复合材料(结构)粘接质量检测的错位散斑技术

系统地分析了错位散斑条纹的形成机制,并在多种条件(真空荷载、热流荷载、音频扫描荷载等)下对各种复合材料结构粘接质量进行了检测及评估,可检测出厚1mm层合板内直径>5mm的缺陷,夹芯结构内直径>10mm的缺陷;对于包覆层结构可检测出深度在12mm以内、直径>5mm的空隙脱粘缺陷,而零粘接力缺陷也能检测出厚度为2mm、直径>30mm的缺陷。同时引入相移技术使错位散斑检测方法不仅具备非接触、高精度和全场实时观测等特点,而且也实现了复合材料结构粘接质量的定量无损检测。

Digital shearing speckle for nondestructive testing of composite materials

The behaviors of the digital shearing speckle fringe formation are discussed systematically with the theory of statistical optics.The technique has already received considerable industrial acceptance for nondestructive testing of composite materials.In the application shearing speckle reveals defects in an object by looking for defect-induced deformation anomalies under different loadings including vacuum load,thermal-stream load and sweep-frequency load.Quantitative NDT of composite structures are achieved by using the phase-shifting shearing speckle interferometry system with non-contact,high accuracy,full-field and real-time.The experimental results have shown that these defects of more than 5mm diameter in 2mm-thickness laminated structure,more than 10mm diameter in sandwich structure,more than 5mm diameter within 12mm-thickness covering structure,as well as the kissing debond defect of more than 30mm diameter within 2mm-thickness covering structure are tested.