• Title, Summary, Keyword: Wear

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A Fundamental Study for the Sliding Wear Characteristics of the Crane Sheave Against a Rope Wire (크레인시브와 로프소선간의 미끄럼 마멸특성에 관한 기초연구)

  • Ryu, Jung-Buk;Chae, Young-Hun;Kim, Seock-Sam
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.27 no.11
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    • pp.1873-1880
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    • 2003
  • The sliding wear characteristics of the crane sheave were investigated using a pin on disk rig tester. The experiment was conducted using a high carbon steel wire that was upper material, also carbon steel castings that was disk material. There are various operating conditions in this work. At the room temperature, we carried out the wear test under a grease lubrication and dry condition. The results of wear test showed that an annealed-casted have lower, also the wear curves are linearly increased with increasing of sliding distance. For the specific wear rate of annealed-casted, the wear resistance was increased with decreasing diameter of wire. The wear of a wire and a disk have a different mechanism, the one is the abrasive wear due to fatigue wear under lubrication, another is the adhesion wear under dry condition.

Wear Mechanism of Tube Fretting Affected by Support Shapes

  • Kim, Hyung-Kyu;Lee, Young-Ho;Yoon, Kyung-Ho;Kang, Heung-Seok;Song, Kee-Nam;Ha, Jae-Wook
    • KSTLE International Journal
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    • v.3 no.1
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    • pp.68-73
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    • 2002
  • A fretting wear experiment in roam temperature air was performed to evaluate the wear mechanism of fuel rod using a fretting wear tester, which has been developed for experimental study, The main focus was to compare the wear behaviors of fuel rod against support springs with different contact contours (i.e. concave and convex). Wear volume, degree or surface hardening and adhesion tendency of wear particle were examined by the surface roughness tester. The result indicated that with a change of contact condition from contact force of 5 N to 0.1 mm gap, the wear volume of tube increased in the condition of concave spring, but slowly decreased in convex spring. From the results of SEM observation, wear mechanism of each test condition was also dependent on the spring shapes. The wear mechanism of each test condition in room temperature air is discussed.

A Study on Automatic wear Debris Recognition by using Particle Feature Extraction (입자 유형별 형상추출에 의한 마모입자 자동인식에 관한 연구)

  • ;;;A. Y. Grigoriev
    • Tribology and Lubricants
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    • v.15 no.2
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    • pp.206-211
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    • 1999
  • Wear debris morphology is closely related to the wear mode and mechanism occured. Image recognition of wear debris is, therefore, a powerful tool in wear monitoring. But it has usually required expert's experience and the results could be too subjective. Development of automatic tools for wear debris recognition is needed to solve this problem. In this work, an algorithm for automatic wear debris recognition was suggested and implemented by PC base software. The presented method defined a characteristic 3-dimensional feature space where typical types of wear debris were separately located by the knowledge-based system and compared the similarity of object wear debris concerned. The 3-dimensional feature space was obtained from multiple feature vectors by using a multi-dimensional scaling technique. The results showed that the presented automatic wear debris recognition was satisfactory in many cases application.

Measurement of Wear and Friction Coefficients for the Prediction of Fretting Wear (프레팅 마멸계수 및 마찰계수 측정에 관한 연구)

  • Cho, Yong Joo;Kim, Tae Wan
    • Tribology and Lubricants
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    • v.28 no.3
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    • pp.124-129
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    • 2012
  • The prediction of fretting wear is a significant issue for the design of contacting mechanical components such as flexible couplings and splines, jointed structures and so on. In our earlier study, we developed a numerical model to predict the fretting wear using boundary element method. The developed algorithm needs experimental fretting wear coefficients and friction coefficients between two moving materials to get more reliable results. In this study, therefore, we demonstrated the measurement method of the fretting wear coefficients and friction coefficients using disk on plate tribometer with piazo actuator and gap sensor. For four different material combinations, the fretting wear coefficients and friction coefficients are acquired through the fretting wear experiment and the analysis of the measured values. Thess results are useful to predict the quantative fretting wear rate in the developed algorithm.

The Relationship between a Wear Depth :and a Decrease of the Contacting Force in the Nuclear Fuel Fretting (핵연료봉 프레팅마멸에서 마멸깊이와 접촉하중 감소사이의 관계)

  • Lee Young-Ho;Kim Hyung-Kyu
    • Tribology and Lubricants
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    • v.22 no.1
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    • pp.8-13
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    • 2006
  • Sliding wear tests have been performed to evaluate the effect of normal load decrease on the wear depth of nuclear fuel rods in room temperature air. The objectives of this study are to quantitatively evaluate the supporting ability of spacer grid springs, to estimate the wear depth by using the contacting force decrease and to compare the wear behavior with increasing test cycles (up to $10^7$) at each spring condition. The result showed that the contacting load decrease depends on the spring shape and the applied slip amplitude. The estimated wear depth is smaller when compared with measured wear depth. Based on the test results, the wear mechanism, the role of wear debris layer and the spring shape effect were discussed.

The Sliding Wear Characteristics of the Carbon Steel Castings against High Carbon Steel Wire Rods (탄소주강품과 경강선재간의 미끄럼 마멸특성)

  • 류중북;채영훈;김석삼
    • Tribology and Lubricants
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    • v.19 no.4
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    • pp.223-229
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    • 2003
  • The sliding wear characteristics of the crane sheave were investigated using a pin-on-disk rig tester. The experiment was conducted using a high carbon steel wire that was upper material, also carbon steel castings that was disk material. There are various operating conditions in this work. At the room temperature, we carried out the wear test under a grease lubrication and dry condition. The results of wear test showed that an annealed-casted have lower, also the wear curves are linearly increased with increasing of sliding distance. For the specific wear rate of annealed-casted, the wear resistance was increased with decreasing diameter of wire. The wear of a wire and a disk have a different mechanism, the one is the abrasive wear due to fatigue wear under lubrication, another is the adhesion wear under dry condition.

Study on Wear of Journal Bearings during Start-up and Coast-down Cycles of a Motoring Engine - II. Analysis Results (모터링 엔진의 시동 사이클 및 시동 정지 사이클에서 저어널베어링의 마모 연구 - II. 해석 결과)

  • Chun, Sang Myung
    • Tribology and Lubricants
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    • v.31 no.3
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    • pp.125-140
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    • 2015
  • In this paper, we present the results of the wear analysis of journal bearings on a stripped-down single-cylinder engine during start-up and coast-down by motoring. We calculate journal bearing wear by using a modified specific wear rate considering the fractional film defect coefficient and load-sharing ratio for the asperity portion of a mixed elastohydrodynamic lubrication (EHL) regime coupled with previously presented graphical data of experimental lifetime linear wear in radial journal bearings. Based on the calculated wear depth, we obtain a new oil film thickness for every crank angle. By examination of the oil film thickness, we determine whether the oil film thickness at the wear scar region is in a mixed lubrication regime by comparing dimensionless oil film thickness, h/σ, to 3.0 at every crank angle. We present the lift-off speed and the crank angles involved with the wear calculation for bearings #1 and #2. The dimensionless oil film thickness, h/σ, illustrates whether the lubrication region between the two surfaces is still within the bounds of the mixed lubrication regime after scarring of the surface by wear. In addition, we present in tables the asperity contact pressure, the real minimum film thickness at the wear scar region, the modified specific wear rate, and the wear angle, α, for bearings #1 & #2. To show the real shape of the oil film at wear scar region, we depict the actual oil film thickness in graphs. We also tabulated the ranges of bearing angles related with wear scar. We present the wear volume for bearings #1 and #2 after one turn-on and turn-off of the engine ignition switch for five kinds of equivalent surface roughness. We show that the accumulated wear volume after a single turn-on and turn-off of an ignition switch normally increases with increasing surface roughness, with a few exceptions.

Quantitative characteristics of particle size distribution by the wear mode transition (마모유형 천이에 따른 입자크기분포의 정량적 특성)

  • 공호성;권오관
    • Tribology and Lubricants
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    • v.2 no.1
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    • pp.39-45
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    • 1986
  • Wear simulation test have been conducted in mild, severe and transient wear regions by a four-ball wear tester. Wear particles are separatively deposited by the RPD technique, and quantitatively analysed in terms of wear particles size distribution. Characteristics of the wear particle size distribution are compare to the results of wear tests through both weibull parameters and center moment method of the weibull distribution function.

Characteristics of rubber friction and wear (고무의 마찰과 마모 특성에 대한 고찰)

  • Kim, Hyun-Jae;Kim, Se-Nyung;Kim, Su-Hyung;Kim, Doo-Man
    • Journal of Aerospace System Engineering
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    • v.4 no.4
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    • pp.1-10
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    • 2010
  • The basic factor that affect wear performance is the wear characteristics, which come from sliding friction between rubber compound and road. Thus, this study focused on friction and wear of rubber. This paper briefly explain some characteristics of friction and wear referring to the papers on wear of rubber that scholars researched on. Research activities to predict the performance of the rubber wear is also explained.

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A Study on the monitoring of tool wear in face milling operation (밀링공구의 마모 감시에 관한 연구)

    • Journal of The Korean Society of Manufacturing Technology Engineers
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    • v.7 no.1
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    • pp.69-74
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    • 1998
  • In order to monitor the tool wear in milling operation, cutting force is measured as the tool wear increased. The digital signal processing methods are used to detect the tool wear . As AR parameter extract the feature of tool wear , it can be used as input parameter of pattern classifier. The FFT monitor the tool wear exactly , but it can not do real time signal processing. The band energy method can be used to real time monitoring of tool wear ,but int can degrade the exact monitoring.

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