具有四自由度二元弹性机翼颤振特性研究

Flutter Characteristics Analysis of 4-DOF Two Dimensional Flexible Wing

考虑机翼的弹性体结构特征,采用多项式函数假设形态法建立了二元机翼的弯曲和扭转形态,基于瑞利能量法推导了弹性机翼的动力学方程。利用特征值法获得弹性机翼在某一风速下的精确数值解,以及利用MATLAB软件获得弹性机翼不同风速下的频率、阻尼趋势图以及临界颤振速度特性。分析结果表明:与刚性机翼相比,具有四个自由度的弯曲和扭转形态的弹性机翼,能更加准确地反映其在实际飞行过程中的振动动态特性,且理论数值解与模拟分析解完全相同,从而验证了理论分析的正确性。

Considering the flexible structure characteristic of the two-dimensional wing,the bending and torsion shapes were established by using the polynomial function of assumed shapes method,and the dynamic model of flexible wing was derived based on Rayleigh-Ritz method.Furthermore,numerical solution under the wind velocity of 50m/s was obtained exactly by employing the eigenvalue method;the frequency and damping parameters were given by simulating the flexible wing under different velocities with the help of MATLAB.The results show that the flutter dynamic characteristics were better reflected by using four-degree freedom of flexible wing comparing with the rigid wing,and the theoretical solution agrees well with the simulation,which has proved the validity of the described theories.