Method for detecting isotropic material surface Young modulus by using surface acoustic wave technology

Abstract

A method for detecting isotropic material surface Young modulus by using surface acoustic wave technology. The method is as below: exciting broadband surface acoustic wave in an isotropic specimen surface to obtain a dispersion curve on a surface acoustic wave propagation direction; fitting the actual phase velocity data to obtain a closest truth-value phase velocity and a phase velocity fluctuation section; establishing a Cartesian coordinate geometry model to obtain a surface wave basic propagation equation containing unknown medium Young modulus, Poisson ratio, direction cosine of the propagation direction, amplitude attenuation coefficient given according to experience value, wave number and wave velocity; calculating assumption corresponding relation between wave velocity and wave number in the Cartesian coordinate geometry model and simultaneous theoretical relationship, to obtain mutual relationship of velocity, frequency and Young modulus under ideal conditions; and conducting reverse calculation to obtain the Young modulus in medium according to the mutual relationship of velocity, frequency and Young modulus under ideal conditions and the dispersion curve under actual conditions. The invention realizes effective measurement of isotropic material surface young modulus.

Description

technical field [0001] The invention relates to a Young's modulus detection method. In particular, it relates to a detection method for detecting the Young's modulus of the surface layer of the isotropic material using surface acoustic wave technology for detecting the Young's modulus of the surface layer of the isotropic material. Background technique [0002] As the main means of product quality control and equipment safety operation guarantee, detection technology plays a vital role in the field of advanced manufacturing and automation. Especially with the rapid development of science and technology and the gradual broadening of interdisciplinary fields, the modern industry marked by high temperature, high pressure, high speed and high load has stricter requirements on product quality, and new testing methods and equipment are constantly emerging . Its development trend is mainly high-precision, non-contact, non-destructive, fast, remote control, simple operation, and l...

AI Technical Summary

Problems solved by technology

However, this test still has many shortcomings

First, its measurement results are obtained indirectly and often need to be cross-validated with other techniques; second, the lateral resolution of nanoindentation technology is limited by the size of the indenter; third, the measurement results of nanoindentation technology are vulnerable to Influenced by internal and external conditions, such as creep and thermal drift of internal piezoelectric devices; fourth, when nano-indentation technology is used to measure thin films, it will be greatly affected by the substrate material; fifth, the measurement method is offline, Destructive measurement, and it is difficult to determine the absolute value of the elastic modulus of the material. Sixth, the purchase cost of the instrument is relatively high

There are many methods for measuring Young's modulus of isotropic materials, such as dynamic mechanical spectrum analysis technology, Brillouin light scattering technology, acoustic scanning microscopy, etc., but these detection methods have many shortcomings.

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