基于多频率数据融合的Lamb波损伤定位研究
Research on multi-frequency data fusion based Lamb wave damage localization

确定损伤位置是结构健康监测中的重要环节，而时间延迟是确定损伤位置的关键问题。针对Lamb波的频散效应对定位精度的影响，提出了一种基于Morlet小波时频分析和多频率数据融合的损伤定位方法，首先采用小波分析的手段，提取多组特定频率下的信号，实现多频率成分下波达时刻的准确判定，进而采用加权平均处理的方法获得损伤位置到两换能器的距离之和，最后基于椭圆定位法确定了损伤的位置。试验结果表明，该方法能够有效减少Lamb波频散效应的影响，相较时域峰值包络的方法，可有效提高定位的精度，同时增强了系统抗干扰的能力。
Determination of damage location is an important part of structural health monitoring, and time delay is the key parameter to determine the damage location. A damage localization method based on Morlet wavelet transform and data fusion is put forward to reduce the influence of Lamb wave dispersion on the localization accuracy. Travel time information at several special frequencies is extracted, so the signal arrival time is determined. The distance of damage to sensors is obtained based on weighted processing. Damage localization is determined based on ellipse localization method. Simulation results show that the method can reduce the influence of dispersion effect, improve the accuracy of localization and enhance the system anti-interference ability.