基于解析模态分解和希尔伯特变换的模态参数辨识新方法

针对航天器结构低频、密频的模态参数辨识问题，提出一种将解析模态分解(AMD)与希尔伯特变换(HT)相结合的模态辨识方法(AMD+HT)，根据结构上任意一点的脉冲响应信号，对系统结构的频率和模态阻尼比进行参数识别。以箱型卫星模型为例，分别对固定状态下卫星帆板和卫星整体结构的低阶模态进行模态辨识，并与LMS数据采集系统分析结果和ANSYS有限元仿真结果对比，验证了该方法对低频、密频结构模态辨识的正确性和优越性。

A new method for the modal parameters identification based on analytical modal decomposition and Hilbert transforms

In order to identify the modal parameters of the spacecraft structures with low frequency, closely spaced modes, a new method based on analytical modal decomposition (AMD) and Hilbert transforms (HT) is proposed. The frequency and modal damping ratio of the structure are obtained by the impulse responses of the structure at any point. A satellite model composed of a central rigid body and two panels is taken as a typical example of spacecraft structures. The low-order modal parameters of a single panel and the satellite model at a fixed boundary condition are identified by this method. The comparison of the results obtained from the test data and the numerical simulation shows that the new method proposed in this paper is valid, especially in low frequency and closely spaced modes identification.