风-波浪荷载对海上风机地震响应的影响

EFFECTS OF WIND-WAVE LOADINGS ON THE SEISMIC RESPONSE OF OFFSHORE WIND TURBINES

建立广义单自由度模型,考虑运行、停机两种工作状态,揭示风-波浪荷载影响海上风机地震响应的机理。针对NREL 5MW单桩式海上风机,通过风-波浪统计关系确定波浪谱参数,采用FAST软件分析结构地震响应,验证初步分析结果的正确性,并探讨风-波浪影响海上风机地震响应的规律。结果表明:风-波浪作用的气动阻尼和动荷载效应使其显著影响海上风机地震响应;对于运行状态的海上风机,轮毂高度处平均风速等于额定风速时,支撑结构最危险;强震作用下,风-波浪作用减小泥面内力和塔顶位移幅值;弱震作用下,风-波浪荷载增大泥面内力和塔顶位移幅值。

Considering the operational and parked states,a generalized single degree of freedom model was established to explore the influence mechanism of wind-wave loadings on the seismic response of offshore wind turbines(OWTs).The statistical relationship between the wind and wave was employed to determine the parameters of the power spectra of the wave.Subsequently,the seismic response of the NREL 5MW OWT was analyzed using FAST to validate the conclusions of the preliminary analysis and evaluate the effects of windwave loadings on the seismic response of OWTs.The results reveal that the aerodynamic damping and dynamic loading effects of the wind and wave had a significant influence on the seismic response of OWTs.For wind turbines in the operational state,the support structure is the most dangerous when the mean wind speed of hubheight equals to the rated speed.In addition,the wind-wave loadings reduce the internal force of the mudline and tower-top displacement under the excitation of strong earthquakes.However,they increase the internal forces and displacement amplitudes at these locations while the OWT is excited by a weak earthquake.