• 제목/요약/키워드: Dynamic Capacity

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시계열하중을 이용한 PSC 박스 거더 고속철도교량의 동적성능 평가에 관한 연구 (A Study on Dynamic Capacity Assessment of PSC Box Girder High Speed Railway Bridges Using Time Series Load)

  • 한성호;방명석;이우상
    • 대한토목학회논문집
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    • 제30권3A호
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    • pp.211-219
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    • 2010
  • 고속철도교량의 설계개념은 정적하중에 따른 충격계수를 고려하여 기존 교량 구조물의 강성을 증가시키기 위한 방안을 적용하고 있으며, 전반적인 구조설계 과정은 선진 외국기술에 의존하고 있는 실정이다. 그러나 고속철도(Korea Train eXpress: KTX)의 긴 연장(380 m)과 고속(300 km/h) 주행은 공진현상에 상당한 영향을 미치기 때문에 고속철도교량의 동적증폭계수(DAF) 및 동적성능 평가는 상세한 검토가 필수적으로 수행되어야 할 것이다. 따라서 이 연구에서는 전형적인 PSC 박스 거더 고속철도교량을 대상으로 동적성능을 효율적으로 검토하고자 하며, 합리적인 구조설계를 위한 기초자료를 제시하고자 한다. 이를 위해, 기존문헌을 토대로 KTX의 하중선도를 고려하여 정적해석을 수행하였다. 또한 다양한 해석변수를 고려하여 KTX의 이동하중을 시계열하중으로 변환하였으며, 변환된 시계열하중을 이용하여 시간이력해석을 합리적으로 평가하였다. 이때, 시계열하중을 산정하기 위한 변수는 KTX의 하중재하 절점간격, 시간증분 및 속도변화를 고려하였다. FE해석 결과를 바탕으로 PSC 박스 거더 고속철도교량의 동적성능을 체계적으로 검토하였으며, 국내외 관련규정에 따라 구조안전성을 정량적으로 평가하였다.

대구경 해상 강관말뚝의 설계지지력 확인을 위한 여러 가지 재하시험의 적용 (Case Studies of Several Load Tests for Large Diameter Battered Steel Pipe Piles Constructed on the Offshore Area.)

  • 이정학;서덕동;정헌주
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2001년도 봄 학술발표회 논문집
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    • pp.291-298
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    • 2001
  • It is very difficult to accomplish load tests of piles with large diameter constructed on the offshore area, because of requirement for large scaled loading equipment and bad testing conditions. Therefore, so far in many cases pile driving dynamic formulas have applied to quality control, and recently dynamic load test method is widely used for confirming bearing capacities of such piles. However, in cases of piles with very large diameter about 2,500mm, it is nearly impossible for regular type load test methods of piles such as static and dynamic to apply owing to very large design load. This is case studies of load tests such as modified static and dynamic load tests of piles and point load tests of rock samples for estimating rational allowable bearing capacity of very large diameter piles constructed on the marine area.

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마이크로셀룰러 시스템에서 동적 섹터결정을 위한 MACS (Multiple Ant Colony System (MACS) for the Dynamic Sectorization in Microcellular System)

  • 김성수;홍순정;안승범
    • 산업공학
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    • 제19권1호
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    • pp.1-8
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    • 2006
  • The mobile communication network has to offer good quality of services (QoS), high capacity, and more coverage at a lower cost. However, with the increase of cellular user, the shortage of capacity due to unbalanced call distribution and lack of QoS are common. This paper deals with dynamic sectorization for efficient resource management to solve load unbalancing among microcells in CDMA (Code Division Multiple Access) microcellular system. Dynamic load balancing can be effected by grouping micro-cells properly and grouping can be developed through a routing mechanism. Therefore, we use ants and their routes to choose the optimum grouping of micro-cells into sectors using Multiple Ant Colony System (MACS)in this paper.

Deadlock과 Workload에 따른 FMS의 버퍼 Capacity 결정에 관한 연구 (A Study of Buffer Allocation in FMS based on Deadlock and Workload)

  • 김경섭;이정표
    • 한국시뮬레이션학회논문지
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    • 제9권2호
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    • pp.63-73
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    • 2000
  • Due to the complexity of part flow and limited resources, FMS(Flexible Manufacturing System) develops blocking, starvation and deadlock problems, which reduce its performance. In order to minimize such problems buffers are imposed between workstations of the manufacturing lines. In this paper, we are concerned with finding the optimal buffer allocation with regard to maximizing system throughput in limited total buffer capacity situation of FMS. A dynamic programming algorithm to solve the buffer allocation problem is proposed. Computer simulation using Arena is experimented to show the validation of the proposed algorithm.

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Evaluation of ductility capacity of steel-timber hybrid buildings for seismic design in Taiwan

  • Chen, Pei-Ching;Su, I-Ping
    • Earthquakes and Structures
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    • 제23권2호
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    • pp.197-206
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    • 2022
  • Recently, steel-timber hybrid buildings have become prevalent worldwide because several advantages of both steel and timber structures are maintained in the hybrid system. In Taiwan, seismic design specification related to steel-timber hybrid buildings remains void. In this study, the ductility capacity of steel-timber hybrid buildings in Taiwanese seismic design specification is first proposed and evaluated using nonlinear incremental dynamic analysis (IDA). Three non-linear structural models, 12-story, 8-story, and 6-story steel-timer hybrid buildings were constructed using OpenSees. In each model, Douglas-fir was adopted to assemble the upper 4 stories as a timber structure while a conventional steel moment-resisting frame was designated in the lower part of the model. FEMA P-695 methodology was employed to perform IDAs considering 44 earthquakes to assess if the ductility capacity of steel-timber hybrid building is appropriate. The analytical results indicate that the current ductility capacity of steel moment-resisting frames can be directly applied to steel-timber hybrid buildings if the drift ratio of each story under the seismic design force for buildings in Taiwan is less than 0.3%. As a result, engineers are able to design a steel-timber hybrid building straightforwardly by following current design specification. Otherwise, the ductility capacity of steel-timber hybrid buildings must be modified which depends on further studies in the future.

두개의 차별적인 용량형태를 갖는 단일설비에 대한 용량 확장계획 모형 (A Capacity Expansion Planning Model for Single-Facility with Two Distinct Capacity Type)

  • 장석화
    • 대한산업공학회지
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    • 제16권1호
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    • pp.51-58
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    • 1990
  • A deterministic capacity expansion planning model for a two-capacity type facility is analyzed to determine the sizes to be expanded in each period so as to supply the known demands for two distinct capacity type(product) on time and to minimize the total cost incurred over a finite planning horizon of T periods. The model assumes that capacity unit of the facility simultaneously serves a prespecified number of demand units of each capacity type, that capacity type 1 can be used to supply demands for capacity type 2, but that capacity type 2 can't be used to supply demands for capacity type 1. Capacity expansion and excess capacity holding cost functions considered are nondecreasing and concave. The structure of an optimal solution is characterized and then used in developing an efficient dynamic programming algorithm that finds optimal capacity planning policy.

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강합성교각의 내진성능평가 Part II: 유사동적실험 및 잔류내진성능 평가 (Seismic Performance of Concrete-Filled Steel Piers Part II: Pseudo-Dynamic Test and Residual Seismic Capacity)

  • 조창빈;서진환;장승필
    • 한국지진공학회논문집
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    • 제6권2호
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    • pp.21-28
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    • 2002
  • Ductile behavior and strength of concrete-filled steel(CFS) piers was supported by many quasi-static cyclic loading tests. This test method, however, only estimates the member′s deformation capacity under escalating and repetitive displacement and ignores dynamic and random aspects of an earthquake load. Therefore, to understand complete seismic behavior of the structure against an earthquake, dynamic tests such as shaking table test and pseudo-dynamic tests are required as well as quasi-static tests. In this paper, following "Seismic Performance of Concrete-Filled Steel Piers Part I : Quasi-Static Cyclic Loadint Test", the seismic behavior of CFS and steel piers designed for I-Soo overpass in Seoul in investigated by the pseudo-dynamic test. In addition, the residual strength of both piers after an earthquake is estimated by the quasi-static test. The results show that both piers have satisfactory ductility and strength against well-known EI Centro earthquake although the CFS pier has better strength and energy dissipation than the steel pier.

Study on Thermal Load Capacity of Transmission Line Based on IEEE Standard

  • Song, Fan;Wang, Yanling;Zhao, Lei;Qin, Kun;Liang, Likai;Yin, Zhijun;Tao, Weihua
    • Journal of Information Processing Systems
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    • 제15권3호
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    • pp.464-477
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    • 2019
  • With the sustained and rapid development of new energy sources, the demand for electric energy is increasing day by day. However, China's energy distribution is not balanced, and the construction of transmission lines is in a serious lag behind the improvement of generating capacity. So there is an urgent need to increase the utilization of transmission capacity. The transmission capacity is mainly limited by the maximum allowable operating temperature of conductor. At present, the evaluation of transmission capacity mostly adopts the static thermal rating (STR) method under severe environment. Dynamic thermal rating (DTR) technique can improve the utilization of transmission capacity to a certain extent. In this paper, the meteorological parameters affecting the conductor temperature are analyzed with the IEEE standard thermal equivalent equation of overhead transmission lines, and the real load capacity of 220 kV transmission line is calculated with 7-year actual meteorological data in Weihai. Finally, the thermal load capacity of DTR relative to STR under given confidence is analyzed. By identifying the key parameters that affect the thermal rating and analyzing the relevant environmental parameters that affect the conductor temperature, this paper provides a theoretical basis for the wind power grid integration and grid intelligence. The results show that the thermal load potential of transmission lines can be effectively excavated by DTR, which provides a theoretical basis for improving the absorptive capacity of power grid.