风力机旋转叶片的刚柔耦合动力学响应特性分析

Dynamic response characteristics analysis of rigid-flexible coupling of wind turbine rotating blade

为获得风力机风轮在时变载荷作用下的动力学响应规律,在将轮毂假设为刚性圆盘和叶片假设为柔性悬臂梁的基础上,考虑剪切应变对叶片引起的附加位移、叶片的旋转运动与弹性变形间的耦合及离心力的作用,运用Hamilton原理建立了旋转叶片子系统的非线性动力学模型.以河西地区某风场1.2 MW风电机组为例,采用有限元法和Newmark数值积分法对其叶片在时变载荷作用下的动态响应进行了计算.结果表明:考虑剪切变形影响时得到的叶片振动幅值比不考虑剪切变形影响时会平均增大约7.5%;在考虑叶片的旋转运动与弹性变形间的耦合作用时,离心力对叶片振动动态特性的影响将会被弱化.

In order to obtain the pattern of dynamic response of large wind turbine blade subjected to time- varying load, the hub is assumed to be a rigid circular disc and the blade is assumed to be a flexible cantile- ver beam. Taking account of the effect of the centrifugal force and the coupling of blade additional dis- placement induced by shear strain with both, the rotation of blade and elastic deformation, a the nonlinear dynamic model of rotating blade subsystem is established by using Hamilton principle. Taking an 1.2 MW wind turbine installed in Hexi area of China as example, the dynamic response of the blade subjected to time-varying load is evaluated by applying Newmark numeric integration and FEM. The result shows that the shear deformation may make the blade vibration amplitude increased by 7. 5% target than that when the shear deformation is not taken into consideration. The coupling of the rotating movement of blade with its elastic deformation may weaken the influence of the centrifugal force.