基于含误差测量结果的Lamb波损伤检测

Lamb Waves Damage Detection Based on Measurement Results with Errors

针对当前考虑测量结果误差的Lamb波损伤检测中使用的测量结果正态分布假设进行了研究,通过对数值仿真结果分析证明即便是在较为理想的高斯白噪音干扰下,使用阈值法获取到的损伤反射波波达时间测量结果仍不是典型正态分布。为此引入了非参数统计中的新算法来给出测量结果分布的准确估计。损伤检测数值仿真结果表明:使用正确的测量结果概率密度函数对提高损伤位置检测精度有直接的影响。

The normal distribution assumption of measured results in the Lamb waves-based damage de- tection work was studied. Through the analysis of the results of numerical simulations, it was proved that the distribution of the arriving time measured by using threshold method was still not a topical normal dis- tribution even under ideal Gaussian white noise. Therefore, the new algorithm of non-parametric statistics was introduced to give the accurate estimate about the distribution. The damage detection numerical result shows that the using of the correct probability density function of the measurement results have a direct impact on the damage location detection accuracy.