Multilayer inconsistent medium interface stripping damage detection method based on ultrasonic energy diffusion

Abstract

The invention discloses a multilayer non-uniform medium interface stripping damage detection method based on ultrasonic energy diffusion. The method comprises the following steps: designing a model test piece with different interface stripping damage working conditions; a signal generator is used as an excitation source to excite a piezoelectric actuator to emit an ultrasonic signal, denoising, smoothing and filtering processing is carried out on the collected ultrasonic echo signal, after rectangular pane division is carried out, fast Fourier transform is carried out on each time pane, and frequency window frequency dispersion energy is solved; all the frequency window energy is combined, and the logarithm value of the total energy is solved; fitting an ultrasonic energy diffusion coefficient and an ultrasonic energy dissipation coefficient by using improved three-dimensional ultrasonic energy diffusion equation data; selecting an optimal excitation frequency based on the two parameters; and on the basis of the normalized damage information characterization parameters, calibrating conditions without interface separation and conditions with interface separation, and constructing a damage judgment model. According to the method, the size of the tiny stripping damage can be accurately identified, and the stripping damage in multiple layers of non-uniform media can be quantitatively identified.

Description

technical field [0001] The invention relates to the scientific research field of active detection technology of ultrasonic nondestructive testing, and relates to a method for detecting peeling damage of multi-layer non-uniform medium interfaces based on ultrasonic energy diffusion. Background technique [0002] Ultrasonic testing technology has a wide range of applications in structural infrastructure safety and material performance testing, such as: material non-destructive testing, damage form and size detection, etc. Since the ultrasonic stress wave wave mode, detachment state, and shape of different media detachment have influence on the extracted signal information, the difficulty of signal information extraction will increase due to the small detachment of the medium. Therefore, the effective collection of ultrasonic signals and the integrity of the extracted signal Breaking away from damage information is a necessary means to improve detection accuracy. [0003] In 2...

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Problems solved by technology

[0003] In 2000, it was first proposed to use ultrasonic waves to detect the interface bonding between different media [1] , the results show that the measured acoustic parameters can roughly reflect the bonding between the two, but the limitations of ultrasonic instruments at that time led to limited accuracy of the measurement results

[0004] In 2002, the electromechanical impedance analysis of the collected ultrasonic signals based on the piezoelectric ceramic PZT sensor was performed for the first time [2] , the results show that the damage factor of the sensor changes significantly near the interface damage, and the influence of the farther position is less, and the absolute size and shape details of the damage cannot be determined

[0005] In 2013, for the first time based on the ultrasonic signal collected by the piezoelectric ceramic sensor to detect the detachment damage of the non-uniform medium interface [3] , according to the wavelet packet weighted analysis of the collected ultrasonic signals, it shows that this method has a good effect on large-scale detachment damage, but it is difficult to identify small detachment damage analysis

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