铝蜂窝夹芯结构的数字成像检测研究

Digital Imaging Detection of Aluminum-honeycomb Sandwich Structure

蜂窝夹芯结构常见缺陷有蒙皮与蜂窝芯脱粘、蜂窝芯变形、蜂窝芯节点开裂和蜂窝积水等,目前单一的无损检测方法还不能有效地解决蜂窝夹芯结构中的各种缺陷检测问题。针对铝蜂窝夹芯结构,首先制作了6种典型人工缺陷,利用射线DR(Digital Radiography)和计算机射线照相(Computed Radiography,CR)技术对夹杂、蜂窝芯变形、蜂窝芯格断裂、富胶等缺陷进行了数字射线成像检测,得到了高质量的缺陷数字检测图像,并进行了对比分析。针对蜂窝积水检测问题,采用射线DR技术进行了数字成像检测研究,表明积水量大小会影响图像灰度。对含有人工脱粘缺陷的铝蜂窝夹芯结构件,采用脉冲反射法对其粘接质量进行了超声C扫描成像检测研究,通过底波幅值成像得到了脱粘缺陷的超声C扫描数字图像。结果表明:数字射线成像和超声C扫描成像结合为蜂窝夹芯结构提供了一种数字化的无损检测方法。

The typical defects of honeycomb sandwich structure are debonding between the skin and the honeycomb core,deformation of honeycomb core,cracking of honeycomb core,water accumulation in honeycomb and so on,yet a single nondestructive testing method can not effectively solve the defect detection problems of honeycomb sandwich structure. Firstly,six kinds of typical artificial defects are manufactured for aluminum honeycomb sandwich structure. Secondly,inclusion,honeycomb core deformation,honeycomb core fracture,rich glue and other volumetric type defects were detected using digital X-ray imaging of digital radiography and computed radiography,the digital image of defects are acquired and image quality is well,and the contrast analysis were carried out. Thirdly,digital X-ray imaging of digital radiography was used to detect the water accumulation in honeycomb,the amount of water will affect the image gray. Lastly,aiming at the aluminum honeycomb sandwich structure which contains artificial debonding defect,the bonding quality of honeycomb sandwich structure was detected by ultrasonic pulse reflection method of C-scan imaging,ultrasonic C-scan digital imaging of debonding defect was obtained by amplitude imaging of bottom wave. The results show that： the combination of digital X-ray imaging and ultrasonic C-scan imaging will provide a digital non-destructive testing method for honeycomb sandwich structure.