针对复合材料制件里常见的变厚度层压板结构,提出了一种基于多电子闸门的脉冲回波法超声C扫成像技术。其基本原理是在变厚度层压板最厚区域的上下表面回波之间设置多个首尾相连的闸门分别采集信号成像,形成若干副C扫图像,通过分析这些图像的组合得到试件各个区域的内部缺陷信息,从而解决脉冲回波法检测中变厚度层压板底波位置变动的问题。通过对含人工缺陷变厚度层压板的超声检测,验证了上述技术的可行性。 Aiming at the structure of variable thickness laminates commonly used in composite parts, a pulse Echo C-scan imaging technique based on multi-electron gate was proposed. The basic principle is to set up a plurality of gates connected end to end between the upper and lower surface echoes of the thickest area of ​​the variable thickness laminate to collect signals for imaging and form a plurality of secondary C-scan images. By analyzing the combination of these images, Internal defect information, so as to solve the problem that the bottom wave position of the variable thickness laminates in the pulse echo method is detected. The feasibility of the above technique was verified by ultrasonic testing of variable thickness laminates with artificial defects.