Frequency shift of monopile supported wind power turbine under lateral cyclic loading in sand

被引：0

作者：

Wang Y. ^{[1
,2
]}

Gong W. ^{[1
,2
]}

Zhu M. ^{[3
]}

Dai G. ^{[1
,2
]}

Wan Z. ^{[1
,2
]}

机构：

[1] Key Laboratory of C&PC Structures, Ministry of Education, Southeast University, Nanjing

[2] School of Civil Engineering, Southeast University, Nanjing

[3] School of Civil Engineering and Architecture, Jiangsu University of Science and Technology, Zhenjiang

来源：

Zhongnan Daxue Xuebao (Ziran Kexue Ban)/Journal of Central South University (Science and Technology) | 2022年 / 53卷 / 11期

基金：

中国国家自然科学基金;

关键词：

cyclic loading; monopile; natural frequency; sand; shift;

D O I：

10.11817/j.issn.1672-7207.2022.11.017

中图分类号：

学科分类号：

摘要：

The theoretical evaluation method of natural frequency shift of monopile supported OWT system under cyclic loading was proposed. Considering the mass conservation principle of subsidence pit and densified soil, the variation of soil parameters caused by cyclic loading was quantified. Based on the limit equilibrium theory of rigid pile, the stiffness matrix of pile head considering the lateral resistance of pile tip was established. Based on the existing natural frequency evaluation method, the natural frequency shift caused by loading cycles was studied. The results show that the smaller the relative density of soil and the smaller the slenderness ratio of pile, the more significant the influence of cyclic loading on the natural frequency shift of the structure system is. However, with the process of soil subsidence and densification during loading cycles, the offset rate of natural frequency will decrease. The offset and shift trends of natural frequency are related to the pile-soil relative stiffness. For the perfectly rigid pile, the natural frequency increases obviously under the cyclic loading, and the increasement rate may be over three times, which should be carefully considered in the design. However, the natural frequency of semi-rigid pile decreases by less than 5% under cyclic loading. © 2022 Central South University of Technology. All rights reserved.

引用

页码：4372 / 4380

页数：8

共 24 条

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