【摘要】 采用有限单元法对自带冠叶片冠间接触碰撞的减振机理进行了研究。首先应用弹塑性力学理论对叶片冠间接触碰撞问题建立碰撞弹性力模型,并采用Herbert直接法建立碰撞阻尼力模型,进而对已建立的冠间接触碰撞的非线性动力学模型进行数值模拟,并分析自带冠叶片冠间接触碰撞的非线性动力学特性、响应特性及接触碰撞减振机理。研究结果表明:随着分岔参数的增加,发生擦边碰撞,碰撞振动系统直接由周期运动状态进入混沌,然后又突变回周期运动状态;在冠间接触碰撞减振结构的设计时应该避开混沌状态,以免由于气流力输入能量增大导致叶片振动过大。更多还原

【Abstract】 The mechanism of contact collision between the tips of blades is studied by the finite element method in this paper.Firstly the theory of elastic-plastic mechanics is employed to establish the model of collision elastic forces,the model of collision damping forces is established by the Herbert direct method.Then the nonlinear dynamic model is simulated by the numerical method and the nonlinear dynamic characteristics,response characteristics and vibration reducing mechanism are analyzed.It indicates that as the bifurcation parameters increases,the edge collision occurs,the system varies from periodic motion to chaotic,and then changes into periodic motion;the design of the blade tip vibration reduction with contact collision should avoid the chaotic motion and the keep out of the large vibration of the blade which comes from the energy of aerodynamic forces.更多还原