基于混沌理论的地震诱导近海风力机动力响应研究

Dynamic Response of Offshore Wind Turbine Induced by Earthquake Based on Chaos Theory

为探究极端环境下地震诱导大型单桩式近海风力机的非线性结构动力特性,以DTU 10 MW风力机为研究对象,构建地震-湍流风-波浪多物理场模型,研究其动力响应特性,根据混沌理论,采用相空间重构法和最大Lyapunov指数法,从定性和定量角度分析了单桩式近海风力机动力响应的混沌特性。结果表明:地震与环境载荷联合作用下,塔底位移最大值相比仅有环境载荷时明显增大,地震载荷主要影响塔架中部及底部动力响应,其诱导塔顶振动幅值较小;随地震强度的增加,塔顶流向及侧向加速度响应最大Lyapunov指数变大,混沌特性增强,塔顶稳定性减弱。

A DTU 10 MW wind turbine was studied to explore the nonlinear dynamic characteristics of large monopile offshore wind turbine induced by earthquake under extreme environment. A multi-physical model of seismic, turbulent wind and wave was established to study dynamic response characteristics. Based on chaos theory, phase space reconstruction and maximum Lyapunov exponential method were adopted to analyze the chaotic characteristics of the dynamic response of a single pile offshore wind turbine from both qualitative and quantitative perspectives. Results show that the maximum displacement of tower bottom under the combine of seismic and environmental load significantly increases compared with the case under only environmental load. The seismic load mainly affects the dynamic response of the middle and bottom of the tower, and the amplitude of tower top vibration induced by seismic load is small. With the increase of the earthquake intensity, the maximum Lyapunov exponent of the response of the tower top direction and lateral acceleration increases, the chaotic characteristics increase, and the stability of the tower top weakens.