【作者】 王刚；

【导师】 张大勇；

【作者基本信息】 大连理工大学 ， 船舶与海洋工程（专业学位）， 2021， 硕士

【摘要】 随着全球气候变暖问题的日益凸显,全球各国及地区都致力于节能减排。海上风电作为新能源发展的重要阵地,其在全球范围内发展十分迅速,我国也把建设海上风电场能源基地作为国家能源发展的战略性目标。作为高耸的柔性海洋工程结构物,海上风力机主要面临风荷载、波浪荷载,在风能资源更为丰富的寒区海域,风力机基础还面临海冰威胁。在复杂环境荷载尤其是风、冰荷载的作用下,风力机结构存在振动失效的危险,风力机减振设计研究有益于海上风电的长远发展。通过总结分析,明确海上风力机基础风、波浪以及海冰荷载模型;基于现场实测数据和数值计算,得到海上风力机结构阻尼比、基频,以及在不同荷载下结构振动显著性。结果显示,在各环境荷载激励下结构发生较明显的位移放大现象,风荷载对结构位移响应贡献度最大,冰荷载对结构振动加速度响应贡献度最大,在进行减振设计时应综合考虑。同时,基于振动加速度和热点应力分析,建立了基于实测的风力机基础疲劳损伤评估方法,实现结构损伤快速简单评估。进行风力机大直径锥体基础减振设计。基于现有的渤海导管架平台抗冰锥设计经验,明确大直径锥体基础设计的关键问题。构建寒区海上风力机基础现场监测系统,基于实测数据,分析海冰与宽大锥体的相互作用行为特征和冰荷载相关参数,并对锥体基础的抗冰振效果进行分析。计算分析波浪荷载对不同角度锥体基础的不良影响,考虑冰环境条件,进行锥体角度,高度及结构形式的简单优化设计,提出设计建议。对基于阻尼隔振原理的风力机减振措施进行方案设计,分析隔振层在不同刚度系数、阻尼系数、隔振层位置等设计参数下的减振效果。结果表明,在面对不同荷载时,隔振层都起到了较为理想的减振效果。相比于在顶部,隔振层在中部时,虽然对冰、浪致结构响应的控制效果减弱,但对风致上部位移的控制作用增强,且隔振层层间相对位移减小。隔振层在顶部时,其刚度取下部塔筒刚度的1.4-1.8倍比较合理,隔振层在中部时,其刚度为下部结构刚度的1.0-1.4倍时效果较好。更多还原

【Abstract】 With global climate warming becoming more and more serious,all countries and regions in the world pay attention to energy conservation and emission reduction.As an important front for the development of clean energy,offshore wind turbine is developing very rapidly all over the world.China also takes the construction of offshore wind energy base as the strategic goal of national energy development.As a tall and flexible offshore engineering structure,offshore wind turbine is mainly faced with wind and wave-current loads.In cold region sea areas where are rich in wind energy,the wind turbine foundation is also threatened by ice force.Under complex environment load,especially the action of wind and ice load,the wind turbine is at risk of vibration failure.The research of wind turbine anti-vibration design is beneficial to the long-term development of offshore wind power.By summarizing and analyzing,the wind,wave-current and sea ice load models of offshore wind turbine foundation are defined.Based on the field measured data and numerical calculation,the damping ratio and fundamental frequency of the offshore wind turbine are obtained.The significance of vibration under different loads is analyzed.Under the motivation of various environmental loads,the structure has obvious displacement amplification.The wind load has the largest contribution to the displacement response,and the ice load has the largest contribution to the acceleration response,which should be considered in the anti-vibration design.Based on the analysis of vibration acceleration and hot spot stress,the fatigue damage assessment method of wind turbine foundation based on field monitoring was established,which could evaluate structural damage rapidly and simply.Based on the existing experience of the anti-ice cone design of Bohai Sea jacket platform,the design of large diameter cone foundation of wind turbine is carried out,And the key problems in design of large-diameter cone foundation are clarified.The field monitoring system of offshore wind turbine foundation in cold area is built.Based on the measured data,the interaction characteristics between sea ice and large cone are analyzed,the ice load related parameters are analyzed and anti-ice vibration effect of cone foundation is analyzed.Based on the numerical calculation,the adverse effects of wave load on different angles cone foundation are analyzed.Considering the ice conditions,simple optimization design of cone angle,height and structure shape is carried out,and design suggestions are given.The wind turbine vibration reduction scheme which based on damping and vibration isolation principle are analyzed.The vibration control of the vibration isolation layer under different design parameters such as stiffness and damping coefficient is analyzed.The results show that under different loads,the vibration isolation layer has ideal vibration suppression effect.Instead of being at the top,in the middle position,the isolation layer’s control effect on the upper displacement caused by wind load increases,and the relative displacement between layers decreases although the control effect of response to ice and wave load is reduced.When the vibration isolation layer is at the top,it is reasonable to take 1.4-1.8 times of the stiffness coefficient of the lower tower barrel.When in the middle,the effect is better under the stiffness coefficient is 1.0-1.4 times of the stiffness coefficient of the substructure.更多还原