• Title/Summary/Keyword: friction face

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Rock mass classification and slope stability using the stronet analysis technique in Boryung Dam site (보령댐 절취사면의 암반평가 및 평사투영법에 의한 사면안정성 연구)

  • Choon Sunwoo
    • Tunnel and Underground Space
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    • v.5 no.4
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    • pp.308-317
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    • 1995
  • The stability study on the rock slope where have produced failures in Boryung dam site was evaluated using the streonet analysis techniques. SMR(Slope Mass Rating) approach which is suitable for preliminary assessment of slope stability in rock was also carried out for rating rock mass. The 3-4 major discontinuity sets are distributed and all type of failure(plane, wedge and toppling failure) are presented in this slope face. The dip of slope must be lowered to friction angle(26degree), otherwise the possibility of plane and toppling faiue will always exist in this slope.

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A Safety Evaluation on Structure of Panel for Railway (철도용 보판의 구조안전성 평가)

  • 윤성철;정종덕;김원경;박기준
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2003.06a
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    • pp.1553-1556
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    • 2003
  • As the public use part of the railway and the road, the railway crossing is important to work properly by two transportation means. Also, It is important to provide the good face of friction on the railway crossing in aspect of protecting the railway crossing accident. Lately, the material of railway crossing panel is the wood. the asphalt, and the steel. As they have a various fault, it was studied to analyze the structural action of the new material. rubber panel. This paper analyzed eigenvalue, stress and displacement by truck passing weight and thermal stress using the FEM model.

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Analysis and Measurement of Rough Surface Temperature Rise in Lubricated Condition (거친 표면의 마찰온도 해석 및 온도측정 실험에 관한 연구)

  • Lee, Sang-Don;Cho, Yong-Joo
    • Tribology and Lubricants
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    • v.23 no.2
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    • pp.56-60
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    • 2007
  • The main object of this study is to compare the results that have been concluded by the experiment and to estimate the temperature rise that can cause the contacting surface to be damaged. The former studies are based on the Blok and Jaeger formula. By these formulas we assume that two of the contacted objects are a kind of semi-infinite solid and with this assumption we can make a temperature analysis. But this method doesn't consider lubrication conditions and the calculation time requires a lot of time in that we have to face many difficulties in measuring the actual temperature rise. In this study we combines the semi-infinite solid method and the finite volume method to analyze the temperature of the contacting surface. And we measure temperature rise of the contact surface by dynamic thermocouple.

Kinetic Analysis of the Probability of Hexagonal Face in Juryeonggu (주령구에서 육각면이 나올 확률에 대한 운동역학적 해석)

  • Yoo, Wan Suk;Lee, Jeong Han
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.41 no.11
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    • pp.1085-1089
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    • 2017
  • Juryeonggu is a cuboctahedral die that was used during the Silla period in ancient Korea. This cuboctahedral die consists of two different penal servitudes of 14 sides; however, its equal probability distribution enables it to be used as a die. In this paper, a precise cuboctahedral die, Juryeonggu, was manufactured, and its probability was measured through experiments. Next, the probability was verified through Multibody-dynamics (MBD) modeling and analysis, and the effect of the coefficient of friction on the probability distribution was studied.

Numerical analysis on the material flow in stepped rod forming (단붙이 로드의 성형에서 소재유동에 관한 해석)

  • Go, Byung-Du;Gang, Dong-Myung;Lee, Ha-Sung
    • Design & Manufacturing
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    • v.2 no.2
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    • pp.43-47
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    • 2008
  • This paper is concerned with the analysis of material flow characteristics of stepped rod forming. The analysis in this paper concentrated on the evaluation of the design parameters for deformation patterns of tube forming, load characteristics, extruded length, and die pressure. The design factors such as punch nose radius, die corner radius, friction factor, and punch face angle are involved in the simulation. The stepped rod forming is analyzed by using a commercial finite element code. This simulation makes use of stepped rod material and punch geometry on the basis of punch geometry recommended by International Cold Forging Group. As radius ratio is large, forming load was reduced but extruded length ratio was increased.

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The Lubrication Effect of Liquid Nitrogen in Cryogenic Machining [I]- Part 1: Cutting Force Component with Physical Evidences - (Liquid Nitrogend의 감찰효과 -물리적 현상에 의한 절삭력-)

  • Jun Seong Chan;Jeong Woo Cheol
    • Journal of the Korea Safety Management & Science
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    • v.4 no.2
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    • pp.209-221
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    • 2002
  • Machinability improvement by the use of liquid nitrogen in cryogenic machining has been reported in various studies. This has been mostly attributed to the cooling effect of liquid nitrogen. However, No study has been found in discussion on whether liquid nitrogen possesses lubrication effect in cryogenic cutting. In machining tests, cryogenic machining reduced the force component in the feed direction, indicating that the chip slides on the tool rake face with lower friction. This study also found that the effectiveness of LN2 lubrication depends on the approach how LN2 is applied regarding cutting forces related.

Evaluation of the Aerodynamic Performance of A Hybrid Mesh Based Finite Volume Code

  • ZHENG, H.W.
    • International Journal of Aerospace System Engineering
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    • v.2 no.2
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    • pp.40-43
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    • 2015
  • A hybrid mesh based finite volume compressible flow code (PolySim) has been developed recently. Instead of the simple average method for the gradients of variables at each face, the volume average is applied for the calculation of the viscous flux. What is more, an improved Green Gauss method for the calculation of the gradient is also presented. These two techniques will improve both the accuracy and robustness of the code. The aerodynamic performance of this in-house cell centered code is examined by several widely-used bench-mark test cases. These cases include flows over flat plate and RAE 2822 etc. The comparisons on results between calculation and experiment are conducted. They show that the code can produce good numerical results which agree well with the corresponding experiment data.

A Safety Evaluation on the Rubber Panel for Railway Crossing (철길건널목용 고무보판 안전성 평가)

  • 윤성철;정종덕
    • Journal of the Korean Society for Railway
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    • v.5 no.2
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    • pp.125-132
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    • 2002
  • As the public use part of the railway and the road, the railway crossing is important to work properly by two transportation means. Also, It is important to provide the good face of friction on the railway crossing in aspect of protecting the railway crossing accident. Lately, the material of railway crossing panel is the wood, the asphalt, and the steel. As they have a various fault, it was studied to analyze the structural action of the new material, rubber panel. This paper analyzed eigenvalue, stress and displacement by truck passing weight, thermal stress and train moving weight, using the Finite Element Method model

Effect of Bundle Junction Face and Misalignment on the Pressure Drops Across a Randomly Loaded and Aligned 12 Bundles in Candu Fuel Channel

  • H. C. Suk;K. S. Sim;C. H. Chung;Lee, Y. O.
    • Nuclear Engineering and Technology
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    • v.28 no.3
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    • pp.280-289
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    • 1996
  • The pressure drop of twelve fuel bundle string in the CANDU-6 fuel channel is equal to the sum of the eleven junction pressure losses, the bundle string entrance and exit pressure losses, the skin friction pressure loss, and other appendage pressure losses, where the junction loss is dependent on the bundle end faces and angular alignments of the junctions. The results of the single junction pressure drop tests in a short rig show that the most probable pressure drop of the eleven junctions was analytically equal to the eleven times of average pressure drop of all the possible single junction pressure drops, and also that the largest and smallest junction pressure drops across the eleven junctions probably occurred only with BA and BB type junctions, respectively, where A and B denote the bundle end sides with an end-plates on which a company monogram is stamped and unstamped, respectively.

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Lubrication Characteristics of Laser Textured Parallel Thrust Bearing : Part 3 - Effect of Number of Dimples (Laser Texturing한 평행 스러스트 베어링의 윤활특성 : 제3보 - 딤플 수의 영향)

  • Park, Tae-Jo
    • Tribology and Lubricants
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    • v.27 no.6
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    • pp.302-307
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    • 2011
  • Laser surface texturing (LST) methods are widely applied recently to reduce friction and improve reliability of machine components such as thrust bearings, mechanical face seals and piston rings, etc. In this paper, numerical analysis is carried out to investigate the effect of number of dimples on the lubrication characteristics of parallel thrust bearing using a commercial computational fluid dynamics (CFD) code, FLUENT. Pressure distributions of present analysis are physically consistent than those obtained from numerical analysis of Reynolds equation. The overall lubrication characteristics are highly affected by number of dimples and their locations. The results can be use in design of optimum dimple characteristics to improve thrust bearing performance and further researches are required.