地震强度对小型风力机动力学响应影响研究

Study of the Influence of the Seismic Intensity on the Dynamic Response of a Small-sized Wind Turbine

为研究地震强度与小型风力机塔架动力学响应之间的关系，以AOC50kW风力机为研究对象，采用wolf理论建立土-构耦合模型，基于FAST（多体动力学仿真软件）预留数据接口，开发地震载荷计算模块，建立了湍流风与地震实时耦合的动力学仿真模型。通过比例缩放ASCE（美国土木工程师协会）标准地震反应谱，得到了20种不同强度的PSA（设计加速度），从而计算不同地震与湍流风联合作用下的风力机结构动力学响应。结果表明：PSA为0．6g（g为9．80665m／s^2）时，塔基弯矩增大133．3％，但地震强度对塔顶弯矩影响较小。随着地震强度的增大，塔架不同高度处的最大弯矩与高度之间的关系逐渐由线性转变为非线性，塔架不同高度处的最大剪切力与高度之间的关系维持线性。此外，在地震载荷与风载荷共同作用下，IEC（国际电工委员会）和AWEA／ASCE（美国风能协A／美国土木工程师协会）载荷预估模型结果偏大。本文提出了一种新的高精度预估模型，可为小型风力机地震载荷预估和预防地震风险提供一定的参考。

To study the relationship between the seismic intensity and the dynamic response of the derrick of a small-sized wind turbine, with an AOC 50 kW wind turbine serving as the object of study, the Wolf theory was used to establish a soil body-structure coupled model. Based on the data interface provided in the software FAST, a module for calculating seismic loads was developed and a dynamic simulation model for turbulent winds real-time coupled with earthquakes was established. By scaling down and up the standard seismic response spectrum defined by ASCE （ American Society of Civil Engineers） , the pseudospectrum accelerations （PSA） at 20 intensities were obtained, therefore, the structural dynamic response of the wind turbine under the joint action of various earthquakes and turbulent winds was calculated. It has been found that,when the PSA is 0.6 g （ a g equals to 9. 806 65 m/s2 ） ,the bending moment of the derrick at the elevation of the foundation will increase by 133.3%, however, the seismic intensity will has a relatively small influence on the bending moment of the derrick at the top. With an increase of the seismic intensity, the relationship between the maximum bending moments of the derrick of the derrick at various elevations and the heights will gradually turn from linearity to non-linearity and the relationship between the maximum shear forces at various elevations and the heights will maintain its linearity. In addition, under the joint action of the seismic and wind load, the results calculated by using the load prediction models provided by the IEC （International Electrotechnical Commission） and AWEA/ASCE （American Wind Energy Association/American Society of Civil Engineers） will be excessively big. In these circumstances, the authors proposed a novel high precision prediction model,which can offer certain reference for predicting loads exerted on small-sized wind turbines from earthquakes and preventing from any risks of earthquakes.