A Crack Detection Method of Double-layer Metal Composite Pipe Based on Boundary Wave

Abstract

The invention relates to a crack detection method for a double-layer metal compound pipe based on an interface wave. The method comprises the following steps: analyzing a signal which is generated by a surface wave acting on the double-layer metal compound pipe, thereby confirming if a crack exists, and if the crack exists, and further confirming an axial position and a circumferential position of the crack by utilizing the surface wave which is converted into the interface wave on a joint surface of an inner layer metal pipe and an outer layer metal pipe. The interface wave is free from frequency dispersion in the diffusing process on the joint surface of the metal compound pipe, the energy is concentrated on the interface, the interface wave is sensitive to the damages, such as, cracks, on the interface, the model number of the interface wave in the metal compound pipe is less and the recognition for a crack reflected signal in the signal processing process is benefited, so that the validity and accuracy of the crack recognition and positioning can be increased. According to the invention, the detection operation is convenient, the recognition for the damage on the interface of the whole compound pipe can be realized by stimulating and receiving the signal at one end of the pipe and the crack detection efficiency is increased.

Description

technical field [0001] The invention relates to the field of non-destructive testing of mechanical structures, in particular to a method for crack detection of double-layer metal composite pipes based on interface waves. Background technique [0002] The double-layer metal composite pipe is prepared by two different metal pipes through physical or chemical processing methods, and the pipe interface is tightly bonded. The general design principle of double-layer metal composite pipe is that one metal pipe is used as the base pipe, which has high strength and rigidity to meet the design stress of the pipeline; the other metal pipe is used as the liner, which is resistant to environmental medium corrosion or wear performance loss. Compared with single-layer metal pipes, double-layer metal composite pipes fully combine the best properties of base pipe and liner materials, overcome the limitations of single metal materials, and meet the requirements of modern industry for transp...

AI Technical Summary

Problems solved by technology

[0003] However, in the process of manufacturing or installing the double-layer metal composite pipe, due to the relatively backward technology, it is easy to form tiny crack defects between the joint surfaces of the two metal materials of the composite pipe, which cannot be seen by the naked eye, and the general testing equipment is also very difficult. difficult to identify

Initiated cracks expand during the long-term high-temperature and high-pressure working conditions of the internal fluid in the pipeline, and then lead to cracking, pressure and puncture of the composite pipeline, resulting in degradation of service performance and failure, and even bring catastrophe to people's lives and property safety s consequence

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