• Title/Summary/Keyword: 안전사용하중

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비선형 유한요소-경계요소 조합에 의한 사용 후 핵연료 폐기 저장고 주변 암반 해석

  • 김문겸;허택녕;김민규
    • Proceedings of the Korean Nuclear Society Conference
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    • 1995.05b
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    • pp.805-812
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    • 1995
  • 산업의 다변화로 인한 에너지의 수요는 증가하고 있고 이에 따라 핵연료의 사용과 사용 후 연료의 안전한 처분은 큰 관심사가 되고 있다. 본 연구에서는 사용후 핵연료의 폐기에 따른 지하동굴의 해석을 비선형 유한요소와 경계요소의 조합에 의하여 수행하였다. 지하 암반의 열 하중에 의한 거동을 해석하기 위해 응력이 집중되는 대상영역은 유한요소로, 무한영역에는 경계요소를 적용하여 해석하였다.

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Studies on the Structural Design of Biological Production Facility (2) A Simple Method for Design Load Estimation and Safety Test (생물생산시설의 구조설계에 관한 연구 (2) 설계하중 산정 및 안전성 검토를 위한 간이적 방법 개발)

  • 김문기;손정익;남상운
    • Proceedings of the Korean Society for Bio-Environment Control Conference
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    • 1992.12a
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    • pp.31-32
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    • 1992
  • 일반적으로 시설을 설계함에 있어서 고정하중(자중)은 부재단면이 결정되기 전이므로 추정에 의한 값을 사용한다. 그러나 생물생산시설에 관한 기준이 마련되어 있지 않기 때문에 국내 실정에 맞는 자료가 요청된다. 또한 구조설계 과정은 복잡하고 전문적 지식을 요하므로 전문가에 의해서 수행된다. 그러나 생물생산시설의 규모나 형태는 비슷한 경우가 많으므로 대표적인 몇가지 시설에 대하여 구조해석을 실시하고, 이것을 일반화함으로써 비전문가인 농민이나 생물생산분야 종사자가 간편하게 시설의 구조적 안전성을 진단할 수 있을 것으로 생각한다.(중략)

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Buckling Analysis of Arches Using DQM (DQM을 이용한 아치의 좌굴해석)

  • Ji-Won Han;Ki-Jun Kang
    • Journal of the Korean Society of Safety
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    • v.12 no.4
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    • pp.220-229
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    • 1997
  • The differential quadrature method (DQM) is applied to computation of the eigenvalues of the equations governing in plane and out-of-plane buckling. In-plane buckling and twist-buckling under uniformly distributed radial loads are investigated by this method. Critical loads are calculated for various end conditions and opening angles. Results are compared with existing exact solutions where available. The differential quadrature method gives good accuracy even when only a limited number of grid points is used. New results are given for two sets of boundary conditions not previously considered for this problem clamped-clamped and clamped simply supported ends.

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A Case Study on the Introduction to Fire Retardative Plastic Pallet (난연 플라스틱 파렛트의 도입에 관한 사례 연구)

  • Jeong, Ui-Su;Gang, Seong-U;Gang, Gyeong-Sik
    • Proceedings of the Safety Management and Science Conference
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    • 2009.11a
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    • pp.169-176
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    • 2009
  • 2008년 1월과 12월의 경기도 이천시에서의 창고화재는 재산상의 피해보다도 방재대책이 허술함과 인명피해에 대하여 사회적인 문제가 제기되었으나 건축자재, 입고 화물이외에 화재하중 등을 가중시키는 플라스틱 파렛트에 대한 거론은 없었다. 그러나 일본의 소방청 소방연구소에서는 1995년의 자동화창고의 전소화재시 화재조사를 실시한 후 방재대책으로서 플라스틱 파렛트의 화재하중 경감, 발연량 및 유해가스감축을 위한 후속대책으로 난연 파렛트에 대한 연구를 수행하였다. 그 결과 수산화마그네슘 또는 적린과 수산화마그네슘을 난연제로 사용한 플라스틱 파렛트 난연화에 성공하였다. 본고에서는 시험시설 등의 연구환경의 한계로 일본의 연구사례를 조사하고 우리나라의 난연 플라스틱 파렛트 도입방안에 대해 살펴보기로 한다.

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Performance Evaluation of Weir Structures Under Blast Loads (폭발하중에 의한 다기능-수중보 구조물 거동평가)

  • Jeon, Jun-Tai;Jung, Woo-Young;Ju, Bu-Seog
    • Proceedings of the Korean Society of Disaster Information Conference
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    • 2015.11a
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    • pp.168-169
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    • 2015
  • 최근 위험물질에 의한 폭발 및 테러의 위험성 증가로 인하여 사회간접자본 시설물인 댐/보, 원자력 발전소, 병원 구조물과 같은 주요 시설물의 폭발 안전성 평가 연구가 이슈화 되고 있어, 본 연구에서는 가스폭발에 의한 다기능 보 구조물의 거동을 평가하고 안전성을 분석 하고 자 한다. 본 연구에서 폭발 해석에 필요한 하중 조건 산정은 PHAST 프로그램을 사용하여 주변 온도 및 공기 특성 등을 고려한 약 5톤의 가스 폭발 조건을 구축 하였다. 또한 다기능 보 구조물의 거동 분석을 위해 구조물-지반 상호 작용을 고려한 2차원 유한 요소 모델을 구축하여 폭발에 의한 구조물 거동을 평가 하였다. 다기능 보 구조물의 수치해석 결과 보 구체와 Stilling Basin구조물 사이의 연결부에 응력집중 현상이 발생하는 것으로 평가 되었다.

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Evaluation of Yield Load in Pile Load Tests on Driven Piles (관입말뚝에 대한 연직재하시험시 항복하중의 판정법)

  • 홍원표;심기석
    • Geotechnical Engineering
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    • v.5 no.1
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    • pp.7-18
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    • 1989
  • In pile load tests on end bearing piles, generally, it is not possible to continue loading to the ultimate load. Thus, the concept of yield load has been introduced for determining design loads Iron the pile load test records. The conventional rules to determine the yield load were not available for evaluation on pile load test records obtained in 6 fields nearby westers 8r Southern Coasts in Korea. A new rule 9.as presented to determine easily the yield load, based on investigations on the pile load test records. The yield load of piles is determined at the infiection point on semi-logarithmic coordinates (P-logS), in which load is plotted in normal scale and settlement is plotted in logarithmic scale. This method may not only save much costs and times but also present safe luorking circumstances for pile load tests in field. It was found that the yield load represented the elastic limit of the pile load-settlement behalf.iota. The ultimate load, which is given at 25.4mm settlement on pile head, was 1.5 times of the yield load. The allowable long-term and short-term load capacities were, respectively, 50% and 75% of the yield load. The safety factors to get the allowable pile capacity were obtained as 2.0~4.0 for the equations to predict the static pile capacity.

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Numerical Simulation on the Behavior of Air Bubble Discharging into a Water Pool through a Sparger without Load Reduction Ring (하중저감 링이 없는 증기분사기를 통해 수조로 방출되는 기포 거동에 대한 수치해석)

  • 김환열;배윤영;송진호;김희동
    • Journal of Energy Engineering
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    • v.12 no.4
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    • pp.259-266
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    • 2003
  • Load reduction ring (LRR) was installed on the ABB-Atom sparger to reduce the oscillatory loadings due to the air bubble clouds in the water pool in case of safety relief system operations. In order to investigate the effect of LRR on the pressure field, a numerical simulation on the behavior of air bubble clouds discharging into a water pool through a ABB-Atom sparser without LRR was performed by using a commercial thermal hydraulic analysis code, FLUENT 4.5. Among the multi-phase models contained in the code, the VOF (Volume Of Fluid) model was used to simulate the interface of water, air and steam flows. By comparing the analysis results with the previous ones, the load reduction ring has an effect on reducing the oscillatory loads at the wall. It also includes the effect of air mass and inlet boundary conditions of the pipe on the pressure oscillations at the wall.

Structural Safety Evaluation for the Hydraulic Power Unit of Topside Module According to the Movement of Offshore Plant (해양구조물 움직임에 따른 Topside Module의 HPU에 대한 구조안전성 평가)

  • Ryu, Bo-Rim;Lee, Jin-Uk;Kang, Ho-Keun
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.26 no.6
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    • pp.723-731
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    • 2020
  • The design of offshore plants should reflect the various requirements of the owner and the classification society. For a topside module mounted on an of shore structure, the design process is very demanding because of the large spatial constraints and the many requirements related to marine environmental conditions and safety such as the movement of the structure. In this study, the load acting on the hydraulic power unit, which is one of the main equipment in the topside module, was calculated according to the DNVGL rule; the structural safety was evaluated according to each load condition and the structural reliability of the developed product was improved. For structural analysis, MSC software was used, and structural analysis was performed under five load conditions to review structural safety for various movements. The results show that the maximum stress occurred during pitching toward the stern (Load Case 5). The stress level was approximately 85 % of the allowable stress, and the maximum deformation was approximately 5 % of the allowable value. The structural safety was confirmed, and no intermember interference occurred.

Structural Design and Experimental Investigation of A Medium Scale Composite Wind Turbine Blade Considering Fatigue Life (피로 수명을 고려한 중형 복합재 풍력터빈 블레이드의 구조설계 및 실험 평가)

  • Gong, Chang Deok;Bang, Jo Hyeok
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.31 no.3
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    • pp.23-30
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    • 2003
  • In this study, the various load cases by specified by the IEC61400-1 international specification and GL Regulations for the wind energy conversion system were considered, and a specific composite structure configuration which can effectively endure various loads was proposed. In order to evaluate the structure, the structural analysis for the composite wind turbine blade was performed using the finite element method(FEM). In the structural design, the acceptable configuration of blade structure was determined through the parametric studies, and the most dominant design parameters were confirmed. In the stress analysis using the FEM, it was confirmed that the blade structure was safe and stable for all the considerd load cases. Moreover the safety of the blade root joint with insert bolts, newly devised in this study, was checked against the design loads and also the fatigue loads. The fatigue life for operating more than 20 years was estimated by using the well-known S-N linear damage rule, the load spectrum and Spera's empirical equations. The full-scale static test was performed under the simulated aerodynamic loads. from the experimental results, it was found that the designed blade had the structural integrity. Furthermore the measured results were agreed with the analytical results such as deflections, strains, the mass and the radial center of gravity. The studied blade was successfully certified by an international institute, GL, of Germany.

Effects of Seismic Loads with Different Return Period on Residential Building with RC Shear Wall Structure under Construction (주거용 RC 벽식 건물의 시공 중 재현주기에 따른 지진하중의 영향)

  • Choi, Seong-Hyeon;Kim, Jea-Yo
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.26 no.2
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    • pp.43-50
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    • 2022
  • Even though the structural safety is confirmed in the design stage, the structural safety is not guaranteed in the construction stage because the structural system is not completed. In addition, since the construction period is shorter than the period of use of the building after completion, it is excessive to apply the same seismic load to the construction stage as in the design stage. ASCE 37-14 presents the concept of seismic load reduction factor during construction, but does not provide a clear application method. Therefore, in this study, the seismic load reduced according to the return period was applied to the example model of a residential middle-rise RC building. The construction stage of the example model was divided into five-story units, and seismic load with the change of the return period was applied to the construction stage models to analyze the change of seismic load during construction and to check the sectional performances of structural members. By comparing the design strength ratio of the shear wall at the design stage and the construction stage, the range of seismic load magnitudes that can assure the safety during construction of a residential middle-rise RC building was analyzed in terms of the return period.