Method for extracting time-frequency amplitude characteristic and time-frequency phase characteristic of ultrasonic signals on dissimilar material diffusion welding interface

A technology of ultrasonic signals and heterogeneous materials, applied in the direction of processing detection response signals, etc., can solve problems such as inability to accurately reflect diffusion welding defect information, and achieve the effects of reducing the amount of calculation, avoiding phase distortion, and high similarity

Inactive Publication Date: 2010-06-09
HARBIN INST OF TECH
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Problems solved by technology

[0003] In order to solve the problem that the amplitude of the reflected echo of the conventional diffusion welding interface cannot accurately reflect the defect information of the diffusion welding,

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  • Method for extracting time-frequency amplitude characteristic and time-frequency phase characteristic of ultrasonic signals on dissimilar material diffusion welding interface
  • Method for extracting time-frequency amplitude characteristic and time-frequency phase characteristic of ultrasonic signals on dissimilar material diffusion welding interface
  • Method for extracting time-frequency amplitude characteristic and time-frequency phase characteristic of ultrasonic signals on dissimilar material diffusion welding interface

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specific Embodiment approach 1

[0014] Specific implementation mode 1: According to the instructions attached figure 1 To describe this embodiment in detail, the method for extracting time-frequency amplitude characteristics and time-frequency phase characteristics of ultrasonic signals at the interface of dissimilar material diffusion welding described in this embodiment, said dissimilar material diffusion welding interface is the interface of dissimilar material diffusion welding sample, and The dissimilar material diffusion welding sample is welded by the upper material I and the lower material II, and the steps of the extraction method are:

[0015] Step 1: In the sampling interval [0, n], the ultrasonic signal is incident from the top surface of the dissimilar material diffusion welding specimen to the interface of the dissimilar material diffusion welding specimen, and the ultrasonic signal of the diffusion bonding interface is collected, and n is a decimal. The ultrasonic signal of the diffusion welding ...

specific Embodiment approach 2

[0024] Specific embodiment 2: This embodiment is a further description of the method for extracting time-frequency amplitude characteristics and time-frequency phase characteristics of ultrasonic signals at the interface of dissimilar material diffusion welding described in specific embodiment 1, as described in step three in specific embodiment 1. Continuous wavelet transform function of ultrasonic signal of diffusion welding interface W f (a, b) reflected And reference signal continuous wavelet transform function W f (a, b) reference By formula Obtained, where f(t) correspondingly represents the ultrasonic signal or reference signal of the diffusion welding interface, ψ(t) represents the wavelet mother function, and the wavelet mother function is the complex Morlet wavelet, Represents the continuous wavelet function dependent on the parameters a and b generated by the wavelet mother function ψ(t), called wavelet for short, a represents the scale parameter, which reflects the ...

specific Embodiment approach 3

[0025] Embodiment 3: This embodiment is a further description of the method for extracting time-frequency amplitude characteristics and time-frequency phase characteristics of ultrasonic signals at the interface of dissimilar material diffusion welding described in the first embodiment. In step six of the first embodiment, according to the diffusion The time-frequency amplitude of the ultrasonic signal of the welding interface|R(a,b)|The time-frequency amplitude characteristic value C of the ultrasonic signal of the diffusion welding interface is obtained R The method is based on each time parameter b in the sampling interval [0, n] j The time-frequency amplitude of the ultrasonic signal of the diffusion bonding interface|R(a, b j )|Get the time-frequency amplitude characteristic value C of the ultrasonic signal of the diffusion welding interface R , The specific process is: the each time parameter b j The time-frequency amplitude of the ultrasonic signal of the diffusion bonding ...

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Abstract

The invention relates to a method for extracting the time-frequency amplitude characteristic and the time-frequency phase characteristic of ultrasonic signals on a dissimilar material diffusion welding interface, belonging to the filed of the nondestructive detection and aiming at solving the problem that the conventional method for detecting the diffusion welding quality according to the amplitude of the reflection echo on the diffusion welding interface can not accurately reflect the information on the diffusion welding defect. The method comprises the following steps: collecting ultrasonic signals from the dissimilar material diffusion welding interface; collecting reference signals from a reference sample; continuously changing the wavelets of the ultrasonic signals collected from the dissimilar material diffusion welding interface and the reference signals collected from the reference sample by using the parameter-optimized complex Morlet wavelets to obtain the ratio (R) (a, b) of the ultrasonic signals and the reference signals; respectively calculating the time-frequency amplitude |R (a, b)| and the time-frequency phase Phi (a, b) of the ultrasonic signals collected from the dissimilar material diffusion welding interface by using the R (a, b); respectively calculating the time-frequency amplitude characteristic value CR and the time-frequency phase characteristic value CPhi by using the time-frequency amplitude |R (a, b)| and the time-frequency phase Phi (a, b); and reconstructing the time-frequency amplitude characteristic value CR image and the time-frequency phase characteristic value CPhi image of the ultrasonic signals collected from the dissimilar material diffusion welding interface. The invention is suitable for detecting and evaluating the quality of the diffusion welding interface.

Description

Technical field [0001] The invention relates to the field of non-destructive testing, in particular to a method for extracting time-frequency amplitude characteristics and time-frequency phase characteristics of ultrasonic signals at the interface of dissimilar material diffusion welding. Background technique [0002] At present, diffusion welding is more and more widely used in advanced technology fields such as aviation, aerospace and nuclear industry. How to detect and evaluate the quality of diffusion welding interface has become an important topic in the field of non-destructive testing. Diffusion welding defects mainly include unsoldering, weak joints and micro gaps. Since the defects are located at the interface, conventional ultrasonic flaw detection methods are often used for detection. This method uses the reflected echo generated by the ultrasonic wave at the defect, and judges the size and orientation of the defect by the magnitude of the echo amplitude, which is very...

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Application Information

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IPC IPC(8): G01N29/44
Inventor 栾亦琳刚铁徐振亚
Owner HARBIN INST OF TECH
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