本研究以巨災風險之角度建立風力發電機之易損性曲線，其研究目的為評估風機受災後發生損害之風險，易損性曲線能夠快速評估結構物受損害之程度及其發生機率，本論文主要研究對象為風機塔柱之損壞過程。以兩全尺寸風機案例進行分析及比較，風機之高度分別為53 m及78 m，研究方法採用非線性靜力側推分析，以第一模態及質量之乘積比模擬地震在各質點的豎向分佈力，分析採用商用軟體SAP2000及ABAQUS，由於本研究主要探討塔柱之受損過程，因此採用簡化模型進行分析，將上部結構簡化為靜載重進行模擬。 側推分析結果顯示兩風機挫曲位置非常不同，53 m之風機挫曲位置已超過塔柱一半之位置；78m之風機挫曲位置位於柱底約15至20 m之位置。由此兩案例分別建立易損性性曲線，以對數常態分佈的累積分佈函數進行超越機率的計算，強度量測採用ADRS格式中之譜加速度。損害等級參考Asareh論文中定義之損害等級，經調整過後定義為三個損害等級，分別為(1)柱頂位移達柱高之1.25% (2)塔柱桿件達降伏應力 (3)風機塔柱出現挫曲現象。 兩組易損性分析之參數採用側推分析之結果作為結構反應之平均，由於分析之樣本不足，因此採用之對數標準差為Nuta【20】及Asareh【23】論文中非線性動力分析結果之統計。分析結果顯示，78 m高之風機在相同之譜加速度下，各個損害等級之發生機率都較高，尤其為第一損害等級之差距最為明顯。 由兩案例分析結果可發現，結構之容量及損壞過程不盡相同，因此在建立易損性曲線時，建議以相同類型及尺寸作為分析樣本才能增加分析之準確性，此研究成果未來可用於訂定風機地震保險費率。 ;ABSTRACT The fragility curves of wind turbine are established according to the concept of catastrophic risk. The purpose of the study is to assess the risk of wind turbine due to disasters. Fragility curve can quickly assess the damage degree of structures and its probability of occurrence. The main object of this thesis is the damage process of wind turbine tower. Two full-size wind turbines were analyzed and compared. The height of the wind turbines are 53m and 78m. They were analyzed by nonlinear pushover analysis. The pushover loads simulate the earthquake loads, and they were calculated according to the first mode. The commercial software SAP2000 and ABAQUS were used in this research. As this research mainly discusses the damage process of the wind turbine tower, the analysis adopts a simplified model for analysis. The superstructure is simplified as static load for analysis. The results show that these two wind turbines buckle at different location. The 53m wind turbine tower buckles at the height over half of the tower. The 78m wind turbine tower buckles at 15 to 20m over the foundation. The cumulative distribution function of a lognormal distribution is used to evaluate the probability of exceedance of these two cases. Spectral acceleration is used for intensity measure. Refer to the damage states which defined in Asareh’s dissertation, three damage states are defined in this research. The first damage state is the horizontal displacement exceeds 1.25% height of the tower. The second damage is the stress in any point of the tower exceeds the yield stress of the material. The last damage state is the complete loss of the tower, or when buckling has occurred. The pushover curves of the nonlinear pushover analysis were taken as the mean parameter of the fragility analysis. Due to lack of samples, the standard deviation of the fragility equation was refered from Asareh and Nuta’s dissertation. The analysis results show that under the same spectral acceleration, the 78 m high wind turbines have higher probability of occurrence of each damage state, especially the first damage state. From the analysis of the two cases, it can be found that the capacity and damage process of the structure are not similar. Therefore, when establishing the fragility curve, it is recommended to use the same type and size as the analysis sample to increase the accuracy of the analysis. The results of this research can be used to price the earthquake insurance premium of wind turbine in the future.
