结构非线性颤振分析的KBM法及实验对比

KBM Method of Flutter Analysis with Structural Nonlinearity and the Comparison with Wind Tunnel Test

本文讨论由初偏间隙型弹簧连接的三角翼带外挂系统的极限环颤振。分别用基于ＫＢＭ法一次渐近解、二次渐近解的等效线化方法对初偏间隙型非线性作等效线化处理，并将颤振分析结果与模型风洞实验结果作对比。结果表明，无论是对于单稳定极限环颤振或是双稳定极限环颤振，基于ＫＢＭ法二次渐近解的等效线化分析都比描述函数法具有更高的精度。对于初偏间隙型非线性，当极限环幅值不大时，高次谐波项对系统的响应影响较大。

The limit cycle flutter of a delta wing/store with free-play in the junction is investigated in the paper.The equivalent linearication method based on the first order or the second order asymptotic solution of KBM method is used to analyze the limit cycle nutter of the delta wing/store syStem,the results of which are compared with those of wind tunnel test. It is shown that the equivalent linearication method based on the second order asymptotic solution of KBM method is more reliable than that based on describing function method either for single stable limit cycle nutter or for double stable limit cycle flutter. For free-play,the effects of high order harmonics on the respponse of the system are stronger when the amplitude of limit cycle is small.