蜂窝共固化结构高分辨率超声C扫描方法及应用

High Resolution Ultrasonic C-scan Method for Co-cured Honeycomb Structures and Its Applications

针对复合材料蜂窝夹芯共固化结构穿透法超声检测信号衰减严重、难以确定检出缺陷的性质和深度位置等问题,基于超声反射原理,研究了一种宽带窄脉冲高分辨率超声C扫描检测方法,并进行了检测试验。试验结果表明,该方法可以获取高质量的时域可分辨的回波信号,蒙皮-芯脱粘和好区的回波信号相差达11dB,膜上和膜下脱粘呈现不同的图像灰度分布特征,检出的脱粘大小与其设计值的差值不大于蜂窝芯格边长,可有效检测此类结构,并得到了较好的实际检测应用。

The main problems of transmission ultrasonic method for co-cured composite sandwich honeycomb structure（CCSHS）are of signal dramatic attenuation and difficulty in determination of detected defect depthlocation in skin or skin-core interface of CCSHS.In view of these problems,a high-resolution ultrasonic C-scan method,which was based on wide-band narrow-pulse ultrasonic reflection technique,was developed and used to NDTE of CCSHS sandwiched defect quantitative evaluation.Testing and application results have demonstrated that high-quality time-resolved echo signals resulted from ultrasonic reflections in body of CCSHSs can be obtained.The signal amplitude difference between disbond and good-bonding zones is up to 11 dB approximately.The distribution characterization of imaging grey resulted from disbonds,located in upper and lower adhesive film interfaces between skin-core,is obvious different from each other.Maximum deviation of detected disbond sizes by the C-scan is not larger than a single side length of the honeycomb.It provides an efficient and powerful quantitative NDTE method for CCSHSs.A good practical application has been obtained.