Multi-material inspection system and velocity measurement method of critically refracted longitudinal wave based on single-angle wedges

Patent metadata

Field	Value
Publication number	US-11635409-B2
Application number	US-202217742237-A
Country	US
Kind code	B2
Filing date	May 11, 2022
Priority date	Jan 16, 2021
Publication date	Apr 25, 2023
Grant date	Apr 25, 2023

Abstract

A multi-material inspection system and velocity measurement method of critically refracted longitudinal wave based on single-angle wedges belong to the field of nondestructive testing of high-end equipment. The method includes the following steps: designing a transmitting wedge and a receiving wedge with the same inclination angle, and building phased array ultrasonic-based inspection systems of critically refracted longitudinal wave; estimating a longitudinal wave velocity range of a material to be tested, calculating and optimizing a phased array ultrasonic delay law, and building a relation between a longitudinal wave velocity and an amplitude of critically refracted longitudinal wave; reading and interpolating the arrival time of a received signal, and calculating a longitudinal wave velocity of the material to be tested; determining an optimal delay law, and exciting and receiving a critically refracted longitudinal wave.

First claim

What is claimed is:

1. A multi-material sound velocity measurement method of critically refracted longitudinal wave based on single-angle wedges, wherein a phased array ultrasonic law is calculated and optimized, the arrival time of a received signal is read and interpolation is performed, and a critically refracted longitudinal wave velocity of a material is calculated, the method including the steps of:
(1) preliminarily calculating a phased array ultrasonic delay law
preliminarily selecting a number of array elements in an aperture n according to the ultrasonic attenuation coefficient of the wedges, giving a longitudinal wave velocity v m value, calculating a corresponding first critical angle α I by formula (1), and calculating a phased array ultrasonic incident deflection angle θ by formula (2) according to the angle of the wedges:
θ=α I −θ w   (2)

then, calculating a delay law of the phased array ultrasonic transmitting probe by formula (3):

{

t
i

=

(

i
-
I

)

×
P
×
sin
⁢

θ

V
w

θ
>
0

t
i

=

(

J
-
i

)

×
P
×
sin
⁢

(

-
θ

)

V
w

θ
<
0

(
3
)

where i is a serial number of any aperture array element, I is a serial number of an initial aperture array element, J is a serial number of a final aperture array element, I≤i≤J≤n (i, I, J, and n are all positive integers), t i is a delay time of the i-th array element, and P is a spacing between array elements;
(2) optimizing the calculated delay law
selecting a certain value from 5% to 10% in a longitudinal wave velocity range of the to-be-measured material as a step, setting the longitudinal wave velocity v m of the to-be-measured material in sequence from low to high in the phased array ultrasonic inspection system, and exciting and receiving a critically refracted longitudinal wave according to the calculated delay law of the transmitting probe when the receiving probe is not delayed; adjusting a gain of instruments and fixing the gain to a certain value to ensure that a maximum amplitude in the received signals is not less than 80% of a full screenland does not exceed the full screen; building a relation curve between longitudinal wave velocities v m of the material and amplitudes A of critically refracted longitudinal waves, fitting and determining a v m corresponding to the maximum A;
setting different numbers of array elements in an aperture n, obtaining a relation curve between the numbers of array elements in an aperture n of the transmitting probe and the amplitudes A of the critically refracted longitudinal waves by exciting and receiving a critically refracted longitudinal wave according to the calculated delay law of the transmitting probe when the receiving probe is not delayed; selecting a number of array elements in an aperture n according to quality of the received signals, adjusting the gain of instruments, and determining an optimized delay law to ensure that the amplitude of the received signals is not less than 50% of the full screen, and a signal-to-noise ratio is not less than 12 dB;
(3) reading and interpolating the arrival time of a received signal
exciting and receiving a critically refracted longitudinal wave on the basis of the optimized calculated delay law, and recording A scan and B scan signals in the computer at a sampling frequency of not less than 50 MHz; performing linear interpolation on the A scan signal corresponding to each array element, to ensure that a sampling frequency is not less than 500 MHz;
(4) calculating the longitudinal wave velocity of the material to be tested
calculating a delay time t ij between two array elements in the aperture used by the receiving probe by reading and interpolating the arrival time of a received signal, and calculating an angle Δθ between the critically refracted longitudinal wave and a plane of phased array ultrasonic array elements in the B scan in step (5) by formula (4):

Δ
⁢
θ

=

sin

-
1

(

t

t
⁢
j

Assignees

• Univ Dalian Tech

Inventors

• Luo Zhongbing
• Lin Li
• Zhang Song
• Wang Hong
• Jin Shijie
• Ma Zhiyuan

Classifications

• G01N29/2487

  Directing probes, e.g. angle probes (directing arrangements G01N29/221) · CPC title

• G01N29/07 Primary

  by measuring propagation velocity or propagation time of acoustic waves · CPC title

• G01N2291/0289

  Internal structure, e.g. defects, grain size, texture · CPC title

• G01N29/0645

  Display representation or displayed parameters, e.g. A-, B- or C-Scan · CPC title

• G01N2291/102

  one emitter, one receiver · CPC title