Imaging method and device based on ultrasonic Lamb wave defect detection

Abstract

The invention relates to an imaging method based on ultrasonic Lamb wave defect detection, the method comprises the following steps: acquiring defect echo signals of a to-be-detected plate-shaped structure, the defect echo signals at least comprising a first mode Lamb wave echo signal and a second mode Lamb wave echo signal; performing focusing processing on the Lamb wave echo signal of the first mode and the Lamb wave echo signal of the second mode, and determining a focused echo signal; based on the focusing echo signal, determining a first distance, wherein the first distance represents the distance between the position of the sensor corresponding to the defect echo signal and the position of the defect; and determining a defect detection image of the to-be-detected plate-shaped structure based on the first distance corresponding to the N defect echo signals. According to the imaging method based on ultrasonic Lamb wave defect detection, high-precision imaging of defects in the two-dimensional plate-shaped structure can be achieved.

Description

technical field [0001] This application relates to the technical field of non-destructive testing, in particular to an imaging method and device based on ultrasonic Lamb wave defect detection. Background technique [0002] Ultrasonic Lamb wave (Lamb wave) detection technology has attracted much attention because of its large detection range and high detection efficiency. It is a fast and effective nondestructive detection method suitable for long-distance and large-area structures. This technology has been widely used in the detection and evaluation of engineering structures. However, due to the influence of the dispersion and multi-mode characteristics of the Lamb wave, the influence of these characteristics is usually avoided when the Lamb wave is used for detection, so it is impossible to form a high-resolution detection image. [0003] Usually, when Lamb wave is used for defect detection, a single mode Lamb wave is selectively excited for detection, but when the wave pr...

AI Technical Summary

Problems solved by technology

However, due to the influence of the dispersion and multi-mode characteristics of the Lamb wave, the influence of these characteristics is usually avoided when the Lamb wave is used for detection, so it is impossible to form a high-resolution detection image

[0003] Usually, when Lamb wave is used for defect detection, a single mode Lamb wave is selectively excited for detection, but when the wave propagates to the defect position and interacts with the defect, the dispersion and multi-mode phenomena cannot be avoided

Conventional imaging algorithms usually only extract the Lamb wave signal of a certain mode for imaging, while ignoring the useful information contained in the dispersed waves of multiple modes, so it is impossible to form a high-resolution detection image

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