时变结构模态参数辨识方法和应用

It has been being difficult to study the dynamics of time-varying structure, because theoretically it has not general solution up to now. But there are many thus problems in engineering to solve urgently, for example: the stretching dynamics of large spacecraft flexible structure, varying mass problem of rocket, bridge vibration causing high-speed train, etc. Therefor methods of identifying time-varying modal parameter for the structural system and it application to the.engineering are presented in the project. Some new procedure for identifying LTIV and LTV modal parameter of a structural system are proposed using wavelet transform, ARMAX method based on output error model, A fast tracking scheme using subspace technology, segmented AR model and sort time FT method. The experiment facility of cantilever beam with time-varying mass is developed and the test data are analyzed with AR model method, wavelet transform method and short FFT method. An analysis for data set from the wind tunnel flutter experiment on a wing model of missile is given using proposed wavelet transform procedure.

时变结构在现代工程中有着广泛的应用，利用时变模态参数的概念去求解复杂的时变结构系统是最有效的方法。本课题将在综合控制理论中时变参数辨识方法的基础上，着重研究时变结构模态参数辨识，根据时变系统响应数据不平稳和短时程的特点，将发展小波辨识方法，这是结构动力学的前沿课题。该项研究将采用理论分析和试验研究并举的方法。