Material fracture energy determination method and related equipment

Abstract

The invention relates to the technical field of fracture analysis, and provides a material fracture energy determination method and related equipment, and the method comprises the steps: obtaining crack data of a target material region in a plurality of instantaneous critical states, and calculating a plurality of transient response values of the target material region based on the crack data in each instantaneous critical state; performing envelope extraction on all the transient response values to obtain a plurality of envelope transient response values; establishing a damping cosine function by using all envelope transient response values; the damping cosine function is used for describing a fluctuation rule of the transient response value; identifying the final critical state of the target material area based on a damping cosine function, and calculating the total stress of the target material area in the final critical state; and calculating the fracture energy of the target material area in the final critical state according to the total stress. According to the method, the accuracy of fracture energy evaluation of the material can be improved.

Description

Technical Field

[0001] This application relates to the field of fracture analysis technology, and in particular to a method and related equipment for determining the fracture energy of a material. Background Technology

[0002] In fields such as tunnel engineering, bridge structures, and building foundations, the cracking behavior of materials such as concrete and rock is a key factor affecting structural safety and durability. Accurately analyzing crack propagation patterns, especially precisely determining the critical state of crack instability propagation and calculating its fracture energy, is crucial for evaluating the overall performance of a structure.

[0003] Digital image correlation (DIC) technology has become an important tool for observing crack propagation processes, providing abundant full-field displacement data. However, current DIC-based fracture analysis largely remains at the stage of macroscopic geometric parameter identification, or merely uses displacement data as input for traditional load-displacement curve calculations, failing to form a computational system that deeply integrates DIC data with fracture mechanics models. Furthermore, the determination of critical states is highly subjective, and fracture energy calculation models fail to reflect the actual energy dissipation process, resulting in low accuracy in assessing the fracture energy of materials. Summary of the Invention

[0004] This application provides a method and related equipment for determining the fracture energy of materials, which can solve the problem of low accuracy in assessing the fracture energy of materials.

[0005] In a first aspect, this application provides a method for determining the fracture energy of a material, the method comprising:

[0006] Crack data of the target material region under multiple instantaneous critical states are acquired, and multiple transient response values ​​of the target material region are calculated based on the crack data under each instantaneous critical state; the crack data includes crack opening displacement and crack opening displacement.

[0007] Envelope extraction is performed on all transient response values ​​to obtain multiple envelope transient response values;

[0008] A damped cosine function is established using all envelope transient response values; the damped cosine function is used to describe the fluctuation pattern of the transient response values.

[0009] The final critical state of the target material region is identified based on the damped cosine function, and the total stress of the target material region under the final critical state is calculated.

[0010] The fracture energy of the target material region under the final critical state is calculated based on the total stress.

[0011] Optionally, multiple transient response values ​​of the target material region are calculated based on crack data at each instantaneous critical state, including:

[0012] Through the formula:

[0013]

[0014] Calculate transient response value ;

[0015] in, Indicates the first The instantaneous critical state of crack opening displacement and the displacement of the crack opening The ratio, Indicates the first The instantaneous critical state of crack opening displacement and the displacement of the crack opening The ratio, the first The instantaneous critical state and the first Each instantaneous critical state is defined as two adjacent instantaneous critical states. , , A set of numbers representing instantaneous critical states.

[0016] Optionally, envelope extraction is performed on all transient response values ​​to obtain multiple envelope transient response values, including:

[0017] Divide all transient response values ​​into multiple windows;

[0018] For each window, calculate the upper envelope transient response value and the lower envelope transient response value corresponding to the window based on all transient response values ​​within the window, and use both the upper envelope transient response value and the lower envelope transient response value as the envelope transient response value.

[0019] Optionally, a damped cosine function can be constructed using all envelope transient response values, including:

[0020] Establish the initial damping cosine function and the corresponding objective function;

[0021] The initial damping cosine function is fitted nonlinearly by all envelope transient response values ​​and the objective function to obtain the intermediate damping cosine function.

[0022] A phase offset is introduced to correct the intermediate damping cosine function, resulting in the damping cosine function.

[0023] Optionally, the initial damping cosine function is:

[0024]

[0025] in, Indicates the transient response value. Indicates the initial amplitude. Indicates the attenuation coefficient. Indicates frequency, This represents the value of the crack opening displacement;

[0026] The objective function is:

[0027]

[0028] in, , , ;

[0029] The damped cosine function is:

[0030]

[0031] in, This indicates the phase offset.

[0032] Optionally, the total stress in the target material region at the final critical state is calculated, including:

[0033] Through the formula:

[0034]

[0035] Calculate the total stress in the target material region at the final critical state. ;

[0036] in, Indicates the tensile strength of the shotcrete-rock interface. Indicates the initial pressure amplitude:

[0037]

[0038] in, This represents the value of the displacement at which the crack opens.

[0039] Optionally, the fracture energy of the target material region under the final critical state is calculated based on the total stress, including:

[0040] Through the formula:

[0041]

[0042] Calculate the fracture energy of the target material region .

[0043] Secondly, this application provides a material fracture energy determination device, comprising:

[0044] The acquisition module is used to acquire crack data of the target material region under multiple instantaneous critical states, and calculate multiple transient response values ​​of the target material region based on the crack data under each instantaneous critical state; the crack data includes crack opening displacement and crack opening displacement;

[0045] The envelope extraction module is used to extract the envelope of all transient response values ​​to obtain multiple envelope transient response values;

[0046] A module is established to construct a damped cosine function using all envelope transient response values; the damped cosine function is used to describe the fluctuation pattern of the transient response values.

[0047] The identification module is used to identify the final critical state of the target material region based on the damped cosine function, and to calculate the total stress of the target material region under the final critical state.

[0048] The calculation module is used to calculate the fracture energy of the target material region under the final critical state based on the total stress.

[0049] Thirdly, embodiments of this application provide a terminal device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the aforementioned method for determining material fracture energy.

[0050] Fourthly, embodiments of this application provide a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described method for determining material fracture energy.

[0051] The above-mentioned solution in this application has the following beneficial effects:

[0052] In the embodiments of this application, crack data of the target material region under multiple instantaneous critical states are acquired, and multiple transient response values ​​of the target material region are calculated based on the crack data under each instantaneous critical state. Then, envelope extraction is performed on all transient response values ​​to obtain multiple envelope transient response values. A damping cosine function is then established using all envelope transient response values. The final critical state of the target material region is then identified based on the damping cosine function, and the total stress of the target material region under the final critical state is calculated. Finally, the fracture energy of the target material region under the final critical state is calculated based on the total stress. Establishing a damping cosine function based on the transient response values ​​can accurately represent the changes in the transient response values, facilitating the analysis of the cracking state of the target material region, improving the accuracy of the final critical state identification, and calculating the fracture energy of the final critical state with high accuracy, effectively improving the accuracy of fracture energy assessment.

[0053] Other beneficial effects of this application will be described in detail in the following detailed description section. Attached Figure Description

[0054] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0055] Figure 1 A flowchart illustrating a method for determining the fracture energy of a material according to an embodiment of this application;

[0056] Figure 2 This is a schematic diagram of critical state determination provided in an embodiment of this application;

[0057] Figure 3 This is a schematic diagram illustrating the relationship between pressure and crack opening displacement according to an embodiment of this application;

[0058] Figure 4 This is a schematic diagram of the structure of a material fracture energy determination device provided in an embodiment of this application;

[0059] Figure 5 This is a schematic diagram of the structure of a terminal device provided in an embodiment of this application. Detailed Implementation

[0060] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application may also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods have been omitted so as not to obscure the description of this application with unnecessary detail.

[0061] It should be understood that, when used in this application specification and the appended claims, the term "comprising" indicates the presence of the described features, integrals, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or a collection thereof.

[0062] It should also be understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0063] As used in this application specification and the appended claims, the term "if" may be interpreted, depending on the context, as "when," "once," "in response to determination," or "in response to detection." Similarly, the phrase "if determined" or "if detected [the described condition or event]" may be interpreted, depending on the context, as meaning "once determined," "in response to determination," "once detected [the described condition or event]," or "in response to detection [the described condition or event]."

[0064] Furthermore, in the description of this application and the appended claims, the terms "first," "second," "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0065] References to "one embodiment" or "some embodiments" as described in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0066] To address the issue of low accuracy in existing material fracture energy assessments, this application provides a method for determining material fracture energy. This method acquires crack data of a target material region under multiple instantaneous critical states, calculates multiple transient response values ​​of the target material region based on the crack data at each instantaneous critical state, extracts the envelope of all transient response values ​​to obtain multiple envelope transient response values, establishes a damping cosine function using all envelope transient response values, identifies the final critical state of the target material region based on the damping cosine function, calculates the total stress of the target material region at the final critical state, and finally calculates the fracture energy of the target material region at the final critical state based on the total stress. The method of establishing a damping cosine function based on transient response values ​​accurately describes the changes in transient response values, facilitating the analysis of the cracking state of the target material region, improving the accuracy of identifying the final critical state, and calculating the fracture energy at a high-precision final critical state, thus effectively improving the accuracy of fracture energy assessment.

[0067] The following is an exemplary description of the method for determining the fracture energy of materials provided in this application.

[0068] like Figure 1 As shown, the method for determining the fracture energy of materials provided in this application includes the following steps:

[0069] Step 11: Obtain crack data of the target material region under multiple instantaneous critical states, and calculate multiple transient response values ​​of the target material region based on the crack data under each instantaneous critical state.

[0070] The target material region mentioned above is the material region requiring fracture energy analysis, such as concrete areas like bridge piers and tunnels. The crack data includes crack opening displacement (the relative displacement of corresponding points on both sides of the crack in a direction perpendicular to the crack surface under external force, including the crack tip and any position along the crack propagation path) and crack opening displacement (the displacement caused by the relative movement of the normal vector of the crack opening on the material surface, i.e., the displacement of the normal vector of the material surface position, focusing only on the exposed crack opening, used to describe the degree of opening of the outermost layer of the material). The instantaneous critical state refers to the transient change process of crack propagation. The crack propagation process is divided into dense discrete stages, and each tiny propagation stage can be considered an instantaneous critical state. The aforementioned transient response values ​​are used to describe the degree of fracture in the target material region.

[0071] In some embodiments of this application, DIC technology can be used to monitor the crack propagation process of the target material region in real time to obtain crack data. Models such as convolutional neural networks can be used to intelligently identify multiple instantaneous critical states of the target material region within a certain period of time based on the crack data. Multiple instantaneous critical states correspond to multiple moments.

[0072] Specifically, for each pair of adjacent instantaneous critical states, the formula is:

[0073]

[0074] Calculate transient response value .

[0075] in, Indicates the first The instantaneous critical state of crack opening displacement and the displacement of the crack opening The ratio, Indicates the first The instantaneous critical state of crack opening displacement and the displacement of the crack opening The ratio, the first The instantaneous critical state and the first Each instantaneous critical state is defined as two adjacent instantaneous critical states. , , A set of numbers representing instantaneous critical states.

[0076] For example, after obtaining crack data and transient response values, the data needs to be cleaned and sorted: the 3σ criterion based on statistical distribution can be used to automatically identify and remove COD and other related data. Invalid values ​​in the data are typically caused by signal loss or interference from the measuring equipment. The system then sorts all valid data points in ascending order based on their corresponding COD values. This sorting process ensures strict monotonicity and continuity of the data along the crack propagation dimension.

[0077] It can also perform data quality assessment and repair: by calculating the data point density (the number of data points per unit COD length), the reliability of the data can be automatically determined. If the data density is found to be too low, an alert will be issued. When a certain proportion of outliers are detected, the system will automatically use a cubic spline interpolation method to intelligently repair the data, thereby ensuring the integrity and smoothness of the data sequence.

[0078] Step 12: Extract the envelope of all transient response values ​​to obtain multiple envelope transient response values.

[0079] In some embodiments of this application, the step of extracting the envelope of all transient response values ​​to obtain multiple envelope transient response values ​​includes:

[0080] The first step is to divide all transient response values ​​into multiple windows.

[0081] Specifically, set the window size, and divide all transient response values ​​into multiple windows according to the time sequence corresponding to the transient response values ​​(the time corresponding to the transient response value can be set to the average of the times of the two instantaneous critical states corresponding to the transient response value) and the window size, according to the arrangement direction of the transient response values. Each window contains multiple transient response values ​​equal to the window size.

[0082] For example, window size = max(5,(N / 20)), where N is the number of transient response values.

[0083] The second step is to calculate the upper envelope transient response value and the lower envelope transient response value for each window based on all transient response values ​​within the window, and then use both the upper envelope transient response value and the lower envelope transient response value as the envelope transient response value.

[0084] Specifically, the 95th percentile of all transient response values ​​within the window is calculated to obtain the upper envelope transient response value, and the 5th percentile is calculated to obtain the lower envelope transient response value.

[0085] For example, after obtaining the envelope transient response value, it can be smoothed: a Savitzky-Golay filter can be used for smoothing. This filter is a smoothing method based on local polynomial least squares fitting. Its advantage lies in its ability to effectively filter out noise while preserving the original peaks and valleys of the envelope to the greatest extent possible, avoiding signal distortion that may be caused by using a simple moving average method. The size of the smoothing window is also related to the data scale, achieving adaptive optimization.

[0086] Step 13: Use all envelope transient response values ​​to establish a damped cosine function.

[0087] The aforementioned damped cosine function is used to describe the fluctuation pattern of the transient response value.

[0088] In some embodiments of this application, the step of establishing a damped cosine function using all envelope transient response values ​​includes:

[0089] The first step is to establish the initial damping cosine function and the corresponding objective function.

[0090] Specifically, the initial damping cosine function is:

[0091]

[0092] in, Indicates the transient response value. Indicates the initial amplitude. Indicates the attenuation coefficient. Indicates frequency, This represents the value of the crack opening displacement.

[0093] The objective function is:

[0094]

[0095] in, , , .

[0096] The second step is to perform nonlinear least squares fitting on the initial damping cosine function using all envelope transient response values ​​and the objective function to obtain the intermediate damping cosine function.

[0097] For example, by substituting all envelope transient response values ​​into the objective function, the Levenberg-Marquardt algorithm can be used to perform a nonlinear least-squares fit on the objective function to obtain... , , The values ​​of the three parameters.

[0098] It should be noted that the directly calculated local amplitude sequence may contain jitter. To ensure the smoothness of the final generated curve, the amplitude sequence needs to be smoothed and optimized. A Gaussian weighted moving average method can be used for this purpose. This method assigns different weights to the data points within the window (the center point has the highest weight, gradually decreasing towards both ends), and then performs a weighted average, thus smoothing the data while better preserving the original trend.

[0099] The main oscillation frequency can be automatically estimated using zero-crossing point analysis. Specifically, the deviation of the original data from the center line is first calculated, and then the position where the deviation signal changes from positive to negative or from negative to positive (i.e., crosses the zero point) is detected. The COD span between two consecutive zero-crossing points is half a cycle, from which the average cycle length and oscillation frequency can be calculated.

[0100] The third step is to introduce a phase offset to correct the intermediate damping cosine function, thus obtaining the damping cosine function.

[0101] Specifically, the damping cosine function is:

[0102]

[0103] in, This indicates the phase offset.

[0104] Step 14: Identify the final critical state of the target material region based on the damping cosine function, and calculate the total stress of the target material region under the final critical state.

[0105] In some embodiments of this application, the steps of identifying the final critical state of the target material region based on the damping cosine function and calculating the total stress of the target material region under the final critical state include:

[0106] The first step is to identify the final critical state of the target material region based on the damped cosine function.

[0107] Specifically, a physically meaningful attenuation threshold is set. An algorithm is used to find the COD position corresponding to the center of the period when the transient response values ​​of the damping cosine function's period are both below the set threshold for the first time; this position is denoted as the critical crack opening displacement CODc.

[0108] For example, by fitting a damped cosine function, the transient response value ξ at a certain crack location can be obtained as a function of crack opening displacement (COD).

[0109] Set attenuation threshold The algorithm will examine each oscillation cycle in turn:

[0110] When COD=0.045mm, within this cycle The upper and lower envelopes are [+0.003, -0.0035], which are still greater than the threshold.

[0111] When COD=0.066mm, within this cycle The upper and lower envelopes are [+0.0018, -0.0015], and their absolute values ​​are all less than 0.002.

[0112] At this point, the algorithm determines that the cycle is the first cycle that satisfies the condition that "both upper and lower bound transient response values ​​are less than the attenuation threshold", and takes the COD=0.066mm corresponding to the center point of the cycle as the critical crack opening displacement CODc.

[0113] The second step is to calculate the total stress in the target material region under the final critical state.

[0114] Specifically, through the formula:

[0115]

[0116] Calculate the total stress in the target material region at the final critical state. .

[0117] in, Indicates the tensile strength of the shotcrete-rock interface. Indicates the initial pressure amplitude:

[0118]

[0119] in, This represents the value of the displacement at which the crack opens.

[0120] An exemplary diagram illustrating the critical state determination is shown below. Figure 2 As shown, the horizontal axis represents the crack opening displacement (COD) in millimeters (mm), and the vertical axis represents the transient response value. The dots represent the original data, the solid line is the sinusoidal oscillation curve, and the dashed line is the envelope reference.

[0121] It is worth mentioning that re-determining the critical state of the target material region based on the damping cosine function can improve the accuracy of the critical state determination.

[0122] Step 15: Calculate the fracture energy of the target material region under the final critical state based on the total stress.

[0123] Specifically, through the formula:

[0124]

[0125] Calculate the fracture energy of the target material region .

[0126] For example, the traditional expression for fracture energy is:

[0127]

[0128] The expression for the percentage increase in energy is:

[0129]

[0130] For example, the relationship between pressure and crack opening displacement is as follows: Figure 3 As shown, the horizontal axis represents crack opening displacement in millimeters (mm), and the vertical axis represents stress in MPa. The parameters are set to... MPa , Hz, mm, MPa. The curves in the figure represent the stress variation curves under four conditions: the traditional exponential model, considering transient effects, transient stress components, and critical crack opening displacement.

[0131] Calculated according to the embodiment , The energy increased by approximately 2.21%, demonstrating that the method described in this application can more comprehensively reveal the energy dissipation mechanism of materials.

[0132] It is worth mentioning that establishing a damped cosine function based on the transient response value can accurately describe the change of the transient response value, which facilitates the analysis of the cracking state of the target material region, improves the identification accuracy of the final critical state, and can effectively improve the accuracy of fracture energy assessment by calculating the fracture energy of the final critical state with high accuracy.

[0133] Furthermore, the method of this application has the following advantages:

[0134] An algorithm based on moving quantile envelope extraction is proposed, which accurately captures the upper and lower boundaries of the data through adaptive windowing technology.

[0135] An algorithm for generating periodic cosine oscillation curves was developed to achieve a complete envelope from the highest to the lowest point of the data.

[0136] A model incorporating transient oscillatory stress terms was created, enabling the calculation of fracture energy to include a more comprehensive energy dissipation mechanism.

[0137] The following is an exemplary description of the material fracture energy determination device provided in this application.

[0138] like Figure 4 As shown, this application embodiment provides a material fracture energy determination device 400, which includes:

[0139] The acquisition module 401 is used to acquire crack data of the target material region under multiple instantaneous critical states, and calculate multiple transient response values ​​of the target material region based on the crack data under each instantaneous critical state; the crack data includes crack opening displacement and crack opening displacement.

[0140] The envelope extraction module 402 is used to extract the envelope of all transient response values ​​to obtain multiple envelope transient response values;

[0141] Module 403 is established to construct a damped cosine function using all envelope transient response values; the damped cosine function is used to describe the fluctuation pattern of the transient response values.

[0142] The identification module 404 is used to identify the final critical state of the target material region based on the damping cosine function, and to calculate the total stress of the target material region under the final critical state.

[0143] Calculation module 405 is used to calculate the fracture energy of the target material region under the final critical state based on the total stress.

[0144] It should be noted that the information interaction and execution process between the above-mentioned devices / units are based on the same concept as the method embodiments of this application. For details on their specific functions and technical effects, please refer to the method embodiments section, and they will not be repeated here.

[0145] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is merely an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiments can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit. Furthermore, the specific names of the functional units and modules are only for easy differentiation and are not intended to limit the scope of protection of this application. The specific working process of the units and modules in the above system can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0146] like Figure 5 As shown, an embodiment of this application provides a terminal device, wherein the terminal device D10 of this embodiment includes: at least one processor D100 ( Figure 5The diagram shows only one processor, a memory D101, and a computer program D102 stored in the memory D101 and executable on the at least one processor D100, wherein the processor D100 executes the computer program D102 to implement the steps in any of the above method embodiments.

[0147] Specifically, when the processor D100 executes the computer program D102, it acquires crack data of the target material region under multiple instantaneous critical states, calculates multiple transient response values ​​of the target material region based on the crack data under each instantaneous critical state, extracts the envelope of all transient response values ​​to obtain multiple envelope transient response values, establishes a damping cosine function using all envelope transient response values, identifies the final critical state of the target material region based on the damping cosine function, calculates the total stress of the target material region under the final critical state, and finally calculates the fracture energy of the target material region under the final critical state based on the total stress. Establishing a damping cosine function based on the transient response values ​​accurately describes the changes in transient response values, facilitating the analysis of the cracking state of the target material region, improving the accuracy of identifying the final critical state, and calculating the fracture energy of the final critical state with high accuracy, effectively improving the accuracy of fracture energy assessment.

[0148] The processor D100 can be a central processing unit (CPU), or it can 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. A general-purpose processor can be a microprocessor or any conventional processor.

[0149] In some embodiments, the memory D101 may be an internal storage unit of the terminal device D10, such as a hard disk or memory of the terminal device D10. In other embodiments, the memory D101 may be an external storage device of the terminal device D10, such as a plug-in hard disk, smart media card (SMC), secure digital card (SD), flash card, etc., equipped on the terminal device D10. Furthermore, the memory D101 may include both internal and external storage units of the terminal device D10. The memory D101 is used to store the operating system, applications, bootloader, data, and other programs, such as the program code of the computer program. The memory D101 can also be used to temporarily store data that has been output or will be output.

[0150] This application also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps described in the various method embodiments above.

[0151] This application provides a computer program product that, when run on a terminal device, enables the terminal device to implement the steps described in the various method embodiments above.

[0152] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. The computer-readable medium can include at least: any entity or device capable of carrying the computer program code to the material fracture energy determination method apparatus / terminal device, a recording medium, a computer memory, a read-only memory (ROM), a random access memory (RAM), an electrical carrier signal, a telecommunication signal, and a software distribution medium, such as a USB flash drive, a portable hard drive, a magnetic disk, or an optical disk.

[0153] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0154] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0155] The above description is the preferred embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this invention, and these improvements and modifications should also be considered within the scope of protection of this invention.

Claims

1. A method for determining the fracture energy of a material, characterized in that, include: Crack data of the target material region under multiple instantaneous critical states are acquired, and multiple transient response values ​​of the target material region are calculated based on the crack data under each instantaneous critical state; the crack data includes crack opening displacement and crack opening displacement. Envelope extraction is performed on all transient response values ​​to obtain multiple envelope transient response values; A damped cosine function is established using all envelope transient response values; the damped cosine function is used to describe the fluctuation pattern of the transient response values. The final critical state of the target material region is identified based on the damping cosine function, and the total stress of the target material region under the final critical state is calculated. The fracture energy of the target material region under the final critical state is calculated based on the total stress.

2. The method for determining the fracture energy of a material according to claim 1, characterized in that, The calculation of multiple transient response values ​​of the target material region based on crack data at each instantaneous critical state includes: Through the formula: Calculate transient response value ; in, Indicates the first The instantaneous critical state of crack opening displacement and the displacement of the crack opening The ratio, Indicates the first The instantaneous critical state of crack opening displacement and the displacement of the crack opening The ratio, the first The instantaneous critical state and the first Each instantaneous critical state is defined as two adjacent instantaneous critical states. , , A set of numbers representing instantaneous critical states.

3. The method for determining the fracture energy of a material according to claim 1, characterized in that, The process of extracting the envelope from all transient response values ​​yields multiple envelope transient response values, including: Divide all transient response values ​​into multiple windows; For each window, calculate the upper envelope transient response value and the lower envelope transient response value corresponding to the window based on all transient response values ​​within the window, and use both the upper envelope transient response value and the lower envelope transient response value as the envelope transient response value.

4. The method for determining the fracture energy of a material according to claim 1, characterized in that, The process of establishing a damped cosine function using all envelope transient response values ​​includes: Establish the initial damping cosine function and the corresponding objective function; The initial damping cosine function is fitted nonlinearly using all envelope transient response values ​​and the objective function to obtain the intermediate damping cosine function. A phase offset is introduced to correct the intermediate damping cosine function, resulting in a damping cosine function.

5. The method for determining the fracture energy of a material according to claim 4, characterized in that, The initial damping cosine function is: in, Indicates the transient response value. Indicates the initial amplitude. Indicates the attenuation coefficient. Indicates frequency, This represents the value of the crack opening displacement; The objective function is: in, , , ; The damping cosine function is: in, This indicates the phase offset.

6. The method for determining the fracture energy of a material according to claim 5, characterized in that, The calculation of the total stress in the target material region at the final critical state includes: Through the formula: Calculate the total stress in the target material region at the final critical state. ; in, Indicates the tensile strength of the shotcrete-rock interface. Indicates the initial pressure amplitude: in, This represents the value of the displacement at which the crack opens.

7. The method for determining the fracture energy of a material according to claim 6, characterized in that, The calculation of the fracture energy of the target material region in the final critical state based on the total stress includes: Through the formula: Calculate the fracture energy of the target material region .

8. A device for determining the fracture energy of a material, characterized in that, include: The acquisition module is used to acquire crack data of the target material region under multiple instantaneous critical states, and calculate multiple transient response values ​​of the target material region based on the crack data under each instantaneous critical state; the crack data includes crack opening displacement and crack opening displacement; The envelope extraction module is used to extract the envelope of all transient response values ​​to obtain multiple envelope transient response values; A module is established to construct a damped cosine function using all envelope transient response values; the damped cosine function is used to describe the fluctuation pattern of the transient response values. The identification module is used to identify the final critical state of the target material region based on the damping cosine function, and to calculate the total stress of the target material region under the final critical state. The calculation module is used to calculate the fracture energy of the target material region in the final critical state based on the total stress.

9. A terminal device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the method for determining the material fracture energy as described in any one of claims 1 to 7.

10. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by a processor, it implements the method for determining the fracture energy of materials as described in any one of claims 1 to 7.

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