基于函数拟合提取全息检测缺陷条纹特征研究

Research on Defects Feature Extraction about the Composite Materials by Laser Holographic Test

提出了一种基于函数拟合的全息检测复合材料粘接缺陷特征提取方法,用于缺陷定量评估。包括:对干涉条纹跟踪获取条纹空间分布坐标,多项式函数拟合得到条纹曲线函数,函数求导提取表征缺陷大小特征的干涉条纹突变的起始、终止点坐标和缺陷大小定量估计。为检验其可信性,根据复合材料脱粘缺陷在激光全息检测下的典型条纹表现,构造已知参数的缺陷条纹模型,用该方法进行特征提取和缺陷大小评估。其结果与模型设计值比较,相对误差为25%,从而说明提出的新方法能较好地对脱粘缺陷进行定量评估。该方法被应用于实际激光全息检测条纹缺陷特征提取和缺陷大小评估,得到的结果与实际设计比较,其误差为0.6%。

Based on polynomial-fitting defect feature extraction was proposed for composite materials bonding defects was tested by the laser holographic technique. It was used to estimate defect size. It consists of stripe track was used for locating the fringes, polynomial-fitting was used to get the function of the fringes, derivation function was used to get coordinates of the begin and the end inflection point in the curve and the coordinates was used to estimate defect size. For authentication the method was right,a typical interference defect fringes model was given and used to estimate defect size. In comparison with the theoretical design value,the relative errors were within 25%, so it showed that the method of defects’ feature extraction was feasible. Finally, applying the method to analyze the real defects, the relative error was within 0.6%.