• 제목/요약/키워드: wind-loading

검색결과 428건 처리시간 0.03초

포스트 텐션 플랫 플레이트 슬래브 접합부의 거동 (Structural Behavior of Post-Tensioned Flat Plate Slab-Column Connections)

  • 조경현;한상환;이리형
    • 한국콘크리트학회:학술대회논문집
    • /
    • 한국콘크리트학회 2004년도 추계 학술발표회 제16권2호
    • /
    • pp.53-56
    • /
    • 2004
  • Recently, post tension flat plate slab system is widely used for a new slab structural system. Slab-column connections may fail in brittle manner by punching shear. Flat plate slabs have been widely used for gravity load resisting system in buildings. Lateral resistance usually provided by shear walls or moment resisting frames. Since plat plates move together with lateral loading system during earthquake or wind, it is important to evaluate the gravity resistance under a drift experienced by lateral force resisting system during either design earthquake or wind. Thus, this study investigated post tension flat plate slab systems whether they have sufficient strength and deformability to resist gravity loads during specified drift levels. Experimental research was carried out.

  • PDF

파일의 시공오차를 고려한 스태빙시스템의 구조안전성 평가 (Structural Safety Evaluation of Stabbing System for Pre-Piling Jacket Substructure Considering Pile Construction Errors)

  • 오영철;류재용;이대용
    • 풍력에너지저널
    • /
    • 제14권3호
    • /
    • pp.109-119
    • /
    • 2023
  • A structural safety evaluation was conducted for the stabbing system for the pre-piling jacket substructure currently being developed in South Korea, considering pile construction errors due to its lateral movement that may occur during construction in the ocean. Based on (1) the maximum stress generated by the stabbing system, (2) the maximum rotational displacement of the guide cone, and (3) the maximum stress generated by the horizontal hydraulic pressure cylinder, the structural safety of the stabbing system was examined under the initial loading condition and three possible load combinations during its construction. In order to evaluate the structural safety of the stabbing system, a concept of stress safety factor (= Yield stress / Max. Von-Mises stress) was used. It was found that the stabbing system considered in this study has a sufficient margin of safety.

엑츄에이터를 이용한 송전철탑의 1/2 축소부분실험 (Half-Scaled Substructure Test of a Transmission Tower Using Actuators)

  • 문병욱;박지훈;이성경;민경원
    • 한국소음진동공학회:학술대회논문집
    • /
    • 한국소음진동공학회 2007년도 추계학술대회논문집
    • /
    • pp.178-188
    • /
    • 2007
  • In this paper, a half-scaled substructure test was performed to evaluate the buckling and structural safety of an existing transmission tower subjected to wind load. A loading scheme was devised to reproduce the dead and wind loads of a prototype transmission tower, which uses a triangular jig that is mounted on the reduced model to which the similarity law of a half length was applied. As a result of the preliminary numerical analysis carried out to evaluate the stability of a specimen for the design load, it was confirmed that the calculated axial forces of tower leg members were distributed to $80{\sim}90%$ of an admissible buckling load. When the substructured transmission tower was loaded by 270% of its maximum admissible buckling load, it was failed due to the local buckling that is occurred in joints with weak constraints for out-of-plane behavior of leg members. By inspection of load-displacement curves, displacements and strains of members, it is considered that this local buckling was due to additional eccentric force by unbalanced deformation because the time that is reached to yielding stress due to the bending moment is different at each point of a same section.

  • PDF

Numerical simulation study of the Reynolds number effect on two bridge decks based on the deterministic vortex method

  • Zhou, Zhiyong;Ma, Rujin
    • Wind and Structures
    • /
    • 제13권4호
    • /
    • pp.347-362
    • /
    • 2010
  • Researches on the Reynolds number effect on bridge decks have made slow progress due to the complicated nature of the subject. Heretofore, few studies on this topic have been made. In this paper, aerostatic coefficients, Strouhal number ($S_t$), pressure distribution and Reynolds number ($R_e$) of Great Belt East Bridge and Sutong Bridge were investigated based on deterministic vortex method (DVM). In this method, Particle Strength Exchange (PSE) was chosen to implement the simulation of the flow around bluff body and to analyze the micro-mechanism of the aerostatic loading and Reynolds number effect. Compared with the results obtained from wind tunnel tests, reliability of numerical simulation can be proved. Numerical results also showed that the Reynolds number effect on aerostatic coefficients and Strouhal number of the two bridges can not be neglected. In the range of the Reynolds number from $10^5$ to $10^6$, it has great effect on the Strouhal number of Sutong Bridge, while the St is difficult to obtain from wind tunnel tests in this range.

Influence of failed blade-pitch-control system to FOWT by aero-elastic-control-floater-mooring coupled dynamic analysis

  • Bae, Yoon Hyeok;Kim, Moo-Hyun
    • Ocean Systems Engineering
    • /
    • 제3권4호
    • /
    • pp.295-307
    • /
    • 2013
  • More FOWTs (floating offshore wind turbines) will be installed as relevant regulations and technological hurdles are removed in the coming years. In the present study, a numerical prediction tool has been developed for the fully coupled dynamic analysis of FOWTs in time domain including aero-loading, tower elasticity, blade-rotor dynamics and control, mooring dynamics, and platform motions so that the influence of rotor-control dynamics on the hull-mooring performance and vice versa can be assessed. The developed coupled analysis program is applied to Hywind spar design with 5 MW turbine. In case of spar-type floaters, the control strategy significantly influences the hull and mooring dynamics. If one of the control systems fails, the entire dynamic responses of FOWT can be significantly different. Therefore, it is important to maintain various control systems in a good operational condition. In this regard, the effects of failed blade pitch control system on FOWT performance including structural and dynamic responses of blades, tower, and floater are systematically investigated. Through this study, it is seen that the failure of one of the blade pitch control system can induce significant dynamic loadings on the other blades and the entire FOWT system. The developed technology and numerical tool are readily applicable to any types of floating wind farms in any combinations of irregular waves, dynamic winds, and steady currents.

Semi-analytical numerical approach for the structural dynamic response analysis of spar floating substructure for offshore wind turbine

  • Cho, Jin-Rae;Kim, Bo-Sung;Choi, Eun-Ho;Lee, Shi-Bok;Lim, O-Kaung
    • Structural Engineering and Mechanics
    • /
    • 제52권3호
    • /
    • pp.633-646
    • /
    • 2014
  • A semi-analytical numerical approach for the effective structural dynamic response analysis of spar floating substructure for offshore wind turbine subject to wave-induced excitation is introduced in this paper. The wave-induced rigid body motions at the center of mass are analytically solved using the dynamic equations of rigid ship motion. After that, the flexible structural dynamic responses of spar floating substructure for offshore wind turbine are numerically analyzed by letting the analytically derived rigid body motions be the external dynamic loading. Restricted to one-dimensional sinusoidal wave excitation at sea state 3, pitch and heave motions are considered. Through the numerical experiments, the time responses of heave and pitch motions are solved and the wave-induced dynamic displacement and effective stress of flexible floating substructure are investigated. The hydrodynamic interaction between wave and structure is modeled by means of added mass and wave damping, and its modeling accuracy is verified from the comparison of natural frequencies obtained by experiment with a 1/100 scale model.

풍력발전기용 3점 지지 기어박스에서 캐리어 핀홀 위치 오차가 유성기어의 하중분할에 미치는 정성적 영향에 관한 실험적 연구 (An Experimental Study for the Qualitative Effect of Carrier Pin Hole Position Error on Planet Load Sharing of Wind Turbine Three-point Suspension Gearbox)

  • 남주석;한정우
    • 한국생산제조학회지
    • /
    • 제25권2호
    • /
    • pp.97-104
    • /
    • 2016
  • In this study, the qualitative effects of the positional error of carrier pin holes on the planet load sharing characteristics of the three-point suspension gearbox of wind turbines were investigated experimentally. A 35-kW gearbox comprising two planetary gear stages and a parallel gear stage and size one-fourth of that of a 2-MW three-point suspension gearbox was used as the test gearbox. The strain gauges attached to the ring gear teeth of the input planetary gear stage were used for the purpose of this study. The applied loading conditions were 50%, 75%, and 100% of the rated torque, and the mesh load factor was used as the load sharing index. The experimental results indicated that both the magnitude and direction of the positional error of pin holes had a significant effect on the planet load sharing characteristics of the three-point suspension gearbox. In addition, an increase in the applied torque results in uniform load sharing.

버켓기초를 가진 해상풍력타워의 선박충돌 거동 (Ship Collision Behaviors of Offshore Wind Tower on Bucket Foundation)

  • 이계희;박준석;홍관영
    • 한국재난정보학회 논문집
    • /
    • 제8권2호
    • /
    • pp.138-147
    • /
    • 2012
  • 본 논문에서는 해상풍력발전타워와 선박충돌에 대한 다양한 매개변수에 해석을 수행하여 선박충돌시 버켓파일로 지지된 기초부와 상부타워의 극한하중에 대한 거동을 분석하였다. 또한 충돌에너지의 변화에 따른 버켓기초의 안정성 여부 및 풍력타워의 에너지 소산능력에 대해 파악하였다. 해석결과 선박이 충돌에너지는 주로 타워의 소성변형에너지에 의해 소산 되었으며 이러한 극한상태의 하중에도 기초부는 충분한 지지력을 보이는 것으로 나타났다.

Hull/Mooring/Riser Coupled Dynamic Analysis of a Turret-Moored FPSO Compared with OTRC Experiment

  • Kim Young-Bok;Kim Moo-Hyun
    • Journal of Ship and Ocean Technology
    • /
    • 제8권3호
    • /
    • pp.26-39
    • /
    • 2004
  • A vessel/mooring/riser coupled dynamic analysis program in time domain is developed for the global motion simulation of a turret-moored, tanker based FPSO designed for 6000-ft water depth. The vessel global motions and mooring tension are simulated for the non-parallel wind-wave-current 100-year hurricane condition in the Gulf of Mexico. The wind and current forces and moments are estimated from the OCIMF empirical data base for the given loading condition. The numerical results are compared with the OTRC(Offshore Technology Research Center: Model Basin for Offshore Platforms in Texas A&M University) 1:60 model-testing results with truncated mooring system. The system's stiffness and line tension as well as natural periods and damping obtained from the OTRC measurement are checked through numerically simulated static-offset and free-decay tests. The global vessel motion simulations in the hurricane condition were conducted by varying lateral and longitudinal hull drag coefficients, different mooring and riser set up, and wind-exposed areas to better understand the sensitivity of the FPSO responses against empirical parameters. It is particularly stressed that the dynamic mooring tension can be greatly underestimated when truncated mooring system is used.

지반과 말뚝의 상호작용을 고려한 고정식 해상풍력터빈의 동적 특성에 대한 확률적 평가 (Probabilistic Assessment of Dynamic Properties of Offshore Wind Turbines Considering Soil-Pile Interaction)

  • 이진학;김선빈;한택희;윤길림
    • 한국전산구조공학회논문집
    • /
    • 제28권4호
    • /
    • pp.343-350
    • /
    • 2015
  • 천해역에서의 해상풍력터빈의 기초 형식으로 모노파일, 트라이포드, 재킷 등의 고정식 기초 사이의 최적의 지지구조물 선별에 대한 논의가 세계적으로 활발하게 되어왔다. 다양한 기초 형식 가운데 어떤 기초를 최종 선택하기 위해서는 경제성과 함께 동적설계 측면에서의 검토도 필요하다. 이 연구에서는 고정식 기초를 해상풍력터빈의 기초로 적용하는 경우 전체 구조물의 고유주파수에 미치는 하중 및 지반 물성치의 불확실성의 영향을 정량적으로 검토하였다. 연구결과, 모노파일의 고유주파수의 변동이 가장 심한 것을 알 수 있었고, 따라서 모노파일 기초를 설계에 반영하는 경우에는 지반 물성치의 불확실성을 최소화시키는 것이 중요하다는 것을 알 수 있었다.