CN113777165B - Synthetic aperture dynamic focusing-based ultrasonic detection method for R region component defects and stress - Google Patents
Synthetic aperture dynamic focusing-based ultrasonic detection method for R region component defects and stress Download PDFInfo
- Publication number
- CN113777165B CN113777165B CN202111037507.0A CN202111037507A CN113777165B CN 113777165 B CN113777165 B CN 113777165B CN 202111037507 A CN202111037507 A CN 202111037507A CN 113777165 B CN113777165 B CN 113777165B
- Authority
- CN
- China
- Prior art keywords
- area
- synthetic aperture
- stress
- dynamic focusing
- imaging
- 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.)
- Active
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N29/00—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object
- G01N29/04—Analysing solids
- G01N29/06—Visualisation of the interior, e.g. acoustic microscopy
- G01N29/0654—Imaging
- G01N29/069—Defect imaging, localisation and sizing using, e.g. time of flight diffraction [TOFD], synthetic aperture focusing technique [SAFT], Amplituden-Laufzeit-Ortskurven [ALOK] technique
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L1/00—Measuring force or stress, in general
- G01L1/25—Measuring force or stress, in general using wave or particle radiation, e.g. X-rays, microwaves, neutrons
- G01L1/255—Measuring force or stress, in general using wave or particle radiation, e.g. X-rays, microwaves, neutrons using acoustic waves, or acoustic emission
Landscapes
- Physics & Mathematics (AREA)
- Acoustics & Sound (AREA)
- Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Biochemistry (AREA)
- Analytical Chemistry (AREA)
- Chemical & Material Sciences (AREA)
- General Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Toxicology (AREA)
- Investigating Or Analyzing Materials By The Use Of Ultrasonic Waves (AREA)
Abstract
The invention discloses an ultrasonic detection method for R-region component defects and stress based on synthetic aperture dynamic focusing, which belongs to the technical field of ultrasonic detection and comprises the following steps: designing an R-angle wedge block completely attached to the surface of the to-be-detected part in the R area; fixing the R area to-be-detected piece, the R angle wedge block and the ultrasonic phased array probe; the ultrasonic phased array probe realizes the dynamic focusing of the synthetic aperture by utilizing an acoustic beam focusing delay rule, obtains a dynamic focusing database of the synthetic aperture and the R area interface echo time so as to carry out dynamic focusing imaging on the defect and carry out qualitative and quantitative characterization on the defect; reflecting the change of the sound velocity according to the change of the echo time of the interface of the R area, and combining the relation between the sound velocity and the stress in the acoustic elastic effect to obtain a corresponding stress value. The method is applied to ultrasonic detection of the defects and the stress of the to-be-detected piece in the R area, and realizes simultaneous detection and qualitative and quantitative characterization of the defects and the stress of the to-be-detected piece in the R area on the basis of using the same detection device based on the synthetic aperture dynamic focusing.
Description
Technical Field
The invention relates to the technical field of ultrasonic detection, in particular to an ultrasonic detection method for R-region component defects and stress based on synthetic aperture dynamic focusing.
Background
With the increase of the service life, the aircraft structure is easy to be damaged by cracks, rivet loosening, skin heaving and the like under the action of fatigue load and external environment. These damages reduce the strength and stiffness of the aircraft structure and affect the flight performance and flight safety of the aircraft. Similarly, the defects and stress concentration of the wings also have important influence on the safety of the wings in the using process. If the wing has defects of breakage, fracture and the like in the flying process, great risk is generated to the flying condition, and unpredictable serious consequences are caused to financial resources, personnel safety and the like. Therefore, the airplane wing skin structure is regularly detected and repaired, so that the airplane is in a good state, and the airplane wing skin structure is an important guarantee for guaranteeing the flight fighting capacity of troops.
In order to be suitable for different application occasions, most components on the airplane have complex shape structural regions, such as L-shaped components, T-shaped components, omega-shaped components and the like. These are collectively referred to as having an R-zone component, and the ribbed panel under the wing skin has an R-zone structure. The R transition region is a stress concentration region, and is prone to generate defects such as cracks and voids during production, manufacturing and use, or generate phenomena such as fracture due to excessive stress. In order to guarantee the service life of the ribbed wallboard under the wing skin and the safety and reliability requirements of users, the R region is subjected to defect and stress field detection and safety performance evaluation by adopting an accurate and reliable nondestructive detection technology, and the method has very important significance.
The ultrasonic detection technology is a detection technology which is used for researching reflected, transmitted and scattered waveforms of a test piece after ultrasonic waves interact with the test piece, so that macroscopic defect detection, geometric characteristic detection, mechanical property change and tissue structure detection and characterization of the test piece are completed, and specific application performance of the test piece is evaluated.
In recent years, the ultrasonic nondestructive testing technology is rapidly developed in the field of industrial testing, the ultrasonic nondestructive testing technology is more and more emphasized and becomes a hot point of research, and more researchers carry out deep research on the ultrasonic nondestructive testing technology. The Guilin electronic science and technology university provides a novel ultrasonic detection system for metal internal defects, which comprises a narrow-line-width laser, an isolator, a circulator, an optical fiber regulator, an electric precise displacement platform, a convex lens, a spectroscope, a spatial pulse laser, a photoelectric detector, an oscilloscope and a signal analysis and identification module, wherein a metal sample to be detected is fixed on the electric precise displacement platform, one side of the electric precise displacement platform is sequentially provided with the convex lens, the spectroscope and the spatial pulse laser, laser emitted by the spatial pulse laser is divided into two parts of energy through the spectroscope, one part of the energy is received by the spatial photoelectric detector and converted into an electric signal, and then is transmitted into the oscilloscope to serve as a trigger signal, and the other part of laser is focused on the surface of the metal sample to be detected fixed on the electric precise displacement platform through the convex lens and is used for exciting ultrasonic waves; the device comprises an electric precise mobile platform, a circulator, a narrow-linewidth laser, a signal analysis and identification module, an optical fiber regulator, a photoelectric detector, an oscilloscope, a detector and a circulator, wherein the circulator is arranged on the other side of the electric precise mobile platform and is regulated and fixed through the optical fiber regulator to serve as a detection head, the circulator is connected with the narrow-linewidth laser through an isolator to form an optical fiber Fizeau interferometer detection system, the output end of the circulator is further connected with the input end of the photoelectric detector, the output end of the photoelectric detector is connected with the input end of the oscilloscope, the output end of the oscilloscope is connected with the input end of the signal analysis and identification module, the detection head transmits signals to the photoelectric detector, the photoelectric detector outputs interference signals, the interference signals are input into the oscilloscope, the oscilloscope outputs detection signals, and the detection signals are subjected to integration processing by the signal analysis and identification module to obtain detection results. However, this method has problems in that: the whole device is complex, inconvenient to operate and not suitable for detection of R-zone components and actual occasions.
A phased array ultrasonic detection system and method for defects of a matrix structure skin and a matrix end point which are not connected are provided by Beijing starship electromechanical equipment Limited company, and the phased array ultrasonic detection system comprises a scanning module and an image analysis module; the scanning module is used for scanning the additive manufacturing lattice structure skin, acquiring ultrasonic C scanning imaging of the lattice structure skin and lattice endpoints and sending the ultrasonic C scanning imaging to the image analysis module; the image analysis module is used for analyzing and judging the received ultrasonic C scanning imaging. The method can detect the defect that the skin is not connected with the dot matrix end point more intuitively, and prevent the workpiece from being damaged in the using process; not only can accurately finish product detection, but also greatly improves the detection efficiency and the detection flexibility. However, this method has problems in that: the imaging device and the imaging method cannot be suitable for the R region to-be-detected component, cannot detect the stress field at the same time, and do not consider the mutual coupling and influence of the defect and the stress field when the defect and the stress field exist.
The invention provides a real-time detection method of an angle-division multiplexing digital holographic photoelastic two-dimensional stress field, which is a real-time detection method of a digital holographic photoelastic two-dimensional stress field and adopts two lasers with different wavelengths to simultaneously irradiate a tested piece. The reference light with different wavelengths is respectively divided into two beams of light with different polarization directions to form four beams of reference light with different polarization directions, and the two beams of reference light with different wavelengths are respectively guided into the same light path. The holographic images of the photoelastic test piece before loading are shot by two CCDs, two object light field images are reconstructed by each hologram by using an angle division multiplexing method, four object light field images are obtained in total, and four object light field images during loading are obtained by using the two CCDs. Fourier transformation, filtering and inverse transformation are carried out on the four pairs of object light field images to obtain four light intensity equations related to the magnitude and direction of the main stress, and the four light intensity equations are solved to obtain two main stress values and the main stress direction of the two-dimensional stress field. The method can directly solve the two-dimensional stress field and carry out real-time detection on the changed stress field; the difficulty and the error of the experiment are reduced. However, this method has problems in that: the detection method can only detect the surface stress field, has insufficient detection depth, cannot detect defects at the same time, and has poor adaptability.
At present, defect ultrasonic detection and stress field ultrasonic detection on a to-be-detected piece are often carried out independently in the market, and the influence brought by the other party is not considered when the detection is carried out independently. However, in practical inspection requirements, defects and stress fields in the object to be inspected often exist at the same time, and the defects and the stress fields are coupled with each other and have influence. How to find the unique characteristics of the two and distinguish the two and accurately image the two becomes a problem to be solved urgently.
Therefore, an ultrasonic detection device and an imaging method for qualitative and quantitative characterization, which can be applied to an R-region object to be detected and detect defects and stress fields simultaneously, are urgently needed.
Disclosure of Invention
The present invention is directed to solving, at least to some extent, one of the technical problems in the related art.
Therefore, the invention aims to provide an ultrasonic detection method for R region component defects and stress based on synthetic aperture dynamic focusing, which realizes simultaneous detection and qualitative and quantitative characterization of the R region defects and stress of a piece to be detected on the basis of using the same detection device.
In order to achieve the above object, an embodiment of the present invention provides an ultrasonic detection method for R region component defect and stress based on synthetic aperture dynamic focusing, including the following steps: step S1, designing an R-angle wedge block completely attached to the surface of the to-be-detected piece in the R area; step S2, fixing the R-area piece to be tested, placing the R-angle wedge block and the R-area piece to be tested in a fitting manner, and then fixedly connecting the ultrasonic phased array probe with the R-angle wedge block; step S3, dividing the imaging area of the R area to-be-detected piece, realizing the dynamic focusing of the synthetic aperture of the ultrasonic phased array probe by using an acoustic beam focusing delay rule, obtaining a dynamic focusing database of the synthetic aperture and the R area interface echo time, and constructing R area defect detection imaging according to the dynamic focusing database and the R area interface echo time; step S4, dividing the imaging area of the R area to-be-detected piece, enabling the synthetic acoustic beam of the synthetic aperture to vertically enter respective small arc-shaped grids by adopting an acoustic beam focusing delay method, obtaining the average sound velocity of the arc-shaped area, and processing the average sound velocity according to the acoustoelastic effect to obtain an average stress value.
The ultrasonic detection method for the defects and the stress of the R-area component based on the synthetic aperture dynamic focusing realizes the simultaneous detection of the defects and the stress of the R-area component to be detected on the basis of using the same ultrasonic detection device, and the effective acoustic coupling between the ultrasonic phased array probe and the component to be detected is the premise and the basis for realizing the detection of the R-area and ensuring the detection performance; designing an R angle wedge block matched with the R area to-be-detected piece to be completely attached to the surface of the R area of the to-be-detected piece, ensuring that the sound beam enters the to-be-detected piece as much as possible, and reducing the energy loss of the sound beam; the ultrasonic phased array probe realizes synthetic aperture dynamic focusing by utilizing an acoustic beam focusing delay rule to obtain a synthetic aperture dynamic focusing database and R area interface echo time; the synthetic aperture dynamic focusing database is used for dynamic focusing imaging of later-stage defects and qualitative and quantitative characterization of the defects; the change of the sound velocity is reflected by the change of the echo time of the R area interface, and a corresponding stress value is obtained by combining the relation between the sound velocity and the stress in the acoustic elastic effect.
In addition, the ultrasonic detection method for R-region component defect and stress based on synthetic aperture dynamic focusing according to the above embodiment of the present invention may further have the following additional technical features:
further, in one embodiment of the present invention, a preset amount of coupling agent is coated on a contact surface of the ultrasonic phased array probe and the R-angle wedge.
Further, in an embodiment of the present invention, before performing the step S3 and the step S4, the number of array elements of the synthetic aperture of the ultrasound phased array probe is predetermined, and the acquisition of the echo data is performed in a dynamic focusing transceiving mode according to the number of array elements.
Further, in an embodiment of the present invention, the step S3 specifically includes: step S301, selecting an arc area of the R area to-be-detected piece as an imaging area, dividing grids by preset step values in an arc angle direction and a radius direction, and realizing the dynamic focusing of the synthetic aperture of the ultrasonic phased array probe by using a sound beam focusing delay rule to obtain the coordinates of each imaging focus point in the imaging area so as to determine the index value of each imaging focus point in the echo data; step S302, calculating the sound path of each imaging focus point relative to each array element wafer in the synthetic aperture based on Snell law, determining the position coordinates of refraction points of a tested sample interface according to Fermat principle, further obtaining the minimum R area interface echo time from the transmitting array element to each imaging focus point through the refraction points, and constructing the dynamic focusing database; and step S303, carrying out addressing calculation on the signal data in the dynamic focusing database according to the index value of each imaging focusing point to obtain a plurality of amplitude values to be used as the gray values of the corresponding imaging focusing points, and further finishing R-region defect detection imaging.
Further, in an embodiment of the present invention, the step S4 specifically includes: step S401, selecting an arc area of the R area to-be-detected piece as an imaging area, and dividing grids by adopting an arc angle direction according to a preset step value to obtain an arc grid area; step S402, determining the synthetic aperture of each small arc-shaped grid, enabling the synthetic acoustic beam of the synthetic aperture to vertically enter each small arc-shaped grid according to an acoustic beam focusing delay method, receiving an echo signal to obtain interface echo time of each grid region, and comparing the interface echo time with a calibration value to obtain the average sound velocity of the arc-shaped grid region; step S403, processing the average sound velocity according to the relationship between the sound velocity and the stress in the acoustic elastic effect, and obtaining the average stress value.
Further, in one embodiment of the present invention, the relationship between sound velocity and stress in the acoustic elastic effect is:
where ρ is0Is the density of the object in an unstressed state, and lambda and mu are independent second-order elastic constants; l, m and n are independent third-order elastic constants, v is the average sound velocity, and sigma is the stress value.
Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.
Drawings
The foregoing and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:
FIG. 1 is a flow chart of an ultrasonic inspection method of R-zone component defects and stresses based on synthetic aperture dynamic focusing in accordance with an embodiment of the present invention;
FIG. 2 is a schematic structural diagram of an ultrasonic testing apparatus according to an embodiment of the present invention;
FIG. 3 is a schematic structural diagram of a linear array ultrasonic phased array probe in accordance with one embodiment of the present invention;
FIG. 4 is a schematic illustration of the acoustic wave travel time of one embodiment of the present invention;
FIG. 5 is a schematic diagram illustrating the interface division of the device under test in the R region according to an embodiment of the present invention;
FIG. 6 is a schematic diagram of synthetic aperture dynamic focus defect detection according to one embodiment of the present invention;
FIG. 7 is a flow chart of ultrasonic defect detection according to one embodiment of the present invention;
FIG. 8 is a schematic diagram of a synthetic aperture stress test according to an embodiment of the present invention;
FIG. 9 is a block diagram of a stress ultrasound testing process according to an embodiment of the present invention.
Description of the reference numerals: the device comprises a 1-linear array ultrasonic phased array probe, a 1 a-array element wafer, a 1 b-linear array ultrasonic phased array probe shell, a 2-R angle wedge block and a 3-R area to-be-detected part.
Detailed Description
Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.
The method for detecting the R-region component defect and stress ultrasonic based on the synthetic aperture dynamic focusing, which is provided by the embodiment of the invention, is described below with reference to the attached drawings.
FIG. 1 is a flow chart of an ultrasonic inspection method of R-zone component defects and stresses based on synthetic aperture dynamic focusing according to an embodiment of the present invention.
As shown in FIG. 1, the ultrasonic detection method for R-region component defect and stress based on synthetic aperture dynamic focusing comprises the following steps:
in step S1, an R-corner wedge is designed to completely conform to the surface of the R-region workpiece.
Specifically, the R-angle wedge matched with the R-area piece to be tested is designed to be completely attached to the surface of the R-area of the piece to be tested, so that the sound beam is ensured to enter the piece to be tested as far as possible, and the energy loss of the sound beam is reduced.
In step S2, the R-region object to be measured is fixed, the R-angle wedge block is placed in contact with the R-region object to be measured, and then the ultrasonic phased array probe is fixedly connected to the R-angle wedge block.
Further, in one embodiment of the invention, the contact surface of the ultrasonic phased array probe and the R-angle wedge is coated with a preset amount of coupling agent.
Specifically, as shown in fig. 2, before starting the detection, the R-region to-be-detected piece is fixed, so that the ultrasonic phased array probe is fixedly connected with the R-angle wedge block, and a certain amount of coupling agent is coated on a contact interface between the R-angle wedge block and the R-angle wedge block to ensure effective acoustic coupling, so that the R-angle wedge block and the upper surface of the R-region to-be-detected piece realize effective acoustic coupling through the coupling agent.
Further, in the embodiment of the present invention, an ultrasonic phased array probe with 32 array elements is taken as an example, and is numbered from No. 1 to No. 32, before performing step S3 and step S4, the number of array elements of the synthetic aperture of the ultrasonic phased array probe is predetermined, as shown in fig. 3, starting from the array element No. 1, and taking 8 array elements as a group of synthetic apertures, the ultrasonic phased array probe with 32 array elements performs acquisition of echo data in a dynamic focusing transceiving mode, and performs excitation according to a beam focusing delay rule, so that a synthetic focusing beam of the synthetic aperture passes through the center of an arc surface of an R-region to-be-measured piece 3 and enters the R-region to-be-measured piece 3 perpendicularly to the arc interface of the to-be-measured piece, thereby obtaining echo data of each array element of the synthetic aperture, and stores the acquired data in the register 1, the synthetic aperture moves a distance to the right, and exciting the array elements and acquiring data in the manner, storing the acquired data in the register 2, and so on until the synthetic aperture moves by 25 array element distances, and completing data transceiving of the 25 th dynamic focusing mode. Then, step S3 and step S4 are performed to perform a series of operations such as delay adjustment, signal superposition, and averaging on the time difference calculated by the data in the register according to the delay rule, so as to obtain 25 a dynamic focusing database of the combined aperture, which will be described in detail below.
In step S3, the imaging area of the to-be-detected element in the R region is divided, the dynamic focusing of the synthetic aperture of the ultrasonic phased array probe is realized by using the acoustic beam focusing delay rule, the dynamic focusing database of the synthetic aperture and the echo time of the interface in the R region are obtained, and the defect detection imaging in the R region is constructed according to the dynamic focusing database and the echo time of the interface in the R region.
Further, in an embodiment of the present invention, step S3 specifically includes:
step S301, selecting an arc area of a to-be-detected piece in an R area as an imaging area, dividing grids by preset step values in an arc angle direction and a radius direction, and realizing the synthetic aperture dynamic focusing of an ultrasonic phased array probe by using an acoustic beam focusing delay rule to obtain the coordinates of each imaging focus point in the imaging area so as to determine the index value of each imaging focus point in echo data;
step S302, calculating the sound path of each imaging focus point relative to each array element wafer in the synthetic aperture based on Snell law, determining the position coordinates of refraction points of a tested sample interface according to Fermat principle, further obtaining the minimum R area interface echo time from the transmitting array element to each imaging focus point through the refraction points, and constructing a dynamic focusing database;
and step S303, carrying out addressing calculation on the signal data in the dynamic focusing database according to the index value of each imaging focusing point to obtain a plurality of amplitude values to be used as the gray values of the corresponding imaging focusing points, and further finishing R-region defect detection imaging.
It will be appreciated that when an array of ultrasonic waves is transmitted or received through the sample interface as perpendicularly as possible and propagates to the focal point within the sample, the resulting energy loss is small and the propagation path can be considered to be the optimal path.
Therefore, the embodiment of the invention determines the position of the array element wafer corresponding to the acoustic wave passing through the R-area to-be-detected interface from the imaging focus point vertically, namely the intersection position C of the extension line of the imaging focus point and the arc center point and the array element wafer; then, the wafer position is taken as the center, 8 adjacent array element wafers are selected as the synthetic aperture of the imaging focus point, and the index value of the synthetic aperture in the echo data is determined.
Then, the acoustic path of the imaging focus point relative to each array element wafer in the synthetic aperture, namely the acoustic wave propagation time is calculated based on Snell's law.
As shown in fig. 4, the calculation of the propagation time of the ultrasonic detection sound wave is specifically described. The formula of Snell's law in acoustics is expressed as:
in the formula, thetaiIs the angle of incidence, θrAngle of refraction, c1Longitudinal or transverse waves of incident layer mediumWave velocity, c2The wave velocity of longitudinal wave or transverse wave of the refraction layer medium;
when the sound wave has a secondary coordinate of (x)i,zi) Reaches the refraction point (x) on the interface of the tested sampleb,zb) And reaches the focus point (x) by refractionr,zr) Angle of incidence θiAnd angle of refraction thetarIt can be derived that,
in the formula, xi＝(i-N/2-0.5)·d(i＝1,2,...,N)，zi＝0。
As shown in FIG. 5, the interface between the R-corner wedge 2 and the R-region DUT 3 can be divided into a plane L1Arc surface L2Plane L3The 3 moieties wherein zbAnd the included angle between the normal of the refraction point and the positive direction of the x axis
Can be expressed as
The interface L can be obtained by substituting the formula (3) and the formula (4) for the formula (2)1、L2、L3Solving 3 equations to obtain the unique unknown number xbWhile obtaining zbAt this time, 3 refraction points (x) are obtainedb1,zb1)、 (xb2,zb2) And (x)b3,zb3) The propagation time, t, from the transmitting array element to the focusing point through the 3 different refraction points is calculated respectively1、t2And t3。
Next, according to the sound waveIs the Fermat principle of propagation along the shortest path in use, finds the minimum value, min { t }, among 3 acoustic propagation times1,t2,t3The obtained propagation time is corresponding to the position coordinate of the real refraction point on the tested sample interface, so that the propagation time from the transmitting array element to the imaging focus point through the refraction point is obtained. And finally, performing addressing calculation on the signal data in the dynamic focusing database according to the index values through the obtained sound paths to obtain the amplitude value as the gray value of the imaging focusing point, thereby completing R-region defect detection imaging.
For example, as shown in fig. 6 and 7, an arc region of the R-region workpiece to be measured 3 is selected as an imaging region, a grid is divided by a certain step value in an arc angle direction and a radius direction, coordinates of each imaging focus point in the imaging region are obtained, and an index value of the focus point in the echo data is determined. Determining the position of the array element wafer 1a corresponding to the acoustic wave passing through the R-area to-be-detected piece 3 interface from the imaging focus point vertically, namely the intersection position of the extension line of the imaging focus point and the arc center point and the array element wafer 1 a; then, the wafer position is used as the center, the adjacent M array element wafers 1a are selected as the synthetic aperture of the imaging focus point, and the index value of the synthetic aperture in the echo data is determined. Therefore, the starting and ending elements of the synthetic aperture corresponding to the focal point (x, z) can be derived as:
in the formula, N is the number of array elements of the phased array transducer, d is the spacing of the array elements, H is the vertical distance between the center of a circular arc of an R area and the lower surface of the linear array ultrasonic phased array probe, and [ ] is a rounding symbol; and M is the number of the array elements of the synthetic aperture, and the sound path of the imaging focus point relative to each array element wafer in the synthetic aperture, namely the sound wave propagation time, is calculated based on Snell's law. According to the Fermat principle that sound waves always propagate along the shortest path in use, the position coordinates of the refraction point of the tested sample interface are determined, and therefore the propagation time from the transmitting array element to the imaging focus point through the refraction point is obtained.
And performing addressing calculation on the signal data in the dynamic focusing database according to the index values through the obtained sound paths to obtain the amplitude value as the gray value of the imaging focusing point, thereby completing R-region defect detection imaging.
In step S4, the imaging area of the R-area to-be-measured element is divided, the synthetic acoustic beam with the synthetic aperture vertically enters each small arc-shaped grid by using an acoustic beam focusing delay method, the average acoustic velocity of the arc-shaped area is obtained, and the average acoustic velocity is processed according to the acoustic elastic effect, so as to obtain the average stress value.
Further, in an embodiment of the present invention, step S4 specifically includes:
step S401, selecting an arc area of the R area to-be-detected piece as an imaging area, and dividing grids by adopting an arc angle direction according to a preset step value to obtain an arc grid area;
step S402, determining the synthetic aperture of each small arc-shaped grid, enabling the synthetic acoustic beam of the synthetic aperture to vertically enter each small arc-shaped grid according to an acoustic beam focusing delay method, receiving an echo signal to obtain interface echo time of each grid region, and comparing the interface echo time with a calibration value to obtain the average sound velocity of the arc-shaped grid region;
step S403, processing the average sound velocity according to the relation between the sound velocity and the stress in the acoustic elastic effect to obtain an average stress value.
Specifically, as shown in fig. 8 and 9, since the stress of the R-region to-be-detected member is mainly concentrated near the surface of the R-region, the average stress value of the stress detection is equivalent to the stress value near the surface of the R-region, and qualitative characterization of the plane stress of the R-region member is achieved. Therefore, in the embodiment of the invention, the arc area of the to-be-detected part 3 in the R area is selected as the imaging area, and the grid is divided by a certain stepping value in the arc angle direction. And determining the synthetic aperture of each small arc grid, and enabling the synthetic sound beam of the synthetic aperture to vertically enter the small arc grids according to the sound beam focusing delay rule. Receiving echo signals to obtain interface echo time t of each grid region, and obtaining average sound velocity of the arc grid region
According to the relation between the sound velocity and the stress in the acoustic elastic effect,
in the formula, ρ0λ and μ are independent second-order elastic constants, called Lame constants, for the density of the object in an unstressed state; l, m and n are independent third-order elastic constants called Murnaghan constants; from the average speed of sound
Obtaining the stress value near the surface of the R area of the arc grid area
In summary, the ultrasonic detection method for the defects and stress of the component in the R region based on the dynamic focusing of the synthetic aperture provided by the embodiment of the invention realizes the simultaneous detection of the defects and stress of the component to be detected in the R region on the basis of using the same ultrasonic detection device, and the effective acoustic coupling between the ultrasonic phased array probe and the component to be detected is the premise and the basis for realizing the detection of the R region and ensuring the detection performance; designing an R angle wedge block matched with the R area to-be-detected piece to be completely attached to the surface of the R area of the to-be-detected piece, ensuring that the sound beam enters the to-be-detected piece as much as possible, and reducing the energy loss of the sound beam; the ultrasonic phased array probe realizes synthetic aperture dynamic focusing by utilizing an acoustic beam focusing delay rule to obtain a synthetic aperture dynamic focusing database and R area interface echo time; the synthetic aperture dynamic focusing database is used for dynamic focusing imaging of later-stage defects and qualitative and quantitative characterization of the defects; the change of the sound velocity is reflected by the change of the echo time of the R area interface, and a corresponding stress value is obtained by combining the relation between the sound velocity and the stress in the acoustic elastic effect.
Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.
In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.
Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.
Claims (4)
1. An ultrasonic detection method for R region component defects and stress based on synthetic aperture dynamic focusing is characterized by comprising the following steps:
step S1, designing an R-angle wedge block completely attached to the surface of the part to be tested in the R area;
step S2, fixing the R-area piece to be tested, placing the R-angle wedge block and the R-area piece to be tested in a fitting manner, and then fixedly connecting the ultrasonic phased array probe with the R-angle wedge block;
step S3, dividing the imaging area of the R-region to-be-detected element, implementing the synthetic aperture dynamic focusing of the ultrasonic phased array probe by using an acoustic beam focusing delay rule, obtaining a dynamic focusing database of the synthetic aperture and R-region interface echo time, and constructing R-region defect detection imaging according to the dynamic focusing database and the R-region interface echo time, specifically:
step S301, selecting an arc area of the R area to-be-detected piece as an imaging area, dividing grids by preset step values in an arc angle direction and a radius direction, and realizing the synthetic aperture dynamic focusing of the ultrasonic phased array probe by using an acoustic beam focusing delay rule to obtain the coordinates of each imaging focus point in the imaging area so as to determine the index value of each imaging focus point in the echo data;
step S302, calculating the sound path of each imaging focus point relative to each array element wafer in the synthetic aperture based on Snell law, determining the position coordinates of refraction points of a tested sample interface according to Fermat principle, further obtaining the minimum R area interface echo time from the transmitting array element to each imaging focus point through the refraction points, and constructing the dynamic focusing database;
step S303, carrying out addressing calculation on the signal data in the dynamic focusing database according to the index value of each imaging focusing point to obtain a plurality of amplitude values to be used as the gray values of the corresponding imaging focusing points, and further completing R region defect detection imaging;
step S4, dividing the imaging area of the R area to-be-detected piece, enabling the synthetic sound beam of the synthetic aperture to vertically enter each small arc-shaped grid by adopting a sound beam focusing delay method to obtain the average sound velocity of the arc-shaped area, and processing the average sound velocity according to the acoustoelastic effect to obtain an average stress value, wherein the method specifically comprises the following steps:
step S401, selecting an arc area of the R area to-be-detected piece as an imaging area, and dividing grids by adopting an arc angle direction according to a preset step value to obtain an arc grid area;
step S402, determining the synthetic aperture of each small arc-shaped grid, enabling the synthetic acoustic beam of the synthetic aperture to vertically enter each small arc-shaped grid according to an acoustic beam focusing delay method, receiving an echo signal to obtain interface echo time of each grid region, and comparing the interface echo time with a calibration value to obtain the average sound velocity of the arc-shaped grid region;
step S403, processing the average sound velocity according to the relationship between the sound velocity and the stress in the acoustic elastic effect, and obtaining the average stress value.
2. The ultrasonic detection method for the defects and the stresses of the R-region component based on the dynamic focusing of the synthetic aperture as claimed in claim 1, wherein the contact surface of the ultrasonic phased array probe and the R-angle wedge is coated with a preset amount of coupling agent.
3. The method of claim 1, wherein before the steps S3 and S4, the number of array elements of the synthetic aperture of the ultrasonic phased array probe is predetermined, and the acquisition of the echo data is performed in a dynamic focusing transmit/receive mode according to the number of array elements.
4. The ultrasonic detection method for the defects and the stresses of the R-zone component based on the dynamic focusing of the synthetic aperture as claimed in claim 1, wherein the relation between the sound velocity and the stress in the acoustic elastic effect is as follows:
where ρ is0Is the density of the object in an unstressed state, and lambda and mu are independent second-order elastic constants; l, m and n are independent third-order elastic constants, v is the average sound velocity, and sigma is the stress value.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111037507.0A CN113777165B (en) | 2021-09-06 | 2021-09-06 | Synthetic aperture dynamic focusing-based ultrasonic detection method for R region component defects and stress |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111037507.0A CN113777165B (en) | 2021-09-06 | 2021-09-06 | Synthetic aperture dynamic focusing-based ultrasonic detection method for R region component defects and stress |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113777165A CN113777165A (en) | 2021-12-10 |
| CN113777165B true CN113777165B (en) | 2022-06-17 |
Family
ID=78841164
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111037507.0A Active CN113777165B (en) | 2021-09-06 | 2021-09-06 | Synthetic aperture dynamic focusing-based ultrasonic detection method for R region component defects and stress |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113777165B (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114487114B (en) * | 2021-12-20 | 2023-09-29 | 中国科学院深圳先进技术研究院 | Detection method based on omnidirectional ultrasonic probe, device and ultrasonic detection system thereof |
| CN114994177B (en) * | 2022-05-26 | 2023-06-09 | 哈尔滨工业大学 | Ultrasonic defect detection method and device for composite board and composite board |
| CN114964581B (en) * | 2022-06-01 | 2024-05-03 | 合肥工业大学智能制造技术研究院 | Stress detection method based on ultrasonic phased array focusing principle |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS60236062A (en) * | 1984-05-09 | 1985-11-22 | Toshiba Corp | Ultrasonic test equipment |
| CN1804611A (en) * | 2005-12-27 | 2006-07-19 | 哈尔滨工业大学 | Ultrasonic time-of-flight diffraction detection method based on synthetic aperture focusing technique |
| CN106093205A (en) * | 2016-05-31 | 2016-11-09 | 大连理工大学 | A kind of thick-walled structure defect inspection method based on the ultrasonic synthetic aperture focusing of oblique incidence |
| WO2017219471A1 (en) * | 2016-06-22 | 2017-12-28 | 杨越 | Method for forming ultrasonic three-dimensional image of unmanned vessel monitoring region by using orthogonal array |
| CN111289627A (en) * | 2020-03-31 | 2020-06-16 | 大连理工大学 | Method for improving R-region phased array ultrasonic detection capability of complex-shaped component |
| CN112305080A (en) * | 2020-11-23 | 2021-02-02 | 西安热工研究院有限公司 | Phased array ultrasonic detection method for crack of reverse T-shaped blade root groove |
-
2021
- 2021-09-06 CN CN202111037507.0A patent/CN113777165B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS60236062A (en) * | 1984-05-09 | 1985-11-22 | Toshiba Corp | Ultrasonic test equipment |
| CN1804611A (en) * | 2005-12-27 | 2006-07-19 | 哈尔滨工业大学 | Ultrasonic time-of-flight diffraction detection method based on synthetic aperture focusing technique |
| CN106093205A (en) * | 2016-05-31 | 2016-11-09 | 大连理工大学 | A kind of thick-walled structure defect inspection method based on the ultrasonic synthetic aperture focusing of oblique incidence |
| WO2017219471A1 (en) * | 2016-06-22 | 2017-12-28 | 杨越 | Method for forming ultrasonic three-dimensional image of unmanned vessel monitoring region by using orthogonal array |
| CN111289627A (en) * | 2020-03-31 | 2020-06-16 | 大连理工大学 | Method for improving R-region phased array ultrasonic detection capability of complex-shaped component |
| CN112305080A (en) * | 2020-11-23 | 2021-02-02 | 西安热工研究院有限公司 | Phased array ultrasonic detection method for crack of reverse T-shaped blade root groove |
Also Published As
| Publication number | Publication date |
|---|---|
| CN113777165A (en) | 2021-12-10 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN113777165B (en) | Synthetic aperture dynamic focusing-based ultrasonic detection method for R region component defects and stress | |
| Zhang et al. | Defect characterization using an ultrasonic array to measure the scattering coefficient matrix | |
| Chen et al. | Finite element analysis model on ultrasonic phased array technique for material defect time of flight diffraction detection | |
| Felice et al. | Sizing of flaws using ultrasonic bulk wave testing: A review | |
| EP3112857B1 (en) | System comprising an aircraft structural object attached to an ultrasonic test system, and ultrasonic test method | |
| EP3531123B1 (en) | Laser ultrasound scanning for visualizing damage or irregularities | |
| CN108871640B (en) | Transient grating laser ultrasonic surface wave-based residual stress nondestructive testing system and method | |
| Zhang et al. | Efficient immersion imaging of components with nonplanar surfaces | |
| CN113899816B (en) | Ultrasonic nondestructive testing device and method for T-shaped composite structure and R-region testing method and device | |
| CN105699492A (en) | An ultrasonographic method used for weld seam detection | |
| CN109307713A (en) | A kind of nuclear power steel containment vessel butt weld detection method | |
| CN113899818B (en) | Ultrasonic detection method for R-region defects of T-shaped component for airframe structure | |
| RU2538069C2 (en) | Method and apparatus for determining direction of defect within mechanical structural component | |
| Ouabi et al. | A fastslam approach integrating beamforming maps for ultrasound-based robotic inspection of metal structures | |
| Yang et al. | Ultrasonic detection methods for mechanical characterization and damage diagnosis of advanced composite materials: A review | |
| KR101041942B1 (en) | Calibration block for verification of refracted longitudinal ultrasonic transducer | |
| Chen et al. | Ultrasonic inspection of curved structures with a hemispherical-omnidirectional ultrasonic probe via linear scan SAFT imaging | |
| CN117191948A (en) | Ultrasonic leaky surface wave full-focusing imaging method based on virtual source | |
| EP2984479B1 (en) | Ultrasonic inspection using incidence angles | |
| CN116183726A (en) | Ultrasonic detection capability evaluation method and system for stainless steel small-diameter pipe weld joint | |
| US10883969B2 (en) | System and method for inspecting a structure with coda acoustic waves | |
| US20140260628A1 (en) | Ultrasonic examination of components with unknown surface geometries | |
| Sharif Khodaei et al. | Damage detection and characterization with piezoelectric transducers: Active sensing | |
| KR20120031674A (en) | System and apparatus for measuring non-linearity of ultrasonic wave | |
| Wang et al. | Non-destructive detection of GIS aluminum alloy shell weld based on oblique incidence full focus method |
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 | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |