• 제목/요약/키워드: cross sectional study

검색결과 5,131건 처리시간 0.029초

초음파 용접을 이용한 전선의 접합 (Bonding of Electric Wire by Ultrasonic Welding)

  • 이철구
    • 한국생산제조학회지
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    • 제9권4호
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    • pp.41-47
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    • 2000
  • In this study, the purpose finds out the best welding conditions for bonding of electric wire by ultrasonic welding. The material was plastic-insulating low-voltage-cabels for automobiles. The experiment varied the values of welding time and welding pressure and fixed the values of amplitude and energy. With the facts, the best condition for ultrasonic welding to achieve bonding exactly is gained according to the size of the cross-sectional area of the cable, and the adhesive intensity is greatly influenced by the variables of welding time and welding pressure. Also when the welding time and welding time and welding pressure increase as the cross-sectional areas of the cable increase the welding result in gained exactly.

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Effect of fiber geometry on the electromagnetic shielding performance of mortar

  • Kim, Young Jun;Yemam, Dinberu M.;Kim, Baek-Joong;Yi, Chongku
    • Computers and Concrete
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    • 제17권2호
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    • pp.281-294
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    • 2016
  • The increased awareness of electromagnetic wave hazards has prompted studies on electromagnetic shielding using conductive materials in the construction industry. Previous studies have explored the effects of the types of conductive materials and their mix proportions on the electromagnetic shielding performance; however, there has been insufficient research on the effect of the geometry of the conductive materials on the electromagnetic shielding performance. Therefore, in this study, the dependence of the electromagnetic shielding performance on the cross-sectional geometry, diameter and length of fibers was investigated. The results showed that the electromagnetic shielding performance improved when the fiber length increased or the diameter decreased, but the effect of the cross-sectional geometry of the fibers was smaller than the effect of the fiber spacing factor.

고온초전도 테이프를 이용한 다단 전류 도입선의 최적설계 (Optimal Design of Multi-Step Current Leads Using HTS Tapes)

  • 김민수;나필선;설승윤
    • 한국초전도저온공학회:학술대회논문집
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    • 한국초전도저온공학회 2001년도 학술대회 논문집
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    • pp.84-88
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    • 2001
  • The optimum cross-sectional area Profile of gas-cooled high-temperature superconductor (HTS) current lead is analyzed to have minimum helium boil-off rate. The conventional constant area HTS lead has much higher helium consumption than the optimum HTS lead considered in this study. The optimum HTS lead has variable cross-sectional area to have constant safety factor. An analytical formula of optimum shape of lead and temperature profile are obtained. For multi-step HTS current leads, the optimum tape lengths and minimum heat dissipation rate are also formulated. The developed formulations are applied to the Bi-2223 material, and the differences between constant area, constant safety-factor, and multi-step current leads are discussed.

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단면형상에 따른 횡구속 콘크리트의 성능 평가 (Performance Evaluation of Confined Concrete According to Cross Sectional Shape)

  • 김영식;김민준;김상우;백승철;이정윤;김길희
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2010년도 춘계 학술대회 제22권1호
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    • pp.77-78
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    • 2010
  • 이 연구에서는 고강도 나선철근으로 횡구속된 콘크리트 압축강도의 영향을 평가하였다. 주요 실험 변수는 콘크리트의 압축강도, 나선철근의 항복강도 및 단면형상으로 하였다. 실험체는 총 48체로 원형과 각형 단면을 가지며, 단조 집중하중 상태에서 실험을 수행하였다.

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저온 플라즈마 처리에 의한 전자파 차폐성 금속화 합성섬유의 계면 밀착성 개선 (Improvement of Interfacial Adhesion of Metal Plated Synthetic Fabrics for Electromagnetic Wave Shielding by Using Cold Plasma)

  • 천태일
    • 한국염색가공학회지
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    • 제10권2호
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    • pp.8-17
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    • 1998
  • In this study we have examined electroless chemical plating on the plasma grafted poly [ethylene terephathalate](PET) fabric in order to improve the interfacial adhesion between metal and fiber. The vapour phase of acrylic acid introduced on the PET surface and the graft polymerization was carried out by using cold plasma, resulting in the grafting yield of 0.8-1.3 wt%. The carboxyl group of the plasma grafted was identified by FT-IR-ATR spectra. The Interfacial adhesion was related to the carboxyl group. After electroless chemical plating of nickel, it showed that the more the carboxyl, the better the interfacial adhesion. Comparing to the untreated, the plasma grafted fabric showed fairly good interfacial adhesion(5B grade, ASTM D3359) . The shielding effect of electromagnetic wave showed 95dB. The shielding effect depends on the fabric structure, the surface structure, and the cross sectional shape of fibers. The dense fabric structure, the etched surface like a microcrater, and the trigonal cross sectional shape were prefered.

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알루미늄 합금 피로 스트라이에이션의 나노 스케일 관찰 (Nano-Scale Observation of Fatigue Striations for Aluminum Alloy)

  • 최성종;권재도
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2000년도 춘계학술대회논문집A
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    • pp.153-158
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    • 2000
  • Atomic Force Microscope (AFM) was used to study cross sectional profiles and dimensions of fatigue striations in 2017-T351 aluminum alloy. Their widths (SW) and heights $(SH,\;SH_h)$ were measured from the cross sectional Profiles of three-dimension AFM images. The following results that will be helpful to understand the fatigue crack growth mechanism were obtained. (1) Coincidence of the crack growth rate with the striation width was found down to the growth rate of $10^{-5}$ mm/cycle. (2) The relation of $SH={\alpha}(SW)^{1.2}$ was obtained. (3) The ratio of the striation height to its width SH/SW and did not depend on the stress intensity factor range ${\Delta}K$ and the stress ratio R. From these results, the applicability of the AFM to nano-fractography is discussed.

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엇회전식 축류팬의 3 차원 비정상 유동에 관한 실험적 연구 (Experimental Study on the Three Dimensional Unsteady Flow in a Counter Rotating Axial Flow Fan)

  • 박현수;조이상;강현구;조진수
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2003년도 추계학술대회
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    • pp.822-827
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    • 2003
  • Experiments were done for the three dimensional unsteady flow in a counter rotating axial flow fan under stable operating condition. Flow fields in a counter rotating axial flow fan were measured at cross-sectional planes of the upstream and downstream of each rotor. Cross sectional flow patterns were investigated through the acquired data by the $45^{\circ}$ inclined hot-wire. Flow characteristics such as tip vortex, secondary flow and tip leakage flow were confirmed through axial, radial and tangential velocity vector plot. Swirl velocity, which was generated by the front rotor, was recovered in the form of static pressure rise by the rear rotor except for hub and tip regions.

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Stereolithography를 위한 STL파일로부터 단면정보 변환에 관한 연구 (A study on conversion of cross-sectional information form STL file for Stereolithography)

  • 최홍태;김준안;이석희;백인환
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 1995년도 춘계학술대회 논문집
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    • pp.445-450
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    • 1995
  • This paper deals with conversion from STL file to Slice cross-sectional information for Stereolithography. The STL file consist of three vertices of triangle and normal vectors in order to represent three dimension shape, but It is very difficult to convert STL file intoSlice file directly, because of file size from one Mbyte to tens of Mbytes. So, The system is accomplished data flow such as neutral.dat, .SL1, .SL2, .SL3, and .SLC file. The data processing is as follows: 1. Create a neutral file including common information. 2. Modify STL file within effective scope of SLA. 3. Calculate a point of intersection between plane equation and line equation. 4. Sort z values by increasing order. 5. Search closed loop by method of singlylinked linear list. The system is developed by using Borland C++ 3.1 compiler in the environment of Pentium PC. We get a satisfactory prototype as a result of application about a lot of household electrical appliances.

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퍼지제어를 이용한 냉연공정 형상제어 시뮬레이션 (Simulation of Shape Control in Cold Rolling Using Fuzzy Control)

  • 정종엽;임용택;진철제;이해영
    • 대한기계학회논문집
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    • 제18권2호
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    • pp.302-312
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    • 1994
  • In this study, a fuzzy theory is introduced to control the cross-sectional strip shape in cold rolling. A fuzzy controller is developed based on the production data and the operational knowledge. The cold rolled products are characterized into several types based on their irregularities. For each type of irregular strip shape, fuzzy controller calculates the changes of bender forces of work and intermediate rolls using fuzzy control algorithm. To simulate the continuous shape control, fuzzy controller is linked with emulator which is developed using neural network. The developed fuzzy controller and emulator simulate the cold rolling process until the irregularities converge to the tolerable range to produce unifrom cross-sectional strip shape. The results from this simulation are reasonable for various irregular strip shapes.

Strengthening of RC beams with prefabricated RC U cross-sectional plates

  • Demir, Ali;Tekin, Muhammed;Turali, Tezcan;Bagci, Muhiddin
    • Structural Engineering and Mechanics
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    • 제49권6호
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    • pp.673-685
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    • 2014
  • The topic of this study is to strengthen cracked beams with prefabricated RC U cross-sectional plates. The damaged beams were repaired by epoxy based glue. The repaired beams were strengthened using prefabricated plates. The strengthening plates were bonded to the bottom and side faces of the beams by anchorage rods and epoxy. The strengthened beams were incrementally loaded up to maximum load capacities. The experimental results were satisfactory since the load carrying capacities of damaged beams were increased approximately 76% due to strengthening. It was observed that strengthening plates had a dominant effect on the performance of beams in terms of both the post-elastic strength enhancement and the ductility. The experimental program was supported by a three-dimensional nonlinear finite element analysis. The experimental results were compared with the results obtained from the beam modeled with ANSYS finite element program.