An ultrasonic detection method and an ultrasonic detection system for the damage degree of JHL-3 generation materials

Abstract

The present application provides a method and an ultrasonic detection system for ultrasonic detection of the damage degree of JHL-3 generation materials. The method includes: using a non-linear spring model and a low-frequency Maxwell model in parallel to form a Z-W-T non-linear viscoelastic constitutive model; introducing the material damage degree into the Z-W-T non-linear viscoelastic constitutive model to construct a damaged Z-W-T constitutive model; constructing a damage non-linear ultrasonic detection model according to the ultrasonic non-linear model in the damaged material and the damaged Z-W-T constitutive model; and performing ultrasonic detection on the JHL-3 generation materials according to the damage non-linear ultrasonic detection model. By establishing a Z-W-T non-linear viscoelastic constitutive model including the damage degree, the present application establishes a corresponding relationship between the ultrasonic non-linear coefficient and the elastic damage degree, and quantitatively describes the damage condition of the material during the compression process, so as to realize the detection of the damage degree of the JHL-3 generation materials.

Description

Technical Field

[0001] This application relates to the technical field of ultrasonic nondestructive testing, and particularly to a method for ultrasonic detection of the damage degree of JHL-3 generation materials and an ultrasonic detection system. Background Art

[0002] Polymer Bonded Explosive (PBX) is a particulate-filled polymer composite material, in which the energetic material particles occupy the main components of the material. As a functional energetic material commonly used in aerospace solid propellants and weapon warheads, the reliability of JHL-3 often determines the performance and use safety of equipment. Among them, the hardness and tensile strength indicators are important performance indicators of the material. The hardness and tensile strength of the material can not only directly reflect the comprehensive mechanical properties of the material, but also for important in-service components, the hardness and tensile strength are closely related to their friction performance, fatigue resistance, pitting resistance and plasticity performance. Therefore, the evaluation and characterization of material hardness and tensile strength are important research contents in the testing of material mechanical properties.

[0003] In recent years, it has been a relatively common means to use ultrasonic means to predict the stress state and evaluate the damage of PBX structural components. In the research of ultrasonic nondestructive testing technology, ultrasonic acoustic parameters such as sound velocity, attenuation rate and nonlinear coefficient have become parameters for detecting the internal stress state and damage degree of materials, and this method has been widely used in metal materials and some regularly arranged composite materials such as carbon fiber. However, due to the arrangement pattern of each phase in the polymer mixed explosive and the re-division of the structure during the pressing process, there are still many blind spots in the ultrasonic detection theory for such materials. Summary of the Invention

[0004] In view of this, this application proposes a method for ultrasonic detection of the damage degree of JHL-3 generation materials and an ultrasonic detection system. By establishing a Z-W-T nonlinear viscoelastic constitutive model including the damage degree, a corresponding relationship is established between the ultrasonic nonlinear coefficient and the elastic damage degree, and the damage condition of the material during the compression process is quantitatively described, so as to realize the detection of the damage degree of JHL-3 generation materials.

[0005] In a first aspect, this application provides a method for ultrasonic detection of the damage degree of JHL-3 generation materials, including:

[0006] Adopting a nonlinear spring model and a low-frequency Maxwell model in parallel to form a Z-W-T nonlinear viscoelastic constitutive model;

[0007] Introducing the material damage degree into the Z-W-T nonlinear viscoelastic constitutive model to construct a damaged Z-W-T constitutive model;

[0008] Construct a damage non-linear ultrasonic detection model according to the ultrasonic non-linear model in the damaged material and the damaged Z-W-T constitutive model;

[0009] Perform ultrasonic detection on the JHL-3 generation material according to the damage non-linear ultrasonic detection model.

[0010] Optionally, the Z-W-T non-linear viscoelastic constitutive model is:

[0011]

[0012] f e (ε) = E0ε + αε 2 + βε 3

[0013] where σ is the material stress, ε is the material compressive strain, and f e (ε) is the non-linear spring model of the polymer binder, which is expressed as a cubic function relationship of ε by three elastic constants E0, α, and β, is the low-frequency Maxwell model, is the strain rate, and E2 and θ are the elastic constants and relaxation time of the Maxwell model.

[0014] Optionally, the damaged Z-W-T constitutive model is:

[0015]

[0016] where D is the material damage degree.

[0017] Optionally, it further includes:

[0018] According to the ultrasonic non-linear theory, the relationship between the second-order non-linear coefficient of the material and the damage degree is calculated using the amplitude of the ultrasonic second harmonic as:

[0019]

[0020] where x is the sound path, k is the acoustic wave number, is the second-order non-linear coefficient of the material. When the ultrasonic propagation distance and the incident frequency are kept constant, and the sound path x and the wave number k are constants, let m = αkx / 4E0, and the relationship is simplified to: 2 x / 4E0, the relationship is simplified to:

[0021]

[0022] where m is the damage factor of the material.

[0023] Optionally, the damage non-linear ultrasonic detection model is:

[0024]

[0025] Among them, m is the damage factor of the material, is the second-order nonlinear coefficient of the material, ε0 is the initial damage of the material, and ε c is the critical damage of the material.

[0026] Optionally, when the damage non-linear ultrasonic detection model is strain-related, it is a step function, indicating that it is discontinuous at the initial damage strain ε0, and as the non-linear coefficient rises, the damage degree gradually increases, and the rising rate gradually decreases to failure.

[0027] Optionally, it further includes:

[0028] By linearly processing the undamaged degree and non-linear parameters of the material, the damage factor m of the material is obtained by fitting, and the calculation formula is:

[0029]

[0030] Among them, the undamaged degree R of the material = 1 - D, and the non-linear parameter

[0031] In summary, based on the Z-W-T viscoelastic constitutive model, the concept of damage degree is introduced in this application, and a Z-W-T non-linear viscoelastic constitutive model including the damage degree is established. Using this model for the end sinusoidal small strain perturbation, its ultrasonic wave equation is obtained, and then the relationship between the second-order relative non-linear coefficient and the damage degree is derived. Among them, the damage degree can be indirectly characterized by the undamaged degree. By linearly fitting it with the non-linear parameter, the material damage factor can be obtained, and then the final damage non-linear ultrasonic detection model can be determined, so as to realize the detection of the damage degree of the JHL-3 generation replacement materials.

[0032] In a second aspect, this application provides an ultrasonic detection system, including a transceiver, an ultrasonic probe, a wedge block, and an industrial control computer;

[0033] The transceiver is respectively connected to the ultrasonic probe and the industrial control computer, and is used to stimulate the ultrasonic probe to send ultrasonic waves and output the collected waveform to the industrial control computer;

[0034] The ultrasonic probe is respectively installed at both ends of the wedge block. Ultrasonic waves are sent to the specimen to be tested through the ultrasonic probe at one end, and the waveform of the specimen to be tested is collected through the ultrasonic probe at the other end and sent to the transceiver;

[0035] The industrial control computer uses the above-mentioned damage non-linear ultrasonic detection model to calculate the damage degree of the specimen to be tested according to the collected waveform.

[0036] Optionally, it further includes an oscilloscope, and the oscilloscope is respectively connected to the transceiver and the industrial control computer.

[0037] These and other aspects of the present application will become more readily apparent in the following description of the (multiple) embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 The flowchart of a method for ultrasonic detection of the damage degree of JHL-3 generation materials provided by an embodiment of the present application;

[0039] Figure 2 The schematic diagram of a semi-infinite equal cross-section straight rod coordinate system provided by an embodiment of the present application;

[0040] Figure 3 The structural diagram of an ultrasonic detection system provided by an embodiment of the present application;

[0041] Figure 4 The structural diagram of a computing device provided by an embodiment of the present application.

[0042] It should be understood that in the above structural schematic diagrams, the sizes and forms of the respective block diagrams are for reference only and should not constitute an exclusive interpretation of the embodiments of the present application. The relative positions and inclusion relationships between the respective block diagrams presented in the structural schematic diagrams only schematically represent the structural associations between the block diagrams, rather than limiting the physical connection manners of the embodiments of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0043] In order to make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings.

[0044] An embodiment of the present application provides a method for ultrasonic detection of the damage degree of JHL-3 generation materials and an ultrasonic detection system. Based on the Z-W-T viscoelastic constitutive model, the concept of damage degree is introduced, and a Z-W-T nonlinear viscoelastic constitutive model including the damage degree is established. By performing a small sine strain perturbation at the end with this model, its ultrasonic wave equation is obtained, and then the relationship between the second-order relative nonlinear coefficient and the damage degree is derived. Among them, the degree of damage can be indirectly characterized by the undamaged degree. By performing a linear fitting on it and the nonlinear parameter, the material damage factor can be obtained, and then the final damage nonlinear ultrasonic detection model can be determined, thereby realizing the detection of the damage degree of JHL-3 generation materials.

[0045] As Figure 1 shown, a method for ultrasonic detection of the damage degree of JHL-3 generation materials provided by an embodiment of the present application includes:

[0046] S10: A Z-W-T nonlinear viscoelastic constitutive model is formed by connecting a nonlinear spring model and a low-frequency Maxwell model in parallel;

[0047] In this embodiment, the loading form of the PBX grain is quasi-static loading at a low strain rate. Therefore, the Z-W-T nonlinear viscoelastic constitutive model can be composed of a parallel connection of a nonlinear spring model and a Maxwell model with a low-frequency response, as follows:

[0048]

[0049] In the above formula, σ is the material stress, and ε is the material compressive strain. is the low-frequency Maxwell model. is the strain rate, and E2 and θ are the elastic constant and relaxation time of the Maxwell model, respectively. f e (ε) is the nonlinear spring model of the polymer binder, which is expressed as a cubic function of ε by three elastic constants E0, α, and β, and can be expressed as:

[0050] f e (ε) = E0ε + αε 2 + βε 3 (2)

[0051] S20: Introduce the material damage degree into the Z-W-T nonlinear viscoelastic constitutive model to construct a damaged Z-W-T constitutive model;

[0052] During the compression process, plastic deformation or brittle fracture will occur in the internal particles or binders of the material, which will cause changes in the macroscopic properties of the material. Moreover, the Z-W-T nonlinear viscoelastic constitutive model cannot describe the mechanical behavior of larger deformations until approaching failure. Therefore, it is necessary to introduce mechanical variables to characterize the macroscopic property changes of the PBX;

[0053] For the one-dimensional damage of the model, the damage degree D is introduced to describe such changes, and it can be specifically defined as:

[0054]

[0055] In the formula, A is the cross-sectional area of the PBX grain specimen, and A D is the total damage area caused by stress and cracks and other defects on the material cross-section;

[0056] For PBX materials with low fracture toughness, there is a critical value for the damage degree. When it exceeds this critical value, the material fractures. Therefore, for the value of the damage degree D, generally D0 < D < D c <1, where D0 is the initial damage of the material, and D c is the critical damage of the material.

[0057] For the characterization of material damage, it can be considered that the internal microcracks and other defects are evenly distributed, and the damage is isotropic. According to the strain equivalence principle of materials in damage mechanics, the damage constitutive of the material can be expressed as:

[0058] σ = E(1 - D)(ε e + ε p ) (4)

[0059] From Equation (3), the damage variable is characterized by the effective elastic modulus of the material as: being:

[0060]

[0061] It can thus be obtained that the Z-W-T nonlinear viscoelastic constitutive model introducing the damage concept can be expressed as:

[0062]

[0063] S30: Construct a damage nonlinear ultrasonic detection model according to the ultrasonic nonlinear model in the damaged material and the damaged Z-W-T constitutive model;

[0064] Numerous experimental studies have proven that the decline of the mechanical properties of materials is closely related to the nonlinear behavior of ultrasonic waves propagating inside them. The waveform distortion of ultrasonic waves in damaged materials is called the ultrasonic nonlinear effect, which is currently commonly represented by the second-order and third-order material elastic constants;

[0065] Therefore, in this embodiment, the established damaged Z-W-T nonlinear viscoelastic constitutive model is used to further derive its ultrasonic wave equation, and an ultrasonic wave model of a semi-infinite long straight rod with a constant cross-section is constructed. The coordinate system is established as Figure 2 shown;

[0066] This equation is based on the small strain assumption of solid materials, and the control equation is the same as when there is no initial stress, and there is no mechanical dissipation. Then the wave equation of one-dimensional longitudinal waves in the rod is:

[0067]

[0068] In the above formula, ρ represents the density of the material; σ(x, t) represents the normal stress along the x direction in the rod; u represents the displacement in the same direction. Then the geometric equation can be expressed by the following formula:

[0069]

[0070] To simplify the equation, denote the superscript "f ′ " to represent representing

[0071] From Equation (6), the damaged Z-W-T nonlinear viscoelastic constitutive model is:

[0072]

[0073] Substituting Eqs. (8) and (9) into Eq. (7) gives:

[0074]

[0075] Since the loading strain rate is a constant and the material has the characteristic of high particle filling degree, showing a relatively low viscoelasticity degree, the above equation becomes:

[0076]

[0077] Considering a harmonic perturbation at the end of the rod, expand it as a power series of x:

[0078] u(x, t) = u0(x, t) + xu1(x, t) + x 2 u2(x, t) (12)

[0079] If a single-frequency harmonic sound wave is input at the end of the rod, such as:

[0080] u(x, t) = A0cos(kx - ωt) (13)

[0081] In the above equation, A0 is the amplitude of the input wave, ω is the sound wave frequency, and k is the sound wave number.

[0082] Substituting Eqs. (12) and (13) and simplifying by the same power of x and then organizing, we get:

[0083]

[0084] Among them, ω represents the circular frequency of the perturbation, that is, the ultrasonic circular frequency, and k represents the wave number. If A2 represents the amplitude of the ultrasonic second harmonic cos2(kx - ωt), and A3 represents the amplitude of the third harmonic cos3(kx - ωt).

[0085] Since the damage is elastic damage, in the compression experiment, the relative change in density does not exceed 0.5%, and its density value is defaulted to be constant. According to the ultrasonic nonlinear theory, the calculation formulas for the second-order and third-order relative nonlinear coefficients are respectively:

[0086]

[0087] Since there is the square of the damage degree D in the third-order relative nonlinear coefficient, and it has a quadratic function relationship with the nonlinear coefficient, the complexity of predicting the damage is relatively large. Therefore, in this embodiment, the second-order relative nonlinear coefficient is used for prediction. From Eq. (15), we get:

[0088]

[0089] When the ultrasonic propagation distance and the incident frequency are kept constant, and the acoustic path x and the wave number k are constants, let m = ak 2 x / 4E0, the above equation can be simplified to:

[0090]

[0091] It can be obtained from Equation (18) that the damage fluctuates between (D0, 1), and the greater the second-order ultrasonic nonlinear coefficient of the material during loading, the greater its damage degree, which conforms to the law of the material during actual loading. In the formula, m is the characteristic value of the material in the initial damage state.

[0092] From this, it can be obtained that the damage equation of the damaged Z-W-T constitutive can be written in the following form:

[0093]

[0094] Among them, m is called the damage factor of this type of material, and the unit is V -1 ; is the nonlinear parameter of the material, and the unit is V -1 .

[0095] Similar to the Lemaitre correction model, this damage nonlinear model is a step function when related to strain, indicating that it is discontinuous at the initial damage strain ε0. And as the nonlinear coefficient increases, the damage degree gradually increases, but its rising rate gradually decreases to failure, that is, D = D c .

[0096] To simplify the fitting difficulty between variables in the experiment, let the variable undamaged degree R = 1 - D, and the nonlinear parameter Then the above equation can be expressed as:

[0097]

[0098] Generally, the initial damage of the material can be obtained from the electron microscope observation images of the same batch of materials, but the damage strain of the materials in the experiment is generally greater than the initial damage strain. Therefore, Equation (20) can be used to linearly process the undamaged degree R and the nonlinear parameter λ, and then obtain the damage factor m, and use this to calibrate the materials on the same production line, and then characterize the damage situation of this type of material under load.

[0099] S40: Perform ultrasonic detection on the JHL-3 generation substitute materials according to the damage nonlinear ultrasonic detection model.

[0100] According to the damage nonlinear model obtained above, the ultrasonic detection system can be used to perform ultrasonic detection on the JHL-3 generation substitute materials, so as to obtain the damage degree of the JHL-3 generation substitute materials.

[0101] Such as Figure 3As shown in the figure, an embodiment of the present application further provides an ultrasonic detection system, which includes a transceiver 100, an ultrasonic probe 200, a wedge 300, an oscilloscope 400, and an industrial control computer 500;

[0102] The transceiver 100 is respectively connected to the ultrasonic probe 200, the oscilloscope 400, and the industrial control computer 500, and is used to excite the ultrasonic probe 200 to send ultrasonic waves, and output the collected waveforms to the oscilloscope 400 and the industrial control computer 500; the ultrasonic probe 200 is respectively installed at both ends of the wedge 300, and sends ultrasonic waves to the specimen to be tested through the ultrasonic probe 200 at one end, and collects the waveforms of the specimen to be tested through the ultrasonic probe 200 at the other end and sends them to the transceiver 100; the industrial control computer 500 uses the above-mentioned damage non-linear ultrasonic detection model, and calculates the damage degree of the specimen to be tested according to the collected waveforms.

[0103] In this embodiment, the transceiver 100 can adopt a RITEC high-power transceiver, which is composed of modules such as a broadband gated RF amplifier, a tracking receiver, a quadrature phase-sensitive detector, and two gated amplifiers. The transceiver 100 triggers a high-frequency signal, which acts on a longitudinal wave transducer with a center frequency of f to generate an ultrasonic wave signal, and then is received by a symmetrically installed longitudinal wave probe through the critical refraction longitudinal wave wedge-material interface. In order to make the amplitude of the second or third harmonic caused by ultrasonic non-linearity easy to observe, a longitudinal wave probe with a center frequency of 2f is used for reception, and a fast Fourier transform is performed on the collected waveforms to study the spectral characteristics in the echo.

[0104] During the detection process, the ultrasonic excitation forms used are generally divided into three types, namely single pulse, multi-pulse (pulse train), and continuous sine wave excitation. Among them, the single pulse signal is a single-cycle sine signal, which has high energy but a wide frequency band and is easy to submerge the high-order harmonic information; although the continuous sine wave excitation can obtain the single-frequency spectrum of the incident wave, the transducer cannot withstand the long-term continuous analog signal loading, and it is difficult to maintain a continuous high-power signal; the characteristics of the pulse train signal are between the single pulse signal and the continuous sine signal, which has high energy and a narrower frequency band than the single pulse signal, and can effectively observe the harmonic components. Therefore, a pulse train excitation signal is used as the detection incident signal during the damage detection process.

[0105] Comparing with the continuous signal, it can be known that the spectral characteristics of the pulse train are that the more the number of periods, the narrower the frequency band, which is more conducive to the observation of the harmonic components, but the selection of the period needs to consider the following factors:

[0106] The more the number of selected periods, the longer the propagation distance, and the stronger the non-linear effect accumulated by the sound path;

[0107] The transmitted wave signal cannot overlap with the received wave signal.

[0108] It can be obtained therefrom that the number of pulse train periods satisfying the above two factors is the maximum value of the settable number of periods. Let the ultrasonic propagation path length be L, the excitation ultrasonic frequency be f, and the sound velocity of the sound wave in the medium be v. Then the number of periods N is:

[0109]

[0110] It can be obtained therefrom that the designed path length of the wedge is about 10 mm, the number of pulses is selected as 10 periods, and the sound velocity in 8701 is about 2500 m / s. Since the ultrasonic excitation signal selected in this embodiment is a Hanning modulation signal with a single frequency, the excitation frequency of the pulse train is selected as 2.5 MHz.

[0111] During the damage non-linear detection process, the equipment will also introduce non-linear characteristics. Therefore, a filter needs to be used to limit the non-linear influence caused by the equipment. In the experiment, a high-pass and low-pass filter in the RITEC system is used, the high-pass cut-off frequency is 1 MHz, and the low-pass cut-off frequency is 10 MHz.

[0112] In this embodiment, a KEYSIGHT DSOX3104T oscilloscope can be used. It has a total of three signal acquisition methods: normal sampling, peak detection, and average detection. Since the excitation signal used in this non-linear ultrasonic detection experiment is a 10-period pulse train mode, normal or peak detection cannot well represent the echo waveform and can only describe the instantaneous state of the waveform. Therefore, a 64-time average detection method is selected to homogenize the continuous pulse train. In addition, the power amplifier inside the instrument introduces a certain amount of noise signal while amplifying the amplitude of the excitation signal, and the average detection method can effectively avoid the influence of the noise signal on the echo signal.

[0113] Since the sampling form of the RITEC high-power transceiver is equidistant discrete sampling, to obtain the spectral characteristics of its time-domain signal, the discrete Fourier transform is commonly used to transform the time-domain signal. This function can generally be used to calculate the spectrum, power spectrum, etc. of the signal. For the finite-length discrete signal in this embodiment, the DFT can regard it as a periodic signal after periodic extension and then perform the transformation. Its basic expression form is as follows:

[0114]

[0115] The inverse transform is:

[0116]

[0117] where, X k is the Fourier amplitude. Through Equation (22), 2000 data points within a suitable time-domain range can be Fourier-transformed to obtain the spectrogram corresponding to this group of data, and then the amplitude components of the second harmonic and the third harmonic can be obtained.

[0118] Among them, to save the computational time of signal processing, the fast Fourier transform is generally used to perform time-frequency transformation on the signal. When performing FFT analysis on ultrasonic signals, due to the influence of frequency resolution and the limitation of the sampling rate, the frequency spectrum diagram of the signal cannot be accurately depicted completely. This is because the sampling method is discrete during the sampling process, and it is impossible to describe the real-time domain signal, but only to approximate the real signal infinitely, so frequency leakage occurs.

[0119] For this reason, when the sampling frequency f s is determined, a rectangular window function with a narrower main lobe is added to the FFT to reduce the amplitude of the discontinuous part and make it as continuous as possible, thereby reducing the violently changing part in the waveform.

[0120] In summary, the JHL-3 generation material damage degree ultrasonic detection method and ultrasonic detection system provided by the embodiments of the present application are based on the Z-W-T viscoelastic constitutive model, introduce the concept of damage degree, and establish a Z-W-T nonlinear viscoelastic constitutive model including the damage degree. By performing small sinusoidal strain perturbation at the end with this model, the ultrasonic wave equation is obtained, and then the relationship between the second-order relative nonlinear coefficient and the damage degree is derived. Among them, the degree of damage can be indirectly characterized by the undamaged degree. By linearly fitting it with the nonlinear parameter, the material damage factor can be obtained, and then the final damage nonlinear ultrasonic detection model can be determined, so as to realize the detection of the damage degree of the JHL-3 generation materials.

[0121] Figure 4 FIG. 13 is a structural schematic diagram of a computing device 1000 provided by an embodiment of the present application. The computing device 1000 includes: a processor 1010, a memory 1020, a communication interface 1030, and a bus 1040.

[0122] It should be understood that Figure 4 the communication interface 1030 in the shown computing device 1000 can be used to communicate with other devices.

[0123] Among them, the processor 1010 can be connected to the memory 1020. The memory 1020 can be used to store the program code and data. Therefore, the memory 1020 can be an internal storage unit of the processor 1010, an external storage unit independent of the processor 1010, or a component including an internal storage unit of the processor 1010 and an external storage unit independent of the processor 1010.

[0124] Optionally, the computing device 1000 may further include a bus 1040. Among them, the memory 1020 and the communication interface 1030 may be connected to the processor 1010 through the bus 1040. The bus 1040 may be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus, etc. The bus 1040 may be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Figure 4 only one line is shown in the figure, but it does not mean that there is only one bus or one type of bus.

[0125] It should be understood that in the embodiments of the present application, the processor 1010 may adopt a central processing unit (CPU). The processor may also be other general-purpose processors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc. Or the processor 1010 adopts one or more integrated circuits to execute relevant programs to implement the technical solutions provided by the embodiments of the present application.

[0126] The memory 1020 may include a read-only memory and a random access memory, and provide instructions and data to the processor 1010. A part of the processor 1010 may also include a non-volatile random access memory. For example, the processor 1010 may also store information about the device type.

[0127] When the computing device 1000 is running, the processor 1010 executes the computer-executable instructions in the memory 1020 to perform the operation steps of the above method.

[0128] It should be understood that the computing device 1000 according to the embodiments of the present application may correspond to the corresponding main body that executes the methods according to the embodiments of the present application, and the above and other operations and / or functions of each module in the computing device 1000 respectively implement the corresponding processes of the methods in the present embodiments. For the sake of brevity, they will not be described in detail here.

[0129] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in connection with the embodiments disclosed herein can be implemented in electronic hardware, or in a combination of computer software and electronic hardware. Whether these functions are executed in hardware or software depends on the specific application and design constraints of the technical solution. Skilled artisans may use different methods for each specific application to implement the described functions, but such implementation should not be considered to exceed the scope of this application.

[0130] Those skilled in the art can clearly understand that for the sake of convenience and brevity of description, the specific working processes of the systems, devices, and units described above can refer to the corresponding processes in the foregoing method embodiments and will not be elaborated herein.

[0131] In the several embodiments provided in this application, it should be understood that the disclosed systems, devices, and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the units is only a logical function division, and there may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed couplings or direct couplings or communication connections to each other can be through some interfaces, and the indirect couplings or communication connections of the devices or units can be in electrical, mechanical, or other forms.

[0132] The units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or may be distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0133] In addition, the functional units in each embodiment of this application can be integrated into one processing unit, or each unit can exist physically alone, or two or more units can be integrated into one unit.

[0134] When the above-mentioned functions are implemented in the form of software function units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a part of this technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in various embodiments of this application. The foregoing storage medium includes: various media that can store program codes, such as USB flash drives, mobile hard disks, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical discs.

[0135] An embodiment of this application also provides a computer-readable storage medium, on which a computer program is stored. When the program is executed by a processor, it is used to execute the above-mentioned JHL-3 generation replacement material damage degree ultrasonic detection method, and this method includes at least one of the solutions described in the above-mentioned various embodiments.

[0136] The computer storage medium of the embodiment of this application can adopt any combination of one or more computer-readable media. The computer-readable medium can be a computer-readable signal medium or a computer-readable storage medium. The computer-readable storage medium can be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device, or component, or any combination of the above. More specific examples (non-exhaustive list) of the computer-readable storage medium include: an electrical connection having one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In this document, the computer-readable storage medium can be any tangible medium that contains or stores a program, and this program can be used by or in combination with an instruction execution system, device, or component.

[0137] The computer-readable signal medium can include a data signal propagated in a baseband or as part of a carrier wave, which carries the computer-readable program code. Such a propagated data signal can take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the above. The computer-readable signal medium can also be any computer-readable medium other than the computer-readable storage medium, and this computer-readable medium can send, propagate, or transmit a program for use by or in combination with an instruction execution system, device, or component.

[0138] The program code contained on a computer-readable medium can be transmitted by any suitable medium, including but not limited to wireless, wire, optical fiber cable, RF, etc., or any suitable combination of the above.

[0139] The computer program code for performing the operations of this application can be written in one or more programming languages or combinations thereof. The programming languages include object-oriented programming languages such as Java, Smalltalk, C++, and also include conventional procedural programming languages such as the "C" language or similar programming languages. The program code can be executed entirely on the user's computer, partially on the user's computer, executed as an independent software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In the case of a remote computer, the remote computer can be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or it can be connected to an external computer (for example, by using an Internet service provider to connect through the Internet).

[0140] It should be noted that the embodiments described in this application are only a part of the embodiments of this application, rather than all the embodiments. The components of the embodiments of this application usually described and illustrated in the drawings can be arranged and designed in various different configurations. Therefore, the above detailed description of the embodiments of this application provided in the drawings is not intended to limit the scope of this application claimed, but only represents the selected embodiments of this application. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of this application.

[0141] The terms "first, second, third, etc." or similar terms such as module A, module B, module C, etc. in the description and claims are only used to distinguish similar objects and do not represent a specific order for the objects. Understandably, the specific order or sequence can be interchanged under allowable circumstances so that the embodiments of this application described here can be implemented in an order other than that illustrated or described here.

[0142] In the above description, the reference numerals representing steps do not necessarily mean that the steps will be executed in this order. It may also include intermediate steps or be replaced by other steps. Under allowable circumstances, the order of the front and back steps can be interchanged, or they can be executed simultaneously.

[0143] The term "comprising" as used in the description and claims should not be construed as limited to the content listed thereafter; it does not exclude other elements or steps. Thus, it should be interpreted as specifying the presence of the stated features, integers, steps or components referred to, but not excluding the presence or addition of one or more other features, integers, steps or components and groups thereof. Thus, the expression "a device comprising devices A and B" should not be limited to a device consisting only of components A and B.

[0144] As used herein, "an embodiment" or "embodiments" means that the specific features, structures, or characteristics described in connection with the embodiment are included in at least one embodiment of the present application. Thus, the phrases "in an embodiment" or "in embodiments" that appear throughout this specification do not necessarily all refer to the same embodiment, but may. Further, in the various embodiments of the present application, if there is no special indication and logical conflict, the terms and / or descriptions between different embodiments are consistent and may be cross-referenced to each other, and the technical features in different embodiments can be combined to form new embodiments according to their inherent logical relationships.

[0145] Note that the above are only the preferred embodiments of the present application and the technical principles applied. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, re-adjustments, and substitutions can be made by those skilled in the art without departing from the protection scope of the present invention. Therefore, although the present application has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and without departing from the concept of the present invention, more other equivalent embodiments can be included, all of which fall within the protection scope of the present invention.

Claims

1. An ultrasonic detection method for the damage degree of JHL-3 generation materials, characterized in that, Including: Adopting a non-linear spring model and a low-frequency Maxwell model in parallel to form a Z-W-T non-linear viscoelastic constitutive model; Introducing the material damage degree into the Z-W-T non-linear viscoelastic constitutive model to construct a damaged Z-W-T constitutive model; Constructing a damage non-linear ultrasonic detection model according to the ultrasonic non-linear model in the damaged material and the damaged Z-W-T constitutive model; According to the ultrasonic non-linear theory, using the amplitude of the ultrasonic second harmonic frequency, the relationship formula between the second-order non-linear coefficient of the material and the damage degree is calculated as: Where D is the material damage degree, x is the sound path, k is the acoustic wave number, is the second-order nonlinear coefficient of the material, E0 and α are elastic constants. When the ultrasonic propagation distance and the incident frequency are kept constant, and the sound path x and the wave number k are constants, let m = αk 2 x / 4E0, and the said relational expression is simplified to: where m is the damage factor of the material; Performing ultrasonic detection on the JHL-3 generation substitute material according to the damage non-linear ultrasonic detection model.

2. The method according to claim 1, wherein The Z-W-T non-linear viscoelastic constitutive model is: f e f(ε) = E0ε + αε 2 + βε 3 where σ is the material stress, ε is the material compressive strain, and f e (ε) is the non-linear spring model of the polymer binder, which is expressed as a cubic function of ε by three elastic constants E0, α, and β, is the low-frequency Maxwell model, is the strain rate, and E2 and θ are the elastic constant and relaxation time of the Maxwell model, respectively.

3. The method according to claim 2, wherein The damaged Z-W-T constitutive model is: where D is the material damage degree.

4. The method according to claim 3, wherein The damage non-linear ultrasonic detection model is: where m is the damage factor of the material, is the second-order nonlinear coefficient of the material, ε0 is the initial damage of the material, and ε c is the critical damage of the material.

5. The method according to claim 4, characterized in that The damage non-linear ultrasonic detection model is a step function when related to strain, indicating that it is discontinuous at the initial damage strain ε0, and as the non-linear coefficient increases, the damage degree gradually increases, and the rising rate gradually decreases until failure.

6. The method according to claim 4, wherein Also including: By linearly processing the undamaged degree and non-linear parameters of the material, the damage factor m of the material is obtained by fitting, and the calculation formula is: Among them, the undamaged degree R of the material = 1 - D, and the nonlinear parameter 7. An ultrasonic detection system, characterized in that, Including a transceiver, an ultrasonic probe, a wedge block and an industrial control computer; The transceiver is respectively connected to the ultrasonic probe and the industrial control computer, and is used to stimulate the ultrasonic probe to send ultrasonic waves and output the collected waveform to the industrial control computer; The ultrasonic probes are respectively installed at both ends of the wedge block. Ultrasonic waves are sent to the specimen to be tested through the ultrasonic probe at one end, and the waveform of the specimen to be tested is collected through the ultrasonic probe at the other end and sent to the transceiver; The industrial control computer adopts the damage non-linear ultrasonic detection model described in any one of claims 1 to 6, and calculates the damage degree of the specimen to be tested according to the collected waveform.

8. The system according to claim 7, characterized in that Also including an oscilloscope, and the oscilloscope is respectively connected to the transceiver and the industrial control computer.

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