基于密集阵列的参数化Lamb波检测技术研究

Lamb波具有衰减慢、模态多、对结构几何特性和材料属性变化敏感等特点，在大型板壳结构的远距离、大范围快速检测技术研究领域得到了众多的关注。传统Lamb波成像算法将多组散射信号时间相关参数映射到结构每一个离散空间网格上实现缺陷信息的可视化。该类算法的执行效率低，且无法直接提供缺陷位置参数信息。将缺陷成像问题转换为散射信号源点求解问题进行分析，提出一种基于十字形密集阵列的参数化Lamb波检测技术。首先基于时飞原理建立散射信号源点求解函数模型；并提出一种融合烟火算法和统计分析技术的信号源点求解函数模型分析算法，实现缺陷空间位置的参数化分析。最后通过有限元模型和试验验证了所提出的检测技术对不同角度裂纹缺陷检测的有效性，并分析了模型参数设置对检测效果的影响。

Parametric Lamb Waves Detection Technology Based on Compact Array

Lamb waves have the low attenuation, multi-modes and sensitive to the change of geometry and material property of structures. They have been attractive much attention for rapid detection large plate/shell in long distance and large scale. In classical Lamb waves based imaging algorithms, the visualization of defects information is realized through mapping time relative parameters of multi-scatter signals into every discrete space grid of structures. It has low execution efficiency and cannot provide defect location parameter information directly. In this research, a parametric Lamb waves detection technology used for compact cross array is proposed through transforming the defect imaging problem into the scattering signal source point solving problem to analyse. In the first, a function model to estimate the scattering signal source points is established based on the time-of-flight principle; then an intelligent algorithm to solve the proposed model is developed through combining the fireworks algorithm and the statistical analysis technology. Parameters information of defects location is realized. Finally, the effectiveness of the proposed technology in parametric detection of cracks with different angles is verified with the finite element method and experiment. And the influence of parameter setting on the detection effect is analysed.