• Title/Summary/Keyword: Tension

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Control of Longitudinal Tension and Lateral Position of a Moving Web (이송중인 웹의 장력 및 사행제어)

  • Shin, Kee-Hyun;Kwon, Soon-Oh
    • Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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    • 2002.11a
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    • pp.74-80
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    • 2002
  • A mathematical tension model for a moving web in a multi-span web handling system was derived and validated by using a simulator which includes unwinder, driven roller, winder, load cells, controllers, etc. A tension controller was designed to compensate tension disturbances generated by velocity changes of the unwinder and driven roller. From experimental results it was proved that the tension model properly expressed the tension behavior of a moving web for specific conditions. The distributed tension controller designed by using the pole-placement technique compensated the tension disturbances transfered from upsteram tension variation. Interactions between web spans including "tension transfer phenomenon" were clearly confirmed through the study. A mathematical model of lateral motion of a moving web was verified also by using the same experimental apparatus which includes displacement type guidance systems. And a feedforward control strategy was designed for more accurate control of the lateral motion of a moving web, which utilize a measured signal of the lateral displacement of web in a previous span and a more correctly identified mathematical model to estimate the disturbance of lateral motion from the previous span. This approach was turned out to be effective in improving the performance of the guidance system for more wide range disturbances.

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Experimental Study on Tension Stiffening of RC Tension Members (철근콘크리트 인장부재의 인장강성에 관한 실험적 연구)

  • 이봉학;윤경구;장동일
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.40 no.4
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    • pp.120-129
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    • 1998
  • The tension stiffening in reinforced concrete member means increase of stiffness caused by the effective tensile stress between cracks and the tension softening behavior of concrete. This paper presents on the tensile behavior and tension stiffening of RC tension members. Direct tension tests were performed with a main experimental variables such as concrete strength, rebar diameter and strength. The tension stiffening was analyzed from the load-displacement relationship and was compared with ACI code, CEB model and the proposed by Collins & Mitchell. The results are as follows : The tension behaviors of RC members were quite different from those of bare bar and were characterized by loading and concrete cracking steps. The effect of tension stiffening decreased rapidly as the rebar diameter and strength increased, and the concrete strength increased. The proposed by Collins & Mitchell described well the experimental results, regardless of rebar types and concrete. But, ACI code and CEB model described a little differently, depending on the types. The effect of tension stiffening in RC member was the biggest near at concrete cracking step and decreased gradually to the bare bar's behavior as loading closed to the breaking point. Thus, tension stiffening in RC members should be taken into account when the load-deflection characteristics of a member are required or a precise analysis near the load of concrete clacking is needed.

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Tension Control System for Hot Strip Mills (열간 압연 공정에서의 장력 제어시스템)

  • 박성한;안병준;황이철;홍신표;이만형
    • 제어로봇시스템학회:학술대회논문집
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    • 2000.10a
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    • pp.169-169
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    • 2000
  • The modeling for the looper of a hot strip finishing mill to control the tension of the strip is presented. The looper is an arm pushing against the strip between stands in a tandem mill to keep the strip tension constant and to isolate the interactions of the adjacent stands. Tension is influenced by the difference in mass flow through the up stream and down-stream rolling stands. Tension is critical to strip quality, influencing width, gauge, and shape. This paper presents how looper angle and strip tension are controlled for a hot strip finishing mill.

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Plasto-plastic Finite Element Analysis for the Parametric Process Design of the Tension Leveller(2) -Full Set Analysis (금속인장교정기의 공정변수 설계를 위한 탄소성 유한요소해석 (2)-전체공정 해석)

  • Lee, H.W.;Huh, H.;Park, S.R.
    • Transactions of Materials Processing
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    • v.11 no.2
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    • pp.147-154
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    • 2002
  • The tension levelling Process is Performed to elongate the strip plastically In combination of tensile and bending strain so that all longitudinal fibers In the strip have an approximately equal amount ofn length and undesirable strip shapes are corrected to the flat shape. Thus paper is concerned with a simulation of the tension levelling process based on the analysis of tile unit model for the tension leveller. Analysis technique such as the sequential analysis of the unit model is suggested and verified with the assembly analysis of the unit model for the effective arts economic analysis of the full set of the tension leveller. Analysis of the full tension levelling Process using sequential unit models Is carried out for steel strips with the shape defect and provides the effect of the intermesh and optimum amount of the intermesh in tension levelling process.

Performance Enhancement of Tension Controller for the Yarn Manufacturing Process (실 제조공정을 위한 장력제어기의 성능 개선)

  • Kwak, Young-Shin;Lim, Hoon;Lee, Jang-Myung
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.57 no.11
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    • pp.2054-2060
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    • 2008
  • This paper aims at the performance enhancement of tension controller for the yarn manufacturing process. The tension controller is required to keep the tension constant while the yarn is manufactured by a draw and twist machine, which is essential and critical for good quality production of yarn, steel, paper, etc. This paper proposes a linear model of tension control plant to develop a precise tension control system, which is derived by the close observation of the conventional mathematical model of motor driving and tension control systems. It is shown by experiments that the proposed control system precisely maintains the tension constant within the error bound of 0.05% while the conventional PI controller has about 0.2% error. The control performance of the system has been compared to that of conventional PI control not only for constant speed control but also for transient speed control experiments.

The experimental investigation on the characteristics of the cabling tension (케이블 포설장력 특성에 대한 실험적 고찰)

  • Kim, Dong-Hun;Han, Jin-Woo
    • 한국정보통신설비학회:학술대회논문집
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    • 2009.08a
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    • pp.49-53
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    • 2009
  • If you are installing communications cables in the pipeline based on the kind of cable installation tension within the allowed range of the tension must be maintained. The tension of the installation affected by the cable types, cable jacketed status, cross-sectional shape of the pipeline, the substance present in the pipeline, pipeline linear, the direction of the cable is installed. Depending on the size of the cable installation tension fatal influence on the quality of communication, or, at worst, the cable can be cut. In this paper, test bed for building a pipeline and using optical cable and such cable tension was measured. Freedom of access to the pipeline used in the experiment, and installed in conjunction with the cable tension was measured. It possible for the cable installation to determine whether a duplicate, and have compared the actual measured tension value and the theoretical expression.

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HOT STRIP WIDTH CONTROL METHOD BY USING LOOPER TENSION MEASURING SYSTEM IN FINISHING MILL (열간 사상압연 투퍼장력 측정에의한 열연판폭제어)

  • 홍완기;김필호;문영훈;이준정
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 1999.08a
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    • pp.423-428
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    • 1999
  • A high precision hot strip width control method has been developed in this study by applying interstand looper tension measuring system at finishing mill stands. As with deviation of hot rolled steel strip is closely related to abnormal increase in the interstand strip tension, on-line measuring device of looped tension and data analyzing system was developed in this study. To determine dominant factors that will cause local width shortage, the logged data sets of bar width, bar thickness, looper tension, and strip thickness along the strip length were correlated with the data set of strip width change. With the result of the correlation analysis, existing sequence control logic and parameters for looper actuator were modified for strip width quality and the gains of the looper control were refined for the stable operation during the full passage of rolled strip. The on-line tension measurement and tension feedback control for looper system improved strip travelling stability and reduced strip width deviation in the srip top end region.

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A Study of oriental-western medical research in tension headache (긴장성 두통의 동서의학적 고찰)

  • Park, Young-Hoi
    • Journal of Oriental Neuropsychiatry
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    • v.15 no.1
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    • pp.1-7
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    • 2004
  • Object : The purpose of this study is difference between western medicine and oriental medicine in tension headache. Methods : A literature study on the tension headache was performed. The cause, symptoms, relationship with other diseases, pathology and treatment of oriental and western medicine were investigated. Conclusion : In western medicine, tension headache is mainly caused by emotional stress, tension of head and neck musculatures. Treatments include medication, psychologic care, alteration of habits and biofeedback. Removal of muscle tension is of main interest in western medicine. In oriental medicine, tension headache is classified into internal and external problem. The imbalance of organs of spleen, liver and kidney causes headache. Hyperactivity of liver chi and deficiency of kidney yin are main source of headache. On the treatment, relieve of muscle tension and correction of bad habit are emphasized in western medicine while promotion of harmony among the internal organs is main target in oriental medicine.

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Application by Auto Back Tension System (오토백 인장장치의 적용성)

  • Park, Sang-Kook
    • 기술발표회
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    • s.2006
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    • pp.66-72
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    • 2006
  • The ground anchoring has been utilized over 40 years. It is growing the application of the removal ground anchor with tension force for holding earth retaining constructions in the city. It transmits tension stress of prestressed steel wire through grouting to fixed the ground that is of great advantage adjacent ground stability. Nowadays, we can find the compression dispersion anchor on many site. But, it has some problems in behavior of anchors because of impossible to tense p.c strand uniformly under the existing equipment due to different length of p c strand. Hence, motive of this research was to study the application of the newly developed tension system, that analyze and compare with the current anchoring method build on the data of in-site test and laboratory test. As a result, in case of auto back tension system, it became clear that tension pressure was equally distributed among the steal wires but the existing tension system showed sign of instability by indicating stress deflection of about 30% compare with design load. This can cause an ultimate failure of the concentrated p.c strand and a shear failure of ground.

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Finite Element Elasto-plastic Analysis of a Full Tension Levelling Process using Sequential Unit Models (순차 단순모델을 이용한 전체 인장교정 공정의 탄소성 유한요소해석)

  • Lee H. W.;Huh H.;Park S. R.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2001.05a
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    • pp.201-204
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    • 2001
  • The tension levelling process is performed to elongate the strip plastically in combination of tensile and bending strain so that all longitudinal fibers in the strip have an approximately equal amount of length and undesirable strip shapes are corrected to the flat shape. This paper is concerned with a simulation of the tension levelling process based on the analysis of the unit model for the tension leveller. Analysis technique such as the sequential analysis of the nit model is suggested and verified with the assembly analysis of the unit model for the effective and economic analysis of the full set of the tension leveller. Analysis of the full tension levelling process using sequential unit models is carried out and provides the effect of the intermesh and optimum amount of the intermesh in tension levelling process.

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