复合材料层压板分层缺陷超声相控阵检测与评估

Delamination defects testing and evaluation of composite laminates using phased array ultrasonic technique

针对碳纤维增强树脂基复合材料分层缺陷的无损检测与评估问题,通过制备预埋分层缺陷的标准试样,利用超声相控阵技术对缺陷进行无损检测与定量评估,并对测量误差进行分析。首先,在层压板铺层中间埋入聚酰亚胺薄膜制备分层缺陷试样;然后,对试样进行超声相控阵检测,通过超声S扫和C扫图像对缺陷进行定性分析与定量测量,并结合声场仿真对检测误差进行分析。结果表明:所制备试样内分层缺陷形状规则、埋深及大小与预设一致;超声相控阵步进方向检测尺寸比较准确,而扫查方向尺寸误差较大;超声相控阵技术能够准确识别分层缺陷的形状、尺寸及位置,具有很高的检测精度,对较小缺陷具有很好的检测效果。

Composite materials are prone to delamination defects during the preparation process.For the non-destructive testing and evaluation of carbon fiber reinforced polymer(CFRP)delamination defects,a standard specimen with embedded delamination defects was prepared,and then phased array ultrasonic non-destructive testing technology was used to detect the delamination defects.The qualitative assessment and quantitative evaluation of delamination defects were carried out.First,the delamination defect specimen was prepared with the autoclave forming process,and polyimide films were embedded in the specimen before progress;then,the specimen was inspected using phased array ultrasonic technique,qualitative and quantitative measurement of delamination defects were analyzed with ultrasonic S-scan and C-scan image,uncertainty analysis of test results were also discussed in combination with the sound field simulation.The results show that the shapes of the delamination defects in the sample are regular,the embedment depth and size are consistent with the preset.The index direction size of the delamination defect is more accurate,and the scan direction size is larger than the actual size.Phased array ultrasonic technique can accurately identify the shape,size and position of delamination defects with high detection accuracy and still has good detection effects for small defects.