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1
Kim, Taeo, Sang Whan Han, and Soo Ik Cho. "Effect of Wind Loads on Collapse Performance and Seismic Loss for Steel Ordinary Moment Frames." Applied Sciences 12, no. 4 (February 15, 2022): 2011. http://dx.doi.org/10.3390/app12042011.
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The aim of this study is to investigate the effect of wind loads on the seismic collapse performance and seismic loss for steel ordinary moment frames (OMFs). For this purpose, 9-, 12-, 15-, and 18-story steel OMFs are repeatedly designed for (1) gravity load + seismic load, (2) gravity load + seismic load + wind load (wind speed = 44 m/s), and (3) gravity load + seismic load + wind load (wind speed = 55 m/s). The seismic collapse performance and seismic loss of OMFs are evaluated using the procedures in FEMA P695 (FEMA, 2009) and FEMA P58 (FEMA, 2018), respectively. Steel OMFs designed with consideration of wind loads have larger member sections than corresponding steel OMFs designed without consideration of wind loads as expected. Although member sections are increased when wind loads are considered, the growth in the maximum base shear force and lateral stiffness of OMFs are insignificant. Unlike our expectation, OMFs designed with consideration of wind loads have higher expected annual loss (EAL) than corresponding OMFs designed without consideration of wind loads.
2
Gao, Yong Tao, and Xiao Hu. "Wind Load Analysis on Adherent Billboard Considering the Turbulent Wind." Applied Mechanics and Materials 90-93 (September 2011): 1365–68. http://dx.doi.org/10.4028/www.scientific.net/amm.90-93.1365.
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Due to the applicable installation height, small mass, flexible characteristic, and small damp, the adherent billboard could easily result in vibration with the wind effect. The main factor is the turbulence among the cause effects. Combining the structural dynamic theory, and considering the characteristic of the adherent billboard, a wind effect calculation formula is set up considering the turbulent wind that is resulted by the 1st vibration type. Hope to provide some reference for similar structure designs.
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Ding, Wei, and Yasushi Uematsu. "Discussion of Design Wind Loads on a Vaulted Free Roof." Wind 2, no. 3 (July 8, 2022): 479–94. http://dx.doi.org/10.3390/wind2030026.
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This paper discusses the wind loads for designing vaulted free roofs based on a wind tunnel experiment, in which the wind force coefficients for the main wind force resisting system and the peak wind force coefficients for cladding are considered. The focus is on the dynamic load effects of fluctuating wind pressures on the wind force coefficients. Wind pressure distributions on the top and bottom surfaces were measured in a turbulent boundary layer. The results indicated that the distributions of wind force coefficients changed significantly with wind direction. Then, the wind direction providing the maximum load effect on the structural frame was detected from a dynamic response analysis using the time histories of wind pressure coefficients. In the analysis, the focus was on the bending moment at the windward column base and the axial force in the leeward column as the most important load effects. The LRC method proposed by Kasperski was employed for evaluating the equivalent static wind force coefficients providing the maximum load effects. Based on the results, a model of design wind force coefficient was proposed in the framework of the conventional gust effect factor approach. Finally, positive and negative peak wind force coefficients for designing the cladding were proposed based on the most critical maximum and minimum peak wind force coefficients among all wind directions.
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Guo, Long, Ai Rong Chen, and Li Ping Xu. "Strait Crossing Cable Stayed Bridge Girder Evolution." Advanced Materials Research 250-253 (May 2011): 1407–17. http://dx.doi.org/10.4028/www.scientific.net/amr.250-253.1407.
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The design of bridges, in particular long spanned ones, is challenging in the sense that there are many complicated issues to be considered. Amidst the loads to be considered, like dead load, live load, wind load, and earthquake load, the wind load becomes the prime concern for the design of the bridges. The paper will introduce several newly evolved kinds of girder that were based on commonly known physic natural law by structural engineer. Further structural analysis and wind effect research should be done in the future to validate and decide the structural member dimensions. The main problem to be solved in strait crossing bridge is lateral wind load that will effect traffic safety as well as wind effect on structures (statically and dynamically) for long span bridge arrangement.
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Bao, Wen Bo, Yu Yong Hu, and Yang Cui. "Wind Loads Simulation of Tall Building Structure Subjected to Wind-Structure Interaction." Advanced Materials Research 163-167 (December 2010): 4286–89. http://dx.doi.org/10.4028/www.scientific.net/amr.163-167.4286.
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Wind is an important and complex load and an important basis in the structural analysis and the design of high-rise structure. Based on Davenport wind spectrum, multi-dimensional fluctuating wind and random wind load of tall building structure are simulated by using harmonic wave superposition method. To investigate the coupling effect of wind loads, wind-structure system is solved with Wilson-θ step-by-step numerical integration method, and the wind load of Tall building structure subjected to fluid-structure interaction. Turbulence intensity and its variation are presented in this paper.
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Wei, Hua, Yan Jun Cheng, Zhi Yuan Peng, and Hai Jun Wang. "Finite Element Analysis for the Wind Resistance of the Tower of Wind Turbine." Advanced Materials Research 189-193 (February 2011): 1718–21. http://dx.doi.org/10.4028/www.scientific.net/amr.189-193.1718.
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1MW variable speed constant frequency wind turbine tower of steel structure is analyzed by using the software ANSYS, the coupling between the wind and the tower is realized through the order coupling method. The maximum Von Mises stress and the deformation of the tower in the case of limit loads are obtained, and then these results are compared with that without wind load. Comparison result shows that the effect of wind load on the tower’s displacement along the wind speed is great, and the maximum Von Mises stress of the tower becomes larger after considering the influence of wind load, the increase extent is determined by wind load case.
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Wu, Xiaotong, Ying Sun, Yue Wu, Ning Su, and Shitao Peng. "The Interference Effects of Wind Load and Wind-Induced Dynamic Response of Quayside Container Cranes." Applied Sciences 12, no. 21 (October 29, 2022): 10969. http://dx.doi.org/10.3390/app122110969.
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Strong wind has caused damage to group-arranged quayside container cranes in terminals and ports in recent years. Interference may amplify the wind loads in some cases. However, the interference effect among cranes has rarely been studied. In this study, high-frequency force balance tests were conducted to obtain the wind load of isolated and group-arranged container cranes. The results of the computational fluid dynamics simulation were validated by wind tunnel tests and provided the mean wind loads of all 15 types of member cranes. According to the results from wind tunnel tests, the fluctuating wind loads of each member were generated using the weighted amplitude wave superposition method. Based on dynamic finite element methods, the wind-induced responses were obtained considering the interference effect. It was found that the interference effect is the combined effects of both the shielding effect and the amplification of turbulence. Although in some cases the fluctuating and peak wind loads can increase by up to 16% and 6%, respectively, those in the most unfavorable cases are reduced by the interference effect. The interference factor for extreme nodal deformation is 0.56 and 0.69. The interference effect in container cranes mainly appears as a shielding effect, reducing the wind loads and response of the structures in unfavorable cases.
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Zakhama, R., M. M. Abdalla, Z. Gürdal, and H. Smaoui. "Wind load effect in topology optimization problems." Journal of Physics: Conference Series 75 (July 1, 2007): 012048. http://dx.doi.org/10.1088/1742-6596/75/1/012048.
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Brungardt, M. V., A. V. Brungardt, E. A. Goncharova, and O. A. Li. "Effect of wind load on waveguide strength." Journal of Physics: Conference Series 2373, no. 2 (December 1, 2022): 022037. http://dx.doi.org/10.1088/1742-6596/2373/2/022037.
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Abstract The article considers the features of the influence of wind load in the Arctic and Far North regions on the static and dynamic state of direct waveguides. Waveguides have a thin-walled design with restrictions on wall deflections, so the theory of plates and shells is used to calculate them. In the static state, the wind load is modeled by uniform pressure on one side of the waveguide. This made it possible to obtain an analytical solution to the problem by the plate theory, identify the features of the stress distribution over the waveguide structure, and clarify the solution compared to the beam theory. Comparing the results of the calculation according to the proposed method with the results of beam theory showed good convergence. The dynamic state was estimated by the first natural frequency of waveguides, considering ice deposits. The results of the calculations showed a significant impact of ice deposits on the frequency of oscillations and showed the need for deicing.
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Hafeez, G., A. M. El Ansary, and A. A. El Damatty. "Effect of wind loads on the stability of conical tanks." Canadian Journal of Civil Engineering 38, no. 4 (April 2011): 444–54. http://dx.doi.org/10.1139/l11-017.
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During the past few decades, a number of conical tanks have collapsed in various locations around the globe. Previous studies attributed the reason of collapse to inadequate thickness of the conical vessel especially at the bottom part. Most of the previous studies focused on studying the stability of conical tanks under the effect of only hydrostatic pressure. The current study focuses on studying the combined effect of wind loading and hydrostatic pressure on the stability of conical tanks. The study is conducted numerically, using a three-dimensional finite element model that is developed in-house. The critical imperfection shapes leading to minimum buckling capacity of conical shells under wind load alone, and under the combined effect of wind load and hydrostatic pressure, are determined. The study shows that a non-axisymmetric imperfection shape leads to minimum buckling capacity of empty conical tanks subjected to wind loads, while an axisymmetric distribution is noticed in the case of conical tanks under the combined effect of wind loads and hydrostatic pressure. In addition, the current study assesses the adequacy of an existing design procedure, which accounts for hydrostatic pressure, when the combination of hydrostatic pressure and wind load is considered.
11
Deng, Ying, Dan Zhang, Feng Zhou, and De Tian. "Individual Pitch Control for Load Reduction Based on Norm Theory." Applied Mechanics and Materials 448-453 (October 2013): 1879–83. http://dx.doi.org/10.4028/www.scientific.net/amm.448-453.1879.
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As the capacity of wind turbine increases, unsteady blade loads and performance caused by asymmetrical effects like turbulence, wind shear and tower shadow lead to fatigue loads which seriously affect wind turbine life cycle. This paper focused on wind turbine fatigue load response characteristics, built the multiple input multiple output linearized matrix model, introduced individual pitch control algorithm for optimized disturbance control based on norm theory. Modeling, simulation and verification of the control algorithm are conducted in Matlab. The investigation is conducted based on a 2MW doubly-fed wind turbine. By comparing the results of wind turbine deflection rate and angle deflection rate to collective pitch control method, it shows the individual pitch control algorithm can significantly reduce wind turbine fatigue load, and the control effect is superior to traditional control algorithm.
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Fang, Zi Fen, Zhi Qiang Zhang, and Fei Liu. "Study on a Large-Span Steel Truss Roof Isolation Bearings for Wind Load Effect Isolation Effect." Applied Mechanics and Materials 405-408 (September 2013): 1022–27. http://dx.doi.org/10.4028/www.scientific.net/amm.405-408.1022.
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The isolation of large-span Steel Truss Roof structure is developed on the basis of base isolation. The isolation of large-span Steel Truss Roof structure is to limit the transmission of wind load effect to the substructure. Based on the engineering background, we mainly discuss using rubber bearing isolation structure wind load effects. This paper will explains and demonstrates the isolation mechanism of Large-span Steel Truss Structure,and than test and verify isolation effect by Calculating through the analysis of wind tunnel tests conducted on the Yancheng financial services center, which the steel truss roof isolation bearings for wind load effect isolation effect.
13
Sang, Le Quang, Takao Maeda, and Yasunari Kamada. "Study effect of extreme wind direction change on 3-bladed horizontal axis wind turbine." International Journal of Renewable Energy Development 8, no. 3 (October 22, 2019): 261–66. http://dx.doi.org/10.14710/ijred.8.3.261-266.
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The Horizontal Axis Wind Turbines (HAWT) are used very popular in the world. They were installed mainly on land. However, on the land, the wind regime change is very complex such as high turbulence and constantly changing wind direction. In the International Electrotechnical Commission (IEC) 61400-1 standard, the wind regime is devided into the normal wind conditions and the extreme wind conditions. This study will focus on the extreme wind direction change and estimate the aerodynamic forces acting on a 3-bladed HAWT under this condition. Because the extreme wind direction change may cause extreme loads and it will affect the lifetime of HAWTs. This issue is experimented in the wind tunnel in Mie University, Japan to understand these effects. The wind turbine model is the 3-bladed HAWT type and using Avistar airfoil for making blades. A 6-component balance is used to measure the forces and the moments acting on the entire wind turbine in the three directions of x, y and z-axes. This study estimates the load fluctuation of the 3-bladed wind turbine under extreme wind direction change. The results show that the yaw moment and the pitch moment under the extreme wind direction change fluctuate larger than the normal wind condition. Specifically, before the sudden wind direction change happened, the averaged maximum pitch moment MX is -1.78 Nm, and after that MX is 4.45 Nm at inrush azimuth of 0°.©2019. CBIORE-IJRED. All rights reserved
14
Ouyang, Linze. "Effect of Load and Prospect on High-Rise Buildings." Highlights in Science, Engineering and Technology 28 (December 31, 2022): 407–14. http://dx.doi.org/10.54097/hset.v28i.4870.
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With the acceleration of urbanization, high-rise buildings have become the most familiar buildings in the city because of many advantages such as a small footprint and good lighting. However, due to the height of high-rise buildings, they are particularly affected by transverse loads, such as wind load and earthquake load. To have a better understanding of high-rise buildings, this paper discusses the central structural systems of high-rise buildings. And explains the influence of wind load and earthquake load on high-rise buildings. The main structural styles of high-rise buildings include frame structure, shear wall structure, frame-shear wall structure, and tube structure. Frame structure weight of small but large displacement, shear wall structure integrity but less space, frame - shear wall structure is the advantage of the two, and frame tube structure has strong ability to resist lateral but considerable weight. The randomness of wind load leads to unstable vibration of high-rise buildings. The weakest link of high-rise buildings under seismic load appears at the beam-column joints. Future high-rise buildings will pay more attention to humanistic significance while considering safety. This paper summarizes the advantages and disadvantages of several primary forms of high-rise buildings at present, and analyzes the influence of wind load and earthquake load on high-rise buildings, which has specific guiding significance for the safety research of high-rise buildings.
15
Wiens, Marcus, Sebastian Frahm, Philipp Thomas, and Shoaib Kahn. "Holistic simulation of wind turbines with fully aero-elastic and electrical model." Forschung im Ingenieurwesen 85, no. 2 (April 30, 2021): 417–24. http://dx.doi.org/10.1007/s10010-021-00479-6.
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AbstractRequirements for the design of wind turbines advance facing the challenges of a high content of renewable energy sources in the public grid. A high percentage of renewable energy weaken the grid and grid faults become more likely, which add additional loads on the wind turbine. Load calculations with aero-elastic models are standard for the design of wind turbines. Components of the electric system are usually roughly modeled in aero-elastic models and therefore the effect of detailed electrical models on the load calculations is unclear. A holistic wind turbine model is obtained, by combining an aero-elastic model and detailed electrical model into one co-simulation. The holistic model, representing a DFIG turbine is compared to a standard aero-elastic model for load calculations. It is shown that a detailed modelling of the electrical components e.g., generator, converter, and grid, have an influence on the results of load calculations. An analysis of low-voltage-ride-trough events during turbulent wind shows massive increase of loads on the drive train and effects the tower loads. Furthermore, the presented holistic model could be used to investigate different control approaches on the wind turbine dynamics and loads. This approach is applicable to the modelling of a holistic wind park to investigate interaction on the electrical level and simultaneously evaluate the loads on the wind turbine.
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Lee, Kyoungsoo, Shrabanti Roy, Ziaul Huque, Raghava Kommalapati, Chao Sui, and Nazia Munir. "Pointed Tip Shape Effect on Aerodynamic Load for NREL Phase VI Wind Turbine Blade." Journal of Clean Energy Technologies 4, no. 4 (2015): 284–89. http://dx.doi.org/10.7763/jocet.2016.v4.298.
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Zhang, Zhuoqun, Jiashu Liu, Kangjie Shao, and Peng Zhang. "Analysis of Wind-Sand-Load-Induced Dynamic Response of Transmission Tower-Line Systems." Shock and Vibration 2022 (August 25, 2022): 1–12. http://dx.doi.org/10.1155/2022/4924091.
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Sandstorms are a common natural phenomenon that has the potential to cause severe disruptions to civil infrastructure. However, the effect of sandstorms on transmission tower structures has not received much attention. This paper proposes the simulation of the wind-sand loads for the analysis of transmission tower structures under sandstorm excitation by superposing the wind loads and sand particle loads. The wind load is generated based on Kaimal fluctuating wind power spectrum and the harmonic superposition method, and the sand load is constructed based on the law of conservation of momentum and sandstorm classification. A transmission tower was modeled and simulated in SAP2000 to explore the dynamic response of the tower towards wind-sand loads. A comparison of wind-induced and wind-sand-induced responses shows that the structural dynamic responses of transmission towers due to the wind-sand effect are pronounced. Particularly, the maximum longitudinal displacements and axial forces increased greatly. The results showed that the sandstorm loads for transmission towers cannot be neglected, and more attention should be paid to the structural design of transmission towers to resist such loads.
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Zhong, Yongli, Shun Li, Weichen Jin, Zhitao Yan, Xinpeng Liu, and Yan Li. "Frequency Domain Analysis of Alongwind Response and Study of Wind Loads for Transmission Tower Subjected to Downbursts." Buildings 12, no. 2 (January 31, 2022): 148. http://dx.doi.org/10.3390/buildings12020148.
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Downburst is one of the high-intensity winds that cause transmission tower failures. The regulations of transmission tower-line systems under downburst wind loads cannot meet the design requirements at present. In this paper, the calculation formulas of the background and resonant components of transmission tower under downburst wind loads are obtained, based on the modal analysis theory of non-stationary wind for the single-degree-of-freedom system in the frequency domain. The effects of structural dynamic characteristics, damping ratio, and mean wind speed vertical profile on dynamic effect on structural response are discussed. Then the equivalent static wind load (ESWL) is obtained according to the maximum response and compared with the finite element method (FEM) in the time domain. Applications of these formulas are addressed to the cases from the empirical model of Holmes and field record of a rear flank downdraft (RFD). The results show that the maximum responses obtained by the current formulas match well with those from the modal decomposition method and dynamic analysis with FEM. The internal forces of tower members calculated by ESWL based on maximum response are closer to the results from FEM than those calculated by downburst loads recommended in ASCE guidelines. The presented framework can be used to assist the wind-resistant design of transmission towers considering downburst wind load.
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Yan, Bowen, Yanan Li, Xiao Li, Xuhong Zhou, Min Wei, Qingshan Yang, and Xu Zhou. "Wind Tunnel Investigation of Twisted Wind Effect on a Typical Super-Tall Building." Buildings 12, no. 12 (December 19, 2022): 2260. http://dx.doi.org/10.3390/buildings12122260.
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This paper investigates the twisted wind effect on a typical super-tall building (500-m-tall square prism) by conducting pressure model wind tunnel tests. Two twisted wind fields (TWFs) with maximum yaw angles of approximately 30° and 20°, respectively, near the ground level were generated in the wind tunnel using a guide vane system, and the test results of wind pressure and wind load in TWFs were compared with those obtained in conventional wind fields (CWFs) with constant wind direction along the vertical axis. In particular, the distribution of extreme cladding pressure as well as the correlation and coherence of local wind loads are discussed in detail. It was observed that the mechanism of the structural dynamic responses, such as the vortex shedding, is greatly affected by TWFs. Both the distributions of mean and extreme cladding pressures in TWFs significantly differ from those in CWFs, especially on the windward and side facades. However, in terms of the amplitudes, the extreme wind pressure and the maximum wind load in TWFs do not noticeably exceed those in CWFs. This study aims to provide useful information for the wind-resistant design of future tall buildings.
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Li, Yan, and Hang Sun. "The Effect Analysis of Wind Load on Vehicle-Bridge Coupled Dynamic Behavior." Advanced Engineering Forum 5 (July 2012): 167–72. http://dx.doi.org/10.4028/www.scientific.net/aef.5.167.
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A computer simulation method of solving vehicle-bridge system vibration response considering wind load is presented based on mode integration theory. Vehicle model and fluctuating wind load model are established, corresponding vehicle stiffness and damping matrix is educed in the method. A practical cable-stayed bridge dynamic analysis is completed successfully by programming with fore mentioned method. Wind load have a great influence on bridge vibration acceleration under low wind velocity. Vehicle vertical dynamic response is influenced evidently by wind induced bridge vibration, its lateral response is controlled by wind load and bridge response. The effect on system dynamic response of wind load is remarkable. For other type large span bridges the method also can be referred and have important application value in interrelated research. The accuracy of calculation is high enough for practical purposes.
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You, Ki Pyo, Young Moon Kim, and Jang Youl You. "Interference Effect Tall Building to Fluctuations Wind Load." Advanced Materials Research 871 (December 2013): 9–14. http://dx.doi.org/10.4028/www.scientific.net/amr.871.9.
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The construction of another tall building in the close vicinity of existing building may lead to a modification in its response. Therefore, the wind loads on buildings in realistic environments may be considerably different from these measured on isolated buildings. Neighboring buildings may either decrease or increase the flow-induced forces on a structure, depending mainly on the geometry and arrangement of these buildings, their orientation with respect to the direction of flow and upstream terrain conditions. In this study deals with mean and fluctuating as well as their spectra on a building due to an adjacent building of side ratio 1 for wind direction from 0 to 45 degree and separation distance between two models. Interference effects were presented in the form of interference factors. And experiments were compared to these measured on isolated building.
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Kazakevitch, M., and A. Zakora. "Cable stabilization for wind and moving load effect." Journal of Wind Engineering and Industrial Aerodynamics 74-76 (April 1998): 995–1003. http://dx.doi.org/10.1016/s0167-6105(98)00091-9.
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Amrutheswara Krishnamurthy and Dr.Suresh Nagesh. "Aerodynamic Effect on Stability and Lift Characteristics of an Elevated Sedan Car." ARAI Journal of Mobility Technology 2, no. 2 (May 13, 2022): 205–13. http://dx.doi.org/10.37285/ajmt.1.2.6.
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There is a strong interaction between air and vehicle components. Aerodynamics plays a significant role in a vehicle's fuel efficiency. The contact patch load between the tire and road is directly related to the vehicle load. In this research, the lift forces generated due to the additional wing attached to the car model with different spans and heights of the wing location from the car body is considered for study. The loads due to change in Angle of Attack (AOA) and their effect on the tire loads are studied. The upward vertical force produced from aerodynamic loads reduces the wheel load of the car virtually. A tire's coefficient of friction would decrease with upward vertical force. This balance load implies that a lightweight car would make more efficient use of its tires than a heavier car. ANSYS Fluent is used for the Computational Fluid Dynamics (CFD) study. The validation of airflow characteristics, lift and drag forces from simulations are done with wind tunnel testing data. Varying the angle of attack, wingspan, height between the car and the wing's lower surface, one can increase the capacity of the payload by 10% or fuel efficiency by 10% to 20%.
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Li, Fang Hui, Ming Gu, Zhen Hua Ni, and Shi Zhao Shen. "Method of the Snow Load for Design of the Low Rise Roof Structures in the Different Country Codes." Applied Mechanics and Materials 204-208 (October 2012): 1220–23. http://dx.doi.org/10.4028/www.scientific.net/amm.204-208.1220.
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Snow load is very important for the design of the large span roof structures in the cold region. The determine of the snow loads are influenced by many factors, such as wind, shape of the roof , terrain categories and so on, therefore comprehensive consideration of the transport and drift by the strong wind for design of the roof is very complex. Compared with other countries load codes, the China load code don’t detailed consider wind and snow interaction effect, the method of snow load for design has some further improved terms.
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Sun, Bingcai, Duanzhu Ma, Lei Gao, Mingchuan He, Zengli Peng, Xin Li, and Wenhua Wang. "Wind Buckling Analysis of a Large-Scale Open-Topped Steel Tank with Harmonic Settlement-Induced Imperfection." Buildings 12, no. 11 (November 14, 2022): 1973. http://dx.doi.org/10.3390/buildings12111973.
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In this study, the wind buckling capacity of an open-topped steel tank with harmonic settlement-induced imperfection is numerically investigated. Although the single effect of the wind load or differential settlement on the open-topped steel tanks is widely studied, the interaction of the two loads to the tank shell is scarcely examined. The prototype of a 100,000 m3 open-topped steel tank with a floating roof is selected, and the harmonic settlements (wave numbers n = 2, 3, and 4) and the wind profile considering internal pressure (EN 1993-4-1) are applied. Firstly, the finite element model is established and validated by the replication of peer-reviewed research. Then, the wind buckling analysis of the tank shell with harmonic settlement-induced imperfection is studied. Next, the effects of the harmonic settlement-induced imperfection (HSII) and the wind attack angle (WAA) on the wind buckling capacity are discussed. The results show that the effect of the HSII on the wind buckling capacity is complex. When the wind attack angle is the case of β=0°, the wind load capacities (λcig) with HSIIs decrease to 73.4% (wave number n=2), 37.5% (wave number n=3) and 41.3% (wave number n=4) of the non-settlement wind load capacity (λcg). Given that the case of β=0° is the basis, when the harmonic settlement level is low, such as settlement load No.1 and No.2, the biggest increase of wind buckling capacity is less than 20% with an exception; when the harmonic settlement level is high, such as settlement load No.3, No.4 and No.5, the biggest increase of wind buckling capacity is more than 40%, with a few exceptions.
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Liu, Simin. "Study on Typical Aerodynamic Faults of Variable Pitch Wind Turbine." Frontiers in Computing and Intelligent Systems 3, no. 1 (March 17, 2023): 16–20. http://dx.doi.org/10.54097/fcis.v3i1.6017.
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The variable-speed variable-pitch wind turbine is an important part of China's power and energy systems, and is also the main conversion form of wind energy utilization. Aiming at the problem that the traditional blade element-momentum theory cannot achieve the modeling and simulation of wind turbine plane wind unbalance caused by wind shear and tower shadow effect, the modeling and simulation numerical calculation method of aerodynamic load of wind turbine actuation disk with different blade wind unbalance pitch angles is proposed, This method can derive the analytical expressions for solving the key variables of load calculation, axial induction factor and tangential induction factor, and realize the aerodynamic load solution. At the same time, it is also verified that the characteristic vibration component of 3 times the low speed shaft rotation frequency (3P) is a typical dynamic load feature of tower shadow effect, and is also the most important aerodynamic load fluctuation feature of variable-speed variable-pitch wind turbine, However, under normal conditions, the wind shear effect has little effect on the wind turbine load fluctuation.
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Chen, Chang Zheng, Ping Ping Pan, Shi Wei Zhang, and Meng Qiang. "Dynamic Analysis and Evaluation of Wind Turbine Towers." Applied Mechanics and Materials 193-194 (August 2012): 639–42. http://dx.doi.org/10.4028/www.scientific.net/amm.193-194.639.
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This paper presents static and dynamic analysis of wind turbine towers which is supporting a 1.5MW wind turbine based on the theory of FEM. In static analysis, the modal frequencies of the towers are analyzed without wind load. In dynamic analysis, by the fluid-coupling theory, the dynamic effect of wind loads on the towers is calculated. It can be concluded that the main errors under the different load situations is caused by the impact of fluid structure coupling.
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Yeh, Po-Hung, Shao-Hua Chung, and Bang-Fuh Chen. "Multiple TLDs on Motion Reduction Control of the Offshore Wind Turbines." Journal of Marine Science and Engineering 8, no. 6 (June 24, 2020): 470. http://dx.doi.org/10.3390/jmse8060470.
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This study explores the damping effects of tuned liquid dampers (TLDs) on a monopile offshore wind turbine (OWT). The fluid–solid coupling of ANSYS was used to simulate the damping effect of a TLD on the structures. The environmental conditions refer to the IEC-61400-3 and the Design Load Case (DLC) 1.2 for the annual average environmental conditions and DLC 6.2 for the 50-year regression period, and the extreme environmental conditions were used in the study. The turbulent wind field simulation was performed by TurbSim, and the load of wind waves on structures was generated by FAST, which were all developed by the NREL (National Renewable Energy Laboratory). In addition to wind and waves, the seismic force was also considered. The cylindrical TLD was located above the rotor nacelle assembly (RNA). A TLD has different damping effects when acting under wind, wave, and earthquake loads, respectively. The effect of the TLD regarding motion reduction on the OWT under coupled wind, wave, and seismic loads was studied. This study also designed a simple experiment to verify the correctness of the numerical simulation results. Fatigue analysis shows that multi-layer TLDs can extend the fatigue life (37%) of an OWT. In addition, under extreme environmental load conditions, multi-layer TLDs have a better vibration damping performance than single-layer TLDs. The study demonstrates that multi-layer TLDs can be considered as a vibration reduction damper for OWTs.
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Lee, Sang, Matthew Churchfield, Frederick Driscoll, Senu Sirnivas, Jason Jonkman, Patrick Moriarty, Bjόrn Skaare, Finn Nielsen, and Erik Byklum. "Load Estimation of Offshore Wind Turbines." Energies 11, no. 7 (July 20, 2018): 1895. http://dx.doi.org/10.3390/en11071895.
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The influence of 3 MW Hywind-II wind turbine wakes from an upstream offshore floating wind turbine on a downstream turbine with a separation distance of seven rotor diameters was studied for a site in the Gulf of Maine. The turbines and the platforms were subjected to atmospheric boundary layer flows. Various sensitivity studies on fatigue loads with respect to the positions of the downstream turbine were performed and validated with a large-eddy simulation tool. In particular, the effect of various lateral positions of the downstream turbine relative to the upstream turbine were considered using time-series turbine wake data generated from the large-eddy simulation tool which served as an input to an aero-elastic wind turbine model to assess the loads. The load response from the rotor, tower, and the floating platform for the downstream turbine were sensitive to the lateral offset positions where turbines that were partially exposed to upstream turbine wakes yielded significant increases in the cyclic load range. For the given set of lateral positions for the downstream turbine, the largest damage equivalent load occurred when the turbine was one rotor diameter to the left of the centerline, when looking upstream, which is the position of the turbine fully exposed to upstream turbine wake. On the other hand, the fatigue load on the downstream turbine placed on the right side of the position fully exposed to the upstream turbine wake, yielded lower stress due to the non-symmetric shape of the turbine wake. The configuration associated with the largest damage equivalent loads was further investigated in a large-eddy simulation, modeling both the upstream and downstream turbines. It was found that the energy spectra at the blade rotational frequency were a magnitude order higher for the downstream turbine, especially for surge, heave, pitch, and yaw motion of the platform. The increase of the damage equivalent load for the flapwise blade root moment was 45% compared to the upstream turbine, which can potentially reduce the turbine service life time.
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Zhou, Meng Long, Bin Lin, Xu Zhang, Xiao Feng Zhang, and Peng Fei Liu. "Analysis of Wind Load Effect on Ship Loader in Shipping Process." Materials Science Forum 770 (October 2013): 155–58. http://dx.doi.org/10.4028/www.scientific.net/msf.770.155.
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Research about sea wind load effect on ship loader is completed in this paper. Entity modeling method and solid element is used in the process of finite element modeling. Sea wind is divided into the steady wind and the turbulent wind. The steady wind is disposed as the constant speed wind which can be converted to wind pressure. After the static load solution, modal analysis is conducted which is essential for the following dynamic analysis. Because turbulent wind has random amplitude, direction and frequency, random vibration analysis method is used in the dynamic analysis process. With the results from the three representative positions, it is concluded that the displacement size and dynamic response intensity is in direct proportion to the height of the position.
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Iqbal, Bashar. "Comparative Analysis of RC Building Using Dampers and with Shear Wall under Wind Load: A Review." International Journal for Research in Applied Science and Engineering Technology 9, no. 10 (October 31, 2021): 490–95. http://dx.doi.org/10.22214/ijraset.2021.38442.
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Abstract: The requirement of tall building in recent years increase the construction to satisfy the need of human beings. Very tall buildings located in high velocity wind area are highly sensitive therefore calculation and analysis of wind load is very impotent. Due to change in climatic condition the basic wind speed are increases. The main aim of this paper is to introducing the different techniques which is used to reduce the effect of wind load or lateral loads. Keywords: wind analysis, comparative analysis, TMD (tuned mass damper),friction damper, shear wall
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Yuan, Chenyang, Jing Li, Yunfei Xie, Weifeng Bai, and Jianyou Wang. "Investigation on the Effect of the Baseline Control System on Dynamic and Fatigue Characteristics of Modern Wind Turbines." Applied Sciences 12, no. 6 (March 14, 2022): 2968. http://dx.doi.org/10.3390/app12062968.
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In order to investigate the effect of a baseline control system (BCS) on dynamic and fatigue characteristics of modern wind turbines, the simulation results of a 5-MW wind turbine subjected to wind loading without and with considering BCS (No. 1 and No. 2, respectively) were compared. The displacement and moment of tower and blades were compared, and the rainflow counting algorithm was used to analyze the fatigue load expressed in damage equivalent load (DEL). The results indicate that the mean and maximum values of structural dynamic responses in No. 2 have a great reduction with wind speed exceeding the rated speed comparing to No. 1; the 3P (3-times the frequency of rotor speed) of the wind turbine rotor speed will be close to the tower fore-aft (FA) natural frequency with the wind velocity around the cut-in speed in No. 2, which caused larger dynamic responses, number of load cycles, and DELs for the tower compared with No. 1; when wind velocity exceeds the rated wind speed, the BCS caused higher fluctuation of loads, increasing the related DELs. It is concluded that when analyzing the dynamic responses and designing wind turbine tower and blades, taking the BCS into account during analysis is significant.
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Gul, Rizwan Mehmood, Fahad Ullah Zafar, Muhammad Ali Kamran, and Muhammad Noman. "Effect of Wind Load on Performance of Photovoltaic (PV) Modules Available in Pakistan." Mehran University Research Journal of Engineering and Technology 40, no. 4 (October 1, 2021): 860–66. http://dx.doi.org/10.22581/muet1982.2104.15.
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Mechanical integrity of a Photovoltaic (PV) module plays a major role in its performance and electrical output. Mechanical loads which include loads produced by wind, snow, rain, and hail tend to degrade the performance of PV module by generating stresses and enhancing micro-cracks and defects. This research aims to investigate the impact of wind loads on the performance of PV modules, particularly the degradation in its power output. A load of 2400 Pa was applied as per international standards (ASTM E1830-15 and IEC-61215). A total of four PV module samples, of the same specifications with 60 W rated power, were initially subjected to solar flash testing and Electroluminescence (EL) imaging. This was followed by three cycles of mechanical load test. After the mechanical load tests, the modules were again subjected to solar flash testing and EL imaging and the results were compared. It was noted that static wind load degrades the mechanical integrity of photovoltaic modules in two ways; by aiding the propagation of existing cracks and initiating new cracks. This loss of mechanical integrity degraded the power output of PV module. Maximum drop of 2% in the power output and 0.27% in the efficiency was observed. In addition, the average increase of 3.37% in the series resistance was observed indicating decrease in performance.
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Li, Wei, Hong Li Sun, Zuo Xia Xing, and Lei Chen. "The Study of Individual Pitch Control on Reducing The Load Fluctuation of Tower Shadow." Advanced Materials Research 347-353 (October 2011): 2260–67. http://dx.doi.org/10.4028/www.scientific.net/amr.347-353.2260.
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Load fluctuation of wind turbine under tower shadow was researched，introducing individual pitch control. First，establish the linear time-varying model of the rotor，make it into the linear time invariant model through Coleman transformation. Then，based on this model，achieving the design of individual pitch system with PID controller. Comparing the loads of wind turbine under tower shadow between individual pitch control and collective pitch control and analysing the fatigue damage of wind turbine through rainflow cycle counting.The result shows that load fluctuation of wind turbine using the individual pitch control under tower shadow has better effect and reduces the effect of tower shadow，extend the working life of wind turbine.
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Wang, Cheng Qi, Zheng Liang Li, Zhi Tao Yan, and Qi Ke Wei. "Wind Load on Complex-Shape Building." Advanced Materials Research 163-167 (December 2010): 4389–94. http://dx.doi.org/10.4028/www.scientific.net/amr.163-167.4389.
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Wind load on complex-shape building, the wind tunnel test and numerical simulation were carried out. The two technologies supplement each other and their results meet well. There are mainly positive pressures on the windward surface, negative pressures on the roof, the leeward surface and the side. Especially, negative pressure is higher in the leeward region of the building corner. Its effect induced by the shape of the complex-shape building is remarkable.
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López-Ibarra, Adrián, Adrián Pozos-Estrada, and Rigoberto Nava-González. "Effect of Partially Correlated Wind Loading on the Response of Two-Way Asymmetric Systems: The Impact of Torsional Sensitivity and Nonlinear Effects." Applied Sciences 13, no. 11 (May 24, 2023): 6421. http://dx.doi.org/10.3390/app13116421.
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Load eccentricities in structural systems are associated with an increase in the torsional response. Typically, these eccentricities are defined based on the distance between the center of mass and the center of stiffness at a predefined story. If the structural system is subjected to dynamic loading, such as wind loading, instantaneous load eccentricities due to the displacement of the center of mass may occur. An evaluation of this nonlinear effect for two-way asymmetric systems under wind loading is presented in this study. To model the structural systems and the instantaneous load eccentricities, coupled nonlinear differential equations are assembled and solved by using the state space model. The structural systems proposed are subjected to time histories of turbulent wind forces, which are simulated based on a newly developed methodology that includes the correlation of wind forces. The impact of the instantaneous load eccentricities and correlation of wind forces and torsional moment on the wind-induced response of the structural systems analyzed is discussed in detail.
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Galinos, Christos, Jonas Kazda, Wai Hou Lio, and Gregor Giebel. "T2FL: An Efficient Model for Wind Turbine Fatigue Damage Prediction for the Two-Turbine Case." Energies 13, no. 6 (March 11, 2020): 1306. http://dx.doi.org/10.3390/en13061306.
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Wind farm load assessment is typically conducted using Computational Fluid Dynamics (CFD) or aeroelastic simulations, which need a lot of computer power. A number of applications, for example wind farm layout optimisation, turbine lifetime estimation and wind farm control, requires a simplified but sufficiently detailed model for computing the turbine fatigue load. In addition, the effect of turbine curtailment is particularly important in the calculation of the turbine loads. Therefore, this paper develops a fast and computationally efficient method for wind turbine load assessment in a wind farm, including the wake effects. In particular, the turbine fatigue loads are computed using a surrogate model that is based on the turbine operating condition, for example, power set-point and turbine location, and the ambient wind inflow information. The Turbine to Farm Loads (T2FL) surrogate model is constructed based on a set of high fidelity aeroelastic simulations, including the Dynamic Wake Meandering model and an artificial neural network that uses the Bayesian Regularisation (BR) and Levenberg–Marquardt (LM) algorithms. An ensemble model is used that outperforms model predictions of the BR and LM algorithms independently. Furthermore, a case study of a two turbine wind farm is demonstrated, where the turbine power set-point and fatigue loads can be optimised based on the proposed surrogate model. The results show that the downstream turbine producing more power than the upstream turbine is favourable for minimising the load. In addition, simulation results further demonstrate that the accumulated fatigue damage of turbines can be effectively distributed amongst the turbines in a wind farm using the power curtailment and the proposed surrogate model.
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Clemente, Hiphil S., and Thomas E. Marler. "245 Growth of Papaya Seedlings under Wind Load and Drought Stress." HortScience 34, no. 3 (June 1999): 484D—484. http://dx.doi.org/10.21273/hortsci.34.3.484d.
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Two studies were conducted with `Known You 1' and `Sunrise' papaya seedlings to determine the combined influence of wind and drought stress on growth. For each study, 4-week-old nursery plants were transplanted into 2.6-L containers and placed in a protected site with rain exclusion provided by polypropylene cover. Industrial fans were used to provide unidirectional wind of ≈2 m/s for 12 hours per day to half of the plants; the remaining half of the plants received no wind. One half of the plants for each cultivar and wind combination were designated as well-watered and received daily irrigation. The remaining half of the plants were designated as drought-stressed and received 25% to 50% of the water applied to the well-watered plants. Plants were grown for 3 weeks under these experimental conditions. There were no interactions between the drought and wind main effects. The reduction in height, trunk cross-sectional area, total plant dry weight, and relative growth rate below that for control plants was similar for drought stress or wind stress. Wind stress reduced growth of `Sunrise' plants more than `Known You 1' plants in both studies. Although the main effects did not interact, the combination of drought and wind stress reduced growth of papaya seedlings more than did either main effect alone. The greatest wind load from trade winds occurs on Guam during the annual dry season. These data indicate that chronic wind stress during the dry season may be more detrimental to growth of papaya seedlings than during the rainy season or under sufficient irrigation practices.
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ZHOU, XUANYI, and MING GU. "AN APPROXIMATION METHOD FOR COMPUTING THE DYNAMIC RESPONSES AND EQUIVALENT STATIC WIND LOADS OF LARGE-SPAN ROOF STRUCTURES." International Journal of Structural Stability and Dynamics 10, no. 05 (December 2010): 1141–65. http://dx.doi.org/10.1142/s0219455410003944.
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Due to their sensitivity to wind, the design of large-span roofs is generally governed by wind loads. For some flexible large-span roofs with low damping and concentrated modes, the effect of multi-mode coupling should be taken into account in computing the resonant buffeting response and equivalent static wind loads. Such an effect is considered by the modified SRSS method in this paper via the modal coupling factor. Based on the same SRSS method, the equivalent static wind loads combining the mean, background, and resonant components, are computed. Particularly, the background and resonant components are computed by the LRC method and the equivalent inertia force method considering the modal coupling effects by the modified SRSS method, respectively. The method is then applied to the computation of wind-induced vibration responses and equivalent static wind load distributions of a real large-span roof. The results show that the modal coupling effect on the resonant component can be identified by the present method with high accuracy.
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Tan, Zhengbo, Hao Chen, Fu Wan, Feilong Liao, Yuan Gao, and Can Cai. "Influence of Complex Load on the Strength and Reliability of Offshore Derrick by Using APDL and Python." Applied Sciences 12, no. 22 (November 17, 2022): 11693. http://dx.doi.org/10.3390/app122211693.
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In an offshore operational environment, complex loads such as the hook load, stand load and wind load play a crucial role in the structural strength and reliability of the offshore derrick. Previous studies have mainly focused on the effect of a specific load on the strength of the derrick by using commercial software. Therefore, the influencing mechanism of each complex load on the strength and reliability of the offshore derrick is urgently necessary to explore. Not only is the strength numerical model of the JJ315/45-K typical derrick established and conducted via APDL (ANSYS Parametric Design Language), but also the stress–strength reliability simulation is explored and plotted using Python code and APDL. Furthermore, the influence and contribution of each load to the strength and reliability is determined. With the increase in hook load, the positions of maximum reliability risk appear in section II-1. With the increase in stand load or back wind load, the positions of maximum reliability risk appear in the bottom section. In addition, with the decrease in the columns’ height, the stress proportion of the hook load decreases by 73.5%, the stress proportion of the stand load increases by 22.6%, and the stress proportion of the back wind load changes slightly. When the wind speed is less than 20 m/s, the hook load mainly affects the minimum reliability index of the derrick. Moreover, when the wind speed is more than 20 m/s, the back wind load mainly affects the minimum reliability index of the derrick. This study provides a thorough explanation of the strength distribution law and the reliability of derricks under complex loads.
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Li, Yi Long, Da Hai You, Ke Wang, Ke Tian, and Kai Pan. "Peak-Load Regulating Adequacy Evaluation in Wind Power Accessed System Considering the Correlation of Wind Farms." Advanced Materials Research 724-725 (August 2013): 522–26. http://dx.doi.org/10.4028/www.scientific.net/amr.724-725.522.
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There is a certain degree of correlation between the outputs of different wind farms because of their geographic distribution in power grid. And the complementary effect can alleviate the adverse effects of peak-load regulation caused by the large-scale wind power integration. In this paper, Nataf transformation was used to establish wind speed samples of correlative wind farms to get correlative wind power. Based on this, the peak-load regulating adequacy was evaluated using Monte-Carlo method on IEEE-RTS system with wind farms. The result presents the quantitative analysis of the impact of correlative wind farms on peak-load regulating adequacy. And it improves the original peak-load regulating adequacy evaluation based on Monte-Carlo method, which has the relatively conservative results.
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Jingyang, Zheng, Ji Jinchen, Yin Shan, and Tong Van Canh. "The Load Distribution of the Main Shaft Bearing Considering Combined Load and Misalignment in a Floating Direct-Drive Wind Turbine." E3S Web of Conferences 64 (2018): 07009. http://dx.doi.org/10.1051/e3sconf/20186407009.
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The main shaft tapered double-inner ring bearing (TDIRB) of floating direct-drive wind turbine system (FDDWT) is one of the most critical components in FDDWT, and its failure accounts for a large proportion of wind turbine malfunctions and faults. Over the past decades, a significant number of methods have been proposed to calculate the contact load distribution along the roller length in TDIRB, since the contact load distribution of roller is the key factor of fatigue life of TDIRB. Most of methods, however, neglected the misalignment of inner ring with respect to outer ring and friction force. In this paper, with the help of comprehensive and accurate quasi-static mathematical method, the contact load distribution of internal loads in TDIRB are analysed by considering the effects of combined loads, angular misalignment and friction force at different wind speeds for FDDWT. The simulation results show that the amount of combined load has an apparent effect on the contact load distribution along the TDIRB raceways and flanges in both rows. Furthermore, the slight change of tilted misalignment has a great influence on the contact load distribution. In addition, the slight angular misalignment easily produces noncontact zone for the bearing raceway in both rows, which is significantly disadvantage for the external load uniform transmitting to each roller.
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Berger, Frederik, Lars Neuhaus, David Onnen, Michael Hölling, Gerard Schepers, and Martin Kühn. "Experimental analysis of the dynamic inflow effect due to coherent gusts." Wind Energy Science 7, no. 5 (September 8, 2022): 1827–46. http://dx.doi.org/10.5194/wes-7-1827-2022.
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Abstract. The dynamic inflow effect describes the unsteady aerodynamic response to fast changes in rotor loading due to the inertia of the wake. Fast changes in turbine loading due to pitch actuation or rotor speed transients lead to load overshoots. The phenomenon is suspected to be also relevant for gust situations; however, this was never shown, and thus the actual load response is also unknown. The paper's objectives are to prove and explain the dynamic inflow effect due to gusts, and compare and subsequently improve a typical dynamic inflow engineering model to the measurements. An active grid is used to impress a 1.8 m diameter model turbine with rotor uniform gusts of the wind tunnel flow. The influence attributed to the dynamic inflow effect is isolated from the comparison of two experimental cases. Firstly, dynamic measurements of loads and radially resolved axial velocities in the rotor plane during a gust situation are performed. Secondly, corresponding quantities are linearly interpolated for the gust wind speed from lookup tables with steady operational points. Furthermore, simulations with a typical blade element momentum code and a higher-fidelity free-vortex wake model are performed. Both the experiment and higher-fidelity model show a dynamic inflow effect due to gusts in the loads and axial velocities. An amplification of induced velocities causes reduced load amplitudes. Consequently, fatigue loading would be lower. This amplification originates from wake inertia. It is influenced by the coherent gust pushed through the rotor like a turbulent box. The wake is superimposed on that coherent gust box, and thus the inertia of the wake and consequently also the flow in the rotor plane is affected. Contemporary dynamic inflow models inherently assume a constant wind velocity. They filter the induced velocity and thus cannot predict the observed amplification of the induced velocity. The commonly used Øye engineering model predicts increased gust load amplitudes and thus higher fatigue loads. With an extra filter term on the quasi-steady wind velocity, the qualitative behaviour observed experimentally and numerically can be caught. In conclusion, these new experimental findings on dynamic inflow due to gusts and improvements to the Øye model enable improvements in wind turbine design by less conservative fatigue loads.
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Wang, Zhenyu, Yan Zhao, Fuqiang Li, and Jianqun Jiang. "Extreme Dynamic Responses of MW-Level Wind Turbine Tower in the Strong Typhoon Considering Wind-Rain Loads." Mathematical Problems in Engineering 2013 (2013): 1–13. http://dx.doi.org/10.1155/2013/512530.
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The damage and collapse accidents of wind turbines during violent typhoons and rainstorms have increased in recent years. To determine the dynamic response characteristics of high-power wind turbines under extreme conditions, wind load and rain load are simulated. The typhoon average wind velocity and fluctuating wind velocity are simulated by the unstable wind profile and harmony superposition method. The raindrop size distribution is simulated by the M-P spectrum, and the rain load is calculated according to the momentum theorem. A finite element model is established to study the aerodynamic responses of a wind turbine under random typhoon load and typhoon-rain loads. The maximum displacements and accelerations at the tower top and the maximum von Mises stresses at the tower bottom are calculated and compared after considering various combinations of wind direction deflections and rainfall intensities. The results indicate that instantaneous wind direction deflection has a substantial impact on the dynamic responses of wind turbines, and after introducing the effect of rain, the dynamic responses increase up to 13.7% with increasing rainfall intensities. This study has significant implications for analysing collapse accidents of wind turbines and for optimising the design of wind turbines under extreme typhoon conditions.
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Cai, Xin, Yazhou Wang, Bofeng Xu, and Junheng Feng. "Performance and Effect of Load Mitigation of a Trailing-Edge Flap in a Large-Scale Offshore Wind Turbine." Journal of Marine Science and Engineering 8, no. 2 (January 23, 2020): 72. http://dx.doi.org/10.3390/jmse8020072.
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As a result of the large-scale trend of offshore wind turbines, wind shear and turbulent wind conditions cause significant fluctuations of the wind turbine’s torque and thrust, which significantly affect the service life of the wind turbine gearbox and the power output stability. The use of a trailing-edge flap is proposed as a supplement to the pitch control to mitigate the load fluctuations of large-scale offshore wind turbines. A wind turbine rotor model with a trailing-edge flap is established by using the free vortex wake (FVW) model. The effects of the deflection angle of the trailing-edge flap on the load distribution of the blades and wake flow field of the offshore wind turbine are analyzed. The wind turbine load response under the control of the trailing-edge flap is obtained by simulating shear wind and turbulent wind conditions. The results show that a better control effect can be achieved in the high wind speed condition because the average angle of attack of the blade profile is small. The trailing-edge flap significantly changes the load distribution of the blade and the wake field and mitigates the low-frequency torque and thrust fluctuations of the turbine rotor under the action of wind shear and turbulent wind.
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Fu, Xing, and Hong-Nan Li. "Effect of Raindrop Size Distribution on Rain Load and Its Mechanism in Analysis of Transmission Towers." International Journal of Structural Stability and Dynamics 18, no. 09 (September 2018): 1850115. http://dx.doi.org/10.1142/s0219455418501158.
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Rain load acting on a transmission tower is large enough to receive attention according to previous studies and, therefore, a parametric analysis is necessary to understand its mechanism. In this paper, the effects of different raindrop size distributions on both rain pressure and tower response are studied. First, a theoretical method is proposed to estimate the shape parameters of the gamma raindrop size distribution based on the conservation of rain intensity. The influence of raindrop spectrum on rain pressure in free wind field is then investigated. The results reveal that raindrop spectrum has great effect on the rain pressure distribution and its time interval has a large impact on the total rain pressure. In addition, the time interval has greater influence than the spectrum when the rain intensity is constant. At last, six different raindrop spectra are employed to simulate the tower response induced by wind and rain loads, of which the results indicate that the raindrop spectrum has a significant effect on the tower response. The maximum increasing percentage of rain load relative to wind load can reach up to 13.7%, indicating that the influence of rain load is quite remarkable and should be considered in analyzing the response of transmission towers.
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Gloe, Arne, Clemens Jauch, Bogdan Craciun, Arvid Zanter, and Jörg Winkelmann. "Influence of Continuous Provision of Synthetic Inertia on the Mechanical Loads of a Wind Turbine." Energies 14, no. 16 (August 22, 2021): 5185. http://dx.doi.org/10.3390/en14165185.
Full textAbstract:
In many electrical grids, the share of renewable energy generation increases. As these generators are typically connected to the grid via inverters, the level of grid inertia decreases. Such grids may therefore suffer from high rates of change of frequency during power imbalances. Modern wind turbines can help in controlling the frequency in such grids by providing synthetic inertia. A controller to provide synthetic inertia with wind turbines was developed at the Wind Energy Technology Institute in collaboration with Suzlon Energy. For this controller the influence of providing synthetic inertia on the mechanical loads of the wind turbine is assessed for different grid frequency scenarios. Such a scenario-based load analysis has not been published before, especially as the scenarios are derived from real measurements. The effect of the loads strongly depends on the analyzed grid frequency behavior. Ten months of high quality grid frequency measurements of the Indian grid are analyzed in order to derive inputs for the load calculation. Different types of grid frequency abnormities are identified and categorized with respect to their severity. Based on the observed occurrences of the grid frequency abnormities, realistic scenarios for the load calculations are chosen. The load calculations are performed for a state-of-the-art Suzlon wind turbine generator. The load increases caused by the supply of synthetic inertia are calculated for individual components assuming an otherwise undisturbed power production of the wind turbine in turbulent wind. Furthermore, a hardware-in-the-loop test bench is used to show how the measured grid frequencies are actually perceived by the control system of a typical wind turbine. The original frequency data were recorded with high quality measurement equipment, which is faster and more accurate than a multi-function relay, often used in wind turbines. For exemplary time traces, the effect of the reduced measurement accuracy on the reaction of the wind turbine is shown. This aspect has not been investigated in the literature yet. The results show that wind turbines can provide synthetic inertia without a considerable effect on the lifetime of the wind turbine. However, there are still problems with providing synthetic inertia reliably at high power operating points, which have to be solved.
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Al-Zaidee, Salah Rohaima, and Alfadhel Basil Kasim. "Wind Interference Effect for Overall Design Load on Mid-Rise Building." Journal of Engineering 24, no. 5 (May 1, 2018): 98. http://dx.doi.org/10.31026/j.eng.2018.05.07.
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The constructed building in the urban area is subject to wind characteristics due to the influence of surrounding buildings. The residential complexes currently being built in Iraq represent a case study for the subject of this research. Therefore, the objective of this study is to identify the interference effect because of adjacent buildings effects on the mid-rise building. The speed and pressure of the wind have been numerically simulated as well as wind load has been simulated by using a virtual wind tunnel which is available in Autodesk Robot Structural Analysis, RSA, software. Two identical adjacent buildings have been simulated and many coefficients were included in this study such as the spacing, directionality, and elevation of adjacent building coefficients. The results of the study showed that the neighboring building could increase or decrease the wind pressure significantly so that it cannot be neglected.
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Shankar, H. Sanni, and Gurunathappa Sheelvantar Prabhu. "Effect of corner modifications on wind-induced responses of tall buildings." i-manager's Journal on Structural Engineering 10, no. 4 (2022): 44. http://dx.doi.org/10.26634/jste.10.4.18408.
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Any tall building subjected to high-speed winds will tilt and crack unless precautionary measures are taken. Various active and passive control methods are proposed to control the wind induced responses of the tall buildings. These tall structures can be made aerodynamic by modifying the external geometry of the building. In the present study, minor geometrical modifications are rendered to the structures. G+30 storeys are considered for each model with constant plan layout. The location of the building is considered to be Bengaluru and corresponding wind load data is considered. Modeling and analysis is carried out using ETABS 2017 software. Wind load analysis is carried out to know the effect of these aerodynamic modifications. The parameters considered for the comparison are storey displacement, natural time period and overturning moment. On comparative analysis, it was observed that wind-induced responses of these geometrically modified buildings have reduced by 5% to 10%. It can also be concluded that minor modifications have shown significantly better performance than a conventional square-plan building in addition to an innovative architectural look.
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Zhou, Shui Xing, Jun Xu, Yin Bin Li, and Qian Zhou. "Elasto-Plastic Stability Analysis of a Twin Continuous Rigid Frame Bridge with 195m High Single Pier." Advanced Materials Research 255-260 (May 2011): 1056–60. http://dx.doi.org/10.4028/www.scientific.net/amr.255-260.1056.
Full textAbstract:
Aiming at 195m high single pier of Hezhang Bridge, elasto-plastic stability analysis on static wind loads and temperature gradients at the longest cantilevered stage for single pier has been performed by ANSYS software. To overcome the problem on buckling of main girder ahead of piers, a loading way with concentrated force instead of uniform load was presented. A general expression of beam element-based temperature distribution along pier was given. Stability analysis under three different actions of wind load at the longest cantilevered stage was conducted according to Chinese Wind-resistent Design Specification for Highway Bridges. The results show that whatever static wind load or thermal gradient effect is, the inelastic stability factors against buckling are all over 3.0 and satisfy the engineering requirement.