【作者】 尹文明；

【导师】 任勇生；

【作者基本信息】 山东科技大学 ， 机械电子工程， 2008， 硕士

【摘要】 风能利用的主要方式就是风力发电。而在风力机系统当中,叶片又是必不可少的部分,叶片的结构和强度对风力发电机的可靠性起决定作用。在风力机系统中,复合材料叶片由于有着一般金属材料叶片无法比拟的优势,开始受到重视。本文针对形状记忆合金(SMA)复合材料叶片的结构动力学问题进行了初步的研究探索。首先,介绍了SMA的主要力学行为以及描述其力学行为的本构关系模型,给出了SMA回复力和马氏体含量随温度变化的关系曲线。在采用弯扭耦合梁理论建立风力机复合材料叶片的自由振动方程的基础上,通过计算分析了由NiTi/石墨/环氧树脂粘合而成的复合材料夹芯结构臂梁简化叶片模型固有振动特性。根据拉格朗日方程建立考虑复合材料叶片旋转刚体运动的振动方程,采用Galerkin法建立了广义坐标表示的弯扭耦合叶片的低阶固有振动分析模型。数值分析显示出复合材料的铺层方式和铺层角、SMA含量、温度以及风力机叶片旋转角速度对复合材料风力机叶片的固有频率和振型的影响。根据典型截面结构模型和准定常流的气动力模型,建立了叶片气动弹性稳定性的分析方法。分别计算了不同风速下风力机叶片运动时的特征值,对比分析了叶片运动的稳定性,然后利用龙格-库塔法进行验证。最后,采用ANSYS有限元分析软件对风力机复合材料叶片的固有振动特性进行了仿真。更多还原

【Abstract】 The main form of wind energy is the wind power generation. The blade is the essential part in the wind turbine system.The structure and the intensity of the blade play a decisive role to the reliability of the wind turbine generator. Because of the superiority that the common metallic blade can not compare with, the composite blade becomes more and more popular in the wind turbine system. In this paper, the structural dynamics issues about the blade of SMA composite materials are studied.First of all, the main mechanic behavior of the SMA and the constitutive relational model is introduced in this paper, which describes its mechanic behavior.The curve on which the constrained recovery stress of the SMA and the content of the Martensite change with the temperature, are also given. On the basis of the free vibration equation of the composite wind turbine blades which is developed using the beam theory about the coupling of the bending and torsion, the natural vibration characteristics of the blade of composite sandwich material, which is made of the NiTi/graphite/epoxy resin are investigated. The vibration equation of the composite rotating blade is formulated according to the Lagrange equation. The lower-order natural vibration analysis model is also established, which couples the bending and torsion, in the generalized coordinates is also derived by the method of Galerkin. The numerical results show the effect of the composite ply sequences, the ply angle, SMA content, temperature and the rotational angular velocity on the natural frequency and vibration mode of the composite wind turbine blades.According to the classic section structural model and quasi steady flow aerodynamic model, the blade aeroelastic stable method is presented. And the eigenvalues under different wind speed are calculated, when the wind turbine blade rotates. The results are also compared with the results by Runge-Kutta method blade aeroelastic stability, agreement between results is verified.Finally, the natural vibration characteristics of composite wind turbine blade are it simulated by the ANSYS finite element analysis software.更多还原