利用声压信号基于HHT方法识别结构模态参数

Identification of structural modal parameters by sound pressure with HHT

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。

S tructura l m odal param eters are id e n tifie d using the n e a r-fie ld sound pressure signal radiated bythe structure w ith H ilb e rt-H u a n g Transform （H H T ）. The re la tio n s h ip between the n e a r-fie ld sound pressureand th e s tru c tu ra l m odal param eters is de rive d . T hen the s tru c tu ra l m odal param eters are o b ta in e d from thepressure using H H T . T he proposed m ethod has th e advantage o f no nco ntact m easurem ent o f sound pressuresignal and also can be used fo r n o n lin e a r and n o n -s ta tio n a ry signal because o f th e use o f H H T . N u m e rica lexam ple shows th a t th e present m ethod has a ccu ra te ly id e n tifie d the m odal fre q u e n cie s and d a m ping ratios.The proposed m ethod m ay p ro vid e a new p ra c tic a l m ethod fo r th e s tru c tu ra l id e n tific a tio n o f m odal param eters.