CN110261473A - Ultrasonic phase array testing methods for tiny crack based on finite element model - Google Patents
Ultrasonic phase array testing methods for tiny crack based on finite element model Download PDFInfo
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- CN110261473A CN110261473A CN201910333397.9A CN201910333397A CN110261473A CN 110261473 A CN110261473 A CN 110261473A CN 201910333397 A CN201910333397 A CN 201910333397A CN 110261473 A CN110261473 A CN 110261473A
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- 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
- G01N29/041—Analysing solids on the surface of the material, e.g. using Lamb, Rayleigh or shear waves
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Abstract
The ultrasonic phase array testing methods for tiny crack based on finite element model that the invention discloses a kind of, suitable probe is selected according to actual condition first, voussoir, couplant and probe chip excitation receive rule, and these all parameters are input to software and suitable acquisition parameter is arranged.Parameter is transported to signal processing system by software, and after system receives parameter, by corresponding electric signal transmission to ultrasonic probe, the electric signal received is converted to acoustical signal by probe, and receives reflected sound signals.Reflected sound signals are converted into electric signal after probe receives and are transferred to signal processing system, finally send back software, the flaw echo time tested and amplitude, the numerical simulation of ultrasonic phased array is carried out, the ultrasonic wave that ultrasonic probe issues can be modeled as applying transient state driving pulse appropriate on the surface node of test specimen model.
Description
Technical field
The invention belongs to technical field of nondestructive testing more particularly to a kind of ultrasonic phase array fine fisssures based on finite element model
Marks detection method.
Background technique
During the non-destructive testing of chemical industry equipment, weld seam detection occupies very big specific gravity.Ultrasound examination is the world
It is most widely used, a kind of highest non-destructive testing technology of frequency of use.The test object of ultrasound examination is in extensive range, detection
Thickness degree is big, high sensitivity, can defect be positioned and be quantified, very sensitive to crack defect, is of relatively low cost
It is harmless and numerous advantages such as use on the spot convenient for scene.
Ultrasonic phase array is the Phased array emission and receiving that acoustic beam is realized with several piezoelectricity array elements composition array energy transducer.It has
It is able to carry out dynamic focusing, image checking can be carried out, complex structure is can detecte, detection sensitivity can be improved, differentiated
The multiple advantages of power and signal-to-noise ratio, realize ultrasonic phase array real time imagery in complex dielectrics, and testing cost also obtains significantly
It reduces, has become the research hotspot of international non-destructive testing circle in recent years.
Finite element analysis model provides a kind of effective tool to solve the analysis that ultrasonic wave is propagated in solid dielectric
Or method.The present invention detects phased array supersonic to weld defect and carries out numbered analog simulation research, it is therefore an objective to can be for weldering
Confinement problems when existing defects determine and recheck in seam detection, are answered numerical simulation as a kind of supplementary defect decision means
For weld seam it is actually detected in.
Summary of the invention
The ultrasonic phase array micro-crack inspection based on finite element model that the technical problem to be solved by the invention is to provide a kind of
Survey method, this method error is smaller, and precision is high.
The technical solution adopted by the present invention to solve the technical problems is: providing a kind of ultrasonic phase based on finite element model
Battle array testing methods for tiny crack is controlled, this approach includes the following steps, step 1, selects probe, voussoir, couplant and spy according to operating condition
Head wafer excitation receives rule, and these parameters are input to software and acquisition parameter is arranged；Step 2, software conveys parameter
To signal processing system, after system receives parameter, by corresponding electric signal transmission to ultrasonic probe, popping one's head in will be received
Electric signal is converted to acoustical signal, and receives reflected sound signals；Step 3, echo-signal carries out A/D conversion and is transferred to signal processing
System finally sends back software, the flaw echo time tested and amplitude；Step 4, the numerical value of ultrasonic phased array is carried out
Simulation process, the ultrasonic wave that ultrasonic probe issues can be modeled as applying on the surface node of test specimen model corresponding transient state and swash
Encourage pulse.
Emulation and experimental result using theoretic calculated value as measurement standard, to the detection of test specimen containing Cracks in Welding Seams
The comparison of the A total number flaw echo time and its amplitude in, compares the flaw echo time numerical values recited of three, Ke Yifa
Existing, theoretical value comparative experiments value and simulation value show good compatibility, and error is smaller, and precision is high.
Experiment porch is mainly made of ultrasonic probe, signal processing system and software three parts, further includes tested test
The Accessory Members such as part, couplant, voussoir, encoder.Signal processing system uses Multi2000 Pocket just in the step 2
Take formula ultrasound phase-control array 1 system.Small in size, light quality detects on site.
According to the above technical scheme, in the step 1, according to tested test block size, material, the velocity of sound containing Cracks in Welding Seams
Spread speed, weld defect range select ultrasonic testing system parameter.It is each to be detected workpiece size, physical property, ultrasonic probe
Parameter, the geometric parameter of voussoir and physical property etc. are by actually entering, then the probe chips of actually detected middle needs is arranged and swashs
After sending out quantity, rule, software calculates the emission delay of each chip automatically and realizes its control, eliminates cumbersome artificial meter
It calculates, significantly improves working efficiency.
According to the above technical scheme, 300 millimeters of length is chosen, 300 millimeters wide, thick 25 millimeters of steel plate is as test specimen, in the steel
In plate, the spread speed of shear wave is about 3200 meter per seconds, and the spread speed of longitudinal wave is about 6300 meter per seconds, in the thickness face of test specimen
Center manufactures a flute profile defect, and length, width, the depth of slot are 4 millimeters, 2 millimeters, 25 millimeters respectively.
According to the above technical scheme, ultrasonic phase array system parameter is as follows in the step 2: digitlization 10bits, 100MHz,
50Ω；Receiver maximum input voltage is ± 1Vpp；Voltage 10V-200V is adjustable, stepping 1V；Pulse width 20-1275ns can
It adjusts, stepping 2.5ns；PRF is that 10Hz-30KHz is adjustable；Gain 6-86dB is adjustable, stepping 0.4dB；The 0-8ms that is delayed is adjustable, step
Into 10ns；Sample rate 100MHz-6.6MHz is adjustable；DAC is that 0-80dB is adjustable, and change rate is 20dB/ μ s；Emission delay 0-25 μ s
It is adjustable, stepping 2.5ns；Reception delay 0-25 μ s is adjustable, stepping 2.5ns.
According to the above technical scheme, echo-signal carries out A/D conversion, the number in each view of collecting part in the step 3
According to display from multiple data sources, collected result is substantially to collect knot using all wafers (or channel) in probe
A set for fruit.B sweeps figure and is presented on as fixed result constant in face of experimenter after acquisition is completed, but has a cross one thereon
The dynamic straight line of perpendicular two intersections, they have an intersection point, and it is the detection case for reflecting this intersection point position that A, which sweeps figure then,
The defects of figure can be so swept by B shows accurate and visual extraction A total number evidence.
According to the above technical scheme, the step 4 specifically: the transient state driving pulse functional equation of ultrasound emulation is as follows,
F indicates pulse excitation frequency, and N indicates the quantity of driving pulse waveform medium wave, the ultrasonic probe ginseng in binding test
Number, in current probe model, f=5 MHz, N=3, according to above-mentioned equation, the various pieces for establishing ultrasound examination are established
Numerical simulation model.The wave source figure of contrast test and simulation model can see experiment and all show relatively good be consistent with emulation
Property.
According to the above technical scheme, it establishes a two-dimensional test specimen modeling with artificial slot defect and is detected test block,
To describe communication process of the ultrasonic wave in test specimen in emulation, moulded dimension is consistent with test sample dimensions.Simulation parameter
Setting see the table below 1.
Table 1
According to the above technical scheme, node load in test specimen model applied exports the node time-as special joint
Displacement data is emulation A pan figure, extracts the A total number evidence of testing result in experiment, and simulation result and experimental result is opposite
Than.
The device for the ultrasonic phase array testing methods for tiny crack based on finite element model that the present invention also provides a kind of, including letter
Number generating unit, signal acquisition unit, signal processing unit, finite element simulation unit, date comprision unit；Signal occurs
Unit selects to pop one's head according to actual condition, voussoir, and couplant and probe chip excitation receive rule, and by these all parameters
It is input to software and acquisition parameter is set；Signal acquisition unit, real-time display testing result can load the data of acquisition aobvious
Show, acquisition view can be defined in acquisition panel, and can display real-time acquisition data；Signal processing unit is ultrasonic phase array
Equipment；Date comprision unit, for being detected to test specimen containing Cracks in Welding Seams using theoretic calculated value as measurement standard
Emulation and experimental result the A total number flaw echo time and its amplitude in comparison.
The beneficial effect comprise that: using based on finite element model ultrasonic phase array testing methods for tiny crack and
Device measures, and measurement error is smaller, and precision is high.
Detailed description of the invention
Present invention will be further explained below with reference to the attached drawings and examples, in attached drawing:
Fig. 1 is that the process of ultrasonic phase array testing methods for tiny crack of the embodiment of the present invention based on finite element model is illustrated
Figure；
Fig. 2 is micro-crack ultrasonic phase array analysis method structural representation of the embodiment of the present invention based on finite element analysis model
Figure；
Fig. 3 is that the emulation of micro-crack ultrasonic phase array analysis method of the embodiment of the present invention based on finite element analysis model is real
Test comparison diagram.
Specific embodiment
In order to make the objectives, technical solutions, and advantages of the present invention clearer, with reference to the accompanying drawings and embodiments, right
The present invention is further elaborated.It should be appreciated that described herein, specific examples are only used to explain the present invention, not
For limiting the present invention.
Embodiment one: as shown in Figure 1, being a kind of ultrasonic phase array microcrack zone based on finite element model of the invention
Method, comprising the following steps:
S1: selecting suitable probe, voussoir according to actual condition first, and couplant and probe chip excitation receive rule,
And these all parameters are input to software and suitable acquisition parameter is set；
S2: parameter is transported to signal processing system by software, after system receives parameter, by corresponding electric signal transmission
To ultrasonic probe, the electric signal received is converted to acoustical signal by probe, and receives reflected sound signals；
S3: echo-signal carries out A/D conversion and is transferred to signal processing system, finally sends back software, is tested
Flaw echo time and amplitude；
S4: carrying out the numerical simulation of ultrasonic phased array, and the ultrasonic wave that ultrasonic probe issues can be modeled as trying
Apply transient state driving pulse appropriate on the surface node of part model.
The present embodiment is using the steel that specification is 300mm*300mm*25mm as test specimen.With theory in the present embodiment
On calculated value as measurement standard, the A total number of emulation and experimental result to the detection of test specimen containing Cracks in Welding Seams defect in
The flaw echo time numerical values recited of three is compared in the comparison of echo time and its amplitude, as shown in figure 3, (a) represents emulation
As a result, (b) representing experimental result.It can be found that theoretical value comparative experiments value and simulation value show good compatibility,
Error is smaller, and precision is high.
Embodiment two: as shown in Fig. 2, the structure for the ultrasonic phase array testing methods for tiny crack based on finite element model is shown
It is intended to, including ultrasonic probe, signal processing system and software three parts are constituted, and further include tested test block, couplant, wedge
The Accessory Members such as block, encoder.
Signal generating unit selects suitable probe, voussoir according to actual condition, and couplant and probe chip excitation receive
Rule, and these all parameters are input to software and suitable acquisition parameter is set；Signal acquisition unit, real-time display detection
As a result, can be to the data loaded and displayed of acquisition.Acquisition view can be defined in acquisition panel, and can display real-time acquisition number
According to；Experimental signal processing unit uses portable ultraphonic phased array equipment, and small in size, light quality detects on site, various
Detection field is widely used；Date comprision unit, for using theoretic calculated value as measurement standard, to containing
The comparison of the A total number flaw echo time and its amplitude in of the emulation and experimental result of Cracks in Welding Seams test specimen detection.
Compare theoretical value, simulation value and the experiment value of the detection echo time of test specimen containing Cracks in Welding Seams, it is found that theoretical
Value comparative experiments value and simulation value show good compatibility, and error is smaller, and precision is high.
It should be understood that for those of ordinary skills, it can be modified or changed according to the above description,
And all these modifications and variations should all belong to the protection domain of appended claims of the present invention.
Claims (9)
1. a kind of ultrasonic phase array testing methods for tiny crack based on finite element model, which is characterized in that this method includes following
Step 1 step selects probe, voussoir, couplant and probe chip excitation to receive rule, and these parameters are defeated according to operating condition
Enter to software and acquisition parameter is set；
Step 2, parameter is transported to signal processing system by software, after system receives parameter, by corresponding electric signal transmission
To ultrasonic probe, the electric signal received is converted to acoustical signal by probe, and receives reflected sound signals；
Step 3, echo-signal carries out A/D conversion and is transferred to signal processing system, finally sends back software, and that is tested lacks
Fall into echo time and amplitude；
Step 4, the numerical simulation of ultrasonic phased array is carried out, the ultrasonic wave that ultrasonic probe issues can be modeled as in test specimen
Apply corresponding transient state driving pulse on the surface node of model.
2. the ultrasonic phase array testing methods for tiny crack according to claim 1 based on finite element model, which is characterized in that
In the step 1, selected according to the tested test block size containing Cracks in Welding Seams, material, velocity of sound spread speed, weld defect range
Select ultrasonic testing system parameter.
3. the ultrasonic phase array testing methods for tiny crack according to claim 1 or 2 based on finite element model, feature exist
In selection is 300 millimeters long, and 300 millimeters wide, thick 25 millimeters of steel plate is as test specimen, and in the steel plate, the spread speed of shear wave is about
For 3200 meter per seconds, the spread speed of longitudinal wave is about 6300 meter per seconds, manufactures a flute profile in the center in the thickness face of test specimen and lacks
It falls into, length, width, the depth of slot are 4 millimeters, 2 millimeters, 25 millimeters respectively.
4. the ultrasonic phase array testing methods for tiny crack according to claim 3 based on finite element model, which is characterized in that
Ultrasonic phase array system parameter is as follows in the step 2: digitlization 10bits, 100MHz, 50 Ω；Receiver maximum input voltage
It is ± 1Vpp；Voltage 10V-200V is adjustable, stepping 1V；Pulse width 20-1275ns is adjustable, stepping 2.5ns；PRF is
10Hz-30KHz is adjustable；Gain 6-86dB is adjustable, stepping 0.4dB；The 0-8ms that is delayed is adjustable, stepping 10ns；Sample rate 100MHz-
6.6MHz adjustable；DAC is that 0-80dB is adjustable, and change rate is 20dB/ μ s；Emission delay 0-25 μ s is adjustable, stepping 2.5ns；It connects
It is adjustable to receive delay 0-25 μ s, stepping 2.5ns.
5. the ultrasonic phase array testing methods for tiny crack according to claim 1 or 2 based on finite element model, feature exist
In echo-signal carries out A/D conversion in the step 3, and the data in each view of collecting part are shown from multiple data
Source.
6. the ultrasonic phase array testing methods for tiny crack according to claim 1 or 2 based on finite element model, feature exist
In the step 4 specifically: the transient state driving pulse functional equation of ultrasound emulation is as follows,
F indicates pulse excitation frequency, and N indicates the quantity of driving pulse waveform medium wave, the ultrasonic probe parameter in binding test,
In current probe model, f=5MHz, N=3, according to above-mentioned equation, the various pieces for establishing ultrasound examination are established numerical value and are imitated
True mode.
7. the ultrasonic phase array testing methods for tiny crack according to claim 4 based on finite element model, which is characterized in that
It establishes a two-dimensional test specimen modeling with artificial slot defect and is detected test block, tried to describe ultrasonic wave in emulation
Communication process in part, moulded dimension are consistent with test sample dimensions.
8. the ultrasonic phase array testing methods for tiny crack according to claim 7 based on finite element model, which is characterized in that
For the node that load in test specimen model is applied as special joint, exporting the node time-displacement data is emulation A pan
Figure extracts the A total number evidence of testing result in experiment, simulation result and experimental result is compared.
9. a kind of device of the ultrasonic phase array testing methods for tiny crack based on claims 1 or 2 finite element model, feature exist
In the device includes signal generating unit, signal acquisition unit, signal processing unit, finite element simulation unit, data comparison point
Analyse unit；
Signal generating unit selects to pop one's head according to actual condition, voussoir, and couplant and probe chip excitation receive rule, and will
These all parameters are input to software and acquisition parameter are arranged；
Signal acquisition unit, real-time display testing result can define the data loaded and displayed of acquisition in acquisition panel
View is acquired, and can display real-time acquisition data；
Signal processing unit is ultrasound phased array devices；
Date comprision unit, for being detected to test specimen containing Cracks in Welding Seams using theoretic calculated value as measurement standard
Emulation and experimental result the A total number flaw echo time and its amplitude in comparison.
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113030260A (en) * | 2021-03-04 | 2021-06-25 | 湘潭大学 | Quantitative method for inclusion defects of composite material |
| CN113916989A (en) * | 2021-09-24 | 2022-01-11 | 广东电网有限责任公司广州供电局 | Method and system for detecting internal defects of high-performance epoxy insulating part of power system |
| CN117589889A (en) * | 2024-01-19 | 2024-02-23 | 江苏省特种设备安全监督检验研究院 | Ultrasonic phased array microcrack detection method and system based on finite element model |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005140575A (en) * | 2003-11-05 | 2005-06-02 | Crc Solutions Corp | Ultrasonic crack detection simulating system, ultrasonic crack detection simulation system method and recording medium of the same, |
| CN105806270A (en) * | 2016-04-28 | 2016-07-27 | 北京工业大学 | Material surface micro-crack depth detecting method |
| CN108872385A (en) * | 2018-07-27 | 2018-11-23 | 武汉工程大学 | A kind of microcrack zone based on ultrasonic phase array and localization method and system |
-
2019
- 2019-04-24 CN CN201910333397.9A patent/CN110261473A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005140575A (en) * | 2003-11-05 | 2005-06-02 | Crc Solutions Corp | Ultrasonic crack detection simulating system, ultrasonic crack detection simulation system method and recording medium of the same, |
| CN105806270A (en) * | 2016-04-28 | 2016-07-27 | 北京工业大学 | Material surface micro-crack depth detecting method |
| CN108872385A (en) * | 2018-07-27 | 2018-11-23 | 武汉工程大学 | A kind of microcrack zone based on ultrasonic phase array and localization method and system |
Non-Patent Citations (3)
| Title |
|---|
| JAMES R. PETTIT ET AL.: "Improved Detection of Rough Defects or Ultrasonic Nondestructive Evaluatio Inspections Based on Finite Element Modeling of Elastic Wave Scattering", 《IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL》 * |
| 陈振华等: "超声相控阵检测声场的有限元仿真建模及其试验验证", 《电子测量与仪器学报》 * |
| 陈汉新等: "超声相控阵有限元建模分析", 《焊接技术》 * |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113030260A (en) * | 2021-03-04 | 2021-06-25 | 湘潭大学 | Quantitative method for inclusion defects of composite material |
| CN113916989A (en) * | 2021-09-24 | 2022-01-11 | 广东电网有限责任公司广州供电局 | Method and system for detecting internal defects of high-performance epoxy insulating part of power system |
| CN117589889A (en) * | 2024-01-19 | 2024-02-23 | 江苏省特种设备安全监督检验研究院 | Ultrasonic phased array microcrack detection method and system based on finite element model |
| CN117589889B (en) * | 2024-01-19 | 2024-04-02 | 江苏省特种设备安全监督检验研究院 | Ultrasonic phased array microcrack detection method and system based on finite element model |
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