公开(公告)号：US12130259B2

公开(公告)日：2024-10-29

申请号：US17704081

申请日：2022-03-25

Applicant: Harbin Institute of Technology

Inventor： Jiaxin Li ,  Jiubin Tan ,  Bo Zhao ,  Weijia Shi

IPC: G01N29/07 ,  G01N29/34 ,  G01N29/36 ,  G01N29/46

CPC classification number: G01N29/07 ,  G01N29/34 ,  G01N29/36 ,  G01N29/46 ,  G01N2291/0427

Abstract: The present disclosure proposes a non-baseline on-line stress monitoring system and monitoring method based on multi-mode Lamb wave data fusion. A Lamb wave dispersion curve is established according to geometric dimensions and material parameters of a measured object, a cut-off frequency of a first-order Lamb wave mode is obtained, an excitation frequency of a Lamb wave signal is determined, and then pure Lamb waves in S0 and A0 modes obtained inside the measured object are obtained; an acoustoelastic equation is established, an elastodynamic equation of the measured object under a prestress condition is solved, and linear relationships between a group velocity and a stress of the Lamb waves in the S0 and A0 modes under the excitation frequency are obtained; data is processed through the on-line monitoring system; a stress gradient in a depth direction is calculated, and finally, a stress state of the measured object is represented. The present disclosure does not require data under a zero stress state as baseline data, does not require designing a wedge block capable of generating a critical refraction longitudinal wave, and combines acoustoelastic effects of Lamb waves in different modes to realize online stress monitoring without the baseline data.

公开(公告)号：US20230061816A1

公开(公告)日：2023-03-02

申请号：US17552493

申请日：2021-12-16

Applicant: Harbin Institute of Technology

Inventor： Weijia Shi ,  Bingquan Wang ,  Bo Zhao ,  Jiubin Tan

IPC: G01N29/44 ,  G01N29/06 ,  G01N29/22 ,  G01N29/34

Abstract: The disclosure discloses an air-coupled ultrasonic detection method and device based on a defect probability reconstruction algorithm. The method includes the following steps: determining the excitation frequency of a transmitting air-coupled transducer according to a frequency dispersion curve of guided waves and the thickness of a to-be-detected piece; determining the group velocity of an antisymmetric mode according to the excitation frequency, and determining the inclination angle of the transmitting/receiving air-coupled transducer according to the Snell law; obtaining an initial waveform of a defect-free test piece as reference data by adopting a same-side penetration method, then rotating the transmitting/receiving transducer by 360 degrees by taking the Z direction as an axis at preset angle intervals by adopting a rotary scanning method, collecting N groups of signal data of the to-be-detected piece again, comparing the N groups of signal data with the reference data to determine whether the signal characteristics have great changes or not, calculating the defect distribution probability on the to-be-detected piece, and carrying out defect imaging on a rotating coverage area of the transmitting/receiving air-coupled transducer according to the defect distribution probability. According to the method, the precision of traditional air-coupled ultrasonic X and Y scanning detection is improved, and compared with a complex imaging technology, the air-coupled ultrasonic detection method consumes less time.

公开(公告)号：US12203818B2

公开(公告)日：2025-01-21

申请号：US17704090

申请日：2022-03-25

Applicant: Harbin Institute of Technology

Inventor： Weijia Shi ,  Bo Zhao ,  Jiubin Tan

IPC: G01L5/173 ,  G01L1/16 ,  G01L5/167 ,  G01N3/06 ,  G01N3/08 ,  G01N29/07 ,  G01N29/44 ,  G01L1/25 ,  G01M5/00 ,  G01N29/04 ,  G01N29/24

Abstract: The disclosure provides a method, system, device and medium for online monitoring of a plane stress field without baseline data based on a piezoelectric transducer array. Since Lamb waves have complex multi-mode characteristics, a suitable excitation frequency needs to be selected according to geometric dimensions of the structure to be measured, and then, only low-order mode Lamb waves are excited inside the measured structure to avoid serious waveform aliasing. For isotropic measured objects, anisotropic characteristics will be generated under the action of pre-stresses, that is, the propagation velocities of ultrasonic waves in all directions are different, but there is a linear relationship between velocity changes in different propagation directions and stresses. Therefore, there is still a linear relationship between the difference of velocity changes in different propagation directions and the stress. According to this characteristic, a characterization method of an absolute stress field without baseline data can be implemented. The method of the disclosure can make full use of the low attenuation characteristics of the Lamb waves to realize online monitoring of the plane stress field with a large coverage area.

公开(公告)号：US12038413B2

公开(公告)日：2024-07-16

申请号：US17551319

申请日：2021-12-15

Applicant: Harbin Institute of Technology

Inventor： Bo Zhao ,  Weijia Shi ,  Jiaxin Li ,  Jiubin Tan

IPC: G01N29/34 ,  G01N29/07 ,  G01N29/30 ,  G01N29/44 ,  G01N29/46

CPC classification number: G01N29/348 ,  G01N29/075 ,  G01N29/30 ,  G01N29/4436 ,  G01N29/46 ,  G01N2291/0234 ,  G01N2291/02827 ,  G01N2291/0421 ,  G01N2291/048 ,  G01N2291/057 ,  G01N2291/102 ,  G01N2291/2694

Abstract: The disclosure discloses a stress gradient high-efficiency non-destructive detection system based on frequency domain calculation of broadband swept frequency signals, and a detection method thereof. The detection method includes: step 1: calibrating an LCR wave velocity of an object to be measured; step 2: calculating a starting frequency and a cut-off frequency of broadband swept frequency signals based on the LCR wave velocity of the object to be measured in the step 1 and a stress gradient measuring range in a depth direction of the object to be measured; step 3: converting phase delay to time delay information based on the phase delay of the starting frequency and the cut-off frequency in the step 2; and step 4: determining stresses of depths corresponding to different frequency components based on the time delay information in the step 3 to finally realize layer-by-layer scanning of stresses at different depths of the measured object. The disclosure is used to solve the problem of low stress gradient measuring accuracy, and realize the high-efficiency characterization of the stress gradient in the depth direction.

公开(公告)号：US20230081998A1

公开(公告)日：2023-03-16

申请号：US17551319

申请日：2021-12-15

Applicant: Harbin Institute of Technology

Inventor： Bo Zhao ,  Weijia Shi ,  Jiaxin Li ,  Jiubin Tan

IPC: G01N29/34 ,  G01N29/42 ,  G06F17/14

Abstract: The disclosure discloses a stress gradient high-efficiency non-destructive detection system based on frequency domain calculation of broadband swept frequency signals, and a detection method thereof. The detection method includes: step 1: calibrating an LCR wave velocity of an object to be measured; step 2: calculating a starting frequency and a cut-off frequency of broadband swept frequency signals based on the LCR wave velocity of the object to be measured in the step 1 and a stress gradient measuring range in a depth direction of the object to be measured; step 3: converting phase delay to time delay information based on the phase delay of the starting frequency and the cut-off frequency in the step 2; and step 4: determining stresses of depths corresponding to different frequency components based on the time delay information in the step 3 to finally realize layer-by-layer scanning of stresses at different depths of the measured object. The disclosure is used to solve the problem of low stress gradient measuring accuracy, and realize the high-efficiency characterization of the stress gradient in the depth direction.

公开(公告)号：US11536700B2

公开(公告)日：2022-12-27

申请号：US17079430

申请日：2020-10-24

Applicant: HARBIN INSTITUTE OF TECHNOLOGY

Inventor： Bo Zhao ,  Jiaxin Li ,  Weijia Shi ,  Jiubin Tan

IPC: G01N29/26 ,  G01N29/22 ,  G01N29/24 ,  G01N29/04

Abstract: The disclosure relates to a control method of a probe with ultrasonic phased array transducers in a hinge array, and belongs to the technical field of ultrasonic detecting. The control method includes the steps: firstly, fixing a part under test, making a central piezoelectric array element of piezoelectric array elements for the ultrasonic phased array transducers in the hinge array make contact with a surface of the part under test, and then fixing a fixed support; before detection is started, driving the hinge array through voice coil motors to make the piezoelectric array elements completely fit the surface of the part under test, wherein the number of the piezoelectric array elements is 2N+1 (N=1, 2, 3, 4 and 5), and different values of N are selected according to a size of the part under test; with the value of pressure of the central piezoelectric array element as a standard and difference values between values of pressures of other piezoelectric array elements and the value of pressure of the central piezoelectric array element as control signals of respective corresponding voice coil motor coils, controlling output rods to drive the hinge array; keeping the values of pressures of all the piezoelectric array elements consistent by means of an incremental digital PID control method; and then realizing deflecting and focusing of ultrasonic waves by means of a time delay rule for ultrasonic detecting, thereby detecting parts under test with planar or curved surfaces.