Method for measuring material acoustics non-linear coefficient using rayleigh surface wave

Abstract

The invention discloses a material acoustic non-linear coefficient measuring method through Relay surface wave, which comprises the following steps: adopting specific signal amplifier as signal source; assembling piezoelectric sensor on the rim of the detector piece directly to excite the Relay wave; using laser interferometer to gather the Relay wave signal on the gathered piece surface; proceeding Fuliye conversion for the gathered Relay wave signal rapidly; obtaining the basic frequency and high frequency component in the signal; affirming the relative acoustic non-linear coefficient of the material effectively and precisely.

Description

technical field [0001] The invention relates to a method for measuring the acoustic nonlinear coefficient of materials by using Rayleigh surface waves, and belongs to the technical field of non-destructive detection of performance degradation of metal materials. Background technique [0002] For in-service structural elements in mechanical equipment and engineering structures, under the action of external loads (including environmental effects), their life can generally be divided into three stages: early degradation of mechanical properties (including physical and chemical aging and degradation) ), initiation and accumulation of damage (microvoids and microcracks), and final fracture failure. Among them, the initiation and accumulation of damage have been widely studied on the basis of mesomechanics, damage mechanics and the combination of the two disciplines. There are now also a large number of data and a large number of models to predict crack growth under cyclic loadin...

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Problems solved by technology

At present, there are only a few reports on the corresponding measurement using body waves, but its disadvantage is that it is not suitable for the measurement of the acoustic nonlinear coefficient of larger plate structures.

There are also very few reports on the measurement of acoustic nonlinear coefficients using Rayleigh waves, but the Rayleigh waves are excited by diagonal chopping, which requires a relatively high signal source voltage, so the acoustic nonlinear coefficients are measured at this higher voltage. When measuring, there will inevitably be nonlinear effects from the test system, and the accuracy and reliability of the measurement results cannot be guaranteed.

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