簡易檢索 / 詳目顯示

回結果列表
研究生： 余國楨
Yu, Guo-Jhen
論文名稱： 離岸風機支撐結構柔性接頭數值模擬之研究
Research on Numerical Simulation of Joint Flexibility for Offshore Wind Turbine Support Structures
指導教授： 朱聖浩
Ju, Shen-Haw
學位類別： 碩士
Master
系所名稱： 工學院 - 土木工程學系
Department of Civil Engineering
論文出版年： 2025
畢業學年度： 113
語文別： 英文
論文頁數： 193
中文關鍵詞： 等效元素法 、局部接頭柔性 、沉箱式離岸風機 、疲勞分析 、最佳化設計 、有限元素分析
外文關鍵詞： Equivalent Element Method, Local Joint Flexibility, Suction Bucket Offshore Wind Turbine, Fatigue Analysis, Optimization Design, Finite Element Analysis
相關次數： 點閱：4  下載：0 
分享至:
查詢本校圖書館目錄 查詢臺灣博碩士論文知識加值系統 勘誤回報

    • 永續能源已經是全球討論以及發展的主要議題，台灣也極力發展永續能源，台灣位處的地帶具備良好的風場，適合發展離岸風機進行風力發電，離岸風機的研究成為重要的議題，下部結構對離岸風機至關重要，下部結構的接頭處因為受到風力、波浪力、颱風、地震等影響而產生破壞，因此需要進一步探討接頭處行為。根據規範DNV-OS-J101內容，接頭處參考接頭局部柔性(LJF)為重要的一環，透過接頭局部柔性可在主梁與支撐連接處加入等效元素模擬接頭處，更能準確捕捉接頭處變形，等效元素所使用的等效截面積與慣性矩可透過公式計算，本研究使用有限元素程式探討等效元素經由局部接頭柔性轉換對接頭處的影響並進行驗證以及透過三種模擬接頭處方法的比較，探討局部接頭柔性對整體離岸風機的影響，第一個方法使用傳統剛性連接模擬接頭處，第二個方法接頭處採用一般梁元素，主梁與支撐以軸心對軸心的原始截面積，第三個方法為等效元素法，使用局部接頭柔性模擬接頭處，三種方法皆計算至主梁表面連接處，程式中風機模型採用15MW的負壓式沉箱(suction pile)離岸風機，於70公尺水深進行極限荷載的最佳化設計及疲勞壽命分析，極限以及疲勞所使用的所有荷載組合採用國際規範IEC-61400-3-1。極限荷載的結果顯示，最佳化設計後三種方法的總用鋼量接近，等效元素法並不會造成成本提升，而疲勞荷載的結果顯示，傳統剛接較無法精準模擬接頭受力而導致設計過於保守，容易使施工過於困難，一般梁元素只考慮梁元素變形同樣無法準確模擬接頭處，局部接頭柔性能反映實際接頭提升離岸風機疲勞壽命，在設計離岸風機參考局部接頭柔性非常重要，對於整體離岸風機可達更佳的經濟性。
    本研究所使用的分析方法及設計程式由朱聖浩教授研究團隊共同開發，程式及研究成果皆為公開資源。

    Sustainable energy is a global priority, and Taiwan, with favorable wind conditions, is actively developing offshore wind power. The substructure of offshore wind turbines is critical, especially at joints prone to damage from wind, waves, typhoons, and earthquakes. According to DNV-OS-J101, local joint flexibility (LJF) is essential for accurately modeling joint behavior. By incorporating LJF, equivalent elements can better capture deformation between the chord and brace, using formulas to calculate equivalent cross-sectional properties. This study uses a finite element program to investigate the effects of LJF and compares three joint modeling methods: rigid connection, normal beam element with original section properties, and an equivalent element method incorporating LJF. All models are defined up to the chord surface. A 15 MW suction pile offshore wind turbine at a water depth of 70 meters is analyzed under both ultimate and fatigue loads, following IEC 61400-3-1. Results show that total steel usage after optimization is similar across all methods, indicating that the LJF-based approach does not increase cost. In fatigue analysis, the rigid connection model is overly conservative and may lead to impractical construction. The normal beam method lacks the ability to accurately simulate joint flexibility. The LJF-based method, however, provides a more realistic representation of joint behavior and significantly improves fatigue life. Therefore, incorporating LJF in offshore wind turbine design enhances structural accuracy and economic performance.
    The analysis methods and design tools used in this study were jointly developed by the research team led by Professor Shen-Haw Ju. All programs and research outcomes are publicly available.

    摘要 I Abstract II Acknowledgment III Contents IV List of Tables VII List of Figures XV Chapter 1 Introduction 1 1.1 Background and Purpose 1 1.2 Literature Review 2 1.2.1 Research on the planar joints 2 1.2.2 Research on the multi-planar joints 6 1.2.3 Equivalent element approach 8 1.2.4 Study on offshore wind turbine’s fatigue 9 1.3 Overview 11 Chapter 2 Theoretical Background of the Local Joint Flexibilities 12 2.1 Introduction of the Local Joint Flexibilities 12 2.2 Calculation of Local Joint Flexibility 13 2.3 The parametric expressions for non-dimensional local joint flexibilities 14 2.4 Classification of joint types 17 2.5 Equivalent Element Method 23 Chapter 3 Finite element procedures with the flexible joint effect 25 3.1 Introduce the program 25 3.1.1 The program AB.exe 26 3.1.2 The program AD.exe 26 3.1.3 The program AN.exe 29 3.2 Beam element 30 3.2.1 Beam element introduction 30 3.2.2 End restraint. 34 3.3 Developing the flexible joint function into the AN program 35 Chapter 4 Comparisons of the flexible joint calculation between finite element and theoretical methods 37 4.1 Comparison of equivalent cross-sectional area and moment of inertia between various literature methods 38 4.2 Comparison of flexible joint results between FE and Buitrago’s methods for a single K-type frame 41 4.3 The following presents an example of a gapped K joints 50 4.3.1 Single-planar joint 50 4.3.2 Multi-planar joint 65 4.4 Summary 79 Chapter 5 Comparisons and error study 80 5.1 Jacket structure case analysis. 80 5.2 Summary 99 Chapter 6 Ultimate analysis and steel design of OWT jacket structures with different models of joints 100 6.1 Introduce the programs 100 6.2 Model Description 102 6.3 Design Load Cases 107 6.3.1 Typhoon 107 6.3.2 Seismic loads 109 6.4 Methodology 122 6.5 Results 123 6.6 Summary 128 Chapter 7 Fatigue analysis and steel design of OWT jacket structures with different models of joints 129 7.1 Design Load Cases 129 7.2 Results 131 7.3 Summary 138 Chapter 8 Conclusion 139 8.1 conclusion 139 8.2 Future work 140 Reference 141 Appendix A. Input File of the OWTs 146

    [1] Design of Offshore Wind Turbine Structures, D. N. VERITAS, 2011.
    [2] J. G. Bouwkamp, J. P. Hollings, B. F. Maison, and D. G. Row, "Effects Of Joint Flexibility On The Response Of Offshore Towers," presented at the Offshore Technology Conference, 1980. [Online]. Available: https://doi.org/10.4043/3901-MS.
    [3] M. Efthymiou, "Local rotational stiffness of unstiffened tubular joints," KSEPL Report RKER, vol. 85, 1985.
    [4] H. Fessler, P. B. Mockford, and J. J. Webster, "PARAMETRIC EQUATIONS FOR THE FLEXIBILITY MATRICES OF SINGLE BRACE TUBULAR JOINTS IN OFFSHORE STRUCTURES," (in English), Proceedings of the Institution of Civil Engineers Part 2-Research and Theory, Article vol. 81, pp. 659-673, Dec 1986, doi: 10.1680/iicep.1986.466.
    [5] H. Fessler, P. B. Mockford, and J. J. Webster, "PARAMETRIC EQUATIONS FOR THE FLEXIBILITY MATRICES OF MULTI-BRACE TUBULAR JOINTS IN OFFSHORE STRUCTURES," (in English), Proceedings of the Institution of Civil Engineers Part 2-Research and Theory, Article vol. 81, pp. 675-696, Dec 1986, doi: 10.1680/iicep.1986.467.
    [6] Y. Ueda, S. M. H. Rashed, and K. Nakacho, "An Improved Joint Model and Equations for Flexibility of Tubular Joints," Journal of Offshore Mechanics and Arctic Engineering, vol. 112, no. 2, pp. 157-168, 1990, doi: 10.1115/1.2919850.
    [7] B. Chen, Y. Hu, and M. Tan, "Local joint flexibility of tubular joints of offshore structures," Marine Structures, vol. 3, no. 3, pp. 177-197, 1990/01/01/ 1990, doi: https://doi.org/10.1016/0951-8339(90)90025-M.
    [8] I. Hoshyari and R. Kohoutek, "Rotational And Axial Flexibility of Tubular T-Joints," in The Third International Offshore and Polar Engineering Conference, 1993, vol. All Days, ISOPE-I-93-341.
    [9] F. Gao, B. Hu, and H. P. Zhu, "Parametric equations to predict LJF of completely overlapped tubular joints under lap brace axial loading," Journal of Constructional Steel Research, vol. 89, pp. 284-292, 2013/10/01/ 2013, doi: https://doi.org/10.1016/j.jcsr.2013.07.010.
    [10] F. Gao, B. Hu, and H. P. Zhu, "Local joint flexibility of completely overlapped tubular joints under in-plane bending," Journal of Constructional Steel Research, vol. 99, pp. 1-9, 2014/08/01/ 2014, doi: https://doi.org/10.1016/j.jcsr.2014.03.004.
    [11] F. Gao and B. Hu, "Local joint flexibility of completely overlapped tubular joints under out-of-plane bending," Journal of Constructional Steel Research, vol. 115, pp. 121-130, 2015/12/01/ 2015, doi: https://doi.org/10.1016/j.jcsr.2015.08.016.
    [12] B. Asgarian, V. Mokarram, and P. Alanjari, "Local joint flexibility equations for Y-T and K-type tubular joints," Ocean Systems Engineering, vol. 4, no. 2, pp. 151-167, 2014, doi: 10.12989/ose.2014.4.2.151.
    [13] R. Khan, K. Smith, and I. Kraincanic, "Improved LJF equations for the uni-planar gapped K-type tubular joints of ageing fixed steel offshore platforms," Journal of Marine Engineering & Technology, vol. 17, no. 3, pp. 121-136, 2017, doi: 10.1080/20464177.2017.1299613.
    [14] H. Nassiraei, "Local joint flexibility of CHS X-joints reinforced with collar plates in jacket structures subjected to axial load," Applied Ocean Research, vol. 93, p. 101961, 2019/12/01/ 2019, doi: https://doi.org/10.1016/j.apor.2019.101961.
    [15] H. Nassiraei, "Local joint flexibility of CHS T/Y-connections strengthened with collar plate under in-plane bending load: Parametric study of geometrical effects and design formulation," Ocean Engineering, vol. 202, p. 107054, 2020/04/15/ 2020, doi: https://doi.org/10.1016/j.oceaneng.2020.107054.
    [16] H. Nassiraei and P. Rezadoost, "Local joint flexibility of tubular T/Y-joints retrofitted with GFRP under in-plane bending moment," Marine Structures, vol. 77, p. 102936, 2021/05/01/ 2021, doi: https://doi.org/10.1016/j.marstruc.2021.102936.
    [17] H. Nassiraei and P. Rezadoost, "Local joint flexibility of tubular X-joints stiffened with external ring or external plates," Marine Structures, vol. 80, p. 103085, 2021/11/01/ 2021, doi: https://doi.org/10.1016/j.marstruc.2021.103085.
    [18] H. Nassiraei and A. Yara, "Local joint flexibility of tubular K-joints reinforced with external plates under IPB loads," Marine Structures, vol. 84, p. 103199, 2022/07/01/ 2022, doi: https://doi.org/10.1016/j.marstruc.2022.103199.
    [19] H. Zhu, Y. Shao, G. Chi, X. Gao, and K. Li, "Simplified bar-system model for tubular structures by considering local joint flexibility," Marine Structures, vol. 81, p. 103122, 2022/01/01/ 2022, doi: https://doi.org/10.1016/j.marstruc.2021.103122.
    [20] H. Nassiraei and A. Yara, "Local joint flexibility of tubular K-joints reinforced with external plates under out of plane bending moments," Ships and Offshore Structures, vol. 18, no. 12, pp. 1688-1700, 2023/12/02 2023, doi: 10.1080/17445302.2022.2140508.
    [21] H. Nassiraei and H. R. Chavoshi, "Collar plate effect on local joint flexibility of tubular K-joints under IPB moments: Parametric study and predictive equations," Marine Structures, vol. 98, p. 103676, 2024/11/01/ 2024, doi: https://doi.org/10.1016/j.marstruc.2024.103676.
    [22] H. Ahmadi and A. Ziaei Nejad, "A study on the Local Joint Flexibility (LJF) of two-planar tubular DK-joints in jacket structures under in-plane bending loads," Applied Ocean Research, vol. 64, pp. 1-14, 2017/03/01/ 2017, doi: https://doi.org/10.1016/j.apor.2017.02.002.
    [23] H. Ahmadi and A. Ziaei Nejad, "Local joint flexibility of two-planar tubular DK-joints in OWTs subjected to axial loading: Parametric study of geometrical effects and design formulation," Ocean Engineering, vol. 136, pp. 1-10, 2017/05/15/ 2017, doi: https://doi.org/10.1016/j.oceaneng.2017.03.011.
    [24] H. Ahmadi and A. Ziaei Nejad, "Geometrical effects on the local joint flexibility of two-planar tubular DK-joints in jacket substructure of offshore wind turbines under OPB loading," Thin-Walled Structures, vol. 114, pp. 122-133, 2017/05/01/ 2017, doi: https://doi.org/10.1016/j.tws.2017.02.001.
    [25] E. Zavvar, P. Rosa-Santos, E. Ghafoori, and F. Taveira-Pinto, "Analysis of tubular joints in marine structures: A comprehensive review," Marine Structures, vol. 99, p. 103702, 2025/01/01/ 2025, doi: https://doi.org/10.1016/j.marstruc.2024.103702.
    [26] H. Ahmadi and V. Mayeli, "Probabilistic analysis of the local joint flexibility in two-planar tubular DK-joints of offshore jacket structures under in-plane bending loads," Applied Ocean Research, vol. 81, pp. 126-140, 2018/12/01/ 2018, doi: https://doi.org/10.1016/j.apor.2018.10.011.
    [27] H. Ahmadi and V. Mayeli, "Development of a probability distribution model for the LJF factors in offshore two-planar tubular DK-joints subjected to OPB moment loading," Marine Structures, vol. 63, pp. 196-214, 2019/01/01/ 2019, doi: https://doi.org/10.1016/j.marstruc.2018.09.009.
    [28] H. Ahmadi and N. M. Janfeshan, "Local joint flexibility of multi-planar tubular TT-joints: Study of geometrical effects and the formulation for offshore design practice," Applied Ocean Research, vol. 113, p. 102758, 2021/08/01/ 2021, doi: https://doi.org/10.1016/j.apor.2021.102758.
    [29] H. Ahmadi and M. Akhtegan, "Effects of geometrical parameters on the local joint flexibility (LJF) of three-planar tubular T-joints in offshore structures," Ships and Offshore Structures, vol. 17, no. 7, pp. 1604-1615, 2022/07/03 2022, doi: 10.1080/17445302.2021.1937794.
    [30] H. Ahmadi and A. A. Niri, "Geometrical effects on the local joint flexibility of three-planar tubular Y-joints in substructures of offshore wind turbines," Ships and Offshore Structures, vol. 19, no. 4, pp. 484-496, 2024/04/02 2024, doi: 10.1080/17445302.2023.2179213.
    [31] H. Ahmadi and M. Saeedi, "Local joint flexibility of two-planar tubular DY-joints in jacket-type substructures of offshore wind turbines: parametric study of geometrical effects and design formulation," Ships and Offshore Structures, pp. 1-13, 2024, doi: 10.1080/17445302.2024.2397301.
    [32] Y. Hu, B. Chen, and J. Ma, "An equivalent element representing local flexibility of tubular joints in structural analysis of offshore platforms," Computers & Structures, vol. 47, no. 6, pp. 957-969, 1993/06/17/ 1993, doi: https://doi.org/10.1016/0045-7949(93)90300-3.
    [33] T.-Y. Chen and H.-Y. Zhang, "Stress analysis of spatial frames with consideration of local flexibility of multiplanar tubular joint," Engineering Structures, vol. 18, no. 6, pp. 465-471, 1996/06/01/ 1996, doi: https://doi.org/10.1016/0141-0296(95)00109-3.
    [34] J. Buitrago, B. E. Healy, and T. Chang, "Local joint flexibility of tubular joints," presented at the Proceedings of the International Conference on Ocean, Offshore & Arctic Engineering (OMAE), Glasgow, United Kingdom, 1993, 1993.
    [35] B. Asgarian, P. Kuzehgar, and P. Rezadoost, "Effect of local joint flexibility on the fatigue lfe assessment of jacket-type offshore platform," Ocean Systems Engineering-an International Journal, vol. 14, no. 1, pp. 1-16, Mar 2024, doi: 10.12989/ose.2024.14.1.001.
    [36] P. Alanjari, B. Asgarian, and M. Kia, "Nonlinear joint flexibility element for the modeling of jacket-type offshore platforms," Applied Ocean Research, vol. 33, no. 2, pp. 147-157, 2011/04/01/ 2011, doi: https://doi.org/10.1016/j.apor.2010.12.005.
    [37] J. Dubois, M. Muskulus, and P. Schaumann, "Advanced Representation of Tubular Joints in Jacket Models for Offshore Wind Turbine Simulation," Energy Procedia, vol. 35, pp. 234-243, 2013/01/01/ 2013, doi: https://doi.org/10.1016/j.egypro.2013.07.176.
    [38] A. A. Golafshani, M. Kia, and P. Alanjari, "Local joint flexibility element for offshore plateforms structures," Marine Structures, vol. 33, pp. 56-70, 2013/10/01/ 2013, doi: https://doi.org/10.1016/j.marstruc.2013.04.003.
    [39] P. Chakrabarti, Effect of Joint Behavior on the Reassessment of Fixed Offshore Platforms in the Bay of Campeche. 2005.
    [40] P. Chakrabarti et al., An Overview of the Reassessment Studies of Fixed Offshore Platforms in the Bay of Campeche, Mexico. 2005, pp. 123-134.
    [41] S.-H. Ju, F.-C. Su, Y.-P. Ke, and M.-H. Xie, "Fatigue design of offshore wind turbine jacket-type structures using a parallel scheme," Renewable Energy, vol. 136, pp. 69-78, 2019, doi: 10.1016/j.renene.2018.12.071.
    [42] S.-H. Ju and Y.-C. Huang, "MTMD to increase fatigue life for OWT jacket structures using Powell's method," Marine Structures, vol. 71, p. 102726, 2020/05/01/ 2020, doi: https://doi.org/10.1016/j.marstruc.2020.102726.
    [43] C. Sun and V. Jahangiri, "Fatigue damage mitigation of offshore wind turbines under real wind and wave conditions," Engineering Structures, vol. 178, pp. 472-483, 2019/01/01/ 2019, doi: https://doi.org/10.1016/j.engstruct.2018.10.053.
    [44] J. Velarde, C. Kramhøft, J. D. Sørensen, and G. Zorzi, "Fatigue reliability of large monopiles for offshore wind turbines," International Journal of Fatigue, vol. 134, p. 105487, 2020/05/01/ 2020, doi: https://doi.org/10.1016/j.ijfatigue.2020.105487.
    [45] X. Huang, T. Chen, K. Chen, G. Yuan, and Z. Xiao, "Fatigue evaluation of grouted connections subjected to Markov matrix based random loading," Marine Structures, vol. 86, p. 103295, 2022/11/01/ 2022, doi: https://doi.org/10.1016/j.marstruc.2022.103295.
    [46] R. Biswal and A. Mehmanparast, "Fatigue damage analysis of offshore wind turbine monopile weldments," Procedia Structural Integrity, vol. 17, pp. 643-650, 2019/01/01/ 2019, doi: https://doi.org/10.1016/j.prostr.2019.08.086.
    [47] "<DNVGL-RP-C203.pdf>."
    [48] 李承鴻, "浮式離岸風力發電機繫泊線控制系統之研究," 碩士, 土木工程學系, 國立成功大學, 台南市, 2024. [Online]. Available: https://hdl.handle.net/11296/2p796t
    [49] "<iec61400-3-1{ed1.0}en.pdf>."
    [50] "<15MW generic WTG design.pdf>."
    [51] 邱毓權, "平行化處理應用於離岸風機套管式支撐結構設計," 碩士, 土木工程學系, 國立成功大學, 台南市, 2017. [Online]. Available: https://hdl.handle.net/11296/q692g4
    [52] "<GL Tropical Cyclone Technical Note.pdf>."
    [53] S.-H. Ju, H.-H. Hsu, and T.-Y. Hsiao, "Three-dimensional wind fields of tropical cyclones for wind turbine structures," Ocean Engineering, vol. 237, p. 109437, 2021/10/01/ 2021, doi: https://doi.org/10.1016/j.oceaneng.2021.109437.
    [54] S.-H. Ju and Y.-C. Huang, "Analyses of offshore wind turbine structures with soil-structure interaction under earthquakes," Ocean Engineering, vol. 187, p. 106190, 2019/09/01/ 2019, doi: https://doi.org/10.1016/j.oceaneng.2019.106190.

    下載圖示 校內：立即公開
    校外：立即公開
    QR CODE