• Title/Summary/Keyword: Line-loading

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The Effects of CCT Specimen Geometry and Loading Condition on the J-Integral (CCT시편의 형상과 하중조건이 J 적분에 미치는 영향)

  • 이억섭;김종호
    • Journal of the Korean Society for Precision Engineering
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    • v.20 no.2
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    • pp.154-161
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    • 2003
  • The effects of specimen geometry, and loading conditions on the J-integral fur CCT (center cracked tension) specimens are investigated by using FEM. It is found that the J-integral tends to decrease according to the parallel tensile loading to crack line. Furthermore, it is verified that the compressive parallel loading to crack line is likely to increase the J-integral. A stress ratio of length to width of the center CCT specimen is confirmed to affect the J-integral significantly.

Dynamic characteristics of transmission line conductors and behaviour under turbulent downburst loading

  • Darwish, Mohamed M.;El Damatty, Ashraf A.;Hangan, Horia
    • Wind and Structures
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    • v.13 no.4
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    • pp.327-346
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    • 2010
  • During the past decade, many electrical transmission tower structures have failed during downburst events. This study is a part of a research program aimed to understand the behaviour of transmission lines under such localized wind events. The present study focuses on the assessment of the dynamic behaviour of the line conductors under downburst loading. A non-linear numerical model, accounting for large deformations and the effect of pretension loading, is developed and used to predict the natural frequencies and mode shapes of conductors at various loading stages. A turbulence signal is extracted from a set of full-scale data. It is added to the mean component of the downburst wind field previously evaluated from a CFD analysis. Dynamic analysis is performed using various downburst configurations. The study reveals that the response is affected by the background component, while the resonant component turns to be negligible due large aerodynamic damping of the conductors.

A Study on the Design and Development of Automatic Optical Fiber Aligner (자동 광섬유 정렬 장치의 설계 및 제작에 관한 연구)

  • Kim, Byung-Hee;Uhm, Chul;Choi, Young-Suk
    • Journal of Industrial Technology
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    • v.22 no.B
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    • pp.241-249
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    • 2002
  • Optical fiber is indispensable for optical communication systems that transmit large volumes of data at high speed, but super precision technology in sub-micron units is required for optical axis adjustment. We developed the automatic optical fiber by image processing and automatic loading system. we have developed 6-axis micro stage system for I/O optical fiber arrays, the initial automatic aligning system software for a input optical array by the image processing technique, fast I/O-synchronous aligning strategy, the automatic loading/unloading system and the automatic UV bonding mechanism. In order to adjust the alignment it used on PC based motion controller, a $10{\mu}m$ repeat-detailed drawing of automatic loading system is developed by a primary line up for high detailed drawing. Also, at this researches used the image processing system and algorithm instead of the existing a primary hand-line up and fiber input array and waveguide chip formed in line by automatic.

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A Study on Similarity Rule of Loading Period and Thickness with One-dimensional Consolidation Process for Clay (점토의 1차원 압밀과정에 있어서 재하시간과 층두께에 대한 상사법칙에 관한 연구)

  • Kim, Jae Young;Ohshima, Akihiko
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.26 no.6C
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    • pp.369-376
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    • 2006
  • Similarity rule in order to predict the field settlement and consolidation time from oedometer test is not clear because of the thickness, loading time, rate of loading increase, dependence on strain inherent of clay. To investigate the one-dimensional consolidation tests with permeability tests varied loading period and specimen thickness were carried out the application of similarity rule. Main conclusions are 1) f(=1+e)-logk line is a unique property of the soil, 2) $c_{\nu}$, k need no correction, 3)similarity rule is depends on the positions of f-logp line and primary consolidation line.

An Experimental Study on the Liquefaction Behavior under Various Loading Conditions (다양한 입력하중에서의 액상화 발생 특성 비교 연구)

  • Kim, Soo-Il;Hwang, Seon-Ju;Park, Keun-Bo;Choi, Jae-Soon
    • Proceedings of the Korean Geotechical Society Conference
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    • 2005.03a
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    • pp.320-327
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    • 2005
  • Liquefaction characteristics of saturated sand under various dynamic loadings such as sinusoidal, wedge, increasing wedge and real earthquake loading are investigated focusing on the excess pore water pressure build up instead of liquefaction resistance strength in this paper. There are large differences between two types of earthquake loading - impact and vibration in liquefaction characteristics. The angle of phase change line of sinusoidal loading is very close to the vibration type, whereas the cumulative deviator stress and cumulative plastic strain are larger than two types of real earthquake loadings. On the other hand, the liquefaction characteristics of increasing wedge loadings are located in the range between vibration and impact earthquake loadings. It is concluded that the sinusoidal loading overestimates the resistance of soil under real earthquake loading. Based on results obtained, the increasing wedge loading can reflect the liquefaction behavior under real earthquake loadings more efficiently than sinusoidal loading based on equivalent uniform stress concept.

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Study on the Effect of Product Line Pricing on Loading Efficiency and Logistics Cost (상품라인별 가격결정이 적재효율 및 물류비에 미치는 영향에 관한 연구)

  • Jung, Sung-Tae;Yoon, Nam-Soo;Han, Kyu-Chul
    • Journal of Distribution Science
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    • v.12 no.8
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    • pp.55-69
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    • 2014
  • Purpose - Despite the importance of price, many companies do not implement pricing policies smoothly, because typical price management strategies insufficiently consider logistics efficiency and an increase in logistics costs due to logistics waste. This study attempts to examine the effect of product line pricing, which corresponds to product mix pricing, on logistics efficiency in the case of manufacturer A, and analyzes how logistics performance changes in response to these variables. Research design, data, and methodology - This study, based on the case of manufacturer A, involved research through understanding the current status, analyses, and then proposing improvement measures. Among all the products of manufacturer A, product group B was selected as the research object, and its distribution channel and line pricing were examined. As a result of simulation, for products with low loading efficiency, improvement measures such as changing the number of bags in the box were suggested, and a quantitative analysis was conducted on how these measures influence logistics costs. The TOPS program was used for the Pallet loading efficiency simulation tool in this study. To prevent products from protruding out of the pallet, the maximum measurement was set as 0.0mm, and loading efficiency was based on the pallet area, and not volume. In other words, its size (length x width) was focused upon, following the purpose of this study and, then, the results were obtained. Results - As a result of the loading efficiency simulation, when the number of bags in the box was changed for 36 products with low average loading efficiency of 73.7%, as shown in

    , loading efficiency improved to 89.9%. Further, from calculating logistics cost based on the cost calculation standard of manufacturer A, the amount of annual logistics cost reduction amounted to 101,458,084 KRW. Given that the sum of the logistics cost of the product group B of manufacturing enterprises A is 400,340,850 KRW, it can be reduced by 25%, to 298,882,766 KRW. Although many methods improve loading efficiency, this study proved that logistics cost could be reduced by changing the number of bags within boxes. If this measure is applied to other items, visible logistics cost reduction effects will be realized through improvements in loading efficiency. Conclusions - Future pricing policies should consider their correlation with quality, loading efficiency, product specifications, and logistics standardization to prevent logistics waste, enabling management to improve earnings for companies. Thus, when companies decide pricing policies for new products, the aspects of merchandising and marketing should take priority; however, the aspect of logistics also needs to be considered as significant. Measures revealed by the study results are not only the responsibilities of manufacturing enterprises. Pricing policy agreements between manufacturing enterprises and distribution companies, and logistics factors related to price determination should be considered; further, governments should also support them for their collaborations. This will enable consumers to purchase quality products with low prices.

  • THREE-DIMENSIONAL FINITE ELEMENT ANALYSIS OF STRESS DISTRIBUTION IN PORCELAIN LAMINATE VENEERS WITH VARIOUS AMOUNTS OF INCISAL COVERAGE AND TYPES OF INCISAL FINISH LINE UNDER TWO LOADING CONDITIONS (절단피개량과 절단변연형태 및 하중각도가 도재라미네이트 베니어 내의 응력분포에 미치는 영향에 관한 삼차원 유한요소법적 연구)

    • Ryoo, Kyung-Hee;Lee, Sun-Hyung;Yang, Jae-Ho;Chung, Hun-Young
      • The Journal of Korean Academy of Prosthodontics
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      • v.37 no.2
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      • pp.143-166
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      • 1999
    • The success of porcelain laminate veneer depends on the bond strength between tooth structure and ceramic restoration and the design of tooth preparation. In particular, incisal coverage and incisal finish line are the two most important factors in long-term fracture resistance. Although the majority of clinicians are practicing incisal coverage and there are various opinions on the geo-metrical ratio between the clinical crown length of the remaining tooth structure and the length of incisal extension in porcelain laminate veneer and the optimal incisal finish lines. scientific evidence still loaves much to be desired. The purpose of this study was to determine the effects of the amounts of incisal coverage and the types of incisal finish line on the stress distribution in maxillary anterior porcelain laminate veneers under two different loading conditions. Three-dimensional finite element models of a maxillary anterior porcelain veneer with differ-ent amounts of incisal coverage ; 0, 1, 2, and 3mm and different incisal finish lines feathered edge, incisal bevel, reverse bevel and lingual chamfer with various amounts of lingual extension were developed. 300N force was applied at the point 0.5mm cervical of the linguoincisal edge in two loading conditions ; A) 125 degrees, B) 132 degrees. Tensile and compressive stress in ceramic and shear stress in the resin cement layer were analyzed using three-dimensional finite element method. The results were as follows : 1. The types of incisal finish line had more influence on the stress distribution in porcelain laminate veneer than the amounts of incisal coverage. 2. In case of no incisal coverage, incisal beveled laminate exhibited more evenly distributed tensile stress than feathered edged laminate. And in case of incisal coverage, reverse beveled laminate and lingual chamfered laminate with 1mm lingual extension exhibited more evenly distributed tensile stress than lingual chamfered laminates with 2mm and 3mm lingual extension. 3. As long as the lingual chamfer goes, less tensile stress was found at the incisal edge, while much more tensile stress was found at the lingual margin area in proportion to the length of lingual extension. 4. Under 125 degree load, tensile stress in porcelain laminate veneer had increased compared with that under 132 degree load and the difference exhibited by the change of the amount of tooth support was larger. 5. The types of incisal finish line and the distance from the incisal finish line to the loading point had more influence on the shear stress distribution in the resin cement layer than the amounts of incisal coverage. In contrast loading condition had little influence.

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    A Variation of Maximum Stress with Axial Loading in Porcelain Insulators for Transmission Line using ANSYS (ANSYS를 이용한 송전용 자기재 애자의 장력에 따른 특성 변화)

    • Woo, B.C.;Han, S.W.;Cho, H.G.
      • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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      • 2003.05e
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      • pp.104-107
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      • 2003
    • The ageing cause in many porcelain suspension insulators which occur on transmission and distribution line with dead-end stings is mechanical stress in interface between porcelain and cement materials. It is known that the principal mechanical stress which give electrical failure is the results of the displacement is due to cement growth. We studied an analysing method to find out a deformation of brittle porcelain with a thermal expansion of cement for suspension insulator. These simulation analysis and experimental results show that cement volume growths affect severely to be mechanical failure ageing. These simulation analysis and experimental results show that axial loading affects of Porcelain insulators severely to be mechanical failure ageing.

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    A Study on Determining the Priority of Supervising Mooring Line while 125K LNG Moss Type Discharging at Pyeong Taek Gas Terminal

    • Kim, Jong Sung
      • Journal of the Korean Society of Marine Environment & Safety
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      • v.25 no.3
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      • pp.278-286
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      • 2019
    • The Port of Pyeong Taek is located on the west coast, meaning that the difference between the rise and fall of tide is great (flood tide 1.8 to 2.9 knots, ebb tide 1.6 to 2.9 knots). Due to mainly N~NW'ly strong winds & high waves during winter, navigating as well as loading & discharging vessels must focus on cargo handling. The strong tidal and wind forces in the Port of Pyeong Taek can push an LNG carrier away from its berth, which will end up causing forced disconnection between the vessel's cargo line and shore-side loading arm. The primary consequence of this disconnection will be LNG leakage, which will lead to tremendous physical damage to the hull and shore-side equipment. In this study, the 125K LNG Moss Type ship docked at No. 1 Pier of the Pyeong Taek is observed, and the tension of the mooring line during cargo handling is calculated using a combination of wind and waves to determine effective mooring line and mooring line priority management. As a result if the wind direction is $90^{\circ}$ to the left and right of the bow, it was found that line monitoring should be performed bearing special attention to the Fore Spring Line, Fore Breast Line, and Aft Spring Line.

    THREE-DIMENSIONAL FINITE ELEMENT ANALYSIS OF STRESS DISTRIBUTION IN ALL-CERAMIC CROWNS WITH VARIOUS FINISH LINE DESIGNS AND INCISAL REDUCTIONS UNDER DIFFERENT LOADING CONDITIONS (전부 도재관을 위한 지대치의 마무리선 형태와 절단연 삭제량 및 교합력 작용점에 따른 응력 분포에 관한 삼차원 유한요소법적 연구)

    • Koh, Eun-Suk;Lee, Sun-Hyang;Yang, Jae-Ho;Chung, Hun-Young
      • The Journal of Korean Academy of Prosthodontics
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      • v.35 no.4
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      • pp.742-766
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      • 1997
    • The purpose of this study was to determine the effect of finish line design, amount of incisal reduction, and loading condition on the stress distribution in anterior all-ceramic crowns. Three-dimensional finite element models of an incisor all-ceramic crown with 3 different finish line designs : 1) shoulder with sharp line angle 2) shoulder with rounded line angle 3) chamfer : and 2 different incisal reductions : 2mm and 4mm were developed. 300 N force with the direction of 45 degree to the long axis of the tooth was applied at 3 different positions : A) incisal 1/3, B) incisal edge, C) cervical 1/5. Stresses developed in ceramic and cement were analyzed using three-dimensional finite element method. The results were as follows : 1. Stresses were concentrated in the margin region, which were primarily compressive in the labial and tensile in the lingual. 2. Stresses were larger in the area near line angle than on the crown surface of the margin region. In case of shoulder with sharp line angle, stresses were highly concentrated in the porcelain near line angle. 3. At the interface between porcelain and cement and at the porcelain above the margin on crown surface, stresses were the highest in chamfer, and decreased in shoulder with sharp line angle and shoulder with rounded line angle, respectively. 4. At the interface between cement and abutment on crown surface, stresses were the highest in shoulder with sharp line angle, and decreased in shoulder with rounded line angle and chamfer, respectively. 5. The amount of incisal reduction had little influence on the stress distribution in all-ceramic crowns. 6. When load was applied at the incisal edge, higher stresses were developed in the margin region and the incisal edge than under the other loading conditions. 7. When load was applied at the cervical 1/5, stresses were very low as a whole.

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