基于多重信号分类算法的复合材料冲击定位

为了提高复合材料结构冲击定位的精度和实时性,将阵列信号处理技术引入到结构健康监测领域,提出了利用小波变换和多重信号分类算法实现复合材料结构冲击定位的新方法:通过小波变换提取冲击响应信号某一窄带频率成分,运用多重信号分类(MUSIC)算法实现冲击源到达方向的估计;根据Lamb波传播特性,用小波变换求出某一中心频率下的对称模式和反对称模式的Lamb波到达同一传感器的时间差,结合对称模式和反对称模式Lamb的速度差就可以估计出冲击源到达传感器的距离,实现冲击定位。对玻璃纤维/环氧树脂复合材料层合板和碳纤维/双马树脂基复合材料层合板2种试件的实验均表明该方法能快速、精确地识别出冲击源位置。

Impact localization in composite using multiple signal classification method

In order to improve accuracy and real-time of impact localization in composite, the array signal processing technique was introduced into the area of structure health monitoring and a new method for impact monitoring in composite was proposed based on the wavelet transform and multiple signal classification (MUSIC) method. Firstly, narrowband frequency components of response signals were extracted by using wavelet transform, followed by the estimation of the direction-of-arrival (DOA) based on MUSIC method. Secondly, based on the propagation characteristics of lamb wave, the time-delay between symmetry and antisymmetry modal waves of one central frequency lamb wave arriving to the same array element was gained by using the wavelet transform, and the distance between impact source and array element was estimated according to velocity difference between symmetry and antisymmetry modal waves, thus the impact localization was realized. Experiments on the laminated glass fiber reinforced epoxy composite and laminated carbon fiber reinforced bismaleimide composite indicate that the present methodology can identify the impact location fast and accurately.