• Title/Summary/Keyword: 슬립 계수

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Prediction of Lift Performance of Automotive Glass Using Finite Element Analysis (유한요소해석을 통한 자동차용 글라스의 승강성능 예측)

  • Moon, Hyung-Il;Kim, Heon-Young;Choi, Cheon;Lee, In-Heok;Kim, Do-Hyung
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.34 no.11
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    • pp.1749-1755
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    • 2010
  • The performance of power window system was decided by driving characteristics of the window regulator part and reaction by the glass run. The performance of power window system usually has been predicted by experimental methods. In this paper, an analytical method using the explicit code was suggested to overcome the limit of the experimental methods. The friction coefficient of glass run was obtained by the friction test at various conditions and the Mooney-Rivlin model was used. Also, a mechanism of window regulator consisted of the fast belt system and the slip ring elements. And, we conducted the analysis considering characteristic of a motor and obtained the lifting speed of automotive glass with high reliability

Slip Effect at the Pile-soil Interface on Dragload (하향력을 받는 말뚝-지반 접촉면의 슬립 효과)

  • Jeong, Sang-Seom;Lee, Cheol-Ju
    • Journal of the Korean Geotechnical Society
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    • v.19 no.3
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    • pp.65-74
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    • 2003
  • The dragload on pile groups in consolidating ground was investigated based on a numerical analysis. The case of a single pile and subsequently the response of groups were analyzed by 2D and 3D finite element studies. Conventional continuum elements and special slip elements were used in the analyses for comparison. Based on a limited parametric study, it is shown that dragload for a single pile and group effect are normally overestimated by continuum analyses, compared with the predictions by the slip analyses. The group effect was examined from the slip analysis by considering various factors such as pile configurations, surface loading, interface friction coefficient, and axial loading on piles. An examplary analysis and one previous experimental observation of dragload and group effects were back-analysed. The case histories demonstrated that the slip analysis might predict a better estimate of dragload and group effect compared to the no-slip continuum analysis.

Study on the reduction of stick-slip noise in acrylonitrile butadiene styrene-based plastics using non-polar additives to reduce friction (마찰 저감을 위한 비극성 첨가제에 따른 acrylonitrile butadiene styrene계 플라스틱의 stick-slip 이음 저감 연구)

  • Sangjun Yeo;Yewon Jeong;Sunguk Choi;Hyojun Kim;Geonwook Park;Minyoung Shon
    • The Journal of the Acoustical Society of Korea
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    • v.43 no.1
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    • pp.49-59
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    • 2024
  • Recently, the electric vehicle market is gradually growing due to strengthened environmental regulations and high oil prices. also, in internal combustion engine vehicles, the sensitivity of Buzz, Squeak, Rattle (BSR) noise is increasing as engine Noise, Vibration, and Harshness (NVH)-related noise is reduced and technology for shielding noise coming from outside is developed. In this study, the stick-slip noise that occurs in Panoramic Curved Display (PCD) of automobile was analyzed for the correlation between the surface energy of polymer plastic and the polar component. For polar polymer materials, Acrylonitrile Butadiene Styrene (ABS) and PolyCarbonate-Acrylonitrile Butadiene Styrene (PC-ABS), compound materials were fabricated and evaluated. As a result, when the polar component of the polymer plastic was 3.86 mN/m or higher, stick-slip motion occurred, and as the absolute transition slope increased in the friction behavior over time, the possibility of stick-slip noise increased and the value of the friction coefficient The greater the difference, the greater the strength of the stick-slip noise.

Development of Rope Winding Device for Safety Fishing Operation of Small Trap Fishing Vessel (소형 통발어선의 안전조업을 위한 로프 권양장치 연구)

  • Kim, Dae-Jin;Jang, Duck-Jong;Park, Ju-Sam
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.28 no.1
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    • pp.19-29
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    • 2022
  • The result of a questionnaire survey conducted on fishermen using coastal fish traps shows that fall accidents during trap dropping and pulling constitute the highest proportion of accidents at 42.1 %, whereas slipping accidents on the deck or stricture accidents to the body due to the trap winding device constitute 21.1 % each. In addition, 53.2 % of all surveyed subjects responded that trap pulling is the most dangerous task, followed by fish sorting 33.8 %, and trap dropping 9.1 %. As for the main items requested by fishermen for improving the trap winding device, 36.8 % indicated a method to easily lift the trap from the water to the work deck, and 31.6 % indicated a method to overcome the rope tension and prevent slip when pulling the trap to reduce the accidents. The small trap fishing vessel winding device proposed herein can increase the winding force by strengthening the rope contact area and friction coefficient via an appropriate contact angle between the driving roller of the winding device and the rope. When the contact angles between the driving roller and the rope are 1°, 5°, 9°, 14° and 19°, the rope tension showed a difference according to each contact angle. When the contact angle is 9°, the rope tension is the highest at 392.62 kgf. Based on these experimental results, a prototype winding device is manufactured, and 25 traps are installed on a rope with a total length of 100 m at 4 m intervals in the sea, and then the rope tension is measured during trap pulling. As a result, the rope tension increases rapidly at the initial stage of trap pulling and shows the highest value of 31.89 kgf, which subsequently decreases significantly. Therefore, it is appropriate to design the winding force of a small trap fishing vessel winding device based on the maximum tension value of the rope specified at the beginning of the trap pulling operation.