Method and apparatus for measuring thickness of intermediate layer of three-layer composite plate

Abstract

The invention relates to a method and apparatus for measuring the thickness of the intermediate layer of a three-layer composite plate. By means of the interface wave transmitted between the interfaces, the intermediate layer of the three-layer composite plate is excited to generate and receive a guided wave signal, and by means of the guided wave signal, the interface wave velocity is measured, and by changing the frequency of the excitation signal several times, the dispersion curve of the interface wave transmitting in the composite plate can be obtained, and the group velocity stable corner frequency can be found; By means of the consistence of the interface wave group velocity and the phase velocity stable corner frequency, by taking the product (namely frequency thickness product) of the phase velocity stable corner frequency and the thickness of the intermediate layer of the three-layer composite plate as a constant value, and by means of the principle that the phase velocity stable corner frequency is related to the thickness of the intermediate layer, in the case of known stable corner frequency, the frequency thickness product is divided by the stable corner frequency to obtain the accurate thickness of the intermediate layer of the three-layer composite plate The measurement method is simple and easy, high in measurement precision, and reliable in measurement result, and is suitable for the accurate measurement of the intermediate layer of the three-layer composite plate.

Description

technical field [0001] The disclosure belongs to the field of precision measurement of mechanical structure length, and in particular relates to a method and equipment for measuring the thickness of the middle layer of a three-layer composite board. Background technique [0002] With the advancement of science and technology, various composite and intelligent materials with excellent performance are emerging and applied to modern engineering structures. Due to their own limitations, traditional materials show certain disadvantages in terms of mechanical properties, material properties, stability, and environmental resistance, making it difficult to meet the high-performance requirements of modern engineering applications. The future materials will inevitably shift from the traditional natural and single to the new man-made and compound. [0003] Composite materials are materials with new properties macroscopically composed of two or more materials with different properties ...

AI Technical Summary

Problems solved by technology

[0004] However, in the process of processing and using layered metal composite materials, there is still a very important problem, that is, it is difficult to directly measure the thickness of each layer of the composite material accurately.

At present, the determination of the thickness of each layer is mainly guaranteed by the processing technology, which is difficult to measure directly, has the disadvantages of poor accuracy, and is easy to change the thickness due to defects in the processing process and is difficult to find, which gives the performance guarantee of layered metal composite materials. bring great danger

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