• Title/Summary/Keyword: operating tension

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A study on the lateral Dynamics of the Moving Web Induced by a Tilted Roller (웹 표면 수직방향으로 기우러진 롤에 의한 측 방향 웹 거동에 대한 연구)

  • Shin, Kee-Hyun
    • Journal of the Korean Society for Precision Engineering
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    • v.17 no.12
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    • pp.209-216
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    • 2000
  • The lateral behavior of the moving web is critical to the quality of the web products. The alignment of the rollers carrying the web is found to be one of important factors to the lateral behavior of the moving web. But, the study on the effect of the tilting roller in the direction of the normal to the moving web on the lateral behavior has not been reported in the literature yet. For example, the contact roller often contacts the winding roll in a tilted fashion and causes the lateral motion of the winding web, which induces the offset on the wound roll. The lateral dynamics of the moving web induced by a tilted roller in normal direction of a web is investigated in this paper. The two-dimensional dynamic model developed by Shelton is extended to investigate the effect of a titled roller in a normal direction of the moving web on the lateral motion of the moving web. New boundary conditions are developed to solve the extended model. Computer simulation study proved that the model developed can be used to predict the lateral motion of the moving web ? to a tilted roller in normal direction of the moving web. The lateral deflection is increased exponentially a the tilting angle is increased. As the length of web span is increased, the amount of lateral deflection was increased almost linearly for the same tilting angle. The lateral dynamics turned out to be almost independent to the operating tension. The model developed can be used to solve the offset problem of the staggered winding and also to design a new web guiding mechanism.

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Investigation of Safety and Design of Mooring Lines for Floating Wave Energy Conversion (부유식 파력발전장치용 계류선의 설계 및 안전성 검토에 관한 연구)

  • Jung, Dong-Ho;Nam, Bo-Woo;Shin, Seung-Ho;Kim, Hyeon-Ju;Lee, Ho-Saeng;Moon, Deok-Soo;Song, Je-Ha
    • Journal of Ocean Engineering and Technology
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    • v.26 no.4
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    • pp.77-85
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    • 2012
  • A study was performed on the design of a mooring line to maintain the position of a floating WEC (wave energy conversion) system. The procedure to design a mooring line is set up and the safety of the designed mooring system is evaluated using commercial software, Orcaflex. The characteristics curve for one line is analyzed to determine the properties and pretension of a mooring line. While considering the ocean environmental condition and importance of a floating WEC system, a multi-line layout is determined. A 4-point mooring system with 4 lines shows the instability in the yaw motion of the floating WEC system under a designed ocean environmental condition. The redesigned 4-point mooring system with 8 lines is found to be safe on the condition of a harsh ocean environment. The floating WEC system with the redesigned mooring system also shows stable motion in surge and pitch under operating conditions. From a parametric study on the mooring line length, the extreme value of the mooring line tension is found to be very sensitive to the pretension and length of mooring line. The results of this study can contribute to the establishment of a design procedure for mooring lines.

A Study on the free dispersal of the Power in Contemporary Architecture and Painting - Focused on the baroque in the Architecture of Frank O. Gehry and the Paintings of Francis Bacon - (현대 건축과 회화에서 힘의 자유로운 분산에 관한 연구 - 프랭크 게리의 건축과 프란시스 베이컨의 회화에 있어 바로크적인 것을 중심으로 -)

  • 이란표
    • Korean Institute of Interior Design Journal
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    • v.13 no.3
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    • pp.84-92
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    • 2004
  • This study concentrates on a new idea that is formulated as a creative spatialization in contemporary architecture and painting. It is stimulated from the classical baroque, which is expressed with the conceptual instruments, 'excessive', 'decorative', 'accidential' Suggested from that, this study tries to open the actual sense area of 'the baroque' by analysing the architectural ideas of wrenching and folding by Frank O. Gehry and in the same context by elucidating the dynamic deformalising of the figures by Francis Bacon. The redefined 'new baroque' operates in the chain of the transformable and flexible images that must be recognized as 'the real' in the sense of 'the most empirical' and are vulnerable to dispersal. The typical instrument of Gehry's 'new baroque architecture' is the enclosing of the space and its folding, and Bacon, whose painting can be called as the modern baroque, takes as the expressing methods a wrenching of the figures, a relieving of the colored background against the figure and a disappearing of figures into the background. These different ideas meet in the theoretical gravitation field of the philosophy of Deleuze, in which the reconstituted baroque conception means the tension between the folds, on expansion and contraction of which the variable space is dependent, Through the general principle of 'the new baroque', a free dispersal of power, to architect and painter is offered the possibility, not only to make the real world intimate to the real life, but also to produce from there a vivid new space. Finally it brings to enjoyer and viewer the possibility, to perceive the operating power in and around oneself.

Evaluation of Limit Loads for Circumferentially Cracked Pipes Under Combined Loadings (원주방향 표면 결함이 존재하는 배관에 가해지는 비틀림을 포함한 복합하중에 대한 한계하중식 제시)

  • Ryu, Ho-Wan;Han, Jae-Jun;Kim, Yun-Jae
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.39 no.5
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    • pp.453-460
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    • 2015
  • Since the Fukushima nuclear accident, several researchers are extensively studying the effect of torsion on the piping systems In nuclear power plants. Piping installations in power plants with a circumferential crack can be operated under combined loading conditions such as bending and torsion. ASME Code provides flaw evaluations for fully plastic fractures using limit load criteria for the structural integrity of the cracked pipes. According to the recent version of Code, combined loadings are provided only for the membrane and bending. Even though actual operating conditions have torsion loading, the methodology for evaluating torsion load is not established. This paper provides the results of limit load analyses by using finite element models for circumferentially cracked pipes under pure bending, pure torsion, and combined bending and torsion with tension. Theoretical limit load solutions based on net-section fully plastic criteria are suggested and verified with the results of finite element analyses.

Fracture Mechanics Analysis of the Weldment in Pulley for Belt Conveyor (컨베이어용 풀리의 용접부위에 관한 파괴역학 설계기술 개발)

  • Han, Seung-U;Lee, Hak-Ju;U, Chang-Su;Lee, Sang-Rok
    • 연구논문집
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    • s.23
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    • pp.127-140
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    • 1993
  • The drive pulley, which is employed for loading and unloading raw materials in a steel mill, is usually manufactured by use of various welding processes. In this study the weldment in the pulley, in which TIG and $CO_2$ welding processes are used, has been analyzed from view point of fracture mechanics. Fracture toughness tests have been performed according to ASTM E813. A servo-hydraulic testing machine (10kN) has been employed. Also the crack propagation tests (Mode I) have been performed with compact tension specimen in compliance with ASTM E647. To predict the critical crack size in the weldment, finite element stress analysis for the drive pulley under real operating conditions have been performed. In addition, the residual stresses at the weldment and in heat-affected zone have been obtained by hole drilling method. The planar critical crack size have been predicted for the drive pulley by considering the stress analysis results and the residual stresses due to welding process. For the drive pulley considered in this study, it has been concluded that the most important factor in determining the critical crack size is the welding residual stress in the transverse direction. Also the effect of stress concentration at the root of the weldment have been noticeable. For the planar crack, the fatigue crack growth life from an initial crack size of 2mm to the critical crack size obtained as in the above have been predicted. The predicted lives were between 55, 900 and 72, 000 cycles depending on the shape of the elliptical crack. The predicted lives were in fairly good agreement for the drive pulley considered in this study.

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On the Baroque in the Architecture of Frank O. Gehry-in relation to the baroque concept of Deleuze (프랭크 게리의 건축에 있어 바로크적인 것)

  • Lee, Ran-Pyo
    • The Journal of Engineering Research
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    • v.6 no.1
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    • pp.65-74
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    • 2004
  • This study concentrates on a new idea that is formulated as a creative spatialization in contemporary architecture. Suggested from the classical baroque, this study tries to open the actual sense area of 'the baroque' by analysing the architectural ideas of wrenching and folding by Frank O. Gehry. The redefined 'new baroque' operates in the chain of the transformable and flexible images that must be recognized as 'the real' in the sense of 'the most empirical' and are vulnerable to dispersal. The typical instrument of Gehry's 'new baroque architecture' is the enclosing of the space and its folding. This idea meet the theoretical gravitation field of the philosophy of Deleuze, in which the reconstituted baroque conception means the tension between the folds, on expansion and contraction of which the variable space is dependent. Through the general principle of 'the new baroque', a free dispersal of power, to architect is offered the possibility, to make the real world intimate to the real life and to produce from there a vivid new space, and to enjoyer and viewer the possibility, to perceive the operating power in and around oneself.

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Integrity comparison for various design specifications of corner protections in LNG storage tank (LNG저장탱크 코너프로텍션의 설계사양에 따른 건전성 비교)

  • Kim Hyoungsik;Hong Seongho;Seo Heungseok
    • Journal of the Korean Institute of Gas
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    • v.6 no.4 s.18
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    • pp.33-39
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    • 2002
  • [ $9\%$ ] nickel steel LNG storage tank have double containments that can store cryogenic LNG independently. Inner tank material is used as $9\%$ nickel steel and outer tank is constructed by concrete. Comer protection which is installed on inner surface of concrete corner is consist of $9\%$ nickel steel liner and form glass insulator that make reduce tension at corner when LNG is leaked from inner tank. It is very difficult to design corner protection because expansion and contraction of liner make stress state complex. Corner protections of operating tank in KOGAS are designed by Japanese engineering company such as TKK, KHI and England company of WHESSOE. This paper is mainly focused on the integrity comparison of them according to requirements of Appendix 4 in ASME Section VIII Div. 2 by using FEM.

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Design concept investigation for corner protection of LNG storage tank by ASME section VIII, Div. 2 (ASME section VIII div. 2에 따른 LNG저장탱크 코너프로텍션의 설계개념 고찰)

  • Kim Hyoungsik;Hong Seongho;Seo Heungseok;Yang Youngchul
    • Journal of the Korean Institute of Gas
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    • v.5 no.3 s.15
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    • pp.73-79
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    • 2001
  • The corner protection which is consist of insulation and $9\%$ nickel liner is designed to mitigate the high hoop tension at the corner of LNG storage tank by LNG leakage. So the design loads depend on thermal and liquid pressure from leaked LNG In this paper design conditions are suggested as operating, major and minor leak conditions. And in order to check integrity of comer protection for the design conditions by appendix 4 in ASME section VIII div.2, acceptability checking process that have stress categorization and finite element analysis is explained.

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Development of Automated Electric Snowplow by Using Clutch Bobbin for Improving Durability (내구성 향상을 위한 클러치 보빈 적용 고강성 전동식 제설기 개발)

  • Kim, Kee Joo;Park, Jun-Hyub
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.40 no.11
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    • pp.949-954
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    • 2016
  • When a snowplow is operating in the up or down direction, the sensor stops the movement automatically and the wire could be broken from an endless drive in the reverse direction impact or conversely winding wire. In the present study, a new bobbin was designed to ensure the durability of snowplows; in this design, the bobbin plays the role of a clutch during power transfer or idling. This will protect the blade of the snowplow during an impact and maintain close contact of the blade with the road. Therefore, the new technology to eliminate the tension and fatigue of the wire is suggested by winding a chain instead of the wire in the newly designed bobbin. From these, it was developed to extend the life of the snowplow without causing damages to the vehicle.

Application of Paint Spray Gun to Atomization of Barley Tea Concentrate (이류식(二流式) 노즐을 이용(理用)한 보리차 추출액(抽出液)의 분무(噴霧)에 관(關)한 연구(硏究))

  • Lee, Jeong-Cheol;Chun, Jae-Kun
    • Korean Journal of Food Science and Technology
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    • v.15 no.4
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    • pp.348-352
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    • 1983
  • The atomization of barley tea concentrate with paint spray gun of two fluid nozzle was investigated. The physical properties of barley tea concentrate were correlated to the operating parameters; soluble solid concentration, viscosity, specific gravity and surface tension. The air to liquid feed ratios at various barley tea concentration were correlated to the air pressures applied. The diameters of sprays at various air pressures (from 164 mmHg to 564 mmHg) and soluble solid concentrations (from 3.1% to 25.2%) were also investigated.

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