• Tribology and Lubricants
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• 제14권4호
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• pp.79-87
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• 1998

Morphological analysis of wear particles in the lubricating oil is a very effective and versatile means of lubricant analysis for machine condition monitoring and fault diagnosis. The prospects for determining quantitative information about wear particle morphology have been considerably enhanced by recent developments reported in the application of image processing and analysis techniques. This study was undertaken to investigate the influence of oiliness agent and extreme pressure agent on the shape of wear particles. The wear test was performed under different experimental conditions with stearic acid, dibenzyl disulfide(DBDS) and tricresol phosphate(TCP) in paraffinic base oil. Wear particles characteristics were described using four shape parameters, namely 50% volumetric diameter, aspect, roundness and reflectivity. The results showed that the four shape parameters of wear particles depend on a kind of the additives. This analysis of wear debris with computer image processing techniques is sufficient to distinguish some types of wear debris. The wear volume of three kinds of the specimens are affected by the additives with boundary films.

• Structural Engineering and Mechanics
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• 제31권2호
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• pp.137-152
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• 2009

Mechanic behavior of Y-shape thin-walled box girder bridge structure is complex, so one can not exactly hold the mechanical behavior of the Y-shape thin-walled box girder bridge structure through general calculation theory and analytical method. To hold the mechanical behavior better, based on elementary beam theory, by increasing the degree of freedom analytical method, taking account of restrained torsiondistortion angledistortion warp and shearing lag effect at the same time, authors obtain a thin-walled box beam analytical element of 10 degrees of freedom of every node, derive stiffness matrix of the element, and code a finite element procedure. In addition, authors combine the obtained procedure with spatial grillage analytical method, meanwhile, they build a new analytical method that is the spatial thin-walled box girder element grillage analysis method. In order to validate the precision of the obtained analysis method, authors analyze a type Y-shape thin-walled box girder bridge structure according to the elementary beam theory analytical method, the shell theory analytical method and the spatial thin-walled box girder element grillage analysis method respectively. At last, authors test a type Y-shape thin-walled box girder bridge structure. Comparisons of the results of theory analysis with the experimental text show that the spatial thin-walled box girder element grillage analysis method is simple and exact. The research results are helpful for the knowledge of the mechanics property of these Y-shape thin-walled box girder bridge structures.

• 한국구조물진단유지관리공학회 논문집
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• 제14권3호
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• pp.123-130
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• 2010

본 논문에서는 기존 건축물의 내진성능을 향상시키기 위해 시공성과 설치 비용적인 측면에서 상대적으로 우수한 강재댐퍼를 대상으로 기존 개발된 장치와 새로 개발된 형상의 장치에 대한 평가를 해석적으로 수행하였다. 해석결과는 강도 및 에너지 소산능력으로 평가하였으며, 제안된 내력 산정식의 적용을 아울러 평가하였다. 연구대상 댐퍼의 스트럿 형상은 V형, S형이며, 댐퍼의 스트럿 높이와 각도를 주요 변수로 한 후 ABAQUS를 이용하여 유한요소 해석하였다. 해석은 최대변위를 50mm로 하고 점진적인 이력변위곡선을 적용하여 수행하였다. 항복강도, 최대강도, 에너지 소산능력 평가결과, V형 및 S형 모두 우수한 성능을 보유한 것으로 평가되었으며, 또한 스트럿 각도 $60^{\circ}$ 및 높이 140, 200 mm의 성능이 안정적인 것으로 평가되었다. 전체적으로는 S형의 응답이 V형보다 안정적인 것으로 평가되어, S형 강재댐퍼의 적용성이 V형보다 유리한 것으로 평가되었다.

• 한국디자인학회:학술대회논문집
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• 한국디자인학회 2001년도 Bulletin of The 5th Asian Design Conference International Symposium on Design Science
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• pp.48.2-48
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• 2001

• 한국공작기계학회논문집
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• 제12권2호
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• pp.37-43
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• 2003

This study makes to flow analysis of computational fluid dynamics(CFD) according to the basic theory of turbulent flow regarding high-pressure injection nozzle. It also makes structural analysis to find out the structural validity of the optimum shape of high-pressure injection nozzle. It divides to two areas such as plunger areas and high-pressure injection nozzle area including plunger.

• 한국디자인학회:학술대회논문집
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• 한국디자인학회 1995년도 디자인 학 연구 1995년 추계 학술연구 발표 대회 개요 집
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• pp.66-67
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• 1995

• 한국의류산업학회지
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• 제19권5호
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• pp.569-578
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• 2017

The purpose of this study is to analyze the lower body shape of varus-typed elderly women. This study intentionally collected elderly women at age 65 years or older who seemed to have a lower body shape of varus-type, and the data of 100 women were used for final analysis. The results are as follows. Elderly women with a lower body shape of varus-type were shorter than regular elderly women and had small circumference and weak lower body. To classify the body shapes, factor analysis was conducted which drew a total of 3 factors, with 74.11% of accumulative variance. Cluster analysis was performed according to factor analysis and the body shapes were divided into 3 types. Type 1 was a body shape with the most severe varus-type that had small measured values of height and the highest BMI. Type 2 was a group of women with a large build with a relatively small tendency of varus-type. Type 3 was a group of women who were not obese, had long lower bodies, and varus-type with small circumference, which were similar to Type 1. Therefore, this study on the body shape is expected to be used as a basic data for the development of the clothes for straightening the varus-typed lower body shape in the future.

• Journal of Advanced Marine Engineering and Technology
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• 제37권2호
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• pp.170-177
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• 2013

본 연구는 200 W급 자이로밀형 소형 수직축 풍력터빈 로터 블레이드의 형상설계 및 유동해석에 의한 성능 검토에 관한 내용을 정리한 것이다. 2차원 형상의 로터 블레이드에 대하여 단일유관이론을 적용하여 설계하였으며, 설계 결과에 대해서 2차원 수치유동해석을 수행하여 해석결과의 검토로부터 3차원 로터 블레이드 기본 형상을 결정하고, 3차원 수치유동해석을 통하여 풍력터빈 로터 블레이드의 형상 결정 및 성능 검토를 하였다. 본 연구의 결과로부터 상대적 저풍속에서 200 W급 자이로밀형 수직축 풍력터빈 로터 블레이드의 형상을 도출하였고, 수치유동해석으로부터 정격출력 200 W를 확보할 수 있음을 확인하여, 본 연구에서 적용한 설계법의 타당성을 확보하였다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2009년도 춘계학술대회 논문집
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• pp.512-515
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• 2009

This research describes on airfoil shape design, crucial to core technique and algorithm optimization for the wind turbine blade development. We grasped the parameter to define the airfoil shape in the wind turbine blade and aircraft, and the important performance characteristic of the airfoil. The airfoil shape function is selected by studying which is suitable for wind turbine blade airfoil development. The selected method is verified by to compare the generated airfoil shape with base airfoil. The new airfoils were created by the selecting shape function based on the well-known airfoil for wind turbine blades. In addition, we performed aerodynamic analysis about the generated airfoils by XFOIL and estimated the point of difference in the airfoil shape parameter using the aerodynamic performance results which is compared with basic airfoil. This result data applies to the fundamental research for a wind turbine blade optimization design and accomplished the aerodynamic analysis manual.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2008년도 춘계학술대회 논문집
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• pp.349-352
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• 2008

In this study, a design method of developed shape for double-curved pressure vessel segment heads was proposed in consideration of in-plane strain induced by forming works. In order to obtain the developed shape of double-curved plate, at first, the segments are subdivided into elements and then they are stacked into a series of strips producing the outline of the approximately developed shape. The developed shape was determined by imposing the in-plane displacement obtained from forming analysis and regression analysis on the outline of the approximately developed shape. The validation of the proposed design method was verified by applying it to the actual products.