多层黏接结构的阵列超声检测评价方法

In the ultrasonic detection for multi-layer bonding structures of metal and non-metal materials such as rubber, the signal to noise ratio of debonding defect is low, and the defect identification is difficult, due to the significant difference in acoustic impedance between media and large ultrasonic attenuation. In order to improve the detection ability of de-bonding defects in multilayer structures, a novel ultrasonic detection and evaluation method based on linear array ultrasonic transducers is proposed. Firstly, the propagation characteristics of ultrasonic waves at the bonding interface are analyzed, and the spectral relationship of the reflection coefficient in a multilayer system is described. Further, a numerical simulation analysis model is built in accordance with the stiffness matrix transfer model of multilayer medium, which is used to realize the design and calculation of the ultrasonic array focusing scheme and detection process. These methods are based on the 3D CAD inspection model. Finally, by analyzing the amplitude spectrum characteristics of interface echo signals under different bonding states, a C-scan imaging method using amplitude spectrum characteristics is proposed. The experiment results show that the method proposed can effectively improve the detection efficiency of multilayer bonded structures and improve the signal-to-noise ratio of detection results, and reduce the complexity of C-scan imaging characterization of de-bonding defects.