• Title/Summary/Keyword: Tension

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The Type of Composition and Classification of Tension Structure Systems in Architecture (건축 인장구조시스템의 분류와 구성유형)

  • Lee, Ju-Na;Park, Sun-Woo;Park, Chan-Soo
    • Journal of Korean Association for Spatial Structures
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    • v.3 no.3 s.9
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    • pp.111-120
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    • 2003
  • Tension members is a type of effective structural member, which is often used in large span structures. The structure systems composed with tension members are combined in various way and specific formations. So, there are need to research into the formations of tension structure and the type of adaptation in tension structure architectures. The structure systems with tension members were considered as tension main system, vector system and tension supported bending system, comprehensively. And tension structures were classified into the formation of tension structure with uniaxial or multiaxial line tension member, with surface member, with hybrid member of line and surface, concerning the flow of tension force. In each the formation of tension structure, the typical adaptations to architecture were also investigated through architecture examples. The type of the formation can be used to plan an architecture with respect to the flow of tension force and structural feature.

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Strip Tension Control Considering the Temperature Change in Multi-Span Systems

  • Lee Chang Woo;Shin Kee Hyun
    • Journal of Mechanical Science and Technology
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    • v.19 no.4
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    • pp.958-967
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    • 2005
  • The mathematical model for tension behaviors of a moving web by Shin (2000) is extended to the tension model considering the thermal strain due to temperature variation in furnace. The extended model includes the terms that take into account the effect of the change of the Young's Modulus, the thermal coefficient, and the thermal strain on the variation of strip tension. Computer simulation study proved that the extended tension model could be used to analyze tension behaviors even when the strip goes through temperature variation. By using the extended tension model, a new tension control method is suggested in this paper. The key factors of suggested tension control method include that the thermal strain of strip could be compensated by using the velocity adjustment of the helper-rollers. The computer simulation was carried out to confirm the performance of the suggested tension control method. Simulation results show that the suggested tension control logic not only overcomes the problem of the traditional tension control logic, but also improves the performance of tension control in a furnace of the CAL (Continuous Annealing Line).

Failure Behavior and Tension Stiffening of RC Tension Members (철근콘크리트 인장부재의 인장강성 및 파괴거동에 관한 연구)

  • 박제선;이봉학;윤경구;홍창우;이주형
    • Proceedings of the Korea Concrete Institute Conference
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    • 1998.04b
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    • pp.737-742
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    • 1998
  • The tension stiffening effect is defined as the increase in stiffness in reinforced concrete member due to the stiffness provided by concrete between cracks. If this is disregarded in analysis of reinforced concrete members, especially at the level of service loads, member stiffnesses may be underestimated considerably. This paper presents on the failure behavior and tension stiffening of RC tension test with main variables such as concrete strength, rebar diameter and strength. The tension stiffening was analyzed from the load-displacement relationship by ACI code and the proposed by Collins & Mitchell. In summary, the effect of tension stiffening decrease rapidly as the rebar diameter increase, rebar strength increase, and concrete strength increase. The effect of tension stiffening on RC member is the biggest near the behavior of concrete cracking and decrease as the load close to the breaking point. Thus, the tension stiffening should be considered for the precise analysis near the load of concrete cracking.

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Tension Stiffening Effect for Reinforced Concrete Members (철근 콘크리트 부재의 인장강성 효과에 관한 연구)

  • 이봉학;윤경구;홍창우
    • Journal of the Korea Concrete Institute
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    • v.11 no.4
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    • pp.83-93
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    • 1999
  • This paper presents tension stiffening effect of Reinforced concrete members obtained from experimental results on direct tension and bending. From the direct tension test program, crack patterns were investigated with tension softening behaviors of concrete. Tension stiffening effects and losses of strain energy were, also, analyzed from the load-deflection curve with the main experimental variables such as concrete strength, yielding stress and reinforcement ratio of rebar. Tension stiffening effect of RC members increase linearly until the first crack initiate, decrease inversely with number of cracks, and then decrease rapidly when splitting cracks are happened. The tension stiffening effect is shown to be more important at the member of lower reinforcement than that of higher. Therefore, it necessitates to consider the tension stiffening effects at a nonlinear analysis. From the above analysis, a tension stiffening model of concrete is proposed and verified by applying it to bending members. From the numerical analysis by finite element approach, it is shown that the proposed model evaluates a little higher in analyzing at nonlinear region of high strength concrete, but, perform satisfactorily in general.

Tesion Control of Unwinder/Winder using a Tension Observer (장력 관측기를 이용한 풀림롤/감김롤의 장력제어)

  • Song, Seung-Ho;Seol, Seung-Gi
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.49 no.1
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    • pp.62-69
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    • 2000
  • The strip tension as well as the line speed should be controlled tightly for the quality of products and productivity of the continuous strip processing line. In this paper, a new tension control algorithm with tension observer is proposed using observed tension as regulator feedback. The tension observer is based on the torque balance of a roller stand including the acceleration torque. Using this estimated tension, new tension controller can be constructed with faster dynamic response in case of line speed acceleration or deceleration. The proposed scheme needs no additional hardware because the inputs of observer, current and speed, are already being monitored by the motor drive system. Through the simulations and experiments with laboratory set up, performances fo conventional schemes and proposed one are compared. The results show the effectiveness of the proposed tension controller.

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Effect of Tension, Compression Lamination and Number of Lamination on the Flexural Properties of Platanus occidentalis L. Laminated Beam (인장(引張) 및 압축부재(壓縮部材)와 적층수(積層數)가 플라타너스 집성재(集成材)의 휨성질(性質)에 미치는 영향(影響))

  • Oh, Se-Chang;Lee, Phil-Woo
    • Journal of the Korean Wood Science and Technology
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    • v.14 no.2
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    • pp.3-12
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    • 1986
  • The aim of this study is to determine the flexural properties(Modulus of Rupture, Modulus of Elasticity) of Platanus occidentalis L. laminated beams fabricated with 1, 3, 5, 8, 15 lamination and Tension, Compression lamination. The results were as follows: 1. MOR increased with increasing number of lamination in 3, 5, 8, 15-beam and Tension lamination beam. MOR of Compression lamination beam was lower than that of 3-beam, MOR of vertical beam not having Tension or compression lamination was lower than that of horizontal beam, but MOR of vertical beam with tension or compression lamination was same or slightly higher than that of horizontal beam. 2. The allowable working stress showed the same tendency. This stress increased with increasing number of lamination. This value of Tension lamination beam was higher than that of compression lamination beam. 3. MOE of all laminated beams was higher than that of solid beam and Tension lamination beam was higher than that of 3-beam. MOE of Tension lamination beam was higher than that of Compression lamination beam. MOE of all vertical beam was higher than that of horizontal beam except for T-2, T-5, C-3. 4. Most beam failures appeared to begin in tension. These tension failures were classified into Splintering tension, Cross-grained tension, Simple tension, Brittle tension. All test beam failures could be classified into three categories. 1) Tension failure 2) Compression failure 3) Horizontal shear failure.

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Experimental Study and Evaluation of Tension Stiffening Model in High Strength Concrete Beams (고강도 콘크리트 보에서 Tension Stiffening 모델을 이용한 실험적 연구 및 평가)

  • Shin, Dae Hwan;Jo, Eunsun;Kim, Min Sook;Kim, Heechuel;Lee, Young Hak
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.27 no.1
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    • pp.45-53
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    • 2014
  • In strength limit states design, it is assumed that after cracking, reinforcement carries all tension in the tension zone of reinforced concrete members. However, it can be seen the concrete between cracks will contribute to carrying a part of the tension stress in actual concrete members particularly at service load levels, this effect is referred as tension stiffening effect. In this study, tension stiffening models and high strength concrete beam flexural test results were verified through comparison. The relationship between moment-curvature and load-deflection was evaluated by result of tension stiffening model and test result values. The analysis results showed that ACI 318 and Owen & Damjanic generally shows good agreement.

Technique of Tension Length Calculation for 350km/h High Speed Catenary System (최고운행속도 350km/h급 전차선로 장력구간길이 계산 기법)

  • Chang, Sang-Hoon;Lee, Ki-Won;Kwon, Sam-Young;Park, Jae-Woong
    • Proceedings of the KSR Conference
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    • 2011.05a
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    • pp.932-939
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    • 2011
  • This paper deal with technique of tension length calculation for 350km/h high speed catenary system. Tension length affects in facility investment. Possibility of overlap increasing a tension length and the equipment investor decreases in order to decrease. Considers the parameter which specifies and the grudge which is possible long the fact that decides a tension length is the aim which is important plans overhead contact line. The element which decides a tension length with next following; (i) Operating range of tension device, (ii) Change of the horizontal tension which affects possibility of the effect which operates to the line and span, (iii) Tension of wire material the tensile force which is relation, (iv) Wire thermal expantion which relates with a standard temperature, (v) Curve radius, (vi) Wind velocity, (vii) Thermal range of overhead contact wire and mechanical design of tension mechanism etc.

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Tension Estimation of Interstand Strip in Looperless Hot Rolling Process Using SVR (SVR을 이용한 Looperless 열연 공정에서의 스텐드간 장력 추정)

  • Han, Dong-Chang;Shim, Jun-Hong;Park, Cheol-Jae;Park, Hae-Doo;Lee, Suk-Gyu
    • Journal of Institute of Control, Robotics and Systems
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    • v.13 no.10
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    • pp.1007-1011
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    • 2007
  • This paper proposes a novel tension estimation of interstand strip in looperless hot rolling process using SVR(Support Vector Regression). The quality of hot coil which is final product of hot rolling process is substantially decided by tension control of finishing rolling in hot rolling process. The fluctuation of the strip tension in conventional hot rolling process is controlled by the strip tension measured by an inter-stand looper. However, the looper can cause a motor trip and tension hunting in hot rolling process, therefore, alternative method is essential to replace it. In this paper, the mathematical modeling of tension mechanism is implemented to estimate the tension using the proposed SVR algorithm without looper in hot rolling process. The simulation results show a reliable estimation performance and a possibility of tension control using SVR technique.

Effect of Initial Track Tension on the Tractive Performance of Tracked Vehicles (궤도의 초기 장력이 궤도 차량의 견인 성능에 미치는 영향)

  • 김채주;김경욱
    • Transactions of the Korean Society of Automotive Engineers
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    • v.5 no.2
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    • pp.1-12
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    • 1997
  • A computer program was developed to simulate effect of the initial track tension on the tractive performance of tracked vehicles. The performance was evaluated in terms of drawbar pull, motion resistance, tractive coefficient and tractive efficiency. Results of the simulation showed that increase in track tension decreases the sinkage and mean maximum pressure in clay, making the ground pressure distribution more uniform. This tendency became more evident when the number of roadwheels increased. However, such change in MMPs was negligible in firm soils. Motion resistance was also decreased with increase in track tension and the number of roadwheels. Under weak soil conditions, tractive coefficient and efficiency increased generally as the track tension increased for a slip range of 10∼30%. For slippage less than 3∼4%, however, the tractive coefficient decreased with increase in track tension. In general, it was known that increasing track tension improves tractive performance in weak soil conditions. However, high track tension can reduce efficiency due to the increment of internal motion resistance caused by increased track tension.

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