• 감성과학
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• 제15권2호
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• pp.177-182
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• 2012

20세기의 자동차는 엔진의 주역할인 파워, 스피드를 중요시 하였으나, 소득수준의 향상에 따른 Well-being Trend의 확산 및 환경문제의 대두로 인해 쾌적성, 안락성, 안정성, 환경성 등을 중요시 하고 있다. 자동차용 Sub-Mat는 바닥 카펫 관리의 편의성 및 안락성 등을 위해 부가적으로 설치하는 매트로, 현재 자동차용 Sub Mat의 Backing 소재는 재생고무, PVC 등이 사용되고 있지만, 재생고무 Sub-Mat는 흡음성능이 나쁘고 PVC Backing Sub-Mat는 중량이 매우 커 연비 면에서 불리하고, 유해물질이 다량 포함되어 있어 점차적으로 사용이 어려워질 전망이다. 본 연구에서는 나일론 표피 파일 층, PE 접착 층, Backing(PET fiber)을 합포하여 제작한 sample1과 PET표피 파일 층, PE 접착층, Backing 부직포 층(PET)을 합포하여 제작한 sample2, Backing층을 PVC로 요철을 부여하여 제작한 sample3의 Non-Slip성을 평가하였으며, 이에 따른 접촉면의 변화를 비교 평가하였다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2008년도 추계학술대회 논문집
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• pp.159-160
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• 2008

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 1999년도 제29회 춘계학술대회
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• pp.38-46
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• 1999

Numerical methods are procured for evaluating the contact stresses, the dissipation of friction energy density and the fatigue cracking emanated from the contact surface under the partial slip condition. A rounded punch is used for the indenter pressing and slipping on the elastic half plane. Plane strain condition is assumed for the present analysis. Several sample calculations are carried out to investigate the effect of the punch roundness, the shear load path, and the crack obliquity and closure on the failure. It is found that the present methods can be a useful tool for studying the physical failure of the of the contacting materials such as fretting wear and fretting fatigue cracking.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2002년도 제35회 춘계학술대회
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• pp.88-95
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• 2002

Fretting of fuel rod cladding material, Zircaloy-4 Tube, in PWR nuclear power plants must be reduced and avoided. Nowadays the introduction of surface treatments or coatings is expected to bean ideal solution to fretting damage since fretting is closely related to wear, corrosion and fatigue. Therefore, in this study the fretting wear experiment was peformed using TiAIN coated Zircaloy-4 tube as the fuel rod cladding and uncoated Zircaioy-4 tube as one of grids, especially concentrating on the sliding component. Fretting wear resistance of TiAIN coated Zircaloy-4 tubes was improved compared with that of TiN coated tubes and uncoated tubes and the fretting wear mechanisms were delamination and plastic flow following by brittle fracture at lower slip amplitude but severe oxidation and spallation of oxidative layer at higher slip amplitude.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2000년도 제32회 추계학술대회 정기총회
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• pp.37-43
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• 2000

The effect of the alignment of the contacting bodies is concerned. Tilting of a body (indenter) is regarded as a mis-alignment. Recently developed method fur evaluating the contact normal traction is introduced and discussed, in which piecewise parabolic profile is considered as a generalized contact profile. Indentation by a wedge with rounded apex is solved as an example problem. In the case of partial slip regime, the variation of shear traction is examined during the closed path of shear force by using the efficient numerical technique. Concentration of the slip region is also investigated. By evaluating the energy dissipation from the contact surface, the effect of the mis-alignment-alignment on wear is discussed.

• Computers and Concrete
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• 제29권4호
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• pp.255-262
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• 2022

The present study investigates the effects of Cattaneo-Christov thermal effects of stagnation point in Walters-B nanofluid flow through lubrication of power-law fluid by taking the slip at the interfacial condition. The impacts of thermophoresis and Brownian motions are further accounted. The fluid impinging orthogonally on the surface is due to power-law slim coating liquid. The generalized newtonian fluid equation is used that obeys the power law constitutive equation to model our problem. The effect of velocity profiles, temperature for different values of n are investigated. The prandtl on the temperature distribution for partial slip and no slip cases is also observed. It is found that for larger values of prandtl number thermal diffusivity of fluid reduces and it enhance the decrease in temperature and boundary layer thickness.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 1996년도 춘계공동학술대회논문집; 공군사관학교, 청주; 26-27 Apr. 1996
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• pp.662-666
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• 1996

The variations of the surface topographical parameters for the analysis of the pedestrian slip and fall accidents during the sliding friction between the specially prepared floor specimens and three working shoes were investigated. The profile ordinate data for each flooring specimen were obtained at 1.1 .mu.m intervals using a laser scanning confocal microscope system along to the direction of sliding. A number of surface roughness parameters, that is, the centre line average (c.l.a.) and root mean square (r.m.s.) roughness, maximum height (Rtm), maximum mean peak height (Rpm), maximum mean depth (Rvm), and average asperity slope were calculated using a computer program and compared with the dynamic friction results. The analysis showed that the surface parameters undergo marked variations during the sliding process, but the variations were statistically significant. It was found that amongst various surface parameters, the maximum depth (Rvm) and the average asperity slope of the asperities were the biggest variation during the sliding proceeding. This result confirms the previous study and may suggests a new approach to monitoring the flooring environments with their service as the effort to reduce the pedestrain slip accident.

• 비파괴검사학회지
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• 제23권1호
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• pp.30-37
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• 2003

수동 초음파검사를 자동검사로 대체하기 위해서는 탐촉자의 위치정보를 정확하게 제어할 수 있는 주사장치가 필수적이다. 위치정보를 알기 위하여 기존의 모터제어 주사장치에서는 엔코더를 사용하고 있으며 엔코더는 여러 가지 측면에서 많은 장점을 가지고 있으나 주사 중에 미끄러짐(slip)이 발생하면 엔코더 위치정보의 정확도에 많은 오차가 포함되게 된다. 따라서, 미끄러짐이 있는 경우의 위치정보는 무의미하게 되며, 자동초음파검사의 신뢰도는 큰 문제가 된다. 그러므로 미끄러짐을 피해야 하나 현재는 이를 완전히 해결하는 방법은 없는 상태이다. 본 논문에서는 이와 같은 문제점을 해결하고 엔코더를 대체할 수 있는 새로운 개념의 초음파검사 자동 주사장치의 위치 제어기술을 제안하고 이 방법이 실제 사용 가능함을 확인하였다 즉, 주사하고자 하는 직선 영역에 송신용 표면파 탐촉자를 부착하고 주사장치에 부착된 수신용 탐촉자에서 표면파를 수신하여 현재의 주사장치의 위치를 계산하고 이를 바탕으로 주사하고자 하는 거리만큼의 주사장치의 이동을 제어할 수 있다.

• 한국자동차공학회논문집
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• 제22권3호
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• pp.33-41
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• 2014

Fretting is a kind of surface degradation mechanism observed in mechanical components and structures. When two pieces of materials, pressed together by an external static load, are subjected to a transverse cyclic loading or various vibrations, so that one contacting face is relatively displaced cyclically parallel to the other face, wear of the mating surfaces occurs. These fretting damages may be observed in electrical connectors for automotive components, where there are special environments and various vibration conditions. This study aims to evaluate the usefulness of fretting test equipment that was developed for reliability test of electrical connector. Fretting tests were carried out using tin coated connectors and friction force, contact resistance, contact area and roughness of contact region were investigated. The following results that will be helpful to understand the fretting wear mechanism, increase process the contact resistance and contact area were obtained. (1) In the same frequency and slip amplitude, the friction force, roughness and contact area increased rapidly until about $10^3$ cycles, after which it was slightly changed. (2) In the various frequency and slip amplitude, the contact area increased with slip amplitude and cyclic numbers, but it did not depend on cyclic frequency. (3) The surface roughness of contact region did not depend on the cyclic frequency. From these results, the applicability of the fretting wear test equipment and reliability of connector were discussed.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 춘계학술대회 논문집
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• pp.560-567
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• 2011

Wheel and rail wear is a fundamental and complicate problem in railway field. The life of railway is usually limited by wear. The wheel surface is subjected to high normal and tangential contact stress. The removal of material from the surface by wear is function of the sliding and contact stress. In the present paper, the wear characteristic depended on slip rate, contact pressure and temperature are investigated and is used to twin disc tester. The result shows that the wear in wheel-rail interface is remarkably depended on slip rate and contact pressure.