Laser ultrasonic excitation and detection system as well as detection method using same

Abstract

The invention relates to a laser ultrasonic excitation and detection system as well as a detection method using the same, and belongs to the technical field of non-destructive inspection. The system comprises a continuous laser device, laser splitting devices, an photoelectric modulation structure, an optical interference light path system, a light beam modulation optical path, a light deflector, a signal processing circuit, a computer and a to-be-detected piece. According to the detection method, laser array excitation and laser array detection can be realized by combining different numbers of beam splitters in the laser splitting device group at different intervals. The system and the detection method have the advantages that one continuous laser device is adopted for realizing both laser ultrasonic excitation and detection, so that the cost of a laser ultrasonic detection system can be remarkably reduced; the signal-to-noise ratio of an ultrasonic signal is remarkably improved through array excitation and detection, and the detection efficiency is improved.

Description

technical field [0001] The invention relates to a laser ultrasonic excitation and detection system and method, belonging to the field of non-destructive testing. Background technique [0002] Laser ultrasound technology is a non-destructive testing technology that uses laser excitation and detection of ultrasound. Laser has the characteristics of good directivity and long-distance non-divergence. Therefore, non-destructive testing using laser non-contact and long-distance characteristics is an important emerging method for fault diagnosis. Laser scanning technology can be used to achieve large-scale non-destructive testing. It has broad application prospects in material defect detection, processing detection, and equipment monitoring in harsh environments such as high temperature, corrosion, and radiation. [0003] The laser ultrasonic system mainly includes an ultrasonic excitation system and a laser ultrasonic detection system. Most of these two systems use special laser ...

AI Technical Summary

Problems solved by technology

[0003] The laser ultrasonic system mainly includes an ultrasonic excitation system and a laser ultrasonic detection system. Most of these two systems use special laser interferometers and pulsed lasers, and the cost is often high.

In addition, most of the existing laser ultrasonic excitation and detection schemes use a single point source or line source to irradiate the test piece, which is limited by the energy and repetition frequency of the laser, the excitation effect and signal detection effect, and the detection speed are limited.

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