• Title, Summary, Keyword: Wear

Search Result 6,969, Processing Time 0.093 seconds

A study on automatic wear debris recognition by using particle feature extraction (입자 유형별 형상추출에 의한 마모입자 자동인식에 관한 연구)

  • ;;;Grigoriev, A.Y.
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
    • /
    • /
    • pp.314-320
    • /
    • 1998
  • 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.

  • PDF

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
    • /
    • v.15 no.2
    • /
    • pp.206-211
    • /
    • 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.

A Study on the Variation of the Fretting Wear Mechanisms under Elastically Deformable Contacts

  • Lee, Young-Ho;Kim, Hyung-Kyu
    • KSTLE International Journal
    • /
    • v.10 no.1_2
    • /
    • pp.27-32
    • /
    • 2009
  • In this study, fretting wear tests of nuclear fuel rods have been performed by using two kinds of spacer grid springs with a concave and a convex shape in room temperature dry and distilled water conditions. The objectives were to examine the variation of the wear mechanism with increasing fretting cycles and to evaluate the difference of the wear debris detachment behavior at each test environment. From the test results, the wear volume of each spring condition increased with increasing fretting cycles regardless of the test environments. However, the wear rate did not show a regular tendency and apparently changed with increasing fretting cycles. This is because the formation of the wear particle layer and/or the variation of the contact condition between the fuel rod and spring surfaces could affect a critical plastic deformation for detaching the wear debris. Based on the test results, the relationship between the wear behavior of each spring shape and test environment condition, and the variation of the surface characteristics are discussed in detail.

The Classification of Tool Wear States Using Pattern Recognition Technique (패턴인식기법을 이용한 공구마멸상태의 분류)

  • Lee, Jong-Hang;Lee, Sang-Jo
    • Transactions of the Korean Society of Mechanical Engineers
    • /
    • v.17 no.7
    • /
    • pp.1783-1793
    • /
    • 1993
  • Pattern recognition technique using fuzzy c-means algorithm and multilayer perceptron was applied to classify tool wear states in turning. The tool wear states were categorized into the three regions 'Initial', 'Normal', 'Severe' wear. The root mean square(RMS) value of acoustic emission(AE) and current signal was used for the classification of tool wear states. The simulation results showed that a fuzzy c-means algorithm was better than the conventional pattern recognition techniques for classifying ambiguous informations. And normalized RMS signal can provide good results for classifying tool wear. In addition, a fuzzy c-means algorithm(success rate for tool wear classification : 87%) is more efficient than the multilayer perceptron(success rate for tool wear classification : 70%).

Relationship between Spring Shapes and the Ratio of wear Volume to the Worn Area in Nuclear Fuel Fretting

  • Lee, Young-Ho;Kim, Hyung-Kyu;Jung, Youn-Ho
    • KSTLE International Journal
    • /
    • v.4 no.1
    • /
    • pp.31-36
    • /
    • 2003
  • Sliding and impact/sliding wear test in room temperature air and water were performed to evaluate the effect of spring shapes on the wear mechanism of a fuel rod. The main focus was to quantitatively compare the wear behavior of a fuel rod with different support springs (i.e. two concaves, a convex and a flat shape) using a ratio of wear volume to worn area (De)-The results indicated that the wear volumes at each spring condition were varied with the change of test environment and loading type. However, the relationship between the wear volume and worn area was determined by only spring shape even though the wear tests were carried out at different test conditions. From the above results, the optimized spring shape which has more wear-resistant could be determined using the analysis results of the relation between the variation of De and worn surface observations in each test condition.

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
    • /
    • v.19 no.4
    • /
    • pp.223-229
    • /
    • 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.

Rolling Wear Mechanism of Ceramics by SEM Observation (SEM 관찰에 의한 세라믹의 구름마모기구)

  • Kim, Seock-Sam;Kato, Kohji;Hokkirigawa, Kazuo
    • Tribology and Lubricants
    • /
    • v.5 no.1
    • /
    • pp.36-43
    • /
    • 1989
  • Scanning electron microscopic observations were carried out on the worn surface and the wear debris of ceramic materials to investigate the wear mechanism of those in dry rolling contact. It was found from the scanning electron microscopic observations that the wear in ceramic materials is related to brittle fracture and has two types of wear mechanisms, small scale wear and larvae scare wear. Plate-like wear debris were created from the initial surface cracks and defects. The small scale wear was related to real contact area and large scale wear was related to HertzJan contact area. A wear model was proposed on the basis of scanning electron microscopic observations.

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
    • /
    • v.27 no.11
    • /
    • pp.1873-1880
    • /
    • 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.

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
    • /
    • v.4 no.4
    • /
    • pp.1-10
    • /
    • 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.

  • PDF

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
    • /
    • v.7 no.1
    • /
    • pp.69-74
    • /
    • 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.

  • PDF