• Title/Summary/Keyword: Holding Force

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An analysis of cutting force according to specific force coefficients (비절삭저항 상수 변화에 따른 절삭력 분석)

  • Kim, Jong-Do;Yoon, Moon-Chul
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.13 no.2
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    • pp.108-116
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    • 2014
  • Considering the run-out effect and cutting force coefficients, the cutting force profile of half immersion end-milling was analyzed in detail. The effects of three specific cutting-force coefficients and three edge-force coefficients are verified. Through a detailed investigation, it is proved that the radial cutting force coefficients and are the major factors which increase the cutting forces Fx and Fy in end-milling. However, the axial cutting force coefficients have no influence on the force Fx and Fy changes in end-milling. Also, the analyzed end-milling force model shows good consistency with the actual measured force with regard to Fx and Fy. Thus, this model can be used for the prediction of the force history in end-milling with run-out, and it incurs a different force history with different start and exit immersion angles as well as holding effects.

Implementation of a Remote Peg-in-Hole Operation using a Two Degrees of Freedom Force-Reflective Joystick

  • Sung K. An;Seung J. Han;Lee, Jang M.
    • 제어로봇시스템학회:학술대회논문집
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    • 1998.10a
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    • pp.340-345
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    • 1998
  • A virtual reality system is implemented for the operator supervising a robot's operation at a remote site. For this implementation, a two D.O.F force-reflective joystick is designed to reflect the force/torque measured at the end of robotic manipulator and to generate the motion command for the robot by the operator using this joystick. In addition, the visual information that is captured by a CCD camera, is transmitted to the remote operator and is displayed on a CRT monitor. The operator who is holding the force reflective joystick and watching the CRT monitor can resolve unexpected problems that the robot confronts with. That is, the robot performs the tasks autonomously unless it confronts with unexpected events that can be resolved by only the operator. To demonstrate the feasibility of this system, a remote peg-in-hole operation is implemented and the experimental data are shown.

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Study on Springback Characteristic of Cold Rolled Steel Sheet (자동차용 냉연 강판의 형상 동결성 연구)

  • 한수식;박기철;남재복
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 1998.06a
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    • pp.17-24
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    • 1998
  • This paper deals with the springback characteristics of cold rolled sheet steel through the use of the V-bending process and U-bending one. The influence of material properties on the springback of forming processes was investigated. In the V-bending process there was an optimum bend radius for each combination of parameters which produced minimal springback. In the U-bending process the blank holder force can control the degree of springback. A high blank holding force resulted in a uniform strain distribution and reduced the level of springback.

A Study on the Avoidance of Typhoon 'Maemi' - Mainly on the training ship KAYA - (태풍 매미의 피항에 관한 연구 -가야호를 중심으로 -)

  • Kim, Min-Seok;Kang, Il-Kwon;Kim, Hyeong-Seok;Jeong, Sun-Beom
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.40 no.3
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    • pp.225-231
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    • 2004
  • The power and scale of 950 hPa typhoon "Maemi" which struck the shore of Gosung in Kyungnam Province was same as that of 951 hPa typhoon "Saraho" in 1959. For the purpose of getting the safety of training ship "KAYA", we anchored at Jinhae Bay with riding at two anchors paid out 8 shackles of cable respectively. By the way when wind force being over 30m/s, we could not keep the safety of the ship "KAYA" by means of the holding power of an anchor only. Just by using the main engine moderately, we were able to maintain the security of the ship. The holding the main engine moderately, we were able to maintain the security of the ship. The holding power of an anchor according to the way of anchoring, the quality of sea bottom, the direction and speed of wind and current, and the length of an anchor cable were analyzed. The obtained results are summarized as follows : 1. When riding at two anchors rather than lying at single anchor we could get a good holding power. 2. There was a big difference in holding power according to the quality of the bottom. 3. It would be best anchoring in a soft mud area than in any other place as possible. 4. It would also be desirable to set anchor shackles much more than equipment number prescribed in regulation in order to get safety of a ship providing against typhoon.

A Study for the Evaluation of the Force by the Wind on the Ship at Anchoring (실선계측을 통한 묘박중인 선박의 풍압력 적용에 관한 연구)

  • Jung, Chang-Hyun;Kong, Gil-Yong
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.15 no.3
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    • pp.223-228
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    • 2009
  • By the typhoon "MAEMI" in 2003, a lot of marine accidents such as stranding, collision etc. occurred to the vessels at anchor in "JINHAE MAN" which was considered one of the most safe sheltering anchorage in Korea. These accidents resulted from the dragging of anchor by the strong winds. It needs to compare the external forces with the holding powers of anchors to estimate if the anchor will be dragged or not. However, the calculation of the force by the wind on the ship, in particular, on the wind pressure area which changes by the swinging of her bow is not yet set on a thesis. Therefore, this paper verified that how many times the front wind pressure area should be applied to calculate the force by the wind on the ship at anchor by comparing and analyzing the numerical calculation with, the actual ship's data which was really dragged by the strong wind.

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Determination of Point of Sale and Consumption for Hanwoo Beef Based on Quality Grade and Aging Time

  • Koh, Kyung Chul;Chung, Ku-Yong;Kim, Hyun-Seok;Kang, Se-Joo;Choi, Chang-Bon;Jo, Cheorun;Choe, Juhui
    • Food Science of Animal Resources
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    • v.39 no.1
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    • pp.139-150
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    • 2019
  • This study aimed to determine the suitable point of sale and consumption of different quality grade (QG) Hanwoo short loin during aging period, based on physicochemical, sensory, and microbiological quality. Short loins obtained from the carcasses of 13 Hanwoo steers and 2 bulls with 5 different QGs (1++, 1+, 1, 2, and 3) were analyzed over 28 d. QG and aging time had significant effect on water holding capacity, color, shear force, total volatile basic nitrogen (TVBN) content, and sensory traits. Higher QG groups generally exhibited a lower shear force, nucleotide content, and water holding capacity, and higher $L^*$, $a^*$, and $b^*$ values. Acceptable tenderness (shear force <5.4 kg) in QG 1++, 1+, 1, and 2 was achieved on days 7, 14, 16, and 18, respectively, and QG 3 showed a shear force of 6.8 kg, even after 28 d. Regardless of QG, TVBN content below threshold levels (20-30 mg%) was observed throughout the 28 d aging period, while total plate counts above 7 Log CFU/g were seen at 21 d. In conclusion, it is recommended that Hanwoo beef with QG 1++, 1+, and intermediate QG (1 and 2) should be sold or consumed between 7 and 21, 14 and 21, 16 and 21 d, respectively. Beef with QG 3 should be sold or consumed within 21 d, based on microbial growth, even though it has not achieved desirable tenderness. For this reason, an additional tenderizing process is recommended before this beef is ready for consumption.

Development of Drawbead Expert Models for Finite Element Analysis of Sheet Metal Forming Processes (Part1:Experiment) (박판성형공정의 유한요소해석을 위한 드로우비드 전문모델 개발(1부: 실험))

  • Lee, Jae-U;Keum, Yeong-Tak
    • Transactions of Materials Processing
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    • v.7 no.1
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    • pp.3-11
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    • 1998
  • During the forming process of sheet metals, the drawbead in the die face controls a restraining force so that the sheet flows into the die cavity with tension. In order to investigate a drawgbead restraining force and a pre-strain just after drawbeads which are essential in the finite element analysis of form-ing processes, the friction test and drawing test are employed. The experiments performed with a cir-cular bead stepped bead double circular bead and circular-and-stepped bead in the various forming conditions and bead sizes show that the restraining force varies linearly with the blank holding force. bead radius blank thickness and friction but the pre-strain nonlinearly does with them.

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Manufacturing Al-scrap into Hypereutectic Al-Si Alloy by Using Electromagnetic Force (전자기력을 이용한 Al scrap으로 부터 과공정 Al-Si합금의 제조)

  • Yoon, Ji-Hyun;Moon, Kwang-Ho;Kim, Yong-Hyun;Lee, Kwang-Hak
    • Journal of Korea Foundry Society
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    • v.21 no.6
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    • pp.328-335
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    • 2001
  • The objective of this study is to investigate on manufacturing Al-scrap into hypereutectic Al-Si alloy by using electromagnetic force. The Fe element in the aluminium scrap was controlled by intermetallic compound method and using EMF(electromagnetic force). The most lumped compound was found after 10min holding at $690^{\circ}C$. A number of segregated compound was revealed when imposed to EMF at 30A. The refinement of primary Si particles was achieved by EMF stirring. Primary Si particles were refined and spheroidized most of all with the magnetic intensity of 180G for 10 min.

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Optimization of Mold for Fineblanking Forming of Sector Gear for Recliner (리클라이너 용 섹터기어의 파인 블랭킹 성형을 위한 금형의 최적화)

  • Lee, K.Y.;Nam, K.W.;Moon, C.K.
    • Journal of Power System Engineering
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    • v.15 no.6
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    • pp.53-58
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    • 2011
  • To optimization of mlod for fineblanking forming of sector gear of recliner, it was analyzed the effect of clearance, V-ring height, V-ring position, blank holding force and counter punch force. In case of 0.003 mm of clearancs, the finest shear plane was obtained, but optimization between die and punch clearance was 0.005 mm. The height of V-ring was 0.7 mm. In case of increasing of hold force, the size of shear plane got better and the decrement of thickness became smaller. Both the size of shear plane and the decrement of thickness increased according to increasing of counter punch force.

Model Test for the Development of Installing Manipulator of Concrete Pile Anchor (콘크리트 파일앵커의 설치 매니퓨레이터의 개발을 위한 모형실험에 관한 연구)

  • 윤길수;김호상
    • Journal of Ocean Engineering and Technology
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    • v.18 no.1
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    • pp.47-52
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    • 2004
  • Greater holding force of an anchor is required for maintaining the position of a larger floating structure. According to the series of model tests of pile anchors with movable fluke, the square type pile anchor, with fluke, showed more than 6 times of the uplift pulling force, compared to the same type pile anchor, without fluke. This uplift force is 100 times its weight. When the water depth is more than 40m, It is difficult to install the pile anchor. For a convenient installation method, a type of manipulator is proposed for the separation of a weight and buoyancy controller, using TRIZ.