基于桩筒复合基础海上风机振动特性分析

海上风机所处环境复杂，在风、波浪等随机动载作用下易发生共振破坏。为研究采用桩筒复合基础海上风机的振动特性，选择合理的基础设计参数，利用有限元软件ABAQUS进行海上风机整体建模，采用Block Lanczos方法进行模态分析，同时将所得自振频率与外荷载频率进行对比研究，并分析不同基础形式与不同基础约束条件下的风机整体振动特性。研究发现:前2阶水平弯曲频率与第3阶扭转频率为判断风机整体共振的主要频率；与单桩基础相比，桩筒复合基础能够有效增加风机抵抗水平荷载的能力，且在该设计参数条件下风机能够避免共振的发生；在基础设计时，应考虑桩土相互作用(PSI)的影响。

Analysis of vibration characteristics of offshore wind turbine with pile-tube composite foundation

The offshore wind turbines are prone to resonance damage under the random dynamic loads, such as the wind and waves, due to their complex environment. In order to study the vibration characteristics of the offshore wind turbine, the reasonable design parameters are selected; and the whole model is built by use of ABAQUS software, considering offshore wind turbine and pile-cylinder composite foundation. The modal analysis is carried out by Block Lanczos method. The self-vibration frequency of the wind turbine system and the external load frequency are compared with each other. The influencing factors of the whole vibration characteristics of the wind turbine are analyzed, including the foundation type and the restraint conditions. The results show that the first and second order bending vibration frequency and the third order torsional vibration frequency are the main resonance frequency of the wind turbine. Compared with the single pile foundation, the pile-cylinder composite foundation can effectively improve the ability to resist horizontal loads. With the design parameters in this paper, the wind turbine can avoid the occurrence of resonance. The influence of pile-soil interaction (PSI) should be considered in the pile foundation design of wind turbines.