高阶振型对风力机塔架地震反应的影响分析  

CONTRIBUTIONS OF HIGHER MODES IN SEISMIC RESPONSE ANALYSIS OF WIND TURBINE TOWERS

作　　者：范洪军[1] 金全洲[1] 潘文欢[1] 刘铁英[1] 

机构地区：[1]中国船级社武汉规范研究所,武汉430022

出　　处：《太阳能学报》2013年第3期513-525,共13页Acta Energiae Solaris Sinica

摘　　要：为了掌握高阶振型对结构地震反应的贡献,以4座不同规模的典型风力机为研究对象,建立考虑塔顶质量转动惯量的堆聚质量动力计算模型。采用振型分解时程分析法,计算各塔架在2条实际地震波作用下的时程反应。基于瑞利阻尼假定,综合考虑结构内阻尼和气动阻尼,保守地将瑞利阻尼的两个参考振型阻尼比确定为0.5%。另外,比较了由相关国际规范和指南推荐的忽略高阶振型和塔架实际质量分布的单质量振子简化模型与该文采用的堆聚质量模型的时程分析结果。分析结果表明:风力机塔架的地震反应显著;高阶振型的贡献大小与结构自身的动力特性和地震波的选取有关;高阶振型对风力机塔架的位移、塔顶加速度影响不大,对塔架弯矩具有一定影响,对剪力反应的影响较为显著;时程分析时,单质量振子简化模型会得到偏于不安全的地震反应结果。In order to assess how the higher modes influence tower＇ s response, four wind turbines of different size and natural period were selected to provide a systematic view. The 3-dimension FEM models were created, the tower was modeled as lumped mass and beam element, the blades, nacelle and hub were modeled as a lumped mass along with mass moment of inertia. Then, the seismic response of four models which were subjected to two historical earthquake records was investigated based on mode decomposition method. In calculating process, structural damping including aerodynamic damping were taken into account by using Rayleigh damping hypothesis, and according to exist research, two specified damping ratio which can be used to determine the coefficients of Ray- leigh damping were set to 0.5 % conservatively. In addition, the time-history results of single mass oscillator model recommended by IEC specification and DNV/Ris~ guideline were compared with lumped mass model adopted by this paper. The study showed that wind turbine tower＇ s seismic response is significant; How the higher modes contribute to towers＇ response depends on structural dynamic characteristics and the selection of seismic waves; The higher modes contribute a little to displacement and acceleration response, and have some influence on bending moment response, however, play an important role in shear force response ; Simplified model of single mass oscilla- tor will be unsafe in time-history analysis.

关 键 词：风力机 塔架 地震反应 振型分解法 高阶振型 

分 类 号：TK83[动力工程及工程热物理—流体机械及工程] TU311.3[建筑科学—结构工程]