Spatial resolution improvement for Lamb wave -based damage detection using frequency dependency compensation
Spatial resolution improvement for Lamb wave -based damage detection using frequency dependency compensation
复制标题
使用频率依赖性补偿改进基于兰姆波的损伤检测的空间分辨率
DOI：
10.1016/j.jsv.2017.01.031
复制
发表时间：
2017
影响因子：
4.7
通讯作者：
Huang Liping
中科院分区：
文献类型：
--
作者：
Zeng Liang;Lin Jing;Bao Jingjing;Joseph Roshan Prakash;Huang Liping
在兰姆波检测系统中，发射器和接收器的传递函数以及兰姆波在结构中传播时的衰减导致兰姆模式的振幅存在频率依赖性。这种幅度的频率依赖性也会影响测试分辨率并使损伤评估复杂化。以提高空间分辨率为目标，提出了频率依赖性补偿方法。在该方法中，首先获得频率相关幅度的准确估计，然后设计细化逆滤波器并将其应用于原始兰姆模式信号以补偿频率相关性。引入一个实验示例来说明该方法的过程。此外，还深入研究了其对传播距离和泰勒展开阶数的敏感性。最后，采用所提出的方法进行损伤检测。损伤的成像结果可以明显地证明其在测试分辨率提高和损伤识别方面的有效性。
In Lamb wave inspection systems, the transfer functions of the transmitter and receiver, and the attenuation as Lamb wave propagates through the structure, result in frequency dependency in the amplitude of Lamb modes. This frequency dependency in amplitude also influences the testing resolution and complicates the damage evaluation. With the goal of spatial resolution improving, a frequency dependency compensation method is proposed. In this method, an accurate estimation of the frequency-dependent amplitude is firstly obtained, then a refined inverse filter is designed and applied to the raw Lamb mode signals to compensate the frequency dependency. An experimental example is introduced to illustrate the process of the proposed method. Besides, its sensitivity to the propagation distance and Taylor expansion order is thoroughly investigated. Finally, the proposed method is employed for damage detection. Its effectiveness in testing resolution improvement and damage identification could be obviously demonstrated by the imaging result of the damage.