CN103743818A - Flaw diagnosis method based on wave energy flow diagram and flaw diagnosis system implementing method - Google Patents

Abstract

The invention discloses a flaw diagnosis method based on a wave energy flow diagram and a flaw diagnosis system implementing the method. The method comprises the following steps: determining a detection area, irradiating a grid point by using laser pulses, exciting a Lamb wave at the grid point, receiving response signals by three or more than three piezoelectric sensors, calculating equivalence strain energy of the grid point, and drawing the wave energy flow diagram. A pulse laser device of the flaw diagnosis system is used for generating a pulse laser beam which is used for irradiating the flow detection area of a tested object, and exciting ultrasonic waves; the piezoelectric sensors are tightly adhered to the surface of the tested object; an amplifier receives and amplifies electric signals of the piezoelectric sensors; an A/D (analogue-to-digital) converter or an oscilloscope converts the electric signals into digital signals and inputs the digital signals into a host computer; the host computer receives the electric signals, performs data processing and draws the energy flow diagram; a display displays the energy flow diagram acquired after the processing of the host computer; the host computer is connected with the pulse laser device and controls the pulse laser device through an interface bus. The method and the system have the advantages that a flaw position can be determined, and the shape and the size of a flaw can be identified rapidly and precisely.

Description

The damage system of the damage diagnosis method of the energy flow chart based on ripple and enforcement the method

Technical field

The invention belongs to diagnosing structural damage field, be specifically related to a kind of damage diagnosis method of the energy flow chart based on ripple and the damage system of enforcement the method.

Background technology

At present in the industry member of China, the quantity of various aging structures is in increase by leaps and bounds, for making these works move more safely and avoid causing the generation of heavy economic losses and personnel casualty accidents, be in the situation that reducing operating cost, to guarantee the trouble free service of works in the situation that of approaching or super designed life simultaneously, apply various nondestructiving detecting means, various aging structures are carried out reliability evaluation and are maintained as the key subjects that face in China's production and life.

Now widely used various nondestructive inspection (NDI) means comprise: the technology such as ultrasound wave, X ray and thermal imaging.But the sense cycle of these technology is longer, the scope of its detection is also very little.In addition, the expense of these technology and the people in testing process make these technology can not ensure reliably the safety and reliability of structure for the reason such as fault.In order to overcome the weakness of said method, in recent years, many researchers utilize the ultrasound wave of some Special Category, as the feature of Lamb wave along thin-walled " direction in structural plane " long-distance communications, some new diagnosing structural damage methods have been proposed, the visualization technique of propagating in time domain such as exploitation ultrasound wave expansion direction in structure object plane, just can very easily identify the ripple at random being caused by fault of construction and damage, thereby confirms simply the existence of damage.Research about the visual aspect of ultrasound wave, people have developed methods such as photoelastic method and Schlieren method, but of this sort method is only to realize the visual of in transparent medium ultrasonic propagation, the solid structure that common metal and compound substance are manufactured is inapplicable.Therefore such technology can only, as a kind of supplementary means of ultrasound wave research, can not directly apply to the damage check of practical structures.Generally speaking, because the ultrasonic amplitude of body structure surface is in 10-3mm magnitude, to opaque structure, complete technically much difficulties of the visual existence of ultrasound wave, people can only complete this task by means of the laser interference system (Laser interferometer system) of expensive price at present.

Recently Japanese industries Technical Integration Studies has been developed and has a kind ofly been utilized pulse laser scanning excitation ultrasound ripple and utilize fixation of sensor acceptance hyperacoustic " ultrasonic propagation visual " technology, one of this technology basic and novel thinking is to utilize the property principles such as Betti is mutual, the signal of energizer → receptacle is changed into the signal of receptacle → energizer, thereby utilize pulse laser as wave-exciting device scanning, avoided the weakness of receptacle motion scan in conventional ultrasound wave technology.Meanwhile, receptacle just becomes a virtual wave-exciting device, finally becomes to take the visualization technique of the virtual supersonic that receptacle propagates in as wave source to surveyed area.The device of this Technology Need has: impulse laser unit, AE sensor, amplifier, oscillograph, main frame and display.Impulse laser unit irradiates the surveyed area of testee for generation of pulse laser beam, and excitation ultrasound ripple; AE sensor is close to testee surface detection faces outer displacement and is translated into continuous electric signal; The electric signal that amplifier receives piezoelectric sensor amplifies, and by oscillograph, continuous electric signal is converted into digital signal, then inputs main frame; Main frame receives electric signal to carry out data processing and draws wave propagation image; The wave propagation image that display obtains host process shows, interface bus connection gating pulse laser aid for main frame.But this technology can only be determined the position of damage at present, can not evaluate damage shape and size.

Summary of the invention

Technical matters to be solved by this invention is just to provide a kind of damage diagnosis method of the energy flow chart based on ripple, and it can realize the visual of the interior ultrasonic propagation of surveyed area, can not only determine the position of damage, quickly and accurately identification of damage shape and size.The present invention also provides a kind of damage system of implementing the method.

Technical matters to be solved by this invention is to realize by such technical scheme, and it comprises the following steps:

1, determine surveyed area, surveyed area is divided into a square net; Determine mesh spacing, mesh spacing should be not more than the half-wavelength of detected structure medium wave;

2, use net point of laser pulses irradiate, at this point, inspire Lamb wave; More than three or three piezoelectric sensor that distributes around surveyed area receives response signal, and the response signal receiving is stored on main frame;

3, the equal value strain energy γ of computing grid point

The wave energy of net point, the calculating formula of equal value strain energy γ is as follows:

$\left\{\begin{array}{cc}\mathrm{\γ}=\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{{\mathrm{\α}}_i}^2& (i=\mathrm{1,2,3},\·\·\·,n)\\ n=T/\mathrm{\ΔT}& \\ {\mathrm{\α}}_i=\mathrm{\β}({\mathrm{\ϵ}}_{\mathrm{xi}}+{\mathrm{\ϵ}}_{\mathrm{yi}})& \end{array}\right.$

In formula, β is proportionality constant; ε _xiit is the strain of directions X in medium face; ε _yiit is the strain of Y-direction in medium face; ε _xi+ ε _yii the sampling ripple signal amplitude (unit: volt) of piezoelectric sensor within the sampling time; T is that ultrasound wave is by the travel-time of surveyed area, namely sampling time; Δ T is sampling interval; N is hits; α _iit is the value of an internal strain of facet while being proportional to this net point.

4, draw the energy flow chart of ripple

Each net point of repeating step 2 scanning, and repeating step 3 calculates the γ of each net point of surveyed area, draws out the distribution plan of surveyed area γ, i.e. the energy flow chart of surveyed area.

In described step 2, piezoelectric sensor is PZT piezoelectric sensor.The calibrate AE sensor (AE) that substitutes expensive price with PZT piezoelectric sensor, can reduce testing cost.

In described step 2, more than three or three piezoelectric sensor that distributes around surveyed area, can improve the accuracy detecting.Because: find under study for action, when the angle of direction of wave travel and direction of check is very little, the reflection wave being produced by crackle very a little less than.And this problem also can not get solving with two sensors in the situation that, because when the straight line parallel that connects two fixation of sensor is during in direction of check, reflect wave intensity still very weak.Therefore, in the surrounding of surveyed area, arrange three or more sensors, have a sensor to receive strong reflection wave to major general, thereby improve the reliability of this technology.In checking work below, three sensors are centered around surveyed area around with the pattern of equilateral triangle, because in this case, even if the line of any two sensors is parallel to direction of check, the existence of crackle also can be measured by the 3rd sensor.

Principle of the present invention is: the propagation of elastic wave in medium can be considered the propagation phenomenon of wave energy, and the form of expression is because of the Particles Moving in the shuttle belt moving medium of wave source, and the elastic potential energy of particle and kinetic energy constantly mutually transform and are accompanied by energy and propagates forward.Therefore, the gross energy of the ripple by certain point in a period of time is defined as to " the elastic wave energy stream " of this point.In known surveyed area, " the elastic wave energy stream " of every, can draw out energy flow chart, and then by energy flow chart, can accurately judge position and the shape of damage.

The present invention also provides a kind of damage system of implementing said method, it includes impulse laser unit, piezoelectric sensor, amplifier, oscillograph, main frame and display, impulse laser unit irradiates the surveyed area of testee for generation of pulse laser beam, and excitation ultrasound ripple; Piezoelectric sensor, amplifier, oscillograph are connected by signal wire with main frame, and interface bus connects and gating pulse laser aid for main frame, and piezoelectric sensor is close to testee surface, with detection faces internal strain and be translated into continuous electric signal; The electric signal that amplifier receives piezoelectric sensor amplifies, by A/D converter or oscillograph, continuous electric signal is converted into digital signal, input again main frame, piezoelectric sensor is more than three or three, main frame receives electric signal, calculates equal value strain energy γ and draw energy flow chart, and the energy flow chart that display obtains host process shows.

Piezoelectric sensor is PZT piezoelectric sensing.

Owing to having adopted technique scheme, the present invention has advantages of as follows: realized the visual of the interior ultrasonic propagation of surveyed area, not only can determine the position of damage, quickly and accurately identification of damage shape and size.

Accompanying drawing explanation

Accompanying drawing of the present invention is described as follows:

Fig. 1 is the through hole aluminium sheet assay maps of this method inventive embodiments 1;

Fig. 2 is the PZT piezoelectric sensor distribution plan of this method inventive embodiments 1;

Fig. 3 is the through hole diagnostic graph of this method inventive embodiments 1;

Fig. 4 is the visual through hole diagnosis effect of the ultrasonic propagation of background technology figure;

Fig. 5 is the crack aluminium sheet assay maps of this method inventive embodiments 2;

Fig. 6 is the crack Diagnosis figure of this method inventive embodiments 2;

Fig. 7 is the carbon fibre reinforced composite delamination assay maps of this method inventive embodiments 3;

Fig. 8 is the PZT piezoelectric sensor distribution plan of this method inventive embodiments 3;

Fig. 9 is the delamination diagnostic graph of this method inventive embodiments 3;

Figure 10 is the delamination diagnostic graph after this method invention further improves;

Figure 11 is the visual delamination diagnosis effect of the ultrasonic propagation of background technology figure;

Figure 12 is for implementing the damage system architecture schematic diagram of this method invention.

In Figure 12: 1. testee; 2. surveyed area; 3. impulse laser unit; 4. piezoelectric sensor; 5. amplifier; 6. main frame; 7. display; 8. oscillograph.

Embodiment

Below in conjunction with drawings and Examples, the invention will be further described:

Embodiment 1:

The target of this embodiment is to detect the aluminium sheet that contains elliptical hole.As shown in Figure 1, the major axis of elliptical hole is 15mm, and minor axis is 12mm, aluminium sheet thickness of slab be 5mm. in order to simplify experiment, elliptical hole is seen as damage here, although elliptical hole naked eyes are visible in actual conditions, does not belong to damage category.With laser pulse (8.5ns), irradiate this aluminium sheet and produce Lamb wave, its principal ingredient is S0 pattern and A0 pattern, and the energy of ripple mainly concentrates between 100kHz and 200kHz.At this frequency domain, the wavelength of A0 pattern is approximately 10mm; The velocity of wave of S0 pattern and A0 pattern is approximately 5000m/s and 3000m/s.

Adopt detecting of this method invention:

Step 1, centered by elliptical hole, get a 200 * 200mm ²the region of size is surveyed area, and surveyed area is divided into a square net, and mesh spacing is got half of wavelength of A0 pattern, i.e. 5mm.

Step 2, net point of use laser pulses irradiate, inspire Lamb wave at this point; Three PZT piezoelectric sensors distribute as shown in Figure 2, and in Fig. 2, large stain represents the damage of elliptical hole, and pore represents PZT piezoelectric sensor, and square box represents surveyed area, around 200 * 200mm ²detect net region, uniform three PZT piezoelectric sensors on the circumference apart from grid central point 150mm, use epoxy adhesive that PZT piezoelectric sensor is sticked on aluminium sheet securely, the response signal that PZT piezoelectric sensor is received imports main frame by charge amplifier and oscillograph, in order to ensure Lamb wave, completely by surveyed area, the length of response signal is got 100 μ s.

The equal value strain energy γ of step 3, computing grid point.The calculating formula of equal value strain energy γ is as follows:

$\left\{\begin{array}{cc}\mathrm{\γ}=\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{{\mathrm{\α}}_i}^2& (i=\mathrm{1,2,3},\·\·\·,n)\\ n=T/\mathrm{\ΔT}& \\ {\mathrm{\α}}_i=\mathrm{\β}({\mathrm{\ϵ}}_{\mathrm{xi}}+{\mathrm{\ϵ}}_{\mathrm{yi}})& \end{array}\right.$

In formula, β is proportionality constant, ε _xiit is the strain of directions X in medium face; ε _yithe strain of Y-direction in medium face, ε _xi+ ε _yii the sampling ripple signal amplitude of piezoelectric sensor within the sampling time; T is that ultrasound wave is by the travel-time of surveyed area, namely sampling time; Δ T is sampling interval, and n is hits; α _iit is the value of an internal strain of facet while being proportional to this net point.

The energy flow chart of step 4, drafting ripple.Each net point of repeating step 2 scanning, and repeating step 3 calculates the γ of each net point of surveyed area, draws out the energy flow chart of surveyed area.

By step 3, calculated the equal value strain energy γ of each net point, the method for application numerical interpolation obtains the equal value strain energy γ of each point of surveyed area.So just can obtain the energy flow chart of surveyed area ripple.This step completes by drawing software.

In order to reduce the impact of noise on result, the sensor response signal of input main frame is carried out to bandpass filtering, on ripple is logical, be limited to 100kHz, roll off the production line as 200kHz.

The diagnostic result of the present embodiment is as shown in Figure 3: the result of the signal that Fig. 3 (a) collects for PZT1 piezoelectric sensor; The result of the signal that Fig. 3 (b) collects for PZT2 piezoelectric sensor; The result of the signal that Fig. 3 (c) collects for PZT3 piezoelectric sensor; The overall result of the signal that Fig. 3 (d) collects for PZT1+PZT2+PZT3 piezoelectric sensor; In Fig. 3 (d), the black dotted lines of sealing represents the damage result being obtained by the present invention's diagnosis, and white ovals represents real damage; The strain energy density that can find out damage field from Fig. 3 (d) is significantly less than other healthy area; Position, shape and the size of elliptical hole damage can accurately be judged.

For compared with prior art, aluminium sheet to elliptical hole, adopt the visual diagnostic result of ultrasonic propagation of background technology as shown in Figure 4: Fig. 4 (a), Fig. 4 (b) and Fig. 4 (c) are respectively the signal collected of three PZT piezoelectric sensors results after treatment, this figure can only determine the position of elliptical hole, can not determine its shape and size.

Embodiment 2

The target of this embodiment is the aluminium sheet detecting containing not penetrating crack.As shown in Figure 5: the length in crack is 20mm, width is 2mm, and the degree of depth is 2.5mm; Aluminium sheet thickness of slab is 5mm.In order to simplify experiment, do not penetrate crack here and be seen as damage.Selecting place, crack face is laser scanning plane.

Detecting step and parameters are identical with embodiment 1.

The diagnostic result of the present embodiment is as shown in Figure 6: the result of the signal that Fig. 6 (a) collects for PZT1 piezoelectric sensor; The result of the signal that Fig. 6 (b) collects for PZT2 piezoelectric sensor; The result of the signal that Fig. 6 (c) collects for PZT3 piezoelectric sensor; The overall result of the signal that Fig. 6 (d) collects for PZT1+PZT2+PZT3 piezoelectric sensor; In Fig. 6 (d), polygon white dashed line represents the damage result of being diagnosed out by the present invention, and white rectangle represents real damage; The strain energy density that can find out damage field from Fig. 6 (d) is significantly less than other healthy area.The position in crack, shape and size can accurately be judged.

Embodiment 3

The target of this embodiment is the carbon-fiber-reinforcomposite composite material layer plywood detecting containing delamination.The composite layer plate structure of using in experiment is [(45 °/0 °/-45 °/90 °) ₄] _s, thickness of slab is 4.8mm.As shown in Figure 7, in the middle part of composite laminated plate, having delamination, this delamination is that the weight low velocity impact by a 4.6kg obtains by tension weight churning testing machine (Dynatup9250HD).With laser pulse (8.5ns), irradiate this carbon-fiber-reinforcomposite composite material layer plate and produce Lamb wave, its principal ingredient is S0 pattern and A0 pattern, and the energy of ripple mainly concentrates between 50kHz and 300kHz.At this frequency domain, the wavelength of A0 pattern is approximately 10mm; The ripple ratio of S0 pattern and A0 pattern is propagated larger in aluminium sheet.

Step 1, centered by delamination, get a 100 * 100mm ²the region of size is surveyed area, and surveyed area is divided into a square net, and mesh spacing is got half of wavelength of A0 pattern, i.e. 5mm.

Step 2, net point of use laser pulses irradiate, inspire Lamb wave at this point; Three PZT piezoelectric sensors distribute as shown in Figure 8, and in Fig. 8, the black circle of dotted line represents the damage of composite laminated plate, and pore represents PZT piezoelectric sensor, and square box represents surveyed area, around 100 * 100mm ²detect net region, uniform three PZT piezoelectric sensors on the circumference apart from grid central point 100mm, use epoxy adhesive that PZT piezoelectric sensor is sticked on carbon-fiber-reinforcomposite composite material layer plate securely; The response signal that PZT piezoelectric sensor is received imports main frame by charge amplifier and oscillograph; In order to ensure Lamb wave, completely by surveyed area, the length of response signal is got 100 μ s.

The equal value strain energy γ of step 3, computing grid point.The calculating formula of equal value strain energy γ is as follows:

$\left\{\begin{array}{cc}\mathrm{\γ}=\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{{\mathrm{\α}}_i}^2& (i=\mathrm{1,2,3},\·\·\·,n)\\ n=T/\mathrm{\ΔT}& \\ {\mathrm{\α}}_i=\mathrm{\β}({\mathrm{\ϵ}}_{\mathrm{xi}}+{\mathrm{\ϵ}}_{\mathrm{yi}})& \end{array}\right.$

In formula, β is proportionality constant, ε _xiit is the strain of directions X in medium face; ε _yithe strain of Y-direction in medium face, ε _xi+ ε _yii the sampling ripple signal amplitude of piezoelectric sensor within the sampling time; T is that ultrasound wave is by the travel-time of surveyed area, namely sampling time; Δ T is sampling interval, and n is hits; α _iit is the value of an internal strain of facet while being proportional to this net point.

Step 4, draw the energy flow chart of ripple, repeating step 2 each net point of scanning, and repeating step 3 calculates the γ of each net point of surveyed area, draws out the energy flow chart of surveyed area.

By step 3, calculated the equal value strain energy γ of each net point, the method for application numerical interpolation obtains the equal value strain energy γ of each point of surveyed area.So just can obtain the energy flow chart of surveyed area ripple.

In order to reduce the impact of noise on result, before processing, signal is carried out to bandpass filtering, on ripple is logical, be limited to 50kHz, roll off the production line as 300kHz.

The diagnostic result of the present embodiment is as shown in Figure 9: the result of the signal that Fig. 9 (a) collects for PZT1 piezoelectric sensor; The result of the signal that Fig. 9 (b) collects for PZT2 piezoelectric sensor; The result of the signal that Fig. 9 (c) collects for PZT3 piezoelectric sensor; The overall result of the signal that Fig. 9 (d) collects for PZT1+PZT2+PZT3 piezoelectric sensor; The white dashed line of sealing represents the damage result of being diagnosed out by the present invention in Fig. 9 (d), black circles represent the to be hit size of side delamination damage, light cylindrical represent the not to be hit size of side delamination damage.

From Fig. 9 (a)-(d), can find out, different with the aluminium sheet situation that does not penetrate crack of embodiment 2 from the elliptical hole of embodiment 1, the strain energy density of damage field is obviously greater than other healthy area, and this is because the in-plane stiffness of delamination location diminishes and the fine crack that generates owing to being hit has caused that stress concentrates; Some local strain energy density of edge is extremely large in Fig. 9 (d), and this is that anisotropy due to superficial layer CFRP material causes.

In order to improve diagnostic result, the equal value strain energy γ calculating formula of net point is improved to:

$\left\{\begin{array}{cc}\mathrm{\γ}=\underset{i=1}{\overset{n}{\mathrm{\Σ}}}\left|{\mathrm{\α}}_i\right|& (i=\mathrm{1,2,3},\·\·\·,n)\\ n=T/\mathrm{\ΔT}& \\ {\mathrm{\α}}_i=\mathrm{\β}({\mathrm{\ϵ}}_{\mathrm{xi}}+{\mathrm{\ϵ}}_{\mathrm{yi}})& \end{array}\right.$

What be about to strain in medium face square changes its absolute value into, and the result obtaining as shown in figure 10.

The abnormal large region of the strain energy density of its edge has disappeared as can be seen from Figure 10, illustrates that the algorithm after improving is effective; The impact that the anisotropy of CFRP material of can reducing this algorithm causes result.

For compared with prior art, to the carbon-fiber-reinforcomposite composite material layer plate containing delamination, adopt the diagnostic result of existing ultrasonic propagation as shown in figure 11: Figure 11 (a), Figure 11 (b) and Figure 11 (c) are respectively the signal collected of three PZT piezoelectric sensors results after treatment, and this figure can not determine the existence of delamination.

As shown in figure 12, a kind of damage system of implementing said method, include impulse laser unit 3, piezoelectric sensor 4, amplifier 5, oscillograph 8, main frame 6 and display 7, impulse laser unit 3 irradiates the flaw detection region 2 of testee 1 for generation of pulse laser beam, and excitation ultrasound ripple; Piezoelectric sensor, amplifier, oscillograph are connected by signal wire with main frame, and main frame 6 use interface buss connect and gating pulse laser aid 3, and piezoelectric sensor 4 is close to the surperficial detection faces internal strain of testee 1 and is translated into continuous electric signal; The electric signal that amplifier 5 receives piezoelectric sensor 4 amplifies, and by A/D converter or oscillograph 8, continuous electric signal is converted into digital signal, then inputs main frame 6; Piezoelectric sensor 4 is more than three or three, and main frame 6 receives electric signal, calculates equal value strain energy γ and draw energy flow chart, and the energy flow chart that 7 pairs of host process of display obtain shows.

In Figure 12, piezoelectric sensor 4 is PZT piezoelectric sensing; Amplifier 5 is charge amplifier.

Claims (8)

1. the damage diagnosis method of the energy flow chart based on ripple, is characterized in that: comprise the following steps:

(1) determine surveyed area, surveyed area is divided into a square net; Determine mesh spacing, mesh spacing should be not more than the half-wavelength of detected structure medium wave;

(2) use net point of laser pulses irradiate, at this point, inspire Lamb wave; More than three or three piezoelectric sensor that distributes around surveyed area receives response signal, and the response signal receiving is stored on main frame;

(3) the equal value strain energy γ of computing grid point;

(4) draw the energy flow chart of ripple.

2. the damage diagnosis method of the energy flow chart based on ripple according to claim 1, is characterized in that: in step (3), the calculating formula of equal value strain energy γ is as follows:

$\left\{\begin{array}{cc}\mathrm{\γ}=\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{{\mathrm{\α}}_i}^2& (i=\mathrm{1,2,3},\·\·\·,n)\\ n=T/\mathrm{\ΔT}& \\ {\mathrm{\α}}_i=\mathrm{\β}({\mathrm{\ϵ}}_{\mathrm{xi}}+{\mathrm{\ϵ}}_{\mathrm{yi}})& \end{array}\right.$

In formula, β is proportionality constant, ε _xiit is the strain of directions X in medium face; ε _yithe strain of Y-direction in medium face, ε _xi+ ε _yii the sampling ripple signal amplitude of piezoelectric sensor within the sampling time; T is that ultrasound wave is by the travel-time of surveyed area; Δ T is sampling interval, and n is hits; α _iit is the value of an internal strain of facet while being proportional to this net point.

3. the damage diagnosis method of the energy flow chart based on ripple according to claim 1, is characterized in that: in step (3), the calculating formula of equal value strain energy γ is as follows:

$\left\{\begin{array}{cc}\mathrm{\γ}=\underset{i=1}{\overset{n}{\mathrm{\Σ}}}\left|{\mathrm{\α}}_i\right|& (i=\mathrm{1,2,3},\·\·\·,n)\\ n=T/\mathrm{\ΔT}& \\ {\mathrm{\α}}_i=\mathrm{\β}({\mathrm{\ϵ}}_{\mathrm{xi}}+{\mathrm{\ϵ}}_{\mathrm{yi}})& \end{array}\right.$

In formula, β is proportionality constant, ε _xiit is the strain of directions X in medium face; ε _yithe strain of Y-direction in medium face, ε _xi+ ε _yii the sampling ripple signal amplitude of piezoelectric sensor within the sampling time; T is that ultrasound wave is by the travel-time of surveyed area; Δ T is sampling interval, and n is hits; α _iit is the value of an internal strain of facet while being proportional to this net point.

4. according to the damage diagnosis method of the energy flow chart based on ripple described in claim 2 or 3, it is characterized in that: in step (4), repeating step (2) scans each net point, and repeating step (3) calculates the γ of each net point of surveyed area, draws out the distribution plan of surveyed area γ.

5. the damage diagnosis method of the energy flow chart based on ripple according to claim 4, is characterized in that: in step (2), described piezoelectric sensor is PZT piezoelectric sensor.

6. a damage system that implements the claims method described in 1, include impulse laser unit (3), piezoelectric sensor (4), amplifier (5), oscillograph (8), main frame (6) and display (7), impulse laser unit (3) irradiates the flaw detection region (2) of testee (1) for generation of pulse laser beam, and excitation ultrasound ripple; Piezoelectric sensor, amplifier, oscillograph are connected by signal wire with main frame, main frame (6) connects and gating pulse laser aid (3) with interface bus, and piezoelectric sensor (4) is close to the surperficial detection faces internal strain of testee (1) and is translated into continuous electric signal; The electric signal that amplifier (5) receives piezoelectric sensor (4) amplifies, A/D converter or oscillograph (8) are converted into digital signal by continuous electric signal, input again main frame (6), it is characterized in that: piezoelectric sensor (4) is more than three or three, main frame (6) receives electric signal, calculates equal value strain energy γ and draw energy flow chart, and display (7) is processed to main frame (6) energy flow chart obtaining and shown.

7. damage system according to claim 6, is characterized in that: piezoelectric sensor (4) is PZT piezoelectric sensor.

8. according to the damage system described in claim 6 or 7, it is characterized in that: described amplifier (5) is charge amplifier.

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