地震作用下固定式海上风机动力模型试验及耦合数值研究

Dynamic model test and coupled numerical analysis of bottom fixed offshore wind turbines under earthquakes

海上风机是复杂环境荷载作用下多自由度复杂结构体系.为揭示环境荷载、转子机舱组件及支撑系统之间相互作用对海上风机结构运动响应的影响,建立水动力和结构弹性联合相似准则、气动力的牛顿相似准则,开展了地震、风、波流联合作用下海上风机整体结构动力模型试验,验证了风浪等环境荷载对于地震作用下五桩基础海上风机结构响应的影响.基于FAST v8推导并建立了地震、风、波浪联合作用下海上风机整体耦合数值仿真模型,揭示了该工况下海上风机结构响应的耦合特性,同时发现停机保护策略并不能有效降低海上风机结构地震响应.进一步,探讨了调谐质量阻尼器对海上风机在地震组合工况下的振动控制效果.

As a multi-degree-of-freedom system under complex environmental conditions,the effects of the interactions among the environmental loads,rotor-nacelle-assembly(RNA)and support system should be studied for the motion responses of the offshore wind turbine(OWT).The hydro-elastic similarity is suggested for the dynamic model test of an integrated OWT which can ensure the similarities of the hydrodynamic loads and dynamic characteristics of the structure.Meanwhile,the Newton similarity is applied to scale the aerodynamic loads of the OWT.Then,the influence of wind and wave loads on the seismic responses of the pentapod OWT is disclosed.The fully coupled numerical model of OWT under seismic,wind and wave loads is derived and established in FAST v8,and the coupling characteristics of the structural responses under such cases are discovered.Meanwhile,the limitations of the mechanical shutdown procedures on the mitigation of seismic responses of OWT are proved.Further,the effectiveness of the tuned mass damper(TMD)is evaluated based on the control of the motion of OWT under combined seismic cases.