• 제목/요약/키워드: weight maintenance

검색결과 762건 처리시간 0.036초

석분을 이용한 터널 뒤채움용 경량기포 충전재의 개발과 현장적용에 대한 연구 (A Study on Development of Lightweight Foam Filling Material for the Voids behind Tunnel Liner using Stone-dust and Application to the Old Tunnel)

  • 마상준
    • 한국구조물진단유지관리공학회 논문집
    • /
    • 제7권4호
    • /
    • pp.139-147
    • /
    • 2003
  • 국내 재래식 터널의 대부분에 존재하는 배면공동은 라이닝의 균열, 누수, 응력집중 등을 유발하여 터널 안정성에 큰 영향을 미치게 된다. 이러한 배면공동의 보강은 공동을 뒤채움하는 방법이 일반적으로 적용되고 있는데, 본 연구에서는 현재 산업폐기물로 취급되어 버려지고 있는 석분토를 이용하여 터널 뒤채움용 경량기포 충전재를 개발하였고, 실내물성시험과 노후터널에 대한 현장적용시험을 수행하여 개발 충전재의 적용성 평가를 실시하였다.

차세대 전동차 BOM구성 방안연구 (A Study of the organization BOM for the next generation train system)

  • 박수중;김영규;이성권;이한민
    • 한국철도학회:학술대회논문집
    • /
    • 한국철도학회 2008년도 추계학술대회 논문집
    • /
    • pp.1999-2004
    • /
    • 2008
  • This study is about to constructing BOM for managing and integrating information, which is drawing, technical data, attribution, design, ordering, cost, weight, process, service, etc. based on train's system, elements, substructure, assembly, components, parts during whole train's lifetime of the next generation. The BOM is the mostly basic structure information as hierarchical data what are parts consisted specific products. The BOM was utilized as essential elements for collectively managing through informing all of the business activity from ordering to supplying. The BOM in railroad is consist of two parts. One is Engineering BOM for design, the other is Production BOM for production, which are utilized in development calculating the quantity of materials. Also the Maintenance BOM is applied to suppling parts and managing malfunction in railroad corporation like the Seoul Metro. There are many kind of BOMs, because of the special character for each step. Therefore We have need to develop BOM which is able to integrate drawing, technical data for helping good circulation between RAMS applied maintenance using database and helpful know-how for development and production. Also the BOM of the next generation must be consisted regard to whole life-cycle.

  • PDF

고등해석과 유전자 알고리즘을 이용한 강뼈대 구조물의 직접설계시스템의 최적화 (Optimization of Direct Design System of Steel Framesusing Advanced Analysis and Genetic Algorithm)

  • 최세휴;노우혁;김종인;박경식
    • 한국구조물진단유지관리공학회 논문집
    • /
    • 제10권5호
    • /
    • pp.203-211
    • /
    • 2006
  • 본 연구에서는 고등해석과 유전자 알고리즘을 이용한 강뼈대 구조물의 직접설계시스템의 최적화를 수행하였다. 본 연구에서 사용한 고등해석은 기하학적 비선형과 재료적 비선형을 동시에 고려한다. 직접설계 시스템의 최적화를 위해 유전자 알고리즘을 사용하였다. 목적함수로 구조물의 중량을 사용하였으며, 제약조건식은 구조시스템의 하중-저항능력, 처짐, 층간 수평변위 및 연성요구 조건을 고려하였다. 제안된 방법에 의해 나타난 결과를 다른 방법에 의한 것들과 비교해서 그 효율성을 증명하였다.

탄소섬유 분말 혼입 모르타르 복합 구조체의 파괴예측 자가진단 특성 (Self-Diagnosis Property of Fracture in Carbon Fiber Composite Mortar)

  • 박석균
    • 한국구조물진단유지관리공학회 논문집
    • /
    • 제11권1호
    • /
    • pp.113-120
    • /
    • 2007
  • 새로운 재료의 적용 실험을 통하여, 탄소섬유 분말 혼입 모르타르 복합 구조체의 파괴예측 자가진단 적용 특성에 대해 검토하였다. 본 연구에서는 자가진단 성능을 부여하기 위해 코크스와 탄소섬유분말(미분쇄 탄소섬유)이 혼입된 전도성 모르타르의 개발 및 자가진단 재료로서의 사용이 제안되었다. 각 하중재하단계에서의 균열발생 전후의 전기저항값과 AE특성치의 변화특성 시험을 통해, 이들 각 인자의 상호 연관성을 검토하였다. 그 결과, 코크스와 탄소섬유분말(미분쇄 탄소섬유)을 사용하여 새롭게 제안된 복합재료는 모르타르 시험체의 파괴 자가진단에 사용이 가능함을 알 수 있었다.

FRP 스트럿을 가진 PSC 박스거더교의 구조안전성 평가를 위한 실험 연구 (An Experimental Study for Structural Safety Evaluation of PSC Box Girder Bridge with FRP Struts)

  • 송재준;박종화;박경훈;조병완
    • 한국구조물진단유지관리공학회 논문집
    • /
    • 제12권6호
    • /
    • pp.205-213
    • /
    • 2008
  • FRP 스트럿을 가진 PSC 박스거더 교량 구조는 기존의 PSC 박스거더를 효율적으로 변형시켜 넓어진 상부 슬래브의 캔틸레버 부분을 스트럿으로 지지하는 구조형식으로, 상부구조의 자중을 줄여 하부구조의 크기를 경감시키므로 경제적이고 미관이 뛰어난 교량 건설을 가능하게 한다. 본 연구에서는 국내에서 처음 시도되는 FRP 스트럿을 가진 PSC 박스거더의 실물모형 재하실험과 유한요소해석을 수행하여 상호 결과를 비교함으로써 FRP 스트럿을 가진 PSC 박스거더 교량 구조에서 FRP 스트럿과 스트럿 적용에 따른 상부 슬래브의 구조적 안전성에 대하여 평가하였다.

2차 비탄성해석과 단면점증법을 이용한 평면 강골조 구조물의 최적설계 (Optimum Design of Plane Steel Frames Using Second-Order Inelastic Analysis and Section Increment Method)

  • 최세휴
    • 한국구조물진단유지관리공학회 논문집
    • /
    • 제12권5호
    • /
    • pp.143-151
    • /
    • 2008
  • 본 연구에서는 2차 비탄성해석과 단면점증법을 이용한 평면 강골조 구조물의 최적설계 방법을 제시하였다. 2차 비탄성해석은 구조시스템과 그에 속한 부재들의 기하학적 비선형과 재료적 비선형을 고려하기 때문에 2차 비탄성해석에 바탕을 둔 설계법에서는 해석 후 개별부재의 강도검토가 필요 없다. 본 논문에서 제안한 단면점증법을 최적화 기법으로 사용하였으며 목적함수로 구조물의 중량을 사용하였다. 제약조건식은 구조시스템의 하중-저항능력, 처짐 및 층간 수평변위 등을 고려하였으며 제안된 방법에 의한 설계결과를 다른 방법에 의한 것들과 비교하여 그 효율성을 증명하였다.

환경 친화적 스마트 아웃도어 재킷제작 및 사용성 평가 (Eco-friendly Smart Outdoor Jacket Production and Usability Evaluation)

  • 이정란
    • 한국의류학회지
    • /
    • 제38권6호
    • /
    • pp.845-856
    • /
    • 2014
  • This study focused on the production and usability evaluation of smart outdoor jackets that are designed to provide convenience to middle-aged people by embedding devices for lighting and location tracing. The results were as follows. 1. Jacket power supplier was a assembled system composed of battery, charger, controller and switch. A solar cell was attached on the upper arm, and a wire type EL on the center line of a raglan sleeve along with a GPS on the left sleeve with a transparent vinyl pocket. The total weight of the jacket embedded with devices was 385-520g. 2. Operation of function, activity, acceptability, safety, convenience for device use, appearance, practical maintenance were selected based on an analysis of evaluation criteria of previous smart wear research. Criteria were narrowed to three major categories of satisfaction, appearance and maintenance. 3. Use satisfaction criterion consisted of wearable device functionality and physical, psychological use convenience. The evaluation indicated actual functionality. EL functions were especially effective and necessary. Convenience of use showed that a smart jacket was thought to be safe and the size was moderate regardless of age and gender. Outer appearance was satisfactory and respondents praised the color. The practical maintenance evaluation indicated that there was no challenge in doing the laundry since the solar battery and GPS were detachable. The practical use of smart outdoor jackets confirmed by fabric that was washable and dried quickly.

농산물용 복합 골판지의 항균성 및 선도유지기능 평가 (Evaluation of Antibacterial Property and Freshness Maintenance of Functional Hybrid Corrugated Board Used for Agricultural Products)

  • 이지영;김철환;최재성;오석주;김병호;임기백;김선영;김준식
    • 펄프종이기술
    • /
    • 제45권3호
    • /
    • pp.45-51
    • /
    • 2013
  • We developed a new antibacterial material, a non-woven fabric, a sulfur solution, and a new adhesive system to manufacture a new type of functional hybrid corrugated board in previous studies. Based on experimental data, the prototypes of functional hybrid corrugated boards were manufactured and their physical properties and functionalities, including antibacterial property and the freshness maintenance of sweet persimmon, were measured in this study. The functional hybrid corrugated board could be manufactured in the actual process with linerboards, non-woven fabrics, and other materials without any troubles, and was strong enough to be used as a packaging box for agricultural products. The antibacterial property of the hybrid corrugated board showed a value high enough to eliminate bacteria, which could deteriorate the sweet persimmons. Based on appearance observations, weight loss and firmness measurements, the freshness of sweet persimmons in the functional hybrid corrugated board was maintained better than it was in the conventional corrugated board.

3MW급 해상풍력 발전시스템 개발 (3MW Class Offshore Wind Turbine Development)

  • 주완돈;이정훈;김정일;정석용;신영호;박종포
    • 한국신재생에너지학회:학술대회논문집
    • /
    • 한국신재생에너지학회 2009년도 춘계학술대회 논문집
    • /
    • pp.491-494
    • /
    • 2009
  • This paper introduces the design concepts and characteristics of WinDS3000$^{TM}$ which is a trade mark of Doosan's 3MW offshore/onshore wind turbine. WinDS3000$^{TM}$ has been designed in consideration of high RAMS (Reliability, Availability, Maintainability and Serviceability) and cost effectiveness for the TC Ia condition in GL guideline. An integrated drive train design with an innovative three-stage gearbox has been introduced to minimize nacelle weight of the wind turbine and to enhance a high reliability for transmission. A permanent magnet generator with full converter system has been introduced to get higher efficiency in part load operation, and grid friendliness use of 50 Hz and 60 Hz grid. A pitch regulated variable speed power control with individual pitch system has been introduced to regulate rotor torque while generator reaction torque can be adjusted almost instantaneously by the associated power electronics. An individual pitch control system has been introduced to reduce fatigue loads of blade and system. The wind turbine has been also equipped with condition monitoring and diagnostic systems in order to meet maintainability requirements. And internal maintenance crane in nacelle has been developed. As a result, the maintenance cost was dramatically reduced and maintenance convenience also enhanced in offshore condition.

  • PDF

A Comparative Study on the Efficiency of Locally Made Low Cost Brooders for Brooding Chicks

  • Hassanuzzaman, M.;Ahammad, M.U.;Bulbul, S.M.;Nurul Alam, A.M.M.;Islam, M.A.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • 제17권11호
    • /
    • pp.1586-1590
    • /
    • 2004
  • An experiment was carried out with day-old "Sonali" (♂RIR$\times$♀Fayoumi) chicks to investigate the efficacy of locally made low cost brooders for brooding chicks in rural areas. Three types of indigenous brooders viz. charcoal, haricane and sawdust brooders were used for brooding chicks throughout the experimental period of 28 days. The efficiency of the brooders was observed in respect of their ability to maintain temperature, fluctuation in temperature during operation and cost effectiveness. Following initial trial of temperature maintenance for 48 h, the chicks were put under the brooder stoves and brooded up to 28 days. The experimental birds were fed on chick starter diet. Maintenance of temperature with sawdust brooders was found satisfactory and optimum for brooding the chicks at different stages of brooding and at the same time involved least cost for brooding in comparison with charcoal and haricane brooders which did not perform well in generating heat necessary for brooding and were not economically feasible for poor farmers. On the other hand, performance of charcoal brooders was better in respect of temperature maintenance during initial stage (when the brooder was started) but the temperature fluctuated rapidly, whereas fluctuation of temperature was gradual in sawdust brooders. Body weight gain and feed conversion were best in sawdust brooders. Survivability was highest in sawdust brooders and lowest in haricane brooders. Sawdust brooders may be appropriate for brooding chicks in rural areas, where electricity is not available.