环境荷载联合作用下海上风电结构动力响应分析

为研究海上风电结构在复杂的海洋环境中承受环境荷载(风、波、冰、流)的联合作用时,结构产生的剧烈的动力响应问题。文章以三脚架基础海上风电结构为研究对象,采用ANSYS有限元软件建立其整体模型并进行荷载(风、波、流和风、冰、流)联合作用下的静力校核,通过对环境荷载联合作用下的三脚架基础海上风电结构进行瞬态分析,掌握其动力响应的特性及规律。结果表明:三脚架基础结构的一、二阶自振频率均为0.285Hz,在所选风机允许的频率范围内,可以保证整体结构不会与风机转动发生共振;风荷载在风、波、流荷载联合作用下主导控制结构响应的稳态波动,冰荷载在风、冰、流荷载联合作用下主导控制结构的稳态振动过程;塔筒顶端呈现的位移和加速度响应均远大于三脚架基础顶端;环境荷载联合作用下结构动力响应是环境荷载单独作用下动力响应叠加的结果。

Dynamic response analysis of offshore wind turbine structures under combined environmental loads

In order to study the violent dynamic response of offshore wind turbine structures under the combined action of environmental loads ( wind，wave，ice and flow) in the complex marine environment，the offshore wind turbine structure based on tripod is taken as the research object in this paper and the ANSYS finite element software is used to establish its overall model． First of all，static strength checking is carried out when tripod base is exposed to the wind，wave and current loads or wind，ice and current loads． Then dynamic analysis is carried out in order to make clear the dynamic response characteristics of the tripod structure． The results show that the first and second order natural vibration frequency of the tripod foundation structure is 0. 285Hz，so the whole structure can be guaranteed not to resonate with the rotation of the wind turbine within the allowable frequency range of the selected wind turbine． Wind load dominates the steady state fluctuation of the structure response under the combined action of wind，wave and flow load，and that ice load dominates the steady state vibration of the structure under the combined action of wind，ice and flow load． The displacement and acceleration responses on the top of the tower barrel are much larger than those on the top of the tripod base． The dynamic response of the structure under the combined action of environmental loads is the result of the superposition of the dynamic response under the single action of environmental loads．