• 제목/요약/키워드: structural feasibility

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FPSO Riser 지지구조의 설계최적화에 대한 근사화 기법의 비교 연구 (A Comparative Study of Approximation Techniques on Design Optimization of a FPSO Riser Support Structure)

  • 심천식;송창용
    • 한국전산구조공학회논문집
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    • 제24권5호
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    • pp.543-551
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    • 2011
  • 본 논문에서는 해양작업 상태의 하중조건을 고려한 부유식 원유생산 저장 하역장치에 설치된 라이져 보강구조의 강도설계에 관련하여 다양한 근사화 기법 기반 설계최적화 및 그 성능을 비교하고자 한다. 설계최적화 문제는 하중조건별 구조강도의 제한조건 하에서 중량을 최소화하여 설계변수인 구조 부재치수가 결정되도록 정식화된다. 비교 연구를 위해 사용된 근사화 기법은 반응표면법 기반 순차적 근사최적화(RBSAO), 크리깅 기반 순차적 근사최적화(KBSAO), 그리고 개선된 이동최소자승법(MLSM) 기반 근사최적화 기법인 CF-MLSM와 Post-MLSM이다. RBSAO와 KBSAO의 적용을 위하여 상용프로세스 통합 설계최적화(PIDO) 코드를 사용하였다. 본 연구에 적용한 MLSM 기반 근사최적화 기법들은 제한조건의 가용성을 보장할 수 있도록 새롭게 개발되었다. 다양한 근사화 모델 기반 설계최적화 기법에 의한 결과는 설계 해의 개선 및 수렴속도 등의 수치적 성능을 기준으로 실제 비근사 설계최적화 결과와 비교 검토하였다.

트러서메쉬 보강 하프 슬래브의 구조적 거동에 관한 실험적 연구 (An Experimental Study on Structural Behavior of Half Slab Reinforced by Truss Mesh)

  • 고만영;김용부;박현수;정란
    • 콘크리트학회지
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    • 제7권4호
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    • pp.119-128
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    • 1995
  • 이 연구는 최근 건설공사에서의 인력 및 원가의 절감, 공기의 단축 등을 도모하기 위하여 도입되고 있는 하프슬래브의 실용화를 위한 구조거동을 알아보기 위한 실험적 연구이다. PC 패널의 두께, 트러스메쉬의 형사, 가력하중의 형태를 변수로 총 17개의 시험체를제작하여 PC 패널, 하프슬래브, 하프슬래브-벽체 접합부의 휨성능 실험을 하였다. 실험결과, 부방향 하중을 받는 PC 패널의 휨강도가 설계강도보다 작게 나타났으나 정방향 하중을 받는 PC판넬과 덧침콘크리트의 분리현상이 발견되지 않았으며 휨강도 또한 일체로 타설한 부재와 같은 휨내력을 발현하였다. 따라서, 본 연구에서는동바리를 2.0-2.5m간격으로 설치하고, PC판넬과 덧침콘크리트와의 접합면을 조면처리하고 청결을 유지하면 사용상 문제가 없는 것으로 판단되었다.

Performance comparison of shear walls with openings designed using elastic stress and genetic evolutionary structural optimization methods

  • Zhang, Hu Z.;Liu, Xia;Yi, Wei J.;Deng, Yao H.
    • Structural Engineering and Mechanics
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    • 제65권3호
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    • pp.303-314
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    • 2018
  • Shear walls are a typical member under a complex stress state and have complicated mechanical properties and failure modes. The separated-elements model Genetic Evolutionary Structural Optimization (GESO), which is a combination of an elastic-plastic stress method and an optimization method, has been introduced in the literature for designing such members. Although the separated-elements model GESO method is well recognized due to its stability, feasibility, and economy, its adequacy has not been experimentally verified. This paper seeks to validate the adequacy of the separated-elements model GESO method against experimental data and demonstrate its feasibility and advantages over the traditional elastic stress method. Two types of reinforced concrete shear wall specimens, which had the location of an opening in the middle bottom and the center region, respectively, were utilized for this study. For each type, two specimens were designed using the separated-elements model GESO method and elastic stress method, respectively. All specimens were subjected to a constant vertical load and an incremental lateral load until failure. Test results indicated that the ultimate bearing capacity, failure modes, and main crack types of the shear walls designed using the two methods were similar, but the ductility indexes including the stiffness degradation, deformability, reinforcement yielding, and crack development of the specimens designed using the separated-elements model GESO method were superior to those using the elastic stress method. Additionally, the shear walls designed using the separated-elements model GESO method, had a reinforcement layout which could closely resist the actual critical stress, and thus a reduced amount of steel bars were required for such shear walls.

Random vibration analysis of structures by a time-domain explicit formulation method

  • Su, Cheng;Xu, Rui
    • Structural Engineering and Mechanics
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    • 제52권2호
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    • pp.239-260
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    • 2014
  • Non-stationary random vibration of linear structures with uncertain parameters is investigated in this paper. A time-domain explicit formulation method is first presented for dynamic response analysis of deterministic structures subjected to non-stationary random excitations. The method is then employed to predict the random responses of a structure with given values of structural parameters, which are used to fit the conditional expectations of responses with relation to the structural random parameters by the response surface technique. Based on the total expectation theorem, the known conditional expectations are averaged to yield the random responses of stochastic structures as the total expectations. A numerical example involving a frame structure is investigated to illustrate the effectiveness of the present approach by comparison with the power spectrum method and the Monte Carlo simulation method. The proposed method is also applied to non-stationary random seismic analysis of a practical arch bridge with structural uncertainties, indicating the feasibility of the present approach for analysis of complex structures.

초고층 건물의 건전성 감시를 위한 변형률 기반 무선 센서 네트워크 기법의 기초적 연구 (Fundamental Research of Strain-based Wireless Sensor Network for Structural Health Monitoring of Highrise building)

  • 정은수;박효선;최석원;차호정
    • 한국방재학회:학술대회논문집
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    • 한국방재학회 2007년도 정기총회 및 학술발표대회
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    • pp.429-432
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    • 2007
  • For smart structure technologies, the interests in wireless sensor networks for structural health monitoring are growing. The wireless sensor networks reduce the installation of the wire embedded in the whole structure and save the costs. But the wireless sensor networks have lots of limits and there are lots of researches and developments of wireless sensor and the network for data process. Most of the researches of wireless sensor network is applying to the civil engineering structure and the researches for the highrise building are required. And strain-based SHM gives the local damage information of the structures which acceleration-based SHM can not. In this paper, concept of wireless sensor network for structural health monitoring of highrise building is suggested. And verifying the feasibility of the strain-based SHM a strain sensor board has developed and tested by experiments.

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Structural control of cable-stayed bridges under traveling earthquake wave excitation

  • Raheem, Shehata E Abdel
    • Coupled systems mechanics
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    • 제7권3호
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    • pp.269-280
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    • 2018
  • Post-earthquake damages investigation in past and recent earthquakes has illustrated that the ground motion spatial variation plays an important role in the structural response of long span bridges. For the structural control of seismic-induced vibrations of cable-stayed bridges, it is extremely important to include the effects of the ground motion spatial variation in the analysis for design of an effective control system. The feasibility and efficiency of different vibration control strategies for the cable-stayed bridge under multiple support excitations have been examined to enhance a structure's ability to withstand earthquake excitations. Comparison of the response due to non-uniform input ground motion with that due to uniform input demonstrates the importance of accounting for spatial variability of excitations. The performance of the optimized designed control systems for uniform input excitations gets worse dramatically over almost all of the evaluation criteria under multiple-support excitations.

칩마운터 구조물의 유연성을 고려한 위치와 진동 동시 제어 (Simultaneous Positioning and Vibration Control of Chip Mounter with Structural Flexibility)

  • 강민식
    • 반도체디스플레이기술학회지
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    • 제12권1호
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    • pp.53-59
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    • 2013
  • Chip mounter which is used to pick chips from the pre-specified position and place them on the target location of PCB is an essential device in semiconductor and LCD industries. Quick and high precision positioning is the key technology needed to increase productivity of chip mounters. As increasing acceleration and deceleration of placing motion, structural vibration induced from inertial reactive force and flexibility of mounter structure becomes a serious problem degrading positioning accuracy. Motivated from these, this paper proposed a new control design algorithm which combines a mounter structure acceleration feedforward compensation and an extended sliding mode control for fine positioning and suppression of structural vibration, simultaneously. The feasibility of the proposed control design was verified along with some simulation results.

FEASIBILITY OF AN INTEGRATED STEAM GENERATOR SYSTEM IN A SODIUM-COOLED FAST REACTOR SUBJECTED TO ELEVATED TEMPERATURE SERVICES

  • Koo, Gyeong-Hoi;Lee, Jae-Han
    • Nuclear Engineering and Technology
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    • 제41권8호
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    • pp.1115-1126
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    • 2009
  • As one of the ways to enhance the economical features in sodium-cooled fast reactor development, the concept of an integrated steam generator and pump system (ISGPS) is proposed from a structural point of view. And the related intermediate heat transfer system (IHTS) piping layout compatible with the ISGPS is described in detail. To assure the creep design lifetime of 60 years, the structural integrity is investigated through high temperature structural evaluation procedures by the SIE ASME-NH computer code, which implements the ASME-NH design rules. From the results of this study, it is found that the proposed ISGPS concept is feasible and applicable to a commercial SFR design.

Optimal reinforcement design of structures under the buckling load using the homogenization design method

  • Min, Seungjae;Kikuchi, Noboru
    • Structural Engineering and Mechanics
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    • 제5권5호
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    • pp.565-576
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    • 1997
  • The material-based homogenization design method generates arbitrary topologies of initial structural design as well as reinforcement structural design by controlling the amount of material available. However, if a small volume constraint is specified in the design of Lightweight structures, thin and slender structures are usually obtained. For these structures stability becomes one of the most important requirements. Thus, to prevent overall buckling (that is, to increase stability), the objective of the design is to maximize the buckling load of a structure. In this paper, the buckling analysis is restricted to the linear buckling behavior of a structure. The global stability requirement is defined as a stiffness constraint, and determined by solving the eigenvalue problem. The optimality conditions to update the design variables are derived based on the sequential convex approximation method and the dual method. Illustrated examples are presented to validate the feasibility of this method in the design of structures.

스펙트럴요소 모델을 이용한 구조손상규명 (Structural Damage Identification by Using Spectral Element Model)

  • 민승규;김정수;이우식
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2003년도 봄 학술발표회 논문집
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    • pp.366-373
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    • 2003
  • This paper introduces a frequency-domain method of structural damage identification. It is formulated in a general form to include the nonlinearity of damage magnitudes from the dynamic stiffness equation of motion for a beam structure. The appealing features of the present damage identification method are: (1) it requires only the frequency response functions measured from damaged structure as the input data, and (2) it can locate and quantify many local damages at the same time. The feasibility of the present damage identification method is tested through some numerically simulated damage identification analyses for a cantilevered beam with three piece-wise uniform damages.

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