SU1578636A1 - Method of recording signals of acoustic emission - Google Patents

Abstract

The invention relates to non-destructive testing. The aim of the invention is to expand the field of application by registering acoustic emission signals (AE) from the surface of a metal product behind a layer of dielectrics. On the surface of the product emit a radio wave of the microwave range, take the microwave wave diffracted on the surface of the product on the signals of AE, having the nature of ultrasonic waves. 1 il.

Description

The invention relates to non-destructive testing of acoustic emission (AE) signals and can be used to record the AE signals of direct access to the surface of the test item.

The aim of the invention is to expand the field of application by registering the signal AE from the surface of the metal product behind the dielectric layer.

The drawing shows the scheme of implementation of the method of registration of signals AE.

In the controlled metal product 1 there is a crack 2 emitting signals 3 AE, having the nature of ultrasonic waves. The 4 SBCh generator and the UHF receiver 5 are directed to the surface of article 1, which is located behind dielectric layer 6. The microwave receiver 5 is connected in series with the preamplifier 7, the amplifier 8 and the signal processing and recording unit 9.

The method of registering AE signals is implemented as follows.

Electromagnetic coherent polarized wave of the radio wave range (microwave range) is generated with the help of microwave generator 4. Emit it on the surface of the controlled product, take the diffracted electromagnetic wave by the receiver 5 microwave. The electrical signal acting at the output of the microwave receiver 5 is amplified in the preamplifier 7, then in the main amplifier 8, processed according to the selected parameter and recorded in the signal processing and recording unit 9. In the case of the absence of AE signals on the surface of product 1, where the emitted microwave wave is falling, absorption, diffraction, and reflection processes occur in the dielectric layer 6

01

s

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with

05

and refracted. These processes determine the parameters of the reflected microwave signal and remain constant for a given thickness and composition of the dielectric. At the appearance of signals A3 due to the diffraction of electromagnetic waves by ultrasound (signals A3), the parameters of the recorded microwave field change, thereby registering the AE signals.

Thus, the proposed method expands the field of application through the use of microwave waves, allowing the recording of A3 signals remotely, including behind a layer of dielectrics.

Claims (1)

The Invention Method A method for recording acoustic emission signals, comprising . that they generate an electromagnetic wave, radiate it to the surface of the monitored product, accept a diffracted electromagnetic wave and, by its parameters, judge the parameters of acoustic emission signals, characterized in that, in order to expand the field of use by detecting signals, acoustic emission from the surface 5 metal products behind a layer of dielectrics, as an electromagnetic wave, generate a coherent polarized microwave wave.