Yield strength estimation method based on full width at half maximum ratio and envelope area of MBN (Magnetic Barkhausen Noise) signal

Abstract

The invention discloses a yield strength estimation method based on the full width at half maximum ratio and the envelope area of a MBN (Magnetic Barkhausen Noise) signal. The method comprises the following steps that: (1) selecting a sine wave signal of which the frequency is 10Hz and the amplitude is 5V as an excitation source, collecting the MBN signal at sampling frequency of 200KHz, and carrying out filtering through a band-pass filter of which the frequency band range is 2-45KHz; (2) extracting two feature values, including the full width at half maximum ratio and the envelope area of the MBN signal; (3) establishing a sample database; (4) carrying out sample data preprocessing, and carrying out normalization on the sample data to be between 0 and 1; (5) constructing a BP (Back Propagation) neural network model; (6) according to a provided training sample, training the BP neural network model, and finishing the training when a training error is smaller than 0.001; and (7) utilizing the trained BP neural network model, and realizing the prediction of the yield strength according to an input parameter provided by a test sample. By use of the method, the quantitative estimationof the material yield strength can be realized.

Description

technical field [0001] The invention relates to the technical field of electromagnetic non-destructive testing based on the Barkhausen principle, and relates to a yield strength neural network estimation method based on the half-height full-width ratio and envelope area of ​​MBN signals. Background technique [0002] The Barkhausen test is a commonly used electromagnetic nondestructive testing method. It was discovered by German physicist Heinrich.Barkhausen in the process of magnetization of ferromagnetic substances at the beginning of the 20th century, hence the name "Barkhausen effect". The Barkhausen effect is essentially the deflection of the internal magnetic domains of ferromagnetic materials in the direction of the applied magnetic field under the action of an external magnetic field, resulting in a jump-like irreversible displacement of the magnetic domain wall. Using the principle of electromagnetic induction, placing detection coils on the surface of ferromagneti...

AI Technical Summary

Problems solved by technology

Traditionally, only the off-line stretching method can be used to evaluate the yield strength and tensile strength of the material. This lossy method is time-consuming and labor-intensive, and the material needs to be broken to obtain the true value of its yield strength and tensile strength. , resulting in a certain waste of resources and material loss

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