CN116087107A - Surface defect laser nondestructive testing method and device based on dynamic speckle illumination - Google Patents

Surface defect laser nondestructive testing method and device based on dynamic speckle illumination Download PDF

Info

Publication number
CN116087107A
CN116087107A CN202211737436.XA CN202211737436A CN116087107A CN 116087107 A CN116087107 A CN 116087107A CN 202211737436 A CN202211737436 A CN 202211737436A CN 116087107 A CN116087107 A CN 116087107A
Authority
CN
China
Prior art keywords
laser
speckle
detection point
surface defect
vibration meter
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN202211737436.XA
Other languages
Chinese (zh)
Inventor
鲁强兵
卢明辉
谢海圣
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Suzhou Acoustic Industrial Technology Research Institute Co ltd
Original Assignee
Suzhou Acoustic Industrial Technology Research Institute Co ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Suzhou Acoustic Industrial Technology Research Institute Co ltd filed Critical Suzhou Acoustic Industrial Technology Research Institute Co ltd
Priority to CN202211737436.XA priority Critical patent/CN116087107A/en
Publication of CN116087107A publication Critical patent/CN116087107A/en
Pending legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
    • G01N21/1702—Systems in which incident light is modified in accordance with the properties of the material investigated with opto-acoustic detection, e.g. for gases or analysing solids
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
    • G01N21/1702—Systems in which incident light is modified in accordance with the properties of the material investigated with opto-acoustic detection, e.g. for gases or analysing solids
    • G01N2021/1706—Systems in which incident light is modified in accordance with the properties of the material investigated with opto-acoustic detection, e.g. for gases or analysing solids in solids

Landscapes

  • Physics & Mathematics (AREA)
  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Biochemistry (AREA)
  • General Health & Medical Sciences (AREA)
  • General Physics & Mathematics (AREA)
  • Immunology (AREA)
  • Pathology (AREA)
  • Investigating Or Analyzing Materials By The Use Of Ultrasonic Waves (AREA)

Abstract

The invention relates to a surface defect laser nondestructive testing method and device based on dynamic speckle illumination, which realize high-sensitivity detection of surface microcracks based on a coherent speckle dispersion effect of a photoacoustic effect, wherein photoacoustic signals in speckles can cancel each other, and stronger signals are obtained only by coherent superposition on a circular boundary of the speckles. But the surface microcracks cause that the speckle photoacoustic signals cannot be coherently counteracted in the circular light spots, so that the speckle photoacoustic signals generated by microcracks are obtained. And detecting at multiple points around the speckle to obtain multiple photoacoustic signals. And finally obtaining a two-dimensional image of the microcrack through an algorithm.

Description

Surface defect laser nondestructive testing method and device based on dynamic speckle illumination
Technical Field
The invention belongs to the field of laser ultrasonic nondestructive testing, relates to nondestructive defect detection of parts, and in particular relates to a surface defect laser nondestructive testing method and device based on dynamic speckle illumination.
Background
Defects can not be avoided in the production and processing processes of the parts. In particular, microcracks extending from the inside to the surface can reflect various important indexes such as air tightness, fatigue resistance, mechanical strength and the like of the parts. In the same way, the structural tearing can occur under the actions of mechanical force, high-temperature circulation, impact, long-time heavy load and the like in the use process of the parts, the structural tearing is represented by the occurrence and growth of microcracks of the parts, and finally the damage of the parts is caused.
On the premise of not damaging the parts, the surface microcracks of the parts are found as early as possible, and the method has important safety and economic significance for improving the production process and replacing and maintaining the parts in service, thereby ensuring the stability of the system and maintaining the safety of production work. There are currently known various nondestructive inspection methods, such as radial inspection (RT), ultrasonic inspection (UT), magnetic particle inspection (MT), liquid penetration inspection (PT), eddy current inspection (ECT), acoustic emission inspection (AE), thermal imaging/infrared (TIR), leakage Test (LT), alternating Current Field Measurement Technique (ACFMT), magnetic leakage inspection (MFL), and the like. The form of carrying information is mainly ultrasonic wave, X-ray, magnetic field, electric field, infrared ray, etc. High-energy rays such as X-rays have strong ionizing radiation to human bodies and have requirements on use environment. Magnetic powder, point-by-point scanning of a probe and the like are often used in an auxiliary manner in detection methods such as a magnetic field, an electric field and the like, and the use efficiency and the convenience are insufficient. For defects smaller than hundred microns, the resolution of infrared thermal imaging is insufficient to achieve high precision measurements.
The nondestructive detection by using the ultrasonic has the advantages of simple operation, no harm to human bodies, various forms and the like. The traditional ultrasonic nondestructive detection uses an ultrasonic transducer to be closely attached to a part for scanning, and because the distance between the surface defect of the part and the transducer is too short, accurate detection is difficult to achieve. Contact measurement is also a requirement for the technical skill of the operator. Although non-contact type hollow coupling probe ultrasonic nondestructive detection is reported, the detection effect is still different from that of a contact type ultrasonic probe. The laser is used for exciting the ultrasonic wave, and the laser vibration meter is used for detecting the ultrasonic wave, so that non-contact and high-precision nondestructive detection can be realized.
Although the above ultrasonic detection means have been applied in a substantial way, for the surface microcrack defect of the component, whether the transmitted wave amplitude attenuation of the sound wave is utilized or the reflected echo is detected, when the defect scale is close to the detected ultrasonic wavelength, the existing method has a defect in defect detection precision due to the diffraction and diffraction phenomena of the sound wave.
Disclosure of Invention
The invention aims to provide a surface defect laser nondestructive testing method and device based on dynamic speckle illumination, which solve the problem of how to effectively test microcracks.
In order to achieve the above purpose, the invention adopts the following technical scheme:
the invention provides a surface defect laser nondestructive testing method based on dynamic speckle illumination, which comprises the following steps:
s1, processing a laser beam emitted by a pulse laser through an optical component to obtain a flat-top beam, obtaining a randomly scattered laser beam after the flat-top beam passes through a scattering sheet, generating high-frequency and broadband ultrasonic waves by laser speckle on a workpiece, and measuring an electric signal by a laser vibrometer arranged at the periphery of a speckle area by the ultrasonic waves
Figure BDA0004033322900000021
Wherein->
Figure BDA0004033322900000022
Representing the position of a detection point of the laser vibration meter; />
S2, rotating the scattering sheet for a certain angle to measure a new electric signal
Figure BDA0004033322900000023
Where i denotes the signal obtained by the ith measurement, measured N times in total, and the average of the N times is taken as the effective signal +.>
Figure BDA0004033322900000024
S3, adjusting the detection point of the laser vibration meter to rotate by a certain angle theta relative to the workpiece, wherein the position of the detection point of the laser vibration meter is
Figure BDA0004033322900000025
Repeating step S2 to obtain a new measurement signal +.>
Figure BDA0004033322900000026
S4, repeating the step S3 to obtain measurement signals of different positions j
Figure BDA0004033322900000027
The image of its surface microcrack defect is defined by the algorithm +.>
Figure BDA0004033322900000028
Obtained by->
Figure BDA0004033322900000029
The constant, the defect coordinate and the central angle of a detection point of a laser vibration meter relative to the track of the whole circular laser speckle detection point are respectively adopted.
Preferably, the plurality of laser vibrometer detection points are evenly distributed around the circular laser speckle region.
Further, scanning the laser vibrometer detection points to corresponding positions by a galvanometer system to form a plurality of laser vibrometer detection points.
Further, a plurality of laser vibrometer detection points are formed by rotating the motor workpiece.
Preferably, the laser uses 532nm wavelength, the pulse width is 6-10ns, and the laser energy of a single pulse is 50mJ.
Further, the highest measured vibration frequency of the laser vibration meter reaches 20MHZ.
Preferably, laser speckle is achieved using 600 mesh frosted glass, such that the individual speckle sizes are around 10-150 microns with an increment of rotation angle θ of 2.5deg. per measurement.
Further, the distribution diameter of the laser speckles is about 2.5cm, and the detection points of the laser vibrometer are distributed on a circle with the diameter of 5 cm.
The surface defect laser nondestructive testing device based on dynamic speckle illumination is also provided: the laser vibration measuring device comprises a pulse laser, a scattering sheet arranged in the beam of the pulse laser, and a laser vibration measuring instrument for detecting the vibration of the surface of a workpiece, wherein the detection point of the laser vibration measuring instrument can be rotationally adjusted relative to the workpiece, and the laser vibration measuring instrument is used for measuring an electric signal
Figure BDA0004033322900000031
Wherein the method comprises the steps of
Figure BDA0004033322900000032
Indicating the position of the detection point of the laser vibration meter, rotating the scattering sheet for a certain angle, and measuring a new electric signal again>
Figure BDA0004033322900000033
Averaging after multiple measurements as effective signal +.>
Figure BDA0004033322900000034
Then adjusting the detection point of the laser vibration meter to rotate a certain angle theta relative to the workpiece, and repeating the steps to obtain a new measurement signal +.>
Figure BDA0004033322900000035
Obtaining measurement signals of different positions j>
Figure BDA0004033322900000036
Image of surface microcrack defect by algorithm +.>
Figure BDA0004033322900000037
And (3) obtaining the laser speckle detection point, wherein alpha, r and theta are respectively constants, coordinates of defects and central angles of a detection point of a laser vibration meter relative to the track of the whole circular laser speckle detection point.
Preferably, the laser vibration measuring device further comprises a vibrating mirror system or a rotating motor, wherein the vibrating mirror system is matched with the laser vibration measuring device to change the position of a detection point of the laser vibration measuring device, and the rotating motor is used for driving the workpiece to rotate.
Due to the application of the technical scheme, compared with the prior art, the invention has the following advantages:
the invention relates to a surface defect laser nondestructive testing method and a device based on dynamic speckle illumination, which are based on the coherent speckle effect of the photoacoustic effect, wherein ultrasonic waves excited by lasers with the same excitation laser parameters and the same spatial distribution are coherent waves, and the waveforms and the amplitudes are identical. Under the excitation of lower light intensity, the photoacoustic signals are symmetrical bipolar signals, and because the size of the speckles is uniformly and randomly distributed, the photoacoustic signals in the speckles can be mutually offset, when the laser vibrometer detects signals, stronger signals are obtained by coherent superposition on the circular boundaries of the speckles, and the ultrasonic signals in the circular speckles are zero. However, when surface microcracks exist in the workpiece, the coherent cancellation effect among scattered spots in the circular light spot is broken, and finally, a limited value of signals collected by the detection points of the laser vibration meter appears in the circular light spot. And the resolution limit is independent of the ultrasonic frequency generated by the laser and is only related to the speckle size of the laser speckle. The existence of the surface microcracks causes that speckle photoacoustic signals cannot be coherently counteracted in the circular light spots, so that speckle photoacoustic signals generated by the microcracks are obtained, detection points of the laser vibration meter are adjusted to rotate relative to a workpiece, signals are measured for multiple times, and finally, a two-dimensional image of the microcracks is calculated through an algorithm.
Drawings
Some specific embodiments of the invention will be described in detail hereinafter by way of example and not by way of limitation with reference to the accompanying drawings. The same reference numbers will be used throughout the drawings to refer to the same or like parts or portions. It will be appreciated by those skilled in the art that the drawings are not necessarily drawn to scale. In the accompanying drawings:
FIG. 1 is a schematic diagram of a dynamic speckle illumination-based surface defect laser nondestructive inspection apparatus of the present invention;
FIG. 2 is a schematic illustration of workpiece surface speckle, defect, and probe point locations;
FIG. 3 is an ultrasonic signal detected by a laser vibrometer disposed outside of the circular excitation light;
FIG. 4 is an ultrasonic signal detected by a laser vibrometer when there are microcracks in the workpiece;
wherein reference numerals are as follows:
1: a diffusion sheet;
2: pulsed laser;
3: detecting points of a laser vibration meter;
4: a workpiece;
5: a rotating electric machine;
6: laser speckle;
7: microcrack;
8: speckle photoacoustic signals generated by microcracks.
Detailed Description
The following description of the embodiments of the present invention will be made apparent and fully in view of the accompanying drawings, in which some, but not all embodiments of the invention are shown. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
The invention provides a surface defect laser nondestructive testing technology and device based on dynamic speckle illumination, and mainly aims to realize high-sensitivity detection of surface microcracks by using a coherent dissipation speckle effect based on a photoacoustic effect, wherein the whole device is shown in figure 1.
The pulse laser 2 passes through the scattering sheet 1 to obtain a randomly distributed irradiation light spot which irradiates the workpiece 4, and the whole irradiation area of the light spot is circularly distributed. By rotating the scattering sheet 1, different speckle patterns of laser can be obtained randomly, and the uniformity of speckle in spatial distribution is improved. The laser speckle irradiates the workpiece 4, absorbs energy of the laser light, and converts it into heat, eventually causing thermal expansion of the workpiece 4, generating ultrasonic waves, a phenomenon called a photoacoustic effect.
According to the photoacoustic effect, ultrasonic waves excited by laser with the same excitation laser parameters and the same spatial distribution are coherent waves, and the waveforms and the amplitudes are identical. And under the excitation of lower light intensity, the photoacoustic signals are symmetrical bipolar signals. As shown in fig. 3, since the speckle sizes are uniformly and randomly distributed, photoacoustic signals in the speckle cancel each other out. The ultrasonic signals detected by the laser vibrometer arranged outside the circular excitation light are coherently superimposed on the circular boundary to obtain stronger signals, as shown in the lower part of fig. 3, and the ultrasonic signals are zero inside the circular speckle.
When the workpiece 4 is irradiated by a circular light spot, and random laser speckles 6 are distributed in the light spot, coherent superposition can occur between photoacoustic waves generated by a considerable part of the laser speckles 6 at this time, so that the photoacoustic signal intensity on the boundary is enhanced, and the internal signal is weakened. The scattering sheet 1 is rotated to change the mode of the laser speckle 6, and by superposing photoacoustic signals excited by different speckle lasers, the degree of randomness of the overall laser speckle 6 distribution can be improved. I.e. the speckle distribution at each point inside the circular spot is strictly uniform from an equivalent point of view. The more modes of the laser spot are then changed by rotating the diffuser 1, the more pronounced the corresponding speckle effect will be.
As shown in fig. 4, when the surface micro-crack 7 exists in the workpiece 4, the coherent cancellation effect between scattered spots in the circular light spot is broken, and finally, the signal collected by the detection point of the laser vibration meter has a limited value in the circular light spot. And its resolution limit is independent of the frequency of the laser generated ultrasonic waves and is only dependent on the speckle size of the laser speckle 6. The presence of the surface micro-cracks 7 causes that the speckle photo-acoustic signals cannot be coherently counteracted inside the circular light spots, and a speckle photo-acoustic signal 8 generated by the micro-cracks is obtained.
If only one laser vibrometer probe point 3 is not yet sufficient to obtain a two-dimensional image of the micro-crack 7. The invention proposes the detection of speckle around an entire circular laser, the finer the image of the microcracks 7 obtained when the number of points taken is greater. At this time, the micro-crack 7 can be regarded as a source of the speckle photoacoustic signal 8 generated by the micro-crack. The photoacoustic signals measured at different positions of the circular speckle are recorded as
Figure BDA0004033322900000061
Wherein->
Figure BDA0004033322900000062
Is the position of the laser vibrometer probe point 3. Spatial distribution of internal surface microcracks 7
Figure BDA0004033322900000063
This can be solved by the following formula:
Figure BDA0004033322900000064
wherein the method comprises the steps of
Figure BDA0004033322900000065
The constant, the defect coordinate and the central angle of a detection point 3 of a laser vibration meter relative to the track of the whole circular laser speckle detection point are respectively adopted. Through the analysis, the whole thought of the invention is clear, and the specific operation process of the provided surface defect laser nondestructive testing technology and device based on dynamic speckle illumination is as follows:
(1) The laser beam emitted by the pulse laser is processed by the optical component to obtain a flat-top beam, and the flat-top beam is processed by the scattering sheet 1 to obtain a randomly scattered laser beam. The laser speckle is beaten on the workpiece 4 to generate high-frequency and broadband ultrasonic waves, and the ultrasonic waves are measured to electric signals by a laser vibration meter
Figure BDA0004033322900000071
Wherein->
Figure BDA0004033322900000072
The position of the laser vibrometer probe point 3 is shown.
(2) The scattering sheet 1 is rotated by a certain angle to measure a new electric signal
Figure BDA0004033322900000073
Where i represents the signal from the ith measurement. A total of N measurements are taken, whereupon the average of N is taken as the effective signal +.>
Figure BDA0004033322900000074
(3) The workpiece 4 is rotated by a certain angle θ using a rotating motor 5, or the laser vibrometer probe point 3 is scanned to a corresponding position using a galvanometer system. At this time, the position of the laser vibrometer probe point 3
Figure BDA0004033322900000075
And then also changed accordingly. Repeating the step (2) to obtain a new measurement signal +.>
Figure BDA0004033322900000076
(4) Repeating the step (3) to obtain measurement signals of different positions j
Figure BDA0004033322900000077
The image of the surface microcrack defect can be obtained by the following algorithm>
Figure BDA0004033322900000078
In the embodiment, an aluminum alloy metal plate is selected as the workpiece 4, and an arc-shaped microcrack with the width of 50 micrometers and the length of 5 millimeters is formed on the aluminum alloy plate, and the crack depth is about 30-80 micrometers. The traditional laser nondestructive testing method is difficult to detect, and because the depth of the defect crack is shallow, the surface wave can be easily diffracted, and no obvious change is seen from the amplitude. The method and the device provided by the invention are used for detection.
The laser used is 532nm wavelength, the pulse width is 6-10ns, the laser energy of a single pulse is 50mJ, and the specific laser energy can be regulated and controlled by using an external optical component; the highest measured vibration frequency of the laser vibration meter reaches 20MHz.
Laser speckle was achieved using 600 mesh frosted glass and after imaging the speckle was found to be on the order of 10-150 microns in size, sufficient to cover the defect area. The increment of the rotation angle θ per measurement was 2.5deg, and 144 positions of data were measured in total. The distribution diameter of the laser speckle is about 2.5cm, and the detection points 3 of the laser vibration meter are distributed on a circle with the diameter of 5 cm.
The result of a comparison test with a perfect sample proves that the technology provided by the invention can be used for detecting the corresponding defect and imaging the shape of the defect.
The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the present invention and to implement the same, but are not intended to limit the scope of the present invention, and all equivalent changes or modifications made according to the spirit of the present invention should be included in the scope of the present invention.

Claims (10)

1. A surface defect laser nondestructive testing method based on dynamic speckle illumination is characterized by comprising the following steps:
s1, processing a laser beam emitted by a pulse laser through an optical component to obtain a flat-top beam, obtaining a randomly scattered laser beam after the flat-top beam passes through a scattering sheet, generating high-frequency and broadband ultrasonic waves by laser speckle on a workpiece, and measuring an electric signal by a laser vibrometer arranged at the periphery of a speckle area by the ultrasonic waves
Figure FDA0004033322890000011
Wherein->
Figure FDA0004033322890000012
Representing the position of a detection point of the laser vibration meter;
s2, rotating the scattering sheet for a certain angle to measure a new electric signal
Figure FDA0004033322890000013
Where i denotes the signal obtained by the ith measurement, measured N times in total, and the average of the N times is taken as the effective signal +.>
Figure FDA0004033322890000014
S3, adjusting the detection point of the laser vibration meter to rotate by a certain angle theta relative to the workpiece, wherein the position of the detection point of the laser vibration meter is
Figure FDA0004033322890000015
Repeating step S2 to obtain a new measurement signal +.>
Figure FDA0004033322890000016
S4, repeating the step S3 to obtain measurement signals of different positions j
Figure FDA0004033322890000017
Image routing algorithm for surface microcrack defects
Figure FDA0004033322890000018
Obtained, wherein alpha, is>
Figure FDA0004033322890000019
θ is a constant, a coordinate of a defect, and a central angle of a detection point of a laser vibrometer with respect to a track of a detection point of the whole circular laser speckle.
2. The dynamic speckle illumination-based surface defect laser non-destructive inspection method according to claim 1, wherein: the plurality of laser vibrometer probe points are evenly distributed around the circular laser speckle region.
3. The dynamic speckle illumination-based surface defect laser non-destructive inspection method according to claim 2, wherein: and scanning the detection points of the laser vibration meters to corresponding positions through the vibration mirror system so as to form a plurality of detection points of the laser vibration meters.
4. The dynamic speckle illumination-based surface defect laser non-destructive inspection method according to claim 2, wherein: a plurality of laser vibrometer probe points are formed by rotating the motor workpiece.
5. The dynamic speckle illumination-based surface defect laser non-destructive inspection method according to claim 1, wherein: the laser adopts 532nm wavelength, the pulse width is 6-10ns, and the laser energy of a single pulse is 50mJ.
6. The dynamic speckle illumination-based surface defect laser non-destructive inspection method according to claim 5, wherein: the highest measured vibration frequency of the laser vibration meter reaches 20MHz.
7. The dynamic speckle illumination-based surface defect laser non-destructive inspection method according to claim 1, wherein: laser speckle was achieved using 600 mesh frosted glass such that the individual speckle sizes were around 10-150 microns with an increment of 2.5deg. of rotation angle θ measured at a time.
8. The dynamic speckle illumination-based surface defect laser non-destructive inspection method according to claim 7, wherein: the distribution diameter of the laser speckle is about 2.5cm, and the detection points of the laser vibration meter are distributed on a circle with the diameter of 5 cm.
9. A surface defect laser nondestructive testing device based on dynamic speckle illumination is characterized by comprising a pulse laser, a scattering sheet arranged in a beam of the pulse laser, and a laser vibration meter for detecting surface vibration of a workpiece, wherein a detection point of the laser vibration meter can be rotationally adjusted relative to the workpiece, and an electric signal is measured by the laser vibration meter
Figure FDA0004033322890000021
Wherein->
Figure FDA0004033322890000022
Indicating the position of the detection point of the laser vibration meter, rotating the scattering sheet for a certain angle, and measuring a new electric signal again>
Figure FDA0004033322890000023
Averaging after multiple measurements as effective signal +.>
Figure FDA0004033322890000024
Then adjusting the detection point of the laser vibration meter to rotate a certain angle theta relative to the workpiece, and repeating the steps to obtain a new measurement signal +.>
Figure FDA0004033322890000025
Obtaining measurement signals of different positions j>
Figure FDA0004033322890000026
Surface microImage of crack defect is defined by algorithm->
Figure FDA0004033322890000027
Obtained, wherein alpha, is>
Figure FDA0004033322890000028
θ is a constant, a coordinate of a defect, and a central angle of a detection point of a laser vibrometer with respect to a track of a detection point of the whole circular laser speckle.
10. The dynamic speckle illumination-based surface defect laser non-destructive inspection apparatus of claim 9, wherein: the laser vibration meter further comprises a vibration mirror system or a rotating motor, wherein the vibration mirror system is matched with the laser vibration meter to change the position of a detection point of the laser vibration meter, and the rotating motor is used for driving the workpiece to rotate.
CN202211737436.XA 2022-12-31 2022-12-31 Surface defect laser nondestructive testing method and device based on dynamic speckle illumination Pending CN116087107A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202211737436.XA CN116087107A (en) 2022-12-31 2022-12-31 Surface defect laser nondestructive testing method and device based on dynamic speckle illumination

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202211737436.XA CN116087107A (en) 2022-12-31 2022-12-31 Surface defect laser nondestructive testing method and device based on dynamic speckle illumination

Publications (1)

Publication Number Publication Date
CN116087107A true CN116087107A (en) 2023-05-09

Family

ID=86213250

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202211737436.XA Pending CN116087107A (en) 2022-12-31 2022-12-31 Surface defect laser nondestructive testing method and device based on dynamic speckle illumination

Country Status (1)

Country Link
CN (1) CN116087107A (en)

Similar Documents

Publication Publication Date Title
CN107747922B (en) Method for measuring subsurface defect buried depth based on laser ultrasound
EP2316018B1 (en) Nondestructive testing apparatus and method
Leong et al. Structural health monitoring using scanning laser vibrometry: III. Lamb waves for fatigue crack detection
US20040262521A1 (en) Methods for determining the depth of defects
CN108871640A (en) Residual stress nondestructive detection system and method based on transient grating Laser thermo-elastic generated surface acoustic waves
CN110779990B (en) Laser ultrasonic three-dimensional positioning quantitative detection method for multiple defects in material
CN111751448B (en) Surface leakage wave ultrasonic synthetic aperture focusing imaging method
CN109211974B (en) Pulse femtosecond laser infrared thermal wave detection device and method for debonding defect of thermal barrier coating
JP5530975B2 (en) Ultrasonic flaw detection method and ultrasonic flaw detection apparatus
CN113588566B (en) Laser-ultrasonic-based laser spot welding micro-welding point quality detection device and method
KR102285477B1 (en) Apparatus and Method for Noncontact and Non Destructive Test of Defects Inside Metal using Photoacoustic Imaging for After Induction Hardening
JP2011163971A (en) Laser ultrasonic flaw detection method for rotor
CN116087107A (en) Surface defect laser nondestructive testing method and device based on dynamic speckle illumination
KR101057586B1 (en) Apparatus for imaging anomalous ultrasonic wave propagation
Marció et al. Nondestructive inspection of metal specimen using tone-burst vibro-acoustography
CN114935547B (en) Pipeline hardness internal detection method and system
CN113588784B (en) Nondestructive testing method for debonding defect of thin film coating based on grating laser ultrasonic acoustic spectrum
CN114280157A (en) Sub-surface crack length quantitative detection method based on laser excitation surface wave
Fomitchov et al. Ultrasonic imaging of small surface-breaking defects using scanning laser source technique
KR100422259B1 (en) A Method The Defect Defection With Using Digital Ultrasonic Testing
Oe et al. Nondestructive internal defect detection using photoacoustic and self‐coupling effect
US20130088707A1 (en) Method and system for crack detection
CN114295731B (en) Method for measuring subsurface defect depth based on laser excitation longitudinal wave
CN115647591A (en) Laser precision spot welding quality detection device and method based on annular light excitation ultrasound
Hayashi et al. Remote defect imaging for plate-like structures based on the scanning laser source technique

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination