CN105606268B - Welding residual stress ultrasonic evaluation method based on the measurement of dynamic magnetostriction coefficient - Google Patents
Welding residual stress ultrasonic evaluation method based on the measurement of dynamic magnetostriction coefficient Download PDFInfo
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- CN105606268B CN105606268B CN201610141460.5A CN201610141460A CN105606268B CN 105606268 B CN105606268 B CN 105606268B CN 201610141460 A CN201610141460 A CN 201610141460A CN 105606268 B CN105606268 B CN 105606268B
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- 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
- G01L1/12—Measuring force or stress, in general by measuring variations in the magnetic properties of materials resulting from the application of stress
- G01L1/125—Measuring force or stress, in general by measuring variations in the magnetic properties of materials resulting from the application of stress by using magnetostrictive means
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Abstract
The invention discloses a kind of welding residual stress ultrasonic evaluation method based on the measurement of dynamic magnetostriction coefficient, general principle is the magnetostriction coefficient of ferrimagnet to stress sensitive, magnetostriction coefficient curve will change during the stress state difference of ferrimagnet, and then influence the magnetosonic conversion efficiency of magnetostriction transverse wave sensor.By measuring under the effect of different exciting field intensity, transverse wave reflection signal amplitude change curve that magnetostriction transverse wave sensor receives in welded seam area, you can dynamically reflect changing rule of the material magnetostriction coefficient curve with stress.By regulating and controlling electromagnet exciting current amplitude and cycle, it is possible to achieve the excitation of multiple constant amplitude and reception of shear wave signal, draw out change curve of the transverse wave reflection signal amplitude with surface tangential magnetic field intensity, i.e. dynamic magnetostriction coefficient curve.The residual stress size of shear wave amplitude or dynamic magnetostriction coefficient slope of a curve parameter representative welding region under arbitrary surfaces tangential magnetic field intensity.
Description
Technical field：
The invention belongs to stress non-invasive measuring technique field, is related to a kind of welding based on the measurement of dynamic magnetostriction coefficient
Residual stress ultrasonic evaluation method.Shadow of this method using welding residual stress to ferrimagnet magnetostriction coefficient curve
Ring, using magnetostriction transverse wave testing method, measure the dynamic magnetostriction coefficient curve of welding region, extract characteristic parameter pair
The drawing of welding region, pressure residual stress size are characterized.
Background technology：
Welding process is the process that a butt-welding fitting local heating then gradually cools down, and uneven temperature field will make weldment
Each several part produces inhomogeneous deformation, so as to produce welding residual stress.Welding residual stress have a strong impact on structure fatigue strength,
The ability such as anti-brittle failure and stress corrosion dehiscence resistant, the non-destructive testing of residual stress are the important technicals for evaluating welding quality.
Supercritical ultrasonics technology is one of important method of welding residual stress nondestructive measurement.Acoustoelectric effect currently is based primarily upon, is adopted
Reflect residual stress size with sonic velocity change of the ultrasonic wave in welding region.Because acoustoelectric effect is more faint, the velocity of sound is corresponding
The sensitivity of power is not high, higher to signal acquisition hardware requirement when being detected using this method, and testing result is easily by noise
Interference.Therefore, it is necessary to explore based on it is different detection mechanism stress measurement new method, and improve method detection sensitivity and
Antijamming capability.
The welding residual stress ultrasonic evaluation method based on the measurement of dynamic magnetostriction coefficient that the present invention announces, using super
Magnitudes of acoustic waves characterizes to welding residual stress with the multinomial characteristic parameter in the change curve of excitation field intensity, belongs to new
Stress non-destructive measuring method.
The content of the invention：
The present invention is a kind of welding residual stress ultrasonic evaluation method based on the measurement of dynamic magnetostriction coefficient, and purpose exists
Efficient, convenient, accurate welding residual stress new method of measuring can be achieved in providing one kind.For achieving the above object, originally
It is as follows to invent the technical scheme provided：
Based on the welding residual stress ultrasonic evaluation method of dynamic magnetostriction coefficient measurement, its principle is related to ferromagnetism material
Magnetostriction coefficient curve will change during the stress state difference of intrinsic magnetic-bullet characteristic, i.e. ferrimagnet of material, and then
Influence magnetic-sound conversion efficiency of magnetostriction transverse wave sensor；Under the effect of different exciting field intensity, magnetostriction shear wave probe
Ultrasonic action can reflect the change of material magnetostriction coefficient curve indirectly with receiving efficiency, cause the ultrasound of flexible shear wave probe
Excitation is represented with receiving efficiency with reflected signal amplitude of the shear wave in welding structure, by transverse wave reflection signal amplitude with material table
The change curve of face tangential magnetic field intensity, i.e. dynamic magnetostriction coefficient curve, after rolling average is handled, extract any table
Amplitude or dynamic magnetostriction coefficient slope of a curve under the tangential magnetic field intensity of face；Record under each welding residual stress level
Amplitude or dynamic magnetostriction coefficient slope of a curve and fitting under arbitrary surfaces tangential magnetic field intensity obtain calibration equation, right
Welding region is drawn, pressure residual stress size is characterized.
When magnetostriction transverse wave sensor is scanned along welding region, change of the residual stress in scanning direction can obtain
Law；The electromagnet of magnetostriction transverse wave sensor is made up of U-shaped magnetic core with being wound in the magnet exciting coil of magnetic core, single-point detection
During, the electromagnet of magnetostriction transverse wave sensor provides magnetic field and welding region is magnetized, and leads in planar rectangular coil
Enter pulse ac signal and produce the shear wave propagated along welding structure thickness direction to encourage, reflection echo is connect by rectangle plane coil
Receive；It is arranged in the surface tangential magnetic field of the Hall element measurement welding region of planar rectangular hub of a spool position；By regulating and controlling electricity
Magnet excitation current amplitude and cycle, realize shear wave signal it is multiple (>2kHz) constant amplitude excitation and reception, measure transverse wave reflection letter
Number amplitude is with the change curve of surface tangential magnetic field intensity, i.e. dynamic magnetostriction coefficient curve.
The specific implementation process of welding residual stress ultrasonic evaluation method based on the measurement of dynamic magnetostriction coefficient includes
Measurement process and calibration process two parts：
Measurement process is achieved in that：Magnetostriction transverse wave sensor is placed on to the surface of weld seam 7, makes magnetostriction
Transverse wave sensor is brought into close contact with tested weldment 8.Pulse ac signal and low is produced using binary channels arbitrary-function generator 1
Frequency sinusoidal excitation signal.Low frequency sinusoidal excitation signal is inputted to bipolar power supply 2 be amplified after, be passed through and be wound on magnetic core 4
Magnet exciting coil 3, to provide bias magnetic field HSWelding region is magnetized.Pulse ac signal is through pulse power amplifier 9
Planar rectangular coil 6 is accessed after amplification, produces dynamic magnetic field HD.Material under bias magnetic field and dynamic magnetic field collective effect, by
Magnetostriction mechanism control produces the shear wave propagated along the thickness direction of weld seam 7.One is installed in the center of planar rectangular coil 6
Hall element 5, to measure the tangential magnetic field intensity H of material surface.Magnetostriction transverse wave sensor uses self excitation and self receiving mode, inspection
Survey transverse wave reflection signal.As dynamic magnetic field HDWhen keeping constant, the launching efficiency β approximate expressions of magnetostriction transverse wave sensor
For：
Wherein λ is magnetostriction coefficient, and M is biased magnetic field strength HSThe intensity of magnetization of the lower material of effect.Magnetostriction system
Number and the relation of material magnetization intensity are represented using magnetostriction coefficient curve λ-M.Above formula shows, as dynamic magnetic field HDKeep not
During change, shear-wave generation efficiency and the magnetostriction coefficient slope of a curve of magneto strictive sensorIt is related.Work as material internal
Residual stress σ differences when, slopeValue is different, and then the launching efficiency β of magnetostriction transverse wave sensor changes,
I.e. identical moving field HDUnder effect, the shear wave energy of sensor excitation is inconsistent, during for detecting fixed thickness test specimen, is reflected back
The signal amplitude of ripple will be corresponding different.When being used to detect fixed thickness test specimen, any table in dynamic magnetostriction coefficient curve
Amplitude under the tangential magnetic field intensity of face can be used for characterizing welding residual stress.
Welding residual stress calibration process is achieved in that：By regulating and controlling electromagnet exciting current amplitude and cycle, with
Realize shear wave signal it is multiple (>2kHz) constant amplitude excitation and reception, it is tangential with surface finally to draw out transverse wave reflection signal amplitude
Magnetic field intensity H change curve, i.e. dynamic magnetostriction coefficient curve.Dynamic magnetostriction coefficient curve is moved average
Processing, to obtain smooth dynamic magnetostriction coefficient curve.Extracting arbitrary surfaces tangential magnetic field intensity (recommends surface tangential
Magnetic field intensity is 0,Or HMAX) under shear wave amplitude or dynamic magnetostriction coefficient slope of a curve.Record each welding
Amplitude under arbitrary surfaces tangential magnetic field intensity or dynamic magnetostriction coefficient slope of a curve under residual stress level are simultaneously intended
Conjunction obtains calibration equation, you can for drawing welding region, pressing residual stress size to characterize.
The present invention uses above technical scheme, ingenious using ultrasonic amplitude information caused by magnetostriction transverse wave sensor
Ground illustrates influence of the welding residual stress to magnetostriction coefficient curve, so as to set up welding residual stress and dynamic mangneto
Relation between coefficient of dilatation curve, realize the nondestructive measurement of welding residual stress.
Brief description of the drawings：
Fig. 1 magnetostriction transverse wave sensor exciting circuits and detecting element schematic diagram；
Fig. 2 magnetostriction transverse wave sensor pumping signals and shear wave detection signal waveform schematic diagram；
Fig. 3 magnetostriction transverse wave sensor fundamental diagrams；
Affecting laws schematic diagram of Fig. 4 stress to magnetostriction coefficient curve；
Dynamic magnetostriction coefficient curved measurement result schematic diagram under Fig. 5 different stress.
In figure：1- binary channels arbitrary-function generator 2- bipolar power supply 3- magnet exciting coil 4- FERRITE COREs 5- is suddenly
That element 6- planar rectangular coil 7- weld seam 8- weldment 9- pulse power amplifiers
Embodiment：
In order that the purpose of the present invention, technical scheme and beneficial effect are clearer, below in conjunction with accompanying drawing to the present invention
Embodiment is described in further detail.
The invention provides a kind of welding residual stress ultrasonic evaluation method based on the measurement of dynamic magnetostriction coefficient, institute
Stating measuring method includes following steps：
1st, as shown in figure 1, magnetostriction transverse wave sensor to be placed on to the surface of weld seam 7, sense magnetostriction shear wave
Device is brought into close contact with tested weldment 8.
2nd, using binary channels arbitrary-function generator 1 produce pulse ac signal (>2kHz) and low frequency sinusoidal excitation signal
(1-100Hz).Low frequency sinusoidal excitation signal is inputted to bipolar power supply 2 be amplified after, be passed through the excitation being wound on magnetic core 4
Coil 3, to provide bias magnetic field HSWelding region is magnetized.Pulse ac signal is after the amplification of pulse power amplifier 9
Planar rectangular coil 6 is accessed, produces dynamic magnetic field HD.Fig. 2 illustrate pulse ac signal and low frequency sinusoidal excitation signal when
Domain waveform, in the positive half period of low frequency sinusoidal excitation signal work, multiple pulses exchange letter is passed through in planar rectangular coil 6
Number, to complete the excitation of shear wave signal and reception；In the negative half-cycle of low frequency sinusoidal excitation signal work, above-mentioned mistake is equally repeated
Journey, to test the shear wave signal waveform for obtaining amplitude and changing with low frequency sinusoidal excitation signal amplitude.
3rd, Fig. 3 shows the bias magnetic field H that magnetostriction transverse wave sensor providesSWith dynamic magnetic field HDDirection, material exists
Under two magnetic field collective effects, the shear wave propagated along the thickness direction of weld seam 7 is produced by magnetostriction mechanism control.Using self-excitation certainly
Debit's formula, planar rectangular coil 6 can receive transverse wave reflection echo.
4th, in shear wave signal detection process is carried out, the Hall element 5 for being placed on the center of planar rectangular coil 6 is utilized
The tangential magnetic field intensity time varying signal H of material surface is measured.
5th, Fig. 4 shows the magnetostriction coefficient curve of material under different stress.When material is in same magnetization shape
During state M, due to stress σ difference, the slope for causing magnetostriction coefficient curve each point is changed, namelyIt is different
(1,2,3 three position marked in such as figure, their magnetization M is the same, but their stress are different and causeIn the presence of
Difference).Row energization is entered to magnetostriction transverse wave sensor by using pumping signal shown in Fig. 2, the shear wave detection letter received
Number amplitude can represent the slope variation on magnetostriction coefficient curve at diverse location.And stress to diverse location on curve at
The influence of slope can be obtained by calibration experiment.
6th, Fig. 5 is the dynamic magnetostriction coefficient curve drawn according to excitation shown in Fig. 2 with reception signal, is moved flat
After handling, the shear wave amplitude E or dynamic magnetostriction coefficient slope of a curve K under arbitrary surfaces tangential magnetic field intensity are extracted
Parameter, record the horizontal lower arbitrary surfaces tangential magnetic field intensity of each welding residual stress (it is 0 to recommend surface tangential magnetic field intensity,Or HMAXBut be not limited to these surface tangential magnetic field intensity, select it is multiple after can therefrom Select Error it is smaller
The size for characterize residual stress σ) under amplitude or dynamic magnetostriction coefficient slope of a curve and being fitted demarcated
Equation, you can for characterizing welding residual stress σ size.
7th, magnetostriction transverse wave sensor is moved along the surface of weld seam 7, repeated the above steps, you can obtain the dynamic of different parts
State magnetostriction coefficient curve, extract shear wave amplitude E or dynamic magnetostriction coefficient under arbitrary surfaces tangential magnetic field intensity
Slope of a curve K parameters, bring calibration equation into, are evaluated with the distribution situation to residual stress σ.
Claims (1)
1. based on the welding residual stress ultrasonic evaluation method of dynamic magnetostriction coefficient measurement, the effect of different exciting field intensity
Under, cause the ultrasonic action of flexible transverse wave sensor to be represented with receiving efficiency with reflected signal amplitude of the shear wave in welding structure,
Change curve by transverse wave reflection signal amplitude with material surface tangential magnetic field intensity, i.e. dynamic magnetostriction coefficient curve, warp
After rolling average processing, the oblique of amplitude under arbitrary surfaces tangential magnetic field intensity or dynamic magnetostriction coefficient curve is extracted
Rate；Record the amplitude or dynamic magnetostriction coefficient song under the arbitrary surfaces tangential magnetic field intensity under each welding residual stress level
The slope of line and fitting obtains calibration equation, welding region is drawn, pressure residual stress size characterizes；Dynamic magnetostriction system
Amplitude in number curve under arbitrary surfaces tangential magnetic field intensity can be used for characterizing welding residual stress；
When magnetostriction transverse wave sensor is scanned along welding region, obtains change of the residual stress in scanning direction and advise
Rule；The electromagnet of magnetostriction transverse wave sensor is made up of U-shaped magnetic core with being wound in the magnet exciting coil of magnetic core, single-point detection process
In, the electromagnet of magnetostriction transverse wave sensor provides magnetic field and welding region is magnetized, and arteries and veins is passed through in planar rectangular coil
Rush AC signal and produce the shear wave propagated along welding structure thickness direction to encourage, reflection echo is received by rectangle plane coil；
It is arranged in the surface tangential magnetic field of the Hall element measurement welding region of planar rectangular hub of a spool position；By regulating and controlling electromagnet
Exciting current amplitude and cycle, realize the multiple constant amplitude excitation of shear wave signal and receive, measure transverse wave reflection signal amplitude with table
The change curve of face tangential magnetic field intensity, i.e. dynamic magnetostriction coefficient curve.
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| CN107423506B (en) * | 2017-07-24 | 2020-10-23 | 广东工业大学 | Method for calculating maximum external magnetization intensity of magnetostrictive material |
| CN108760117A (en) * | 2018-03-09 | 2018-11-06 | 南京航空航天大学 | The method that electromagnetic acoustic based on magnetostrictive effect measures plate stress |
| CN109142057A (en) * | 2018-09-11 | 2019-01-04 | 北京工业大学 | The Barkhausen noise non-destructive measuring method and system of ferrimagnet local stress and strain field |
| CN111521310A (en) * | 2019-02-02 | 2020-08-11 | 中国特种设备检测研究院 | Method and system for determining residual stress and residual elimination effect of ferromagnetic material |
| CN110512053A (en) * | 2019-04-01 | 2019-11-29 | 内蒙古科技大学 | A kind of device based on electromagnetic energy removal welding residual stress |
| CN110471010B (en) * | 2019-09-18 | 2021-09-10 | 北京工业大学 | SH of magnetostriction curve of ferromagnetic material0Modal ultrasonic guided wave measuring method |
| CN113922003B (en) * | 2021-09-29 | 2023-09-01 | 湖北亿纬动力有限公司 | Ultrasonic welding effect evaluation method and lithium ion battery |
| CN114002627B (en) * | 2021-10-29 | 2023-08-25 | 深圳技术大学 | Microcosmic in-situ measurement system of magnetostrictive material under strong magnetic field |
| CN115452204B (en) * | 2022-08-30 | 2023-05-12 | 华能广西清洁能源有限公司 | Force sensing measurement method based on inverse magnetostriction effect |
| CN116540156B (en) * | 2023-04-27 | 2023-10-31 | 长安大学 | Sensitivity-adjustable magnetic field strength sensor based on laminated magnetoelectric structure and adjusting method |
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