利用声压信号基于HHT方法识别结构模态参数

摘要

Structural modal parameters are identified using the near-field sound pressure signal radiated by the structure with Hilbert-Huang Transform (HHT). The relationship between the near-field sound pressure and the structural modal parameters is derived. Then the structural modal parameters are obtained from the pressure using HHT. The proposed method has the advantage of noncontact measurement of sound pressure signal and also can be used for nonlinear and non-stationary signal because of the use of HHT. Numerical example shows that the present method has accurately identified the modal frequencies and damping ratios. The proposed method may provide a new practical method for the structural identification of modal parame-ters.%文章基于结构振动声辐射的近场声压信号，结合Hilbert-Huang变换推导出声压信号和结构模态参数的关系，实现了利用声压信号对结构模态参数的识别。该方法既结合了声压信号非接触测量的优点，也结合了HHT适合处理非线性非平稳信号的优点，且只需适当一位置近场声压测量值，就可以准确地识别结构的固有频率和模态阻尼比。数值模拟实例也表明了该方法准确有效，为工程实际中结构的模态参数识别提供了一种新的简单实用方法。