基于椭圆定位与核密度估计算法的石墨烯/环氧树脂薄膜损伤检测

Damage Detection of Graphene/Epoxy Resin Film Based on Ellipse Location and Kernel Density Estimation Algorithm

石墨烯/环氧树脂复合薄膜作为纳米复合薄膜材料,在气体检测、应变检测、保护图涂层和吸波涂层等领域具有广泛的应用。而复合薄膜在制备过程中可能会产生缺陷,将影响复合薄膜的性能。因此,快速、准确地检测并定位复合薄膜内部的损伤具有重要意义。提出了一种引入核密度估计算法的超声兰姆(Lamb)波损伤检测、定位系统装置,该系统由柔性损伤检测单元和缺陷位置显示单元组成,其中损伤检测单元由32对检测电极阵列和4个压电陶瓷(PZT)激励源构成;基于飞行时间测量,通过提取Lamb波损伤散射信号与激励信号到达各电极对的时间差,结合椭圆定位与核密度估计算法,利用上位机实现了薄膜内部多损伤检测定位及损伤的云图显示。同时,优化了损伤位置的定位算法,结果表明,改进的二维核密度估计算法提升了损伤定位的精度,其位置偏差优于8%。

Graphene/epoxy composite film is a kind of nanocomposite film material,which has a wide range of applications in the fields of gas detection,strain detection,protective pattern coating,and microwave absorbing coating.Defects may occur during the preparation process,which will affect the properties of the composite films.Therefore,it is of great significance to detect and locate the damage in-side the composite film quickly and accurately.A damage detection and location system device based on a kernel density estimation al-gorithm is proposed,which realizes the detection and location of multiple damages in the film and the cloud image display of damage.The system is composed of a flexible damage detection unit and a defect position display unit.The damage detection unit is composed of 32 pairs of detection electrode arrays and 4 piezoelectric ceramic(PZT)excitation sources.The time difference between the Lamb wave damage scattering signal and the excitation signal reaching each electrode pair is extracted by the electrode.Combined with the ellipse positioning and the Kernel density estimation algorithm,the detection and positioning of multiple damages in the film and the cloud im-age display of the damage are realized by the upper computer.In addition,the damage location algorithm is optimized.The results show that the improved two-dimensional kernel density estimation algorithm improves the accuracy of damage location,and its location devia-tion is better than 8%.