술대회논문집
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    • 한국복합재료학회 2004년도 춘계학술발표대회 논문집
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    • pp.258-261
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    • 2004
  • This paper contains the tension-tension, the tension-tension bearing and the tension-tension steel bolt joint fatigue characteristics of glass fabric/phenol composite laminates. The experimental results show that the bearing and the steel bolt joint fatigue characteristics of the material is so excellent compared with the simple tension fatigue characteristics, that there are no needs of additional strengthening for mechanical joint parts when the parts are properly designed.

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A Quantitative Assessment on a Tension of Securing Rope to evade Marine Accidents caused by Improper Cargo-Securing

  • Kim, Young-Du
    • 해양환경안전학회지
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    • 제21권3호
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    • pp.297-302
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    • 2015
  • To prevent cargo accidents by repeated loads, a continuous monitoring for securing rope or additional safety measures are needed, but most of prevention measures have been conducted only by operator's own experience not a quantitative assessment. Hence, the Load-Displacement curve and approximation formula of securing rope were drawn in this research for a quantitative assessment and simplified measurement on a tension of securing rope using a tensiometer. Moreover, a com parison was conducted between m easuring tension and calculated tension on securing rope with portable tensiometer, 'Load-Displacement' approximation formula. The calculated tension of securing rope is obtained 153.3kfg using the formula and that result has not much difference with initial tension 150.0kgf. Lastly, an analysis of the characteristics of various ropes was suggested to enhance the reliability about quantitative assessment of securing rope's tension through further research.

스프링식 자동장력 조정장치의 소개 및 경제성 분석 (An Introduction and Economical Efficiency analysis of Spring Tension Balancer)

  • 윤용한;임금광;신승식
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2005년도 춘계학술대회 논문집
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    • pp.856-861
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    • 2005
  • This paper presents an introduction and economical efficiency analysis of spring tension balancer in trolly wire system. In the overhead trolly wire systems, one of the most things is tension balancer. Because it can be automatically adjusted tension for expansion and contraction of overhead catenary system. In this paper, we introduced spring tension balancer and analyzed economical efficiency of it.

HYBRID LIGHTWEIGHT STRUCTURES -On Recent Projects aimed at Holistic Design

  • Saitoh, Masao
    • 한국공간구조학회:학술대회논문집
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    • 한국공간구조학회 2005년도 춘계학술발표회 및 정기총회 2권1호(통권2호)
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    • pp.52-66
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    • 2005
  • Tension and Membrane have the potential to enable the realization of lightweight structures that have the attractive features of structures efficiency and aesthetical expression. Compared with pure (thorough-bred) tension structures such as cable net, air dome and tensegrity, so called hybrid tension structures such as beam string, tensegric system and other mixed structures have Potential still to be realized. After synnaruzubg the simple definition of tensegric structure, some holistic designs for hybrid tension structures completed recently in the author's practice are given.

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전차 선로 자동 장력 조정 장치의 개선 방안 (A Suggestion for Improvement of Tension Balancer in Trolly Wire System)

  • 임금광;윤용한
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2004년도 추계학술대회 논문집
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    • pp.1328-1333
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    • 2004
  • This paper presents a suggestion for improvement of tension balancer in trolly wire system. In the overhead trolly wire systems, one of the most things is tension balancer. Because it can be automatically adjusted tension for expansion and contraction of overhead catenary system. In this paper, we introduce and suggest spring tension balancer(STB).

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적출 유두근에서 근육길이에 따른 계단현상 및 칼슘 수축력의 변화 (Length-dependent Staircase Phenomenon and Calcium Inotropisn in Isolated Rabbit Papillary Muscle)

  • 김기환;엄융의;남기용
    • The Korean Journal of Physiology
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    • 제14권2호
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    • pp.7-16
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    • 1980
  • The effects of various inotropic interventions on the shape of the steady state length tension relation and the length-dependent activation process in cardiac muscle were studied. The influence of inotropic interventions upon the action potential was also observed. The range of varying muscle length was from the optimal length$(l_{max})$, where the active tension production is maximal, to 0.85 $l_{max}$. Changes in stimulus frequency or in external bathing Ca concentration constituted the inotropic interventions in this experiment. The papillary muscles were isolated from the rabbit right ventricles and perfused with $HCO-_3\;-buffered$ normal Tyrode solution which was aerated with $3%\;CO_2-97%\;O_2$ mixed gas and kept at $35^{\circ}C$. Resting Passive tension at $l_{max}$ was approximately 30% of the total tension and appeared from the muscle length of 0.90 $l_{max}$. The effect of stimulus frequency on the steady state level of developed tension was: As the stimulus frequency was increased from 0.1 to 0.5 Hz, there was little change in developed tension. As the frequency was increased further, to a value of about 3 Hz, tension increased steeply. Further increase of the frequency to 5 Hz had little additional effect on the developed tension. The length-tension curves for isometric peak tension became more steeper with the degree of potentiation by inotropic interventions. The relative steepness of the normalized length-tension curves where tension production was expressed as a percentage of maximal tension developed at $l_{max}$, varied inversely with the level of inotropic state and these curves were not superimposable one another. Thus at the stimulus frequency of 2 Hz or at the external Ca concentration of 8 mM, the relative decline in the developed tension for a given change in muscle length was considerably less than the decline observed at the frequency of 0.5 Hz or at the concentration of 2 mM Ca. Action potential duration was prolonged significantly as the frequency increased from 0.2 to 2 Hz, and this change in action potential duration was not observable on the changes in muscle length. There was a tendency of the hyperpolarization of membrane potential when the muscle length was shortened from $l_{max}$ to 0.95 $l_{max}$. These results support the hypothesis that there is a length-dependence of the activation process.

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사장교 케이블장력 계측장치의 현장적용성 분석 (Field Application Analysis of Cable Tension Measuring Device on Cable-Stayed Bridges)

  • 이현철
    • 한국산학기술학회논문지
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    • 제22권4호
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    • pp.295-311
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    • 2021
  • 본 연구에서는 사장교 케이블에 대한 장력계측장치의 현장적용성에 대한 실험을 수행하였다. 사장교 케이블의 장력을 추정하기 위해서 진동법을 이용하였으며 대상교량에 대해서 케이블의 가진을 통해서 모드특성을 분석하였고 케이블의 장력을 추정하기 위한 계측장치로는 GTDL360, NI Module, 9 Axes Motion Sensor등을 적용하였고 5개의 대상교량에 대해서 상기 계측장치들을 이용하여 케이블의 모드특성을 분석하여 케이블장력측정실험의 적정성을 평가하고 케이블의 장력을 추정하였다. 또한 5개의 대상교량에 대해서 수치해석을 실시하여 케이블의 고유진동수 및 케이블장력을 해석하였다. 현장 계측결과에 의한 케이블의 추정장력과 수치해석에 의한 케이블의 추정장력을 비교하여 현장계측방법의 적정성을 판단하였으며 분석결과 현장 계측에 의한 케이블의 계측장력과 해석에 의한 추정장력은 오차범위내에 있어서 상기 계측장치들을 현장에 적용하여도 무방할 것으로 판단된다. 현장실증교량의 가속도 기반의 케이블 추정장력과 수치해석에 의한 해석장력과의 값을 비교분석한 결과 값이 허용범위 내로 가속도 기반의 케이블 추정장력값은 적정한 것으로 판단된다. 또한, 현장적용성 분석결과 센서의 설치위치 및 기상조건의 제한 등 계측장치의 한계점이 존재하므로 추후 케이블 스마트 장력계측시스템에 관한 지속적인 후속연구가 필요할 것으로 판단된다.

롤투롤 시스템에서 플렉시블 소재에 인가된 장력과 분사 높이가 액적 접촉각에 미치는 영향 (The Effect of Tension and Drop Height on Contact Angle of Droplet on Flexible Substrate in Roll-to-Roll Systems)

  • 김동국;이창우
    • 한국정밀공학회지
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    • 제34권3호
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    • pp.167-172
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    • 2017
  • This study proposes a method for identifying correlations between tension and drop height for sessile droplets in a roll-to-roll processing system. The effect of tension and drop height on the contact angle of a sessile droplet is presented. Design of experiment (DOE) methodology and statistical analysis are used to define a correlation between the process parameters. The contact angle is decreased while increasing tension and drop height. The influence of the tension is less significant on the contact angle compared with the effect of the drop height. However, tension should be considered as a major parameter because it is not easy to fix with roll eccentricity and compensating speed of the driven roll. The results of this study show that the effect of tension on the contact angle of a sessile droplet is more important than drop height because the drop height is fixed when the process systems are determined.

열간압연 권취공정의 장력제어를 위한 LTBC 제어기 설계 (Design of LTBC Controller for Tension Control in Down Coiler Process of Hot Strip Mills)

  • 이상호;박홍배;박철재
    • 제어로봇시스템학회논문지
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    • 제21권4호
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    • pp.301-308
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    • 2015
  • In this paper, we propose an LTBC (Low Tension and Load Balance Control) scheme to improve a coiling shape control by reduction the tension fluctuation by the torque disturbance in the down coiler process of hot strip mills. The proposed controller is a combination of an LTC to control the overload at load-on in the mandrel and an LBC to regulate the load balance of the upper and bottom pinch roll. A tension calculation model is suggested with the concept of the tension deviation. The effectiveness of the proposed control scheme is verified from simulation under a disturbance of the pinch roll torque. Using a field test, we show that the performance of the shape and tension control is improved by the LTBC control.

금속인장교정기의 공정변수 설계를 위한 탄소성 유한요소해석 (1)-단순모델 해석 (Elasto-plastic Finite Element Analysis for the Parametric Process Design of the Tension Leveller(1) -Unit Model Analysis)

  • 이형욱;허훈;박상래
    • 소성∙가공
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    • 제11권2호
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    • pp.138-146
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    • 2002
  • This paper is concerned with the simulation-based process design method involved non-steady state problem of tension levelling considering the elasto-plastic hardening behavior of a metallic strip by a commercial code ABAQUS/Standard. The tension levelling process is peformed to elongate the strip plastically in combination of tensile and bending strain by a controlled manner so that all longitudinal fibers in the strip have an approximately equal amount of length and undesirable strip shapes are corrected to the flat share. Objectives of this paper are the development of a general method for the design of a tension leveller by a finite element method and parameter studies for the deisgn variables such as the applied tension, the roll intermash includes the determination of the steady state using the simple unit of the tension levelling line and the effect of the finite element mesh size on the amount and distribution of the strain calculated. The analysis provides the information about the intermesh effect on the amount and final shapes of the strip and distribution of the strain in order to determine the amount elongation for correction of the irregular share.