运转工况下风电塔抗震分析

Seismic analyses of wind turbine tower under operational conditions

为了研究运转工况下风电塔的地震响应及倒塔模式,使用风电塔设计软件FAST建立风电塔模型,比较停机和运转不同工况下的结构响应,并在运转工况下通过改变地震动输入方向研究不同风震组合角对结构响应的影响,得到最不利工况;使用ABAQUS建立风电塔的精细化有限元模型,将FAST计算的塔顶风荷载导入ABAQUS开展分析计算.将基于叶素理论计算的塔顶荷载与FAST计算结果进行对比,并进一步将弹性阶段ABAQUS与FAST模拟的塔顶位移进行对比,校验分析方法的合理性.利用ABAQUS模型将地震动调幅,开展倒塔模拟.研究结果表明运转工况下最不利风震组合角是90°,强震下塑性铰在塔身下部出现并向中上部发展,最终该风电塔在中上部发生破坏.

In order to study seismic responses and collapse mode of a wind turbine tower under operational conditions,a wind turbine tower model was developed by the wind turbine design software FAST. The structural responses in idle condition and operational conditions were calculated and compared. The influences of different angles between wind and earthquake inputs on structural responses were investigated. A detailed finite element model of the same tower was developed with ABAQUS. Wind load effects induced by the blades were calculated by FAST simulations and were verified with the results estimated through the blade element theory. Elastic analysis results from the FAST model and the ABAQUS model were also compared for verification purposes. Tower collapse simulations were conducted under earthquake excitations using the ABAQUS model. Study results show that the case with a 90° angle between the wind and earthquake inputs is the most dangerous scenario that could occur for tower dynamic responses. Collapse simulations indicate that the plastic hinges are initiated from the bottom part of the tubular tower wall; later,they develop into the upper part of the structure too. The tower fails at the middle-upper part of the tower wall.