• 제목/요약/키워드: Wear characteristics

검색결과 2,044건 처리시간 0.028초

FRP 선박 외판재의 연삭마모 특성에 관한 상대재 거칠기의 영향 (Effect of Counterpart Roughness on Abrasive Wear Characteristics of Side Plate of FRP Ship)

  • 김형진;고성위;김재동
    • 한국해양공학회지
    • /
    • 제22권6호
    • /
    • pp.35-40
    • /
    • 2008
  • The effect of counterpart roughness on abrasive wear characteristics of side plate materials of FRP ship, which were composed of glass fiber and unsaturated polyester resin composites, were investigated at ambient temperature by pin-an-disc friction test. The friction coefficient, wear rate and cumulative wear volume of these materials against SiC abrasive paper were determined experimentally. The wear rate of these materials decreased rapidly with sliding distance and then maintained a constant value. It was increased as counterpart roughness was rougher in a wear test. The cumulative wear volume tended to increase nonlinearly with sliding distance and depended on applied load and sliding speed for these composites. It could be verified by SEM photograph of fracture surface that major failure mechanisms were overlapping layers, microcutting, deformation of resin, delamination, and cracking.

캐쥬얼 웨어에서 선호하는 한국적 이미지에 관한 연구 (Korean Image Preferences in Casual Wear)

  • 황진숙;김윤희;이진;권선진
    • 한국의상디자인학회지
    • /
    • 제10권2호
    • /
    • pp.179-191
    • /
    • 2008
  • This study investigated Korean image preferences in casual wear of women consumers and the effects of demographic characteristics on Korean image preferences in casual wear. The subjects of the study were 653 women consumers who lived in Seoul. Data were collected during July, 2007. Statistical analyses used in the study were frequency, ANOVA and Duncan test. The results showed that respondents preferred to express Korean image by color in their casual wear. When it comes to specific preferences for pattern, fabric, and color, circular shape was most preferred as pattern, cotton was most preferred as fabric, and white color was most preferred as color. In addition, there were demographic differences in regard to preferences for pattern, fabric, color, and types of casual wear. The results showed that there were differences in age, occupation, income, and residence. For example, in regard to age, there were differences in the preferences for fabric, color, and types of casual wear. The older respondents preferred natural fabrics more while the younger respondents seemed to accept synthetic fabrics in their casual wear. Also, women aged over 40 preferred cotton pants for their casual wear. This study showed that demographic characteristics are important variables in segmenting the preferences of Korean image for casual wear market.

  • PDF

선박엔진 부품의 성능 향상을 위한 초기 마모 및 윤활 해석 연구 (Simulation of the Initial Wear and Lubrication Performance of Marine Engine Components)

  • 차수빈;이향;정구현
    • Tribology and Lubricants
    • /
    • 제38권6호
    • /
    • pp.227-234
    • /
    • 2022
  • Recently, the demand for improving energy efficiency has rapidly increased because of the growing concerns over environmental issues. In this work, the tribo-test and simulation for the initial wear and lubrication performance were performed for the piston pin in the small end system of the connecting rod of a marine engine, to obtain useful data for improving the efficiency of marine engine systems. In addition, a diamond-like carbon (DLC) coating was applied to the piston pin to explore feasibility of eliminating the bush used in the system. The initial wear and lubrication characteristics between the uncoated piston pin and bush were compared with that between the DLC-coated piston pin and connecting rod in the tribo-test. The simulation for the wear and lubrication performance according to the wear progression was conducted based on the data obtained from the test. The wear characteristics were quantitatively assessed by the wear depth and wear volume, and the lubrication performance was characterized with the change of pressure and minimum oil film thickness with respect to the crank angle. It was found that the DLC-coated piston pin may provide better initial wear characteristics and lubrication performance. The results of this work may provide fundamental information for marine engines with improved efficiency.

윤활유 중지 마멸입자의 프랙탈 형상특징 추출 방법 (Extraction of Fractal Shape Characteristics of Wear Particles in Lubricant)

  • 박흥식;우규성;조연상;김동호;예규현
    • Tribology and Lubricants
    • /
    • 제22권5호
    • /
    • pp.276-281
    • /
    • 2006
  • The fractal dimension is quantitatively to define the irregular characteristic of the shape in natural. It can be useful in describing morphological characteristics of various wear particles. This paper was undertaken to diagnose failure condition for sliding members in lubrication by fractal dimension. It will be possible to diagnose wear mechanism, friction and damage state of machines through analysis of shape characteristics for wear particle on driving condition by fractal parameters. In this study, the calculating and analyzing methods of fractal dimensions were constructed for the condition monitoring and wear particle analysis in lubricant condition. So, we carried out the Friction and wear test with the ball on disk type tester, and the fractal parameters of wear particle in lubricated conditions were calculated. Fractal parameters were defined as texture fractal dimension ($D_{t}$), structure fractal dimension ($D_{s}$) and total fractal dimension (D).

내마모성이 우수한 절연구분장치 국산화 개발 (Development of Section Insulator with Improved Wear Characteristics)

  • 이기원;정호성;박영;조호령;이상식
    • 전기학회논문지
    • /
    • 제62권11호
    • /
    • pp.1633-1639
    • /
    • 2013
  • In a section of AC electric railway, a phase between the sections is different although voltage levels supplied from substations are the same. Therefore, section insulators have been installed to electrically divide between the sections. Two differenet types of section insulator, namely an overlap type and insulator type, are used. In Korean high-speed lines, overlap type section insulator has been adopted. And, insulator type is used in conventional line. The overlap type has the advantage of having no speed limit, but has the disadvantage of requiring long section length. However, the insulator type has the advantage of section length, but also has the disadvantage of having speed limit. In Korean conventional line, an insulator type one relies on the import and there is some problem with wear. In this study, we developed the insulator type section insulator which adopts Teflon tube insulation material. The Teflon material has advantage of the excellent electrical characteristics and wear-resistance characteristics for a longer expected life than that made of existing FRP. In order to compare wear characteristics between the materials, wear tests with reciprocal wear tester are performed. And dynamic behavior tests between the insulators and pantograph are also performed for showing its better dynamic characteristics.

직장여성을 위한 이지 캐주얼 웨어 디자인 개발 (The Design Development of Easy Casual Wear for Career Women)

  • 변미연;이인성
    • 한국의류학회지
    • /
    • 제30권8호
    • /
    • pp.1301-1311
    • /
    • 2006
  • This study rearranged a concept of Friday wear considered as casual wear by searching social background through analysis of literature study and photo materials and classifying by characteristics of casual wear. It investigated growing changes of casual wear and the progress of changes casual brands through a market survey based on departments in Seoul. And then, it examined characteristics of a design and the critical point of easy casual selecting GIORDANO, TBJ and NII of three easy casual brands. Conclusions of the study are as follows: Firstly, present casual wear showed subdivision of casual wear as abundant grouping vocabularies appeared contrary to the past. Secondly, easy casual wear has continuously increased by results of investigating departments in Seoul on the progress of changing easy casual wear brand including the concept of Friday wear. Thirdly, if a main target sets the early 20s, women workers in their 20's and 30's are likely to be reluctant to wear it according to results of investigating designs and characteristics based on GIORDANO, TBJ and NII of existing three easy casual brands through the market survey. Also, it was verified that most of these brands have no a luxurious image because they adhere to middle-low price. Fourthly, it improved problems of easy casual through developing designs of easy casual wear. Easy casual wear supplementing weak these points of easy casual wear was evaluated as suitable clothes for workers to wear in on and off their own time in Friday.

무가압함침법으로 제조된 입자강화 금속복합재료의 마모특성 (Wear Characteristics of Particulate Reinforced Metal Matrix Composites Fabricated by a Pressureless Metal Infiltration Process)

  • 김재동;정순억;김형진
    • 한국해양공학회지
    • /
    • 제17권1호
    • /
    • pp.55-60
    • /
    • 2003
  • The effect of size and volume fraction of ceramic particles, with sliding velocity on the wear properties were investigated for the metal matrix composites fabricated by the pressureless infiltration process. The metal matrix composites exhibited about 5.5 - 6 times the wear resistance compared with AC8A alloy at high sliding velocity, and by increasing the particle size and decreasing the volume fraction, the wear resistance was improved. The wear resistance of metal matrix composites and AC8A alloy exhibited different aspects. Wear loss of AC8A alloy increased with sliding velocity, linearly : whereas, metal matrix composites indicated more wear loss than AC8A alloy at the slow velocity region. However, a transition point of wear loss was found at the middle velocity region, which shows the minimum wear loss. Further, wear loss at the high velocity region exhibited nearly the same value as the slow velocity region. In terms of wear mechanism, the metal matrix composites generally exhibited abrasive wear at slow to high sliding velocity; however, AC8A alloy showed abrasive wear at low sliding velocity and adhesive and melt wear at high sliding velocity.

무가압함침법으로 제조된 입자강화 금속복합재료의 마모특성 (Wear Characteristics of Particulate Reinforced Metal Matrix Composites Fabricated by Pressureless Metal Infiltration Process)

  • 김재동;정순억;김형진
    • 한국해양공학회:학술대회논문집
    • /
    • 한국해양공학회 2002년도 추계학술대회 논문집
    • /
    • pp.379-384
    • /
    • 2002
  • The effect of size and volume fraction of ceramic particles with sliding velocity on the wear properties were investigated for the metal matrix composites fabricated by pressureless infiltration process. The particulate metal matrix composites exhibited about 5.5 - 6 times of excellent wear resistance compared with AC8A alloy at high sliding velocity, and as increasing the particle size and decreasing the volume fraction the wear resistance was improved. The wear resistance of metal matrix composites and AC8A alloy exhibited different aspects. Wear loss of AC8A alloy increased with sliding velocity linearly. whereas metal matrix composites indicated more wear loss than AC8A alloy at slow velocity region, however a transition point of wear loss was found at middle velocity region which show the minimum wear loss, and wear loss at high velocity region exhibited nearly same value with slow velocity region. In terms of wear mechanism, the metal matrix composites exhibited the abrasive wear at slow to high sliding velocity generally, however AC8A alloy showed abrasive wear at low sliding velocity and adhesive and melt wear at high sliding velocity.

  • PDF

미끄럼 속도 변화에 따른 폴리우레탄 씰의 마모 특성 (Effect of Sliding Speed on Wear Characteristics of Polyurethane Seal)

  • 김한솔;전홍규;정구현
    • Tribology and Lubricants
    • /
    • 제34권2호
    • /
    • pp.49-54
    • /
    • 2018
  • Hydraulic reciprocating seal has been widely used to prevent fluid leakage in hydraulic systems. Also, hydraulic reciprocating seal plays a significant role to provide lubricant film at contacting interface to minimize tribological problems due to sliding with counter material. To predict lifetime of hydraulic reciprocating seal, quantitative understanding of wear characteristics with respect to operating conditions such as normal force and sliding speed is needed. In this work, effect of sliding speed on wear of polyurethane (PU) hydraulic reciprocating seal were experimentally investigated using a pin-on-disk tribo-tester. The wear characteristics of PU specimens were quantitatively determined by comparing the confocal microscope data before and after test. It was found that the wear rate of PU specimens decreased from $4.9{\times}10^{-11}mm^3$ to $1.1{\times}10^{-11}mm^3/Nm$ as sliding speed increased from 120 mm/s to 940 mm/s. Also, it was observed that the friction decreased slightly as the sliding speed increased. Improvement of lubrication state with increasing sliding speed was likely to be responsible for this enhanced friction and wear characteristics. This result also suggests that decrease in sliding distance between PU elastomer and counter materials at lower sliding speed is preferred. Furthermore, the quantitative assessment of wear characteristics of PU specimen may be useful in prediction of lifetime of PU hydraulic reciprocating seal if the allowed degree of wear for failure of the seal is provided.

자동차 섀시 시스템에 유입되는 먼지입자에 의한 고무-씨일 부품의 마멸특성 -PART II: 먼지유입에 따른 고무-씨일의 마멸특성- (Wear Characteristics of Rubber-Seal for Inflow of Dust Particles in Automobile Chassis System -PART II: The Influence of Dust Particle Inflow on Wear Characteristics of Rubber-Seal-)

  • 이영제;정순오;원태영;김기훈;김대성
    • Tribology and Lubricants
    • /
    • 제25권4호
    • /
    • pp.261-264
    • /
    • 2009
  • Environmental factors affect parts of the automobile. When dust particles are embedded, specially, friction and wear of the rubber-seal in automobile chassis system are increased. Increase in friction and wear leads to weakness of component and reduction of mechanical life. In this study, the wear characteristics of rubber-seal for inflow of dust particles are investigated. Silica($SiO_2$) and alumina($Al_2O_3$) particles are used as a dust particle because these particles are main elements of dust particles. The sliding wear tester are used for investigate the wear characteristics of rubber-seal. If the single dust particle($SiO_2$) is embedded in the rubber-seal component, the influence of dust particle size is more than that of inflow rate on the wear characteristics of rubber-seal. If the mixed dust particles are embedded in the rubber-seal component, the wear rate is increased as the rate of alumina that has a bigger hardness is increased. If the mixed dust particles that have different hardness are embedded in the rubber-seal component, the influence of particle size is more than that of particle hardness.