Aluminum alloy structure micro-damage detection system and method

Abstract

The invention discloses an aluminum alloy structure micro-damage detection system and method. The system comprises a signal generator producing two consecutive first and second sinusoidal signals synchronously and a low-frequency oscillator, a high-frequency oscillator and a fiber grating sensor which are arranged on the upper surface of an aluminum alloy structure to be detected; the first sinusoidal signal is amplified through a power amplifier before being transmitted to the low-frequency oscillator to produce low frequency vibration excitation; the second sinusoidal signal is transmitted to the high-frequency oscillator to produce high frequency ultrasonic excitation; the low frequency vibration excitation and the high frequency ultrasonic excitation are mixed to generate a non-linear response signal to transmit to the fiber grating sensor; an optical signal generated by an ASE light source is transmitted to the fiber grating sensor, and the reflected optical signal and the non-linear response signal are transmitted to a photodetector; the photodetector converts the received signal into a voltage signal, the voltage signal is transmitted to a data processing device for Fourier transform, and the aluminum alloy plate micro crack and damage detection is implemented by judging whether the modulation side frequency of the signal appears or not after Fourier transform.

Description

technical field [0001] The invention relates to the technical field of sensors, in particular to an aluminum alloy structure micro-damage detection system and a method thereof. Background technique [0002] Aluminum alloy plate structures are widely used in the aviation field, such as aircraft wings, hatches, etc. The harsh aviation environment causes various degrees of fatigue damage, such as cracks, to occur in aluminum alloy plate structures during service, resulting in a decrease in structural strength and serious consequences. Moreover, the damage in the initial stage of the crack is relatively small, so it is easy to be ignored by people. Therefore, it is of great significance to ensure the safety of the structure if the crack damage of the aluminum alloy plate structure can be detected in time and dealt with. [0003] Non-destructive ultrasonic testing is a commonly used crack damage detection method at present. It is based on the principle of linear ultrasound and ...

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Problems solved by technology

[0004] In view of the problem that the existing structural crack damage detection system and method cannot realize the accuracy of structural micro-crack damage detection, the object of the present invention is a micro-damage detection system and method for aluminum alloy structures, combined with fiber grating sensors and nonlinear vibration modulation The principle of realizing the accuracy of micro-crack damage detection of aluminum alloy plate structure

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