Rock acoustic emission source positioning method based on ALL-FFT phase difference

Abstract

The invention relates to a rock acoustic emission source positioning method based on the ALL-FFT phase difference. The rock acoustic emission source positioning method based on the ALL-FFT phase difference comprises steps of carrying out an uniaxial compression acoustic emission experiment on a rock sample for testing, applying a load to the rock sample through a loading system, and acquiring an acoustic emission signal through an acoustic emission system; carrying out de-noising processing on the acquired acoustic emission signal by means of wavelet transformation; carrying out phase difference delay calculation on the de-noised acoustic emission signal by means of the ALL-FFT phase difference, solving the phase difference, obtaining time delay estimation of the acoustic emission signal, and obtaining the acoustic emission source coordinate through inversion; serving the obtained coordinate of a G point of the AE source as an iteration initial point in the Geiger positioning method, approaching the final result through iteration, calculating the correction value through a least square method, taking the correction value as the basis of each iteration, adding a vector to the last iteration result to obtain a new iteration point, determining whether the new iteration point satisfies a preset requirement or not, and stopping iteration when the new iteration point satisfies the preset requirement.

Description

technical field [0001] The invention relates to a rock acoustic emission source location method, in particular to a Geiger rock acoustic emission source location method based on ALL-FFT phase difference. Background technique [0002] Acoustic emission AE (Acoustic Emission) signal refers to the transient elastic wave phenomenon generated by the rapid release of energy in the local area of ​​the material under the influence of the outside world (stress or temperature). Acoustic emission as a detection technology started in the 1950s In Germany in the 1960s, this technology rose rapidly in the American atomic energy and aerospace technology, and was first applied to the detection of FRP solid engine casings; in the 1970s, it was developed successively in Japan, Europe and my country, but due to the Due to the limitation of advanced technology and experience, only limited applications were obtained; in the 1980s, it began to obtain a relatively correct evaluation, which attracted...

AI Technical Summary

Problems solved by technology

However, the Geiger iterative algorithm has very strict requirements on the initial value. If the initial value is not properly selected, it will be difficult to enter the convergence range, thus increasing the number of iterations.

Research on rock acoustic emission source location based on phase difference and delay estimation method reduces the error of acoustic emission location, but the accuracy is insufficient

Images