• 제목/요약/키워드: wear evaluation

검색결과 649건 처리시간 0.036초

고경도 금형강(SKD61)의 고속가공에서 절삭조건 변화에 따른 가공성 평가 (Evaluation of machining characteristics according to cutting condition of hardened steel in high speed machining)

  • 김득현;강명창;이득우;김정석;김광호
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2000년도 춘계학술대회 논문집
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    • pp.878-881
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    • 2000
  • Recently high speed machining is being studied actively to reduce machining time and to improve machining precision. To perform efficient high speed machining, evaluation of high speed machinability must be studied preferentially and it can be identified by investigation of cutting force, tool wear and surface roughness. In this study. the cutting force and tool wear and surface roughness are investigated in case of various cutting conditions for hardened die steel.

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고속 머시닝센터의 주축계 진동특성과 가공성 평가 (Evaluation of vibration property and machinability of spindle system in high speed machining center)

  • 김전하;강명창;김정석;김기태
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2002년도 추계학술대회 논문집
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    • pp.16-21
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    • 2002
  • The high speed machining center(HMC) has been widely applied to manufacture a die and trial product in many machine industry. Because the evaluation fer the HMC is not sufficiently performed and the efficient cutting conditions aren't selected, a great loss has been caused in the cost aspect. In this study, the need of preliminary running time and unstable spindle speed is presented from the analysis of acceleration in idling. The Machinability fur the TiAlN coated flat end mill and STD11( $H_{R}$C60) is evaluated from the trends of tool wear and cutting force according to cutting conditions and slenderness ratio and a low response of tool dynamometer in high speed is proved. The resonance spindle speed is identified through the tool wear and natural frequency test.t.

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회주철(GC250)의 고속가공을 위한 엔드밀공구의 형상 설계 및 가공성 평가 (Shape Design and Machinability Evaluation of Flat End mill for High Speed Machining of GC250 Material)

  • 이상용;김전하;강명창;김정석;강호연
    • 한국공작기계학회:학술대회논문집
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    • 한국공작기계학회 2002년도 추계학술대회 논문집
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    • pp.292-296
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    • 2002
  • In the present investigation, the improvement of processing efficiency in the high speed machining of GC250 is explored. This study is to evaluate the tool performance in difficult-to-material using the new developed tool. Tool performance evaluation are conducted by tool wear, surface roughness, chattering in machined surface. The tool wear of A type was smaller than B type. In type B tool the chatter mark was observed in machined surface. The good surface roughness was obtained in type A tool. Consequently, the tool performance of A type is better than B type.

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액티브 시니어 남성을 위한 아웃도어 재킷 개발 (A development of outdoor jackets for active senior males)

  • 김지은;김은경
    • 한국의상디자인학회지
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    • 제20권2호
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    • pp.31-46
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    • 2018
  • This study was carried out to offer basic data that can be used for outdoor wear production for active senior males, emerging as a new consumer bracket in the era of rapid aging. To this end, this study modified and complemented the patterns of outdoor jackets for active senior males based on existing outdoor jackets that received the most excellent evaluation. On the basis of the research outdoor wear wearing assessment results, this study confirmed those areas to be modified and proposed areas to be considered in manufacturing outdoor wear for this demographic. As a result of existing outdoor wear's wearing assessment, the jacket of brand B was shown to be the most excellent one. This study actually designed research outdoor wear patterns by modifying the problematic parts through the addition and subtraction of spare length or circumference in the sections where fit satisfaction was low by referring to the selected brands' patterns. The research outdoor wear was designed by referring to the preferred outdoor types and colors that were highlighted in the previous survey result of consumer wearing reality, based on the designs of the outdoor wear receiving the most excellent assessment in wearing assessment. Fabric that specially glued two-layered mesh that bonded the thin membrane of synthetic resin with polyester fabric was used as the material in this study. Wearing assessment was conducted by comparing the manufactured research outdoor wear and the existing outdoor wear selected as excellently assessed outdoor wear. Consequently, this study verified that the wearing fit of the research outdoor wear was more excellent in most items. This study proposed final patterns for outdoor jackets suitable for active senior males through the modification of several items that required improvements as per the wearing assessment of the research outdoor wear.

월경통(月經痛)에 대한 원적외선 방사 기능성 under inner-wear의 유용성 평가 (The evaluation of usefulness for far-infrared radiating under inner-wear on dysmenorrhea)

  • 조정훈;이경섭;윤영진
    • 대한한방부인과학회지
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    • 제20권3호
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    • pp.129-136
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    • 2007
  • Purpose: We intended to observe the usefulness of far-infrared radiation functional under inner-wear for dysmenorrhea. Methods: We introduced far-infrared radiation functional under inner-wear to women in childbearing-age by internet portal site. Then, we preliminarily examined dysmenorrhea severity by VAS(visual analogue scale) questionnaire to women interested in far-infrared radiation functional under inner-wear. We selected women scored 5 and above of 10 measurement VAS score. Finally, 121 women were the subject of study and used far-infrared radiation functional under inner-wear for one menstrual cycle. Before and after use of far-infrared radiation functional under inner-wear, we conducted a questionnaire survey of dysmenorrhea severity by VAS. After that, we compared VAS score before and after use. Also, we studied correlation between frequency of far-infrared radiation functional under inner-wear use and ${\Delta}VAS$(VAS score before use minus VAS score after use). For statistics, we used Paired samples test and Spearman's rho correlations, SPSS 13.0 for windows. Results: Before and after use of far-infrared radiation functional under inner-wear, VAS score means were different. Frequency of far-infrared radiation functional under inner-wear use was correlated to ${\Delta}VAS$. Statistically they showed significant result (p<0.05>. Conclusion: The results showed that dysmenorrhea severity by VAS decreased after far-infrared radiation functional under inner-wear use. As frequency of use increased, ${\Delta}VAS$ increased. So we can consider far-infrared radiation functional under inner-wear effects dysmenorrhea severity.

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지르칼로이-인코넬 접촉에서의 프레팅 손상 평가 (Fretting Oamage Evaluation of Zircaloy-Inconel Contact)

  • 김태형;김석삼
    • 한국윤활학회:학술대회논문집
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    • 한국윤활학회 2000년도 제31회 춘계학술대회
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    • pp.263-268
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    • 2000
  • The fretting damage of the contact between Zircaloy-4 and Inconel 600 have Investigated. A fretting wear tester was designed to be suitable for this fretting test. In this study, the number of cycles, slip amplitude and normal load were selected as main factors of fretting wear. As the result of this research the wear volume increased with the increase of loads, slip amplitudes and the number of cycles and was more affected by slip amplitudes rather than by load. According to SEM, stick, partial slip, gross slip were observed on the surface of both specimens and wavy worn surfaces as the typical fretting damage were also Investigated due to accumulation of plastic flow.

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환경영향인자를 고려한 궤도수명산정 기법 개발 (Development of evaluation method for the railroad track life cycle considering environmental effect factors)

  • 공정식;정민철;김정훈;이원우
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2011년도 춘계학술대회 논문집
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    • pp.167-172
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    • 2011
  • Generally, the analysis of railroad wear data is most effective method for the efficient railway maintenance. The wear of railway track affects loss of rough ride, noise or vibration of train and traveling safety. Moreover as the track is worn away, this promotes destruction of structural mechanism of rail track which can bring about increasing of rail track maintenance cost drastically. For this reason, it is very important and interested research subject to design railway track structure and to analyse train movement mechanism based on systematic analysis of the reasons causing rail wear possible in real field. In this research, for the efficient maintenance, Life Cycle Performance of rail track and maintenance characteristics are computed considering some track components such as track type, contracting type, sleeper type and roadbed type. Time - Wear probabilistic distribution relationship as well as multiple regression analysis based on time, curvature and wear data are computed to predict the service life remainder of railway track and to be adapted to safety assessment.

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승용차 부품의 정면밀링가공시 공구마모 및 표면거칠기 특성에 관한 연구 (A Study on Characteristics of Tool Wear and Surface Roughness in Face Milling of Automobile Parts)

  • 김성일;오성훈;문상돈;김태영
    • 한국자동차공학회논문집
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    • 제4권5호
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    • pp.223-230
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    • 1996
  • The quality and productivity in machining automobile parts are influenced by various factors such as cutting conditions, vibration, and used tool. To improve the quality and productivity of the automobile parts(torsion beam), lots of research on the evaluation of tool life and control of surface roughness has been required. Therefore, the width of flank wear, cutting force, and surface roughness are monitored to analyse the characteristics of tool wear and surface roughness at different tools. This experimental investigation is mainly focused on the characteristics of the tool wear, tool life and surface roughness in multi-insert milling of automobile parts(torsion beam) by using uncoated tungsten carbide tool(WC), TiN coated tool, and cermet tool.

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