• 제목/요약/키워드: Wear Life

검색결과 835건 처리시간 0.025초

오스템퍼링한 구상흑연주철의 마모특성에 미치는 기지조직의 영향에 관한 연구 (A Study on the Wear Characteristics of Austempered Ductile Iron)

  • 김윤복;김창규;최창옥
    • 한국주조공학회지
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    • 제10권3호
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    • pp.235-246
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    • 1990
  • This study has been carried out to investigate into the rolling wear characteristics of austempered ductile iron under unlubricated dry rolling condition by Amsler type test with 9.09% sliding ratio. Wear amount is increased with increasing of ferrite and retained austenite and it has been found that the amount of rolling wear is decreased when the hardness of matrix are higher. The rolling life up to generation of abnormal condition is conspicusly increased and amount of rolling wear is increased asrolling revolutionis increased and wear of austempered ductile ironunder dry rolling condition. Matrix has been obtained to upper bainite, low bainite at heat treatment, obtained to bull`s eye structure at as cast. It has been found that the amount of rolling wear is decreased when the tensile strength of the casting are increased and then the rolling life up to generation of abnormal wear in conspicuously increased and amount of wear was intend to graphite content.

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스플라인 커플링의 프레팅 마멸 예측에 관한 연구 (A Study on Estimating of Fretting Wear of a Spline Coupling)

  • 김응진;이상돈;조용주
    • Tribology and Lubricants
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    • 제25권4호
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    • pp.256-260
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    • 2009
  • Fretting is a kind of wear which effects on reliability and durability. When machine parts are joined joint in parts such as a bolt or a rivet or a pin, fretting phenomenon is occurred by micro relative movement. When fretting occurs in joint parts, there is wear which is the cause of fatigue crack. Recently, although the ways of assessment of fatigue and damage tolerance are established, there is no way to evaluate fatigue crack initiation life by fretting phenomenon. Consequently, the prediction of life and prevention plan caused by fretting are needed to improve reliability. The objective of this paper is to predict fretting wear by using a experimental method and contact analysis considering wear process. For prediction of fretting wear volume, systematic and controlled experiments with a disc-plate contact under gross slip fretting conditions were carried out. A modified Archard equation is used to calculate wear depths from the contact pressure and stroke using wear coefficients obtained from the disc-plate fretting tests.

시계열 모델과 상관차원 해석을 통한 공구수명의 감시 (Monitoring of Tool Life through AR Model and Correlation Dimension Analysis)

  • 김정석;이득우;강명창;최성필
    • 한국정밀공학회지
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    • 제15권11호
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    • pp.189-198
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    • 1998
  • Recently, monitoring of tool life is a matter of common interesting because tool life affects precision, productivity and cost in machining process. Especially flank wear has a direct effect on cutting mechanism, so the various pattern of cutting force is obtained experimentally according to variation of wear condition. By investigating cutting force signal, AR(Autoregressive) modeling and correlation dimension analysis is conducted in turning operation. In this modeling and analysis, we extract features through 6th AR model, correlation integral and normalized correlation integral. After the back-propagation model of the neural network is utilized to monitor tool life according to flank wear. As a result. a very reliable classification of tool life was obtained.

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생애주기분석을 위한 궤도 마모 및 틀림 데이터 처리 및 분석 (Track Wear and Irregularity Data Processing and Analysis for Life Cycle Performance)

  • 공정식;정민철;김정훈;김건우
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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    • pp.1123-1128
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    • 2011
  • Generally, there are many types of data, such as wear data or irregularity data, are detected for analyzing railway performance. The analysis of railroad wear or irregularity data is most effective method for the efficient railway maintenance. Especially, the track damaged directly by train, have as important position with the inspection data. This study suggest the Life-Cycle performance analysis method and process of railroad by analyzing two types of data, wear data and irregularity data. This analysis methods can be applied to suggest the Life-Cycle performance of railroad based on environmental factors or design factors, such as sleeper type, roadbed type, cant, the radius of curvature, speed, maintenance history and so on.

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접촉조건에 따른 접착형 이황화몰리브덴 피막의 마찰 마모 특성 평가 (Evaluation of the tribological behavior for MoS$_2$ bonded films with different contact geometry)

  • 배일;공호성;박영필
    • 한국윤활학회:학술대회논문집
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    • 한국윤활학회 1997년도 제25회 춘계학술대회
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    • pp.232-241
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    • 1997
  • The tribological behavior for MoS$_2$ bonded films is evaluated according to the international standard testing methods, such as ASTM D 2625(Falex tester) and ASTM D 2714(LFW-1 tester). It has been well known that the tribological behavior for MoS$_2$ bonded films is affected by several factors. However, in this work, the wear life for MoS$_2$ bonded films is mainly experimentally measured with different contact geometry, and evaluated in terms of the frictional heating according to the contact geometry of tribotester. The test results show that the wear life of MoS$_2$ bonded films is significantly affected not only by the frictional heating, but also by the contact pressure, test running-in conditions, and the contact conformity.

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모재의 표면 거칠기가 DLC 코팅의 마멸수명에 미치는 영향 (The Effects of Surface Roughness on Wear-life of DLC Coating in Dry Sliding)

  • 이영제;신경섭;조정우
    • Tribology and Lubricants
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    • 제21권3호
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    • pp.130-135
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    • 2005
  • Dry sliding wear resistance of DLC coated silicon disk with different surface roughness has been evaluated using a ball-on-disk sliding tester. It was found that the transfer layer formed on steel ball produced a low friction regime and the formation of transfer layer was more active with increasing the substrate surface roughness. Wear life of DLC coating was increased as increasing the real area of contact.

접촉조건에 따른 접착형 이황화몰리브덴 피막의 마찰 마모 특성 평가 (Evaluation of the Tribological Behavior for $MoS_2$ Bonded Films with Different Contact Geometry)

  • 배일;공호성;박영필
    • Tribology and Lubricants
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    • 제13권3호
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    • pp.20-27
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    • 1997
  • The tribological behavior for $MoS_2$ bonded films is evaluated according to the international standard testing methods, such as ASTM D 2625 (Falex tester) and ASTM D 2714 (LFW1 tester). It has been well known that the tribological behavior for $MoS_2$ bonded films is affected by several factors. However, in this work, the wear life for $MoS_2$ bonded films is mainly experimentally measured with different contact geometry, and evaluated in terms of the frictional heating according to the contact geometry of tribotester. The test results show that the wear life of $MoS_2$ bonded films is significantly affected not only by the frictional heating, but also by the contact pressure, test running-in conditions, and the contact conformity.

일상복 겸용의 애슬레저 바이크 웨어 디자인 개발 연구 (Design development of athleisure bike wear to be a casual daily wear)

  • 이달아;안인숙
    • 복식문화연구
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    • 제24권6호
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    • pp.788-802
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    • 2016
  • Sportswear transforms itself into a new fashion item to satisfy desires for beauty in addition to having functionality and movability for sports activities. Sportswear is not in fashion just temporarily but comes in various forms along with sociocultural phenomenon that put emphasis on well-being and leisure. This research aims to study the needs of the bikers who ride bicycles or cycles has become a popular outdoor activity, and give suggestions for high functional sports design that can satisfy the needs of the highly demanding taste of athletes. To understand the design development direction and design preference, practical consumer needs were derived through a survey analysis on bike wear purchasing satisfaction and actual wearing state by bike riders. For consumer needs analysis, focus group interview, in-depth interview and questionnaire method were used. Based on analysis of those researches, athleisure bike wears appropriate for urban sports activities were categorized into sports, life, fitness and leisure 4 styles for athleisure bike wear design development. It is believed that this study will contribute to in the category expansion of sports wear market and satisfy the consumer demands for functional and specialized casual bike wears as well as fashion factors optimized to life style of modern people.

아세탈과 나일론피니언의 마멸 및 운전특성에 관한 고찰 (Wear and Operation Characteristics of Acetal and Nylon Pinion Against Steel Gear)

  • 김충현;이성철;안효석;정태형
    • 대한기계학회논문집A
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    • 제24권9호
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    • pp.2387-2396
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    • 2000
  • Wear and operation characteristics of Nylon and Acetal pinion against steel gear were studied to gain a better understanding of their tribological and mechanical behavior. Tests were conducted with power circulating gear test rig under unlubricated conditions. Specific wear rates were measured as a function of applied load and total revolution. The worn tooth surfaces were examined with a profile projector and camera. Nylon pinion showed lower specific wear rates than Acetal pinion, but it revealed breakage at high load. Principal wear depths were developed at tooth tip and below the pitch line of pinion. Life estimation for the Nylon pinion was made by taking into account steel gear equivalent Hertz stress and average sliding velocity. The dominant wear mechanisms were adhesion and abrasion.

열간단조용 금형형의 수명예측기법 개발 (The Development of Life Prediction Method for Hot Forming Dies)

  • 이진호;김병민
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 1998년도 금형가공 심포지엄
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    • pp.54-59
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    • 1998
  • In this study, two kinds of life prediction method for hot forming die are developed . One is empirical method requiring some experiment that evaluate thermal softening of die material accoring to operating conditions. The other is analyticl method that calcuate wear quantity of die occuring during the forming process. Wear is a predominant factor as well as plastic deformation and heat checking . And, these methods are applied to prodict tool life real die producting part for automobile. Thus , the applicability and the accuracy of the presented methods are investigated. Using the verified life prediction method above , optimal blocker die design minimizing the finisher die is done.

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