Air coupling ultrasonic detection method for vertical honeycomb spliced interfaces

Abstract

The invention discloses an air coupling ultrasonic detection method for vertical honeycomb spliced interfaces. The air coupling ultrasonic detection method comprises the following steps: a multi-layerhoneycomb structure is vertically spliced; a layer of detachable skin is laid on each of the upper surface and the lower surface of the obtained multi-layer honeycomb structure; first curing treatment is conducted on the multi-layer honeycomb structure paved with the detachable skin; air coupling ultrasonic detection is conducted on the multi-layer honeycomb structure subjected to primary curingtreatment, and whether all the honeycomb spliced interfaces are debonded or not is detected; if all honeycomb spliced interfaces do not have the debonding defect, the detachable skin on the upper surface and the lower surface of the multi-layer honeycomb structure is torn off; and surface skin is bonded to the upper surface and the lower surface of the multi-layer honeycomb structure, secondary curing is conducted on the multi-layer honeycomb structure bonded with the surface skin, and a vertically-spliced multi-layer honeycomb structure part is obtained. The air coupling ultrasonic detectionmethod for the vertical honeycomb spliced interfaces is high in detection accuracy, the quality of vertically-spliced multi-layer honeycomb sandwich structure part can be guaranteed, and safe and reliable product manufacturing is guaranteed.

Description

technical field [0001] The invention relates to the technical field of nondestructive testing, in particular to an air-coupled ultrasonic testing method for a vertical honeycomb splicing interface. Background technique [0002] With the rapid development of the large civil aircraft manufacturing industry in China, the structural forms of aircraft parts are becoming more and more diverse and complex. For example, the common composite honeycomb sandwich structure is mostly a single-layer honeycomb sandwich structure. With the continuous emergence of new processes and new structures, composite materials with vertically spliced ​​multi-layer honeycomb sandwich structures have been applied to parts of large passenger aircraft. The vertically spliced ​​multi-layer honeycomb sandwich structure is divided into two curings. Taking the three-layer honeycomb sandwich structure as an example, the first curing is to splice the three-layer honeycomb structure vertically with the adhesive ...

AI Technical Summary

Problems solved by technology

If there is a debonding defect in the honeycomb of the middle layer, the air layer blocks the bonding surface and the honeycomb wall of the middle layer due to the formation of a cavity at the debonding point, so that the ultrasonic signal cannot be transmitted through the honeycomb wall of the middle layer, and the receiving probe cannot receive the ultrasound. The signal is different from the signal of the surrounding excellent area, and the defect signal of the air layer can be displayed; and if there is a debonding defect in the surface honeycomb, the cavity at the debonding place is located on the surface of the honeycomb, because the ultrasonic wave emitted by the transmitting probe itself is relying on the air Therefore, even if there is an air layer between the surface honeycomb and the bonding surface, it does not affect the normal propagation of the ultrasonic wave. The receiving probe can receive the ultrasonic signal normally, which is consistent with the signal of the surrounding excellent area, and the defect signal of the air layer cannot be displayed.

Therefore, the test results of the air-coupled ultrasonic testing of the multi-layer honeycomb sandwich structure obtained by one-time curing are also inaccurate

[0006] To sum up, there are technical problems in the existing technology that the detection accuracy of vertical honeycomb splicing interface defects is low, resulting in the inability to guarantee the quality of multi-layer honeycomb sandwich structure parts and increasing the risk of subsequent manufacturing

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