Evolution of dynamic characteristics of large diameter monopile of offshore wind turbine under ultra-long term cyclic load

PDF(2117 KB)

Journal of Vibration and Shock ›› 2023, Vol. 42 ›› Issue (1) : 259-266.

GONG Min1, ZHU Tao2, CHEN Shouxiang1, ZHANG Dongming1, HE Rui2

Author information +

History +

Abstract

As one of the most widely used supporting structures for offshore wind turbines, monopile foundation mainly focuses on bearing capacity, initial dynamic impedance and accumulative deformation. However, the offshore wind turbine is very sensitive to the dynamic loads such as wind, wave, current, seismic wave and its operation load in the marine environment. Therefore, in the process of long-term cyclic load, the law of its vibration characteristics must be fully studied. Through the indoor 1g model test of monopile in dry sand, taking the bearing capacity of model pile as reference value, applying cyclic load of the same frequency and different amplitude, and analyzing the frequency response during the loading process, the frequency response function of horizontal displacement of pile top is obtained, and then the following conclusions are drawn: (1) the resonance frequency of pile increases with the number of cycles; (2) the damping ratio decreases with the times of cyclic loading; (3) the stiffness of pile top is affected by many factors, such as the compaction of cyclic load and the formation of vibration pit; the secant stiffness decreases and the unloading stiffness increases.
Key words: Offshore wind turbine; monopile; indoor 1g test; long-term cyclic loading; frequency response analysis; resonance frequency; damping ratio; horizontal stiffness of pile top

Key words

Offshore wind turbine / monopile / indoor 1g test / long-term cyclic loading / frequency response analysis / resonance frequency / damping ratio / horizontal stiffness of pile top

Cite this article

EndNote

Ris (Procite)

Bibtex

Download Citations

GONG Min1, ZHU Tao2, CHEN Shouxiang1, ZHANG Dongming1, HE Rui2. Evolution of dynamic characteristics of large diameter monopile of offshore wind turbine under ultra-long term cyclic load[J]. Journal of Vibration and Shock, 2023, 42(1): 259-266

References

[1] DNV-OS-J101. Design of Offshore Wind Turbine Structures[S]. Oslo: Det Norske Veritas, 2014.
[2] Francis A J. Analysis pile groups with flexural resistance[J]. Journal of the Soil Mechanics & Foundations Division, 1964(90):1-32.
[3] Dobry R, Gazetas G. Dynamic Response of Arbitrarily Shaped Foundations[J]. Journal of geotechnical engineering, 1986, 112(2):109-135.
[4] Novak M, Nogami T. Soil-pile interaction in horizontal vibration[J]. Earthquake Engineering & Structural Dynamics, 1977, 5(3):263-281.
[5] Muki R, Sternberg E. On the diffusion of an axial load from an infinite cylindrical bar embedded in an elastic medium[J]. International Journal of Solids & Structures, 1969, 5(6):587-605.
[6] Pak R Y S, Jennings P C. Elasto dynamic Response of Pile Under Transverse Excitations[J]. Journal of Engineering Mechanics, 1987, 113(7):1101-1116.
[7] He R, Pak R Y S, Wang L Z. Elastic lateral dynamic impedance functions for a rigid cylindrical shell type foundation[J]. International Journal for Numerical and Analytical Methods in Geomechanics, 2017, 41(4):508-526.
[8] 陶文艳, 贺瑞, 郑金海. 海上风机大直径单桩水平-摇摆耦合振动特性[J]. 河海大学学报（自然科学版）, 2018, 46(3):260-267.
TAO Wen-yan, HE Rui, ZHENG Jin-hai. Analysis on horizontal-rocking vibrations of monopile supporting wind turbine[J]. Journal of Hohai University (Natural Sciences), 2018, 46(3):260-267．
[9] Latini C, Zania V. Dynamic lateral response of suction caissons[J]. Soil Dynamics and Earthquake Engineering, 2017, 100:59-71.
[10] He R, Ji J, Zhang J, et al. Dynamic Impedances of Offshore Rock-Socketed Monopiles[J]. Journal of Marine Science and Engineering, 2019, 7(5):134.
[11] Reese L, Cox W, Koop F. Analysis of laterally loaded piles in sand[J]. Proceedings of the 6th Annual Offshore Technology Conference, Houston, Texas, 1974, 2(OTC): 473-485.
[12] O’Neill M, Murchinson J. An evaluation of p-y relationships in sand[J]. Rep. Prepared for American Petroleum Institute, Washington, D.C., 1983.
[13] Peng J, Clarke B, Rouainia M. A device to cyclic lateral loaded model piles[J]. Geotechnical Testing Journal,2006, 29(4):341.
[14] Peralta J, Achmus M. An experimental investigation of piles in sand subjected to lateral cyclic loads[A]. In: Proceedings of the 7th International Conference on Physical Modelling in Geotechnics[C]. Switzerland: CRC Press, 2010: 985-990.
[15] Li Z, Haigh SK, Bolton MD. Centrifuge modelling of mono-pile under cyclic lateral loads[A]. In: Proceedings of the 7th International Conference on Physical Modelling in Geotechnics[C]. Switzerland: CRC Press, 2010: 965-70.
[16] Roesen H, Andersen L, Ibsen L, et al. Experimental Setup for Cyclic Lateral Loading of Monopiles in sand[A]. In: The 22nd International Offshore and Polar Engineering Conference[C]. Rhodes: International Society of Offshore and Polar Engineers, 2012: 1-8.
[17] Nicolai G, Ibsen L. Small-Scale Testing of Cyclic Laterally Loaded Monopiles in Dense Saturated Sand[A]. In: The 24th International Offshore and Polar Engineering Conference[C]. Rhodes: International Society of Offshore and Polar Engineers, 2014: 1-9.
[18] Cuéllar P, Baeßler M, Rücker W. Ratcheting convective cells of sand grains around offshore piles under cyclic lateral loads[J]. Granular Matter, 2009, 11(6):379-390.
[19] Lombardi D, Bhattacharya S, Muir Wood D. Dynamic soil-structure interaction of monopile supported wind turbines in cohesive soil[J]. Soil Dynamics and Earthquake Engineering, 2013, 49: 165-180.
[20] LeBlanc C, Houlsby G, Byrne B. Response of stiff piles in sand to long-term cyclic lateral loading[J]. Géotechnique, 2010, 60(2):79-90.
[21] Arshad M, O'Kelly B C. Model Studies on Monopile Behavior under Long-Term Repeated Lateral Loading[J]. International Journal of Geomechanics, 2017, 17(1):04016040.1-04016040.12.
[22] Li Jialong, Dawei Guan, Zhang Jiseng, Chiew Yee-Meng. Characterization of sediment particle motion around a vibrating pile-foundation by Particle Image Velocimetry, 14th International Symposium on River Sedimentation, 2019, China, Chengdu.
[23] JTJ254-98.《港口工程桩基规范》局部修订（桩的水平承载力设计）[S]. 北京: 人民交通出版社, 2000.
JTJ254-98. Code for Pile Foundation of Harbour Engineering Supplement[S]. Beijing: China Communications Press, 2000.
[24] Novak M, Nogami T. Soil-pile interaction in horizontal vibration[J]. Earthquake Engineering and Structural Dynamics, 1977, 5: 263-281.
[25] Hardin B, Drnevich V. Shear modulus and damping in soils: Design equations and curves[J]. Journal of soil Mechanics and Foundation Division, 1972, 98:667-692.
[26] 贺瑞. 海底基础动力特性研究[D]. 杭州：浙江大学, 2014.
HE Rui. Dynamic behaviors of subsea foundations[D]. Hangzhou: Zhejiang University. 2014.
[27] 曹树谦, 张文德, 萧龙翔. 振动结构模态分析：理论、实验与应用[M]. 天津: 天津大学出版社, 2001.
CAO Shu-qian, ZHANG Wen-de, XIAO Long-xiang. Modal analysis of vibration structures: theory, experiment and application[M]. Tianjin: Tianjin University Press, 2001.
[28] Poulos, H. G. and T. Hull. 1989. The role of analytical geomechanics in foundation engineering. Foundation Engineering: Current principles and Practices, ASCE, Reston 2: 1578-1606.
[29] 谢定义. 土动力学[M]. 西安：西安交通大学出版社, 1988.
XIE Ding-yi. Soil dynamics[M]. Xi’an: Xi 'an Jiaotong University Press, 1988.
[30] 孟凡超, 赵云辉, 郑志华. 相对密实度对含黏粒砂土动剪切模量与阻尼比影响的试验研究[J]. 地震工程学报, 2021, 43(2): 396-403.
MENG Fan-chao, ZHAO Yun-hui, ZHENG Zhi-hua. Experimental study of the effect of relative compactness on dynamic shear modulus and damping ratio of clayey sand[J]. China Earthquake Engineering Journal, 2021, 43(2): 396-403.