基于正交检验法的颤振分析模态跟踪技术

Mode tracking technique in flutter analysis based on the method of orthogonality check

模态跟踪是颤振分析的关键问题之一。常见的基于模态置信度的跟踪方法在颤振点附近常会出现错误导致跟踪失败。通过探究该方法的数学机理,阐明了基于模态置信度跟踪方法存在的缺陷,进而引入左特征向量,研究了一种基于正交检验法的模态跟踪技术。采用一悬臂直翼盒模型开展仿真研究,在状态空间下进行颤振分析,基于正交检验法得到其根轨迹图,并将模态跟踪结果与MAC值法进行对比,证明了正交检验法具有更好的模态跟踪效果。

Mode tracking is one of the key problems in flutter analysis. The common method based on modal assurance criterion frequently fails near the critical point during the application. The mathematical mechanism of this method is studied in this paper, thus revealing its defects in nature. A method based on orthogonality check is discussed, which introduces the left eigenvector. The method is applied to the flutter analysis of an unswept cantilevered wing box in the state space and the root locus of the system is obtained. The numerical results are compared with those of the MAC method and validate that the orthogonality check is more effective in mode tracking.