• Title/Summary/Keyword: wear analysis

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Estimation of Damage Condition for the Automobile Transmission Gear by Morphological Analysis of Wear Debris (마멸입자 형태분석에 의한 자동차 트랜스미션 기어의 손상상태 평가)

  • 박흥식;조연상;배효준;이상재
    • Tribology and Lubricants
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    • v.17 no.1
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    • pp.16-21
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    • 2001
  • The wear particles is released from the moving surfaces in gear systems of transmission and its morphology is directly related to the damage and failure to gear system from which the particles originated. It is the effective method for damage condition estimation of automobile transmission gear to observe wear debris in gear oil. We tested with new transmission and took out gear oil according to driving distance. To be applied to damage condition of gear system in transmission of automobile,4 shape parameters of wear particles in gear oil were calculated and wear volume were presumed with the image processing system.

THE CHARACTERISTICS OF FRETTING WEAR

  • Iwabuchi, Akira
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 1996.05a
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    • pp.1-3
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    • 1996
  • The characteristics of fretting wear are reviewed. Fretting damage depends on slip amplitude and classified into three groups: (1) an annular damage according to Mindlin's analysis at microslip region, (2) strong adhesive deformation without loose wear particles at the intermediate region, and (3) formation of fine oxide particles at the gross slip region. The critical slip amplitude of fretting is the boundary between (2) and (3). The boundary slip amplitude depends on normal load. The wear rate increases and saturates with increasing slip amplitude. But it is constant by considering the critical amplitude. The role of oxide particles are discussed. Three different actions are noted: accelerating wear, preventing wear and insignificant effect. The oxide shows two opposing effect depends on normal load and slip amplitude. This is related to the removal rate from the interface (abrasive action) and compaction rate at the interface to form a protective layer. The effect of oxidation is significant to determine the wear and friction. The diffusion of oxygen is restricted at the small amplitude. As a result, crack formation at the boundary is a predominant damage, related to fretting fatigue damage.

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Analysis of Wear Debris for Operating Condition Evaluation of Lubricated Machine Surface (기계윤활면의 작동상태 평가를 위한 마멸분 해석)

  • 서영백;박흥식;전태옥;이광영
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1996.11a
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    • pp.85-89
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    • 1996
  • This paper was undertaken to analyze the morphology of wear debris for operating condition evaluatio of lubricated machine surfaces. The lubricating wear test was carried out under different experimental conditions using tile wear test device was made in our laboritory and wear testing spcimen of the pin on disk type was rubbed in paraffine series base oil, by varying specimen, applied load, sliding distance. The four shape parameters (50% volumetric diameter, aspect, roundness and reflectivity) to describe morphology of wear debris have been developed and are outlined in tile paper. A system using such techniques promises to obviate the need for subjective, human interpretation of particle morphology in machine condition monitoring

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Prediction and Detection of Tool Wear and Fracture in Machining (절삭시 발생하는 공구마멸의 예측 및 파괴의 검출에 관한 연구)

  • 김영태;고정한;박철우;이상조
    • Journal of the Korean Society for Precision Engineering
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    • v.15 no.8
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    • pp.116-125
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    • 1998
  • In this paper, main target is to select parameters for prediction of tool wear and detection of tool fracture. The research about choosing parameter for prediction of tool wear is done by using force ratios. Also current sensor, tool-dynamometer, and accelerometer are used for researching detection method of tool fracture. Experiment is done using Taguchi's method in medium machining conditions. Parameter which is best for prediction of tool wear and detection of tool fracture by deviation analysis is selected. In this paper, tool wear means flank wear.

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Image Analysis of Wear Debris on Operating Condition of Lubricated Machine Surface (윤활운동면의 작동상태에 따른 마멸분 화상해석)

  • 서영백;박흥식;전태옥;진동규;김형자
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 1996.04b
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    • pp.60-67
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    • 1996
  • This paper was undertaken to analyze the morphology of wear debris on operating condition of lubricated machine surfaces. The lubricating wear test was carried out under different experimental conditions using the wear test device was made in our laboritory and wear testing spcimen of the pin on disk type was rubbed in paraffine series base oil, by varying specimen, applied load, sliding distance. The four shape parameters (50% volumetric diameter, aspect, roundness and reflectivity) to describe morphology of wear debris have been developed and are outlined in the paper. A system using such techniques promises to obviate the need for subjective, human interpretation of particle morphology for machine condition monitoring.

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Analysis of Sliding Wear Properties for Arc-melted Intermetallic Compounds of Ni3Al, NiAl and TiAl (Arc melting으로 제조한 금속간화합물 Ni3Al, NiAl 및 TiAl의 미끄럼 마모특성 해석)

  • Lee, Han-Young;Kim, Tae-Jun;Cho, Yong-Jae
    • Korean Journal of Metals and Materials
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    • v.47 no.5
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    • pp.267-273
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    • 2009
  • Three types of structural intermetallic compounds, $Ni_3Al$, NiAl and TiAl, having each single phase structure without pores were produced by arc-melting process. Their sliding wear properties were investigated against a hardened tool steel. It was shown that the wear of the intermetallic compounds was hardly occurred against the hardened tool steel. TiAl compound showed the best wear resistance among them. In this case, wear was preferentially occurred on the surface of the hardened tool steel of the mating material which has higher hardness. It could be found that the wear mode on intermetallics without pores by arc-melting process was different from that on its porous layer coated on steel by combustion synthesis.

Association between smoking behavior and denture wear in the elderly aged 65 years and older in South Korea: The 7th Korea National Health and Nutrition Examination Survey (우리나라 65세 이상 노인의 흡연과 의치장착 관련성: 제7기 국민건강영양조사를 바탕으로)

  • Cho, Mi-Do;Lim, Sun-A
    • Journal of Korean society of Dental Hygiene
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    • v.22 no.5
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    • pp.341-346
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    • 2022
  • Objectives: This study was conducted to analyze the relationship between smoking and denture wear in the elderly individuals aged 65 years and older, and a total of 3,112 people were included. Methods: A complex sample chi-square test was performed for denture wear according to general, smoking, and smoking-related characteristics. Factors related to denture wear were assessed using multiple logistic regression analysis. Results: Among non-smokers, present smokers were 4.192 times more likely to wear dentures, and former smokers were 2.195 times more likely to wear dentures. The average number of daily past smokers was 0.564 times less likely to wear dentures if they smoked 15 cigarettes or less per day. Conclusions: Smoking among the elderly and wearing dentures are related, and it is necessary to develop and utilize a smoking cessation education program considers socioeconomic characteristics.

Fuzzy estimation of minor flank wear in face milling (면삭밀링가공시 공구 부절삭날 마모길이의 퍼지적 평가)

  • Ko, Tae Jo;Cho, Dong Woo
    • Journal of the Korean Society for Precision Engineering
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    • v.12 no.4
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    • pp.28-38
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    • 1995
  • The flank wear at the minor cutting edge significantly affects the geometric accuracy and surface roughness in finish machining. A fuzzy estimator based on a fuzzy inference algorithm with a max-min composition rule is introduced to evaluate the minor flank wear length. The features sensitive to minor flank wear are extracted from the dispersion analysis of a time series AR model of the feed directional acceleration signal. These features, dispersions, are used for constructing linguistic rules, and then the fuzzy inferences are carried out with test data sets collected under various cutting conditions. The proposed system turns out to be effective for estimating minor flank wear length.

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A coupled vibration model of double-rod in cross flow for grid-to-rod fretting wear analysis

  • H. Huang;T. Liu;P. Li;Y.R. Yang
    • Nuclear Engineering and Technology
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    • v.56 no.4
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    • pp.1407-1424
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    • 2024
  • In Pressurized Water Reactors, most of the failed fuel rods are often observed at the periphery of the fuel assembly, especially near the core baffle. The rod vibration-induced fretting wear is a significant failure mechanism strongly correlated with the coolant and support conditions. This paper presents a coupled vibration model of double-rod to predict the grid-to-rod fretting (GTRF) wear. A motion-dependent fluid force model is used to simulate the coolant cross flow, the gap constraints with asymmetric stiffness between spring and dimple on the vibration form, and the fretting wear are discussed. The results show the effect of the coupled vibration on the deterioration of wear, providing a sound theoretical explanation of some failure phenomena observed in the previous experiment. Exploratively, we analyze the impact of the baffle jet on the GTRF wear, which indicates that the high-velocity cross-flow will significantly affect the vibration forms while sharply changing the wear behavior.

A Study of Rail Wear by Change of Acceleration and Deceleration (가속도/감속도 변화율에 따른 레일마모 현상에 관한 연구)

  • Ha, Kwan-Yong;Kim, Hie-Sik
    • Journal of the Korean Society for Railway
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    • v.10 no.5
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    • pp.607-612
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    • 2007
  • In this paper, operation mode of train was divided into powering, coasting, and braking and rail wear phenomenon has been done comparative analysis by each section. Data of train velocity is transferred to acceleration and deceleration from ATO Logging data. Amount of rail wear has been done comparative analysis by traction force of acceleration and braking force of deceleration and a plan for management of track irregularity is come up with by the result of the analysis.