• Title/Summary/Keyword: Capacity Ratio

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태양광발전시스템 인버터 용량 산정에 관한 연구 (A Study on the Photovoltaic System Inverter Sizing)

  • 이경수
    • 전기학회논문지
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    • 제65권5호
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    • pp.804-810
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    • 2016
  • Photovoltaic system construction of the module capacity in domestic is specified criteria to less than 105% of the inverter capacity. However, the modules are installed in the outdoor actual output is reduced due to factors such as the irradiation intensity, module surface temperature. Thus, it needs the capacity of the inverter to be designed according to the actual module output. In this paper, the first approach to find the actual module output is to analyze the actual PV system monitoring data. Next, four sites where the loss analysis, system utilization, inverter utilization, and the ratio of the inverter overload are performed using PVSYST software. By changing the ratio of the module capacity, the inverter capacity of the site B is confirmed 20% less than the module capacity. Site A, C, D are identified as the ratio of the inverter capacity is 10% less than the module capacity.

스파이럴 그루브 스러스트 베어링의 부하용량 향상을 위한 설계 변수에 대한 연구 (A Study on Design Parameters to Improve Load Capacity of Spiral Grooved Thrust Bearing)

  • 강지훈;김경웅
    • Tribology and Lubricants
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    • 제18권3호
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    • pp.181-186
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    • 2002
  • A numerical analysis is undertaken to show the influence of bearing design parameters on the load capacity of air lubricated spiral grooved thrust bearing. The governing equation derived from the mass balance is solved by the finite difference method. Optimal values for various design parameters are obtained to maximize the load capacity. The design parameters are the groove angle, the groove width ratio, the groove height ratio, and the seal ratio.

Research on axial bearing capacity of cold-formed thin-walled steel built-up column with 12-limb-section

  • Wentao Qiao;Yuhuan Wang;Ruifeng Li;Dong Wang;Haiying Zhang
    • Steel and Composite Structures
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    • 제47권3호
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    • pp.437-450
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    • 2023
  • A half open cross section built-up column, namely cold-formed thin-walled steel built-up column with 12-limbsection (CTSBC-12) is put forward. To deeply reveal the mechanical behaviors of CTSBC-12 under axial compression and put forward its calculation formula of axial bearing capacity, based on the previous axial compression experimental research, the finite element analysis (FEA) is conducted on 9 CTSBC-12 specimens, and then the variable parameter analysis is carried out. The results show the FEA is in good agreement with the experimental research, the ultimate bearing capacity error is within 10%. When the slenderness ratio is more than 96.54, the ultimate bearing capacity of CTSBC-12 decreases rapidly, and the failure mode changes from local buckling to global buckling. With the local buckling failure mode unchanged, the ultimate bearing capacity decreases gradually as the ratio of web height to thickness increases. Three methods are used for calculating the ultimate bearing capacity, the direct strength method of AISI S100-2007 gives result of ultimate axial load which is closest to the test and FEA results. But for simplicity and practicality, a simplified axial bearing capacity formula is proposed, which has better calculation accuracy with the slenderness ratio changing from 30 to 100.

폐어망 보강 깊이에 따른 모래지반의 지지력 특성 (Bearing Characteristics of Waste Fishing Net - Reinforced Sand With Different Embedded Depths)

  • 하용수;김윤태
    • 한국해양공학회지
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    • 제29권1호
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    • pp.78-84
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    • 2015
  • Geosynthetics such as geogrids or geotextiles have been widely used to improve the bearing capacity of soft ground. This study investigated the California bearing ratio (CBR) of waste fishing net (WFN)-reinforced sand. CBR tests were carried out to evaluate the improvement in the bearing capacity of WFN-reinforced sand with different embedded depths. The experimental results indicated that the CBR increased as the embedded depth of the WFN decreased. The bearing capacity ratio (BCR) is the ratio of the bearing capacity of reinforced ground to that of unreinforced ground. The BCR at the penetration depths of 2.5 mm, 5 mm, and the peak point decreased with an increase in the embedded depth.

양방향말뚝재하시험의 재하용량 기준 설정을 위한 사례분석 연구 (A study on case analysis for loading capacity standard establishment of bi-directional pile load test (BD PLT))

  • 최용규;서정혜;김상일
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2008년도 춘계 학술발표회 초청강연 및 논문집
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    • pp.377-384
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    • 2008
  • In the bi-directional pile load test (BD PLT) for pile load test of Mega foundation, loading capacity specification were not specified exactly. Therefore there are so many confusions and variations of maximum 2 times in loading capacity are come out. In this study, specifications of bi-directional pile load test (BD PLT) were considered. Based on cases of the bi-directional pile load test performed in domestic areas, maximum equivalent test load, test load increasing ratio and sufficiency ratio of design load were analyzed. It can be known that the loading capacity specification of bi-directional pile load test must be defined as 1-directional test load that is established as more than 2 times of design load.

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양방향말뚝재하시험의 재하용량 기준에 관한 연구 (A Study on the Loading Capacity Standard of Bi-directional Pile Load Test (BD PLT))

  • 최용규
    • 대한토목학회논문집
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    • 제28권6C호
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    • pp.379-388
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    • 2008
  • 대형말뚝기초의 양방향 재하시험에서 재하용량 기준이 정확하게 규정되어 있지 않다. 그래서 양방향말뚝재하시험을 수행함에 있어 많은 혼란이 발생하고 있으며 재하용량에서 최대 2배까지의 차이가 나타나고 있다. 본 연구에서는 양방향 말뚝재하시험 기준들을 고찰하였으며, 국내에서 수행된 양방향 말뚝재하시험 사례들에 기초하여 최대등가시험하중, 재하하중 증가비, 재하용량 증가비 및 설계하중 충족비를 분석하였다. 양방향 말뚝재하시험 기준은 1방향 재하용량으로 정의되어야 하며, 1방향 재하용량은 설계하중의 2배 이상 이어야 한다는 것을 알 수 있었다.

Seismic analysis of RC tubular columns in air-cooled supporting structure of TPP

  • Wang, Bo;Yang, Ke;Dai, Huijuan;Bai, Guoliang;Qin, Chaogang
    • Earthquakes and Structures
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    • 제18권5호
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    • pp.581-598
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    • 2020
  • This paper aims to investigate the seismic behavior and influence parameters of the large-scaled thin-walled reinforced concrete (RC) tubular columns in air-cooled supporting structures of thermal power plants (TPPs). Cyclic loading tests and finite element analysis were performed on 1/8-scaled specimens considering the influence of wall diameter ratio, axial compression ratio, longitudinal reinforcement ratio, stirrup reinforcement ratio and adding steel diagonal braces (SDBs). The research results showed that the cracks mainly occurred on the lower half part of RC tubular columns during the cyclic loading test; the specimen with the minimum wall diameter ratio presented the earlier cracking and had the most cracks; the failure mode of RC tubular columns was large bias compression failure; increasing the axial compression ratio could increase the lateral bearing capacity and energy dissipation capacity, but also weaken the ductility and aggravate the lateral stiffness deterioration; increasing the longitudinal reinforcement ratio could efficiently enhance the seismic behavior; increasing the stirrup reinforcement ratio was favorable to the ductility; RC tubular columns with SDBs had a much higher bearing capacity and lateral stiffness than those without SDBs, and with the decrease of the angle between columns and SDBs, both bearing capacity and lateral stiffness increased significantly.

지진피해를 받은 철근콘크리트 건물의 지진피해도 판정 (Post-Earthquake Damage Evaluation for R/C Buildings Based on Residual Seismic Capacity)

  • 이강석;강대언
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2005년도 추계 학술발표회 제17권2호
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    • pp.109-112
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    • 2005
  • In this paper described is the basic concept of the Guideline for Post-earthquake Damage Assessment of RC buildings, revised in 2001, in Japan. This paper discusses the damage rating procedures based on the residual seismic capacity index R, the ratio of residual seismic capacity to the original capacity, that is consistent with the Japanese Standard for Seismic Evaluation of Existing RC Buildings, and their validity through calibration with observed damage due to the 1995 Hyogoken-Nambu (Kobe) earthquake. Good agreement between the residual seismic capacity ratio and damage levels was observed.

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시멘트밀크 배합비에 따른 다양한 지반 내 SDA매입말뚝의 연직지지력 (Bearing Capacity of SDA Augered Piles in Various Grounds Depending on Water-Cement Ratio of Cement Milk)

  • 홍원표;이재호;채수근
    • 한국지반공학회논문집
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    • 제24권5호
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    • pp.37-54
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    • 2008
  • 본 연구에서는 SDA(Separated Doughnut Auger)매입말뚝의 지지성능이 잘 발휘될 수 있는 표준시공법에 대한 매뉴얼을 정리하여 제시하였다. 또한 전국 36개 현장에서 여러 가지 시멘트밀크 배합비를 사용하여 SDA매입공법으로 시공한 379본의 시험말뚝에 대하여 438회의 동재하시험을 시행하였다 동재하시험결과 SDA매입말뚝의 지지력은 시멘트밀크의 배합비에 영향을 받음을 알 수 있었으며, 단위선단지지력과 단위마찰지지력을 시멘트밀크의 배합비와 지반종류별로 정량적으로 계산할 수 있는 식을 제안하였다. 또한 시멘트밀크 배합비가 SDA매입말뚝의 지지력에 미치는 영향을 검토하였고 이들 제안식을 기존의 표준시방서에 제시되어 매입말뚝설계에 적용되는 기존의 식들과 비교 고찰하였다.

스파이럴 그루브 형상의 스러스트 베어링의 부하용량 향상을 위한 설계 변수에 대한 연구 (A Study on Design Parameters to Improve Load Capacity of Spiral Grooved Thrust Bearing)

  • 강지훈;김경웅
    • 한국윤활학회:학술대회논문집
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    • 한국윤활학회 2001년도 제33회 춘계학술대회 개최
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    • pp.257-262
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    • 2001
  • A numerical analysis is undertaken to show tile influence of bearing design parameters on tile load capacity of air lubricated spiral grooved thrust bearing. The governing equation derived from the mass balance is solved by the finite difference method. Optimal values for various design parameters are obtained to maximize the load capacity. The design parameters are the groove angle, the groove width ratio, the groove height ratio, arid the seal ratio.

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