A shock echo data processing method

Abstract

The invention discloses an impact echo data processing method. The method is characterized in that the method comprises the following steps: exciting the outer side of concrete to be measured by using an impact echo instrument to emit stress waves, and receiving impact echo data; calculating a relative root mean square error maximum to determine the upper limit cutoff frequency fp of added noises; carrying out complementary ensemble empirical mode decomposition (CEEMD) on the echo data according to the determined upper cutoff frequency of noises to obtain a group of intrinsic modal functions (IMFs); carrying out Hilbert transformation on all the IMFs to obtain instantaneous frequencies in order to obtain a Hilbert spectrum; and extracting concrete internal quality related characteristics from the Hilbert spectrum. He method has the advantages of reduction of the lump frequency, great shortening of the calculating time in processing of a large amount of the echo data, high accuracy and accurate defect position information reflection of the resolved frequency peak, and obtaining of visual and clear figure.

Description

technical field [0001] The invention belongs to the technical field of acoustic wave signal processing, and in particular relates to a shock echo data processing method. Background technique [0002] The impact echo method is a method of non-destructive evaluation of concrete. Among many non-destructive testing methods, the impact echo method has been listed as "one of the most promising on-site detection methods" for concrete detection. Detection, the test process is simple and fast, and can be used for accurate, non-destructive, ASTM-approved measurement of the thickness of concrete slabs and pavements; it can also be used to detect the location and location of defects in plain concrete, reinforced concrete, and post-tensioned reinforced concrete. size and is not affected by the presence of reinforcement. The principle is: use the impact to generate a stress wave, the stress wave penetrates into the concrete structure, and multiple reflections occur at the internal defect...

AI Technical Summary

Problems solved by technology

[0004] However, the following problems still exist with the above method: First, the echo signal generated by the shock echo method is an unsteady signal, and the Fourier transform is only meaningful for a stationary signal, and is not suitable for the echo signal. spectrum analysis

Due to the modal aliasing phenomenon in the EMD method, a noise-assisted data analysis method - Lumped Empirical Mode Decomposition (EEMD) is proposed, but the EEMD method has the problems of noise residue and large amount of calculation. Decomposition (CEEMD) solves these problems

Images