Gas hydrate-containing coal body model construction method considering particle breaking

Abstract

The invention relates to the technical field of gas hydrate-containing coal bodies, in particular to a gas hydrate-containing coal body model construction method considering particle breakage. The method comprises the following steps: establishing a gas hydrate-containing coal discrete element model; wherein the discrete element model of the coal body containing the gas hydrate comprises coal body particles and rigid clusters, and the normal / tangential bonding strength between the rigid clusters and the normal / tangential bonding strength between the adjacent coal particles are set to be lower than the normal / tangential bonding strength in the rigid clusters; obtaining and fitting a deviatoric stress-strain curve according to the experimental data, fitting a pre-peak nonlinear stage of the deviatoric stress-strain curve according to the macroscopic damage constitutive relation, and performing inversion to obtain characteristic parameters in the macroscopic damage constitutive relation; and correcting the discrete element model of the coal body containing the gas hydrate by using the shape factor and the scale parameter. The invention relates to a gas hydrate-containing coal body model construction method considering particle crushing, and provides a method capable of finely simulating the crushable performance of a gas hydrate.

Description

Technical Field

[0001] This invention relates to the field of gas hydrate technology, and in particular to a method for constructing a gas hydrate coal body model that takes into account particle breakage. Background Technology

[0002] Hydrate solidification technology has become an effective way to prevent and control such dynamic disasters by enhancing the mechanical properties of coal. Studies have shown that the formation of gas hydrates can significantly improve the macroscopic mechanical properties of coal and enhance the strength and stiffness of coal samples. However, during actual loading, gas hydrates are a weak link and are prone to failure. The broken gas hydrates not only reduce the strength of local areas, but also promote the germination and expansion of shear bands, which further leads to changes in the mechanical properties of coal due to structural reorganization, resulting in sample instability and failure, and ultimately potentially causing disasters such as gas outbursts.

[0003] In existing discrete element method (DEM) simulations of hydrate-containing porous media, hydrates are often simplified into small-diameter particles or static bond contacts. However, these methods cannot accurately reflect the complete process of deformation-fracture-disintegration-structural reorganization (shear band formation) of real gas hydrates during loading, making it difficult to accurately reflect the mechanical response of particulate materials. Most importantly, current research only simulates microscopic phenomena and fails to extract a quantifiable critical criterion from the microscopic fragmentation evolution process to predict the initiation of macroscopic damage, making the numerical models difficult to apply to engineering safety early warning.

[0004] Therefore, developing a method that can accurately simulate the breakable properties of gas hydrates is of great theoretical and engineering significance for revealing the disaster mechanism of gas hydrate-bearing coal bodies and realizing advanced early warning. Summary of the Invention

[0005] This invention provides a method for constructing a model of a gas hydrate-containing coal body that takes into account particle breakage, and can provide a method that can accurately simulate the breakability of gas hydrates.

[0006] In a first aspect, embodiments of the present invention provide a method for constructing a model of a gas hydrate-containing coal body considering particle fragmentation, comprising: A discrete element model of coal containing gas hydrate is established; wherein, the discrete element model of coal containing gas hydrate includes multiple coal particles and multiple rigid clusters, and a rigid cluster represents a complete gas hydrate cemented agglomerate. The normal / tangential bonding strength between rigid clusters and between them and their adjacent coal particles is set to be lower than the normal / tangential bonding strength inside the rigid cluster. Based on experimental data, a deviatoric stress-strain curve was obtained and fitted. The pre-peak nonlinear stage of the deviatoric stress-strain curve was fitted according to the macroscopic damage constitutive relation, and the characteristic parameters in the macroscopic damage constitutive relation, namely the shape factor and the scale parameter, were obtained by inversion. The discrete element model of the gas hydrate-containing coal body is modified using the shape factor and the scale parameter.

[0007] Optionally, establishing the discrete element model of the coal body containing gas hydrates includes: Randomly distributed coal particles and gas hydrate particles are generated inside a rigid body; an anti-rolling contact bonding model is used to characterize the influence of coal particle shape on the contact between coal particles and between adjacent hydrate particles to characterize the cementing effect of gas hydrate. Construct a circular wall and randomly generate multiple parallel contact bonding model particles inside it to obtain a rigid cluster; The rigid body's internal gas hydrate particles were replaced with the rigid clusters using the equal area method.

[0008] Optionally, establishing the discrete element model of the coal body containing gas hydrates includes: Define the discrete element model of gas hydrate-containing coal bodies and the hydrate fragmentation event and shear zone germination evolution process.

[0009] Optionally, the hydrate breakup event includes: when the external load applied to the rigid cluster exceeds its normal / tangential bond strength, the rigid cluster is broken into independent sub-particles by breaking the parallel contact bonds between all particles within the rigid cluster, in order to simulate gas hydrate breakup.

[0010] Optionally, the shear band germination and evolution process includes: capturing and tracking the evolution of sample coordination number, porosity, contact force chain and particle rotation field during numerical simulation, defining and identifying the germination location and expansion process of the shear band.

[0011] Optionally, after obtaining the shape factor and scale parameter, the method further includes: The shape factor and the scale parameter are assigned to the discrete element model of the gas hydrate-containing coal body, that is, the normal / tangential bond strength in the parallel contact bond model within the rigid cluster is multiplied by a coefficient related to the shape factor and the scale parameter.

[0012] Optionally, the coefficient is calculated in the following manner. xishu= F 0 ×(-math.ln(1.0-freq))^(1.0 / m )] Where xishu is a coefficient.m and F 0 The shape factor and the scale parameter.

[0013] Secondly, embodiments of the present invention also provide a device for constructing a model of a gas hydrate-containing coal body considering particle fragmentation, comprising: A modeling unit is used to establish a discrete element model of coal containing gas hydrates; wherein, the discrete element model of coal containing gas hydrates includes multiple coal particles and multiple rigid clusters, and a rigid cluster represents a complete gas hydrate cemented agglomerate. The normal / tangential bonding strength between rigid clusters and between them and their adjacent coal particles is set to be lower than the normal / tangential bonding strength inside the rigid cluster. The fitting unit is used to obtain the fitted deviatoric stress-strain curve based on experimental data, and to fit the pre-peak nonlinear stage of the deviatoric stress-strain curve according to the macroscopic damage constitutive relation, and to invert the characteristic parameters in the macroscopic damage constitutive relation: shape factor and scale parameter. The correction unit is used to correct the discrete element model of the gas hydrate-containing coal body using the shape factor and the scale parameter.

[0014] Thirdly, embodiments of the present invention also provide an electronic device, including a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, it implements the method described in any embodiment of this specification.

[0015] Fourthly, embodiments of the present invention also provide a computer-readable storage medium having a computer program stored thereon, which, when executed in a computer, causes the computer to perform the methods described in any embodiment of this specification.

[0016] Compared with the prior art, the present invention has at least the following beneficial effects: In this embodiment, rigid clusters are used to simulate hydrates in coal. By setting the bonding strength of the rigid clusters, that is, setting the normal / tangential bonding strength between rigid clusters and between them and adjacent coal particles to be lower than the normal / tangential bonding strength inside the rigid clusters, the rigid clusters can be used to simulate hydrates to simulate the cemented interface between gas hydrates and coal, thereby enabling the rigid clusters to break under certain stress.

[0017] To further improve the reliability of the model, it can be corrected using experimental data. Specifically, the deviatoric stress-strain curve can be simulated using experimental data. The strength of the model's particle elements follows the Weibull statistical distribution function, and this curve matches. Based on the Weibull statistical distribution function, the corresponding macroscopic damage constitutive relation can be obtained. The fitted deviatoric stress-strain curve matches the macroscopic damage constitutive relation. Based on the fitted curve, the characteristic parameters in the macroscopic damage constitutive relation can be inverted, and the obtained characteristic parameters can be used to correct the model. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of a modeling process provided in an embodiment of the present invention; Figure 2 This is a schematic diagram illustrating the evolution law of shear bands provided in an embodiment of the present invention; Figure 3 This invention provides an experimental deviatoric stress-strain curve and a statistical damage constitutive model fitting curve. Figure 4 This is a damage variable-strain curve provided in an embodiment of the present invention; Figure 5 This is a schematic diagram illustrating the relationship between critical strain, peak strain, and confining pressure, as well as the stability of the critical strain ratio, provided by an embodiment of the present invention. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0021] Please refer to Figure 1 This invention provides a method for constructing a model of a gas hydrate-containing coal body considering particle fragmentation, comprising: A discrete element model of coal containing gas hydrate is established; wherein, the discrete element model of coal containing gas hydrate includes multiple coal particles and multiple rigid clusters, and a rigid cluster represents a complete gas hydrate cemented agglomerate. The normal / tangential bonding strength between rigid clusters and between them and their adjacent coal particles is set to be lower than the normal / tangential bonding strength inside the rigid cluster. Based on experimental data, a deviatoric stress-strain curve was obtained and fitted. The pre-peak nonlinear stage of the deviatoric stress-strain curve was fitted according to the macroscopic damage constitutive relation, and the characteristic parameters in the macroscopic damage constitutive relation, namely the shape factor and the scale parameter, were obtained by inversion. The discrete element model of the gas hydrate-containing coal body is modified using the shape factor and the scale parameter.

[0022] In this embodiment, rigid clusters are used to simulate hydrates in coal. By setting the bonding strength of the rigid clusters, that is, setting the normal / tangential bonding strength between rigid clusters and between them and adjacent coal particles to be lower than the normal / tangential bonding strength inside the rigid clusters, the rigid clusters can be used to simulate hydrates to simulate the cemented interface between gas hydrates and coal, thereby enabling the rigid clusters to break under certain stress.

[0023] To further improve the reliability of the model, it can be corrected using experimental data. Specifically, the deviatoric stress-strain curve can be simulated using experimental data. The strength of the model's particle elements follows the Weibull statistical distribution function, and this curve matches. Based on the Weibull statistical distribution function, the corresponding macroscopic damage constitutive relation can be obtained. The fitted deviatoric stress-strain curve matches the macroscopic damage constitutive relation. Based on the fitted curve, the characteristic parameters in the macroscopic damage constitutive relation can be inverted, and the obtained characteristic parameters can be used to correct the model.

[0024] Specifically, the correction steps are as follows: (1) Obtain the deviatoric stress-strain curves of coal samples containing gas hydrate under different confining pressures. The confining pressures were 10, 12 and 14 MPa, the peak stresses were 7.51 MPa, 10.04 MPa and 11.63 MPa, and the corresponding peak strains were 10.96%, 9.37% and 10.45%, respectively.

[0025] (2) The particle unit strength follows the Weibull statistical distribution function, and its probability density function is: F For the mechanical parameters of the micro-element; F 0 is the scale parameter, which controls the mean of the probability density function graph; m The shape factor controls the peak value of the probability density function graph.

[0026] Corresponding macroscopic damage constitutive relation: in, The initial elastic modulus is denoted by .

[0027] (3) Fit the pre-peak nonlinear stage of the deviatoric stress-strain curves under different confining pressures and invert to obtain its characteristic parameters, i.e. m and F 0 (Containing pressures of 10 MPa, 12 MPa, and 14 MPa respectively, corresponding to) m The values ​​are 0.491, 0.536, and 0.489 respectively. F (The values ​​are 8.13, 4.10, and 3.58 respectively). A mathematical correlation is established between macroscopic experimental data and microscopic parameters, such as... Figure 3 As shown.

[0028] (4) The fitted inversion results under different confining pressures m and F The two characteristic parameter values ​​are assigned to the discrete element model constructed in step one, that is, the normal and tangential bond strengths in the parallel contact bonding model are multiplied by a factor of 0. m and F A coefficient related to 0 [coefficient: xishu= F 0×(-math.ln(1.0-freq))^(1.0 / m )], that is, "contact.prop(cp,'pb_ ')= contact.prop(cp,'pb_ ') × xishu; contact.prop(cp,'pb_ ')= contact.prop(cp,'pb_ ') × xishu".

[0029] (5) Construct a discrete element numerical model of hydrates (rigid clusters) that follows the Weibull distribution, and further optimize the constructed discrete element model of coal containing gas hydrates that considers the fragmentation of gas hydrate particles, so that the gas hydrates (rigid clusters) in the coal exhibit non-uniform characteristics, making the model more similar to the actual experimental situation.

[0030] In addition, to ensure that during the initial loading process of the simulated sample, the contact between coal particles and the interface between adjacent gas hydrate particles is preferentially disrupted, and the rigid cluster breaks down later, the normal and tangential bonding strengths within the rigid cluster can be set. , The coefficient of friction is relatively high (other micro-parameters of this model include: bond stiffness ratio, internal friction angle, cohesion, effective modulus, and coefficient of friction).

[0031] In some embodiments of the present invention, establishing a discrete element model of a coal body containing gas hydrates includes: Randomly distributed coal particles and gas hydrate particles are generated inside a rigid body; an anti-rolling contact bonding model is used to characterize the influence of coal particle shape on the contact between coal particles and between adjacent hydrate particles to characterize the cementing effect of gas hydrate. Construct a circular wall and randomly generate multiple parallel contact bonding model particles inside it to obtain a rigid cluster; The rigid body's internal gas hydrate particles were replaced with the rigid clusters using the equal area method.

[0032] The specific process may include the following steps: (1) Preliminary construction of discrete element model of coal containing gas hydrate: a. Particle generation: Particles are generated inside a rectangular rigid wall with dimensions of 50 mm × 100 mm, and coal particles and gas hydrate particles are generated simultaneously and randomly distributed inside the wall.

[0033] b. Contact model assignment: The anti-rolling contact bonding model is used to characterize the influence of coal particle shape between coal particles, and the parallel contact bonding model is assigned to characterize the cementation effect of gas hydrate between hydrate particles and between adjacent particles.

[0034] (2) Modeling of gas hydrate "rigid clusters": a. Construct a circular wall with a diameter of 0.4 mm, and place sub-particles inside it. Assign a high-strength, irreversible parallel contact bond model between the sub-particles. Specifically, to ensure that during the initial loading process, the contact between coal particles and the interface between adjacent gas hydrate particles preferentially fails, and the rigid cluster breaks down later, the normal and tangential bond strengths within the rigid cluster are set (…). , The coefficient of friction is relatively high (other micro-parameters of this model include: bond stiffness ratio, internal friction angle, cohesion, effective modulus, coefficient of friction, etc.).

[0035] b. The gas hydrate particles are replaced with rigid clusters using the equal-area method to form breakable gas hydrate particles. Each rigid cluster represents a complete hydrate cemented agglomerate. The normal and tangential bond strengths imparted between the rigid clusters and with adjacent coal particles (…) , The value is lower than the internal strength of the rigid cluster, which is used to simulate the cemented interface between gas hydrate and coal.

[0036] In some embodiments of the present invention, establishing a discrete element model of a coal body containing gas hydrates includes: Define the discrete element model of gas hydrate-containing coal bodies and the hydrate fragmentation event and shear zone germination evolution process.

[0037] In some embodiments of the present invention, the hydrate breakage event includes: when the external load applied to the rigid cluster exceeds its normal / tangential bond strength, the rigid cluster can be considered to have broken, and the rigid cluster is disintegrated into independent sub-particles by breaking the parallel contact bonds between all particles in the rigid cluster, so as to simulate the breakage of gas hydrate.

[0038] Please refer to Figure 2 In some embodiments of the present invention, the shear band germination and evolution process includes: capturing and tracking the evolution of sample coordination number, porosity, contact force chain and particle rotation field during numerical simulation, defining and identifying the germination location and expansion process of the shear band.

[0039] After defining the above events and processes, a biaxial compression discrete element numerical simulation experiment can be carried out based on the two-dimensional discrete element model of gas hydrate-containing coal body that considers the fragmentation of gas hydrate particles constructed above.

[0040] This invention also provides a method for predicting damage critical values ​​based on characteristic parameters, specifically including: Biaxial compression experiments were conducted to obtain deviatoric stress-strain curves; Based on the macroscopic damage constitutive relation, the pre-peak nonlinear stage of the deviatoric stress-strain curve is fitted, and the characteristic parameters in the macroscopic damage constitutive relation, namely the shape factor and the scale parameter, are obtained by inversion. The formula for determining the damage variable is based on the shape factor and the scale parameter; The second derivative of the damage variable formula is calculated, and the zero value is taken to obtain the critical strain and critical damage. Determine the critical strain ratio based on the critical strain and peak strain; The critical strain ratios under different confining pressures are averaged to obtain the critical value for characteristic damage warning.

[0041] The specific process includes: Obtain three deviatoric stress-strain curves, and then repeat the above fitting and inversion operation to obtain the specimen size parameters under different confining pressures. F 0 and shape factor m .

[0042] Import the acquired strain and deviatoric stress values ​​into Origin software (X-axis: strain value; Y-axis: deviatoric stress value), and input the damage variable formula "1 - exp( -(col(A) / F 0)^m After that, the software automatically generates damage variables. D and strain ε Finally, the damage variables are plotted. D With strain ε Changing curves, such as Figure 4 As shown.

[0043] Damage evolution analysis and critical threshold determination Based on damage variables D -strain ε Given a curve, take its second derivative and find its zero point. The strain corresponding to this zero point is... ε Critical strain ε _c, the corresponding damage value is the critical damage. D _c (the critical point in the diagram): The critical strains corresponding to confining pressures of 10 MPa, 12 MPa, and 14 MPa were obtained. ε The critical damage values ​​corresponding to _c are 4.30%, 3.88%, and 4.82%, respectively. D The values ​​of _c are 0.61, 0.52, and 0.69, respectively. It can be seen that the critical damage value does not change monotonically, but the critical strain shows a trend of first decreasing and then increasing.

[0044] Establishing critical criteria for universal applicability a. To eliminate the dependence of absolute deviatoric stress or strain threshold on a specific confining pressure, a dimensionless universal criterion is proposed, namely the critical strain ratio. ,in ε _peak represents the peak strain under different confining pressures. By studying the evolution of critical damage values ​​and critical strain, it can be concluded that the critical strain ratio is very stable, mainly concentrated between 39% and 46%.

[0045] b. Analyze the critical strain ratio under different confining pressures, and use the average value as the characteristic damage warning threshold for this material. 3 groups The average value is 0.42, which is the critical value for characteristic damage warning. It is 0.42.

[0046] Therefore, for particulate materials like coal containing gas hydrates, a strain loading to approximately 42% of the peak strain can be considered a precursor to macroscopic failure of the sample. Figure 5 As shown.

[0047] This invention provides a device for constructing a model of a gas-hydrate-containing coal body considering particle breakage. The device can be implemented via software, hardware, or a combination of both. From a hardware perspective, the hardware architecture diagram of the electronic device housing the device for constructing a gas-hydrate-containing coal body considering particle breakage provided in this invention embodiment includes, in addition to the processor, memory, network interface, and non-volatile memory, other hardware such as a forwarding chip responsible for processing messages. Taking software implementation as an example, as a logical device, it is formed by the CPU of the electronic device reading the corresponding computer program from the non-volatile memory into memory and running it. The device for constructing a gas-hydrate-containing coal body considering particle breakage provided in this embodiment includes: A modeling unit is used to establish a discrete element model of coal containing gas hydrates; wherein, the discrete element model of coal containing gas hydrates includes multiple coal particles and multiple rigid clusters, and a rigid cluster represents a complete gas hydrate cemented agglomerate. The normal / tangential bonding strength between rigid clusters and between them and their adjacent coal particles is set to be lower than the normal / tangential bonding strength inside the rigid cluster. The fitting unit is used to obtain and fit the deviatoric stress-strain curve based on experimental data, and to fit the pre-peak nonlinear stage of different deviatoric stress-strain curves according to the macroscopic damage constitutive relation, and to invert the characteristic parameters in the macroscopic damage constitutive relation: shape factor and scale parameter. The correction unit is used to correct the discrete element model of the gas hydrate-containing coal body using the shape factor and the scale parameter.

[0048] It is understood that the structures illustrated in the embodiments of the present invention do not constitute a specific limitation on a device for constructing a model of a gas hydrate-bearing coal body considering particle fragmentation. In other embodiments of the present invention, a device for constructing a model of a gas hydrate-bearing coal body considering particle fragmentation may include more or fewer components than illustrated, or combine some components, or split some components, or have different component arrangements. The illustrated components may be implemented in hardware, software, or a combination of software and hardware.

[0049] The information interaction and execution process between the modules in the above-mentioned device are based on the same concept as the method embodiment of the present invention, and the specific details can be found in the description of the method embodiment of the present invention, and will not be repeated here.

[0050] This invention also provides an electronic device, including a memory and a processor. The memory stores a computer program, and when the processor executes the computer program, it implements a method for constructing a gas hydrate-containing coal body model considering particle fragmentation, according to any embodiment of this invention.

[0051] This invention also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, causes the processor to perform a method for constructing a gas hydrate-containing coal body model considering particle fragmentation, according to any embodiment of this invention.

[0052] Specifically, a system or apparatus equipped with a storage medium may be provided, on which software program code implementing the functions of any of the embodiments described above is stored, and the computer (or CPU or MPU) of the system or apparatus may read and execute the program code stored in the storage medium.

[0053] In this case, the program code read from the storage medium can itself implement the function of any of the above embodiments, and therefore the program code and the storage medium storing the program code constitute part of the present invention.

[0054] Storage media embodiments for providing program code include floppy disks, hard disks, magneto-optical disks, optical disks (such as CD-ROM, CD-R, CD-RW, DVD-ROM, DVD-RAM, DVD-RW, DVD+RW), magnetic tapes, non-volatile memory cards, and ROMs. Alternatively, program code can be downloaded from a server computer via a communication network.

[0055] Furthermore, it should be clear that not only can the program code read by the computer be executed, but also the operating system or other components operating on the computer can be instructed based on the program code to perform some or all of the actual operations, thereby realizing the function of any of the embodiments described above.

[0056] Furthermore, it is understood that the program code read from the storage medium is written to the memory set in the expansion board inserted into the computer or to the memory set in the expansion module connected to the computer. Then, based on the instructions of the program code, the CPU or other components installed on the expansion board or expansion module execute some and all of the actual operations, thereby realizing the function of any of the above embodiments.

[0057] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0058] Those skilled in the art will understand that all or part of the steps of the above method embodiments can be implemented by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When the program is executed, it performs the steps of the above method embodiments. The aforementioned storage medium includes various media that can store program code, such as ROM, RAM, magnetic disk, or optical disk.

[0059] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for constructing a model of gas hydrate-containing coal body considering particle fragmentation, characterized in that, include: A discrete element model of coal containing gas hydrate is established; wherein, the discrete element model of coal containing gas hydrate includes multiple coal particles and multiple rigid clusters, and a rigid cluster represents a complete gas hydrate cemented agglomerate. The normal / tangential bonding strength between rigid clusters and between them and their adjacent coal particles is set to be lower than the normal / tangential bonding strength inside the rigid cluster. Based on experimental data, a deviatoric stress-strain curve was obtained and fitted. The pre-peak nonlinear stage of the deviatoric stress-strain curve was fitted according to the macroscopic damage constitutive relation, and the characteristic parameters in the macroscopic damage constitutive relation, namely the shape factor and the scale parameter, were obtained by inversion. The discrete element model of the gas hydrate-containing coal body is modified using the shape factor and the scale parameter.

2. The method according to claim 1, characterized in that, The establishment of the discrete element model for coal containing gas hydrates includes: Randomly distributed coal particles and gas hydrate particles are generated inside a rigid body; an anti-rolling contact bonding model is used to characterize the influence of coal particle shape on the contact between coal particles and between adjacent hydrate particles to characterize the cementing effect of gas hydrate. Construct a circular wall and randomly generate multiple parallel contact bonding model particles inside it to obtain a rigid cluster; The rigid body's internal gas hydrate particles were replaced with the rigid clusters using the equal area method.

3. The method according to claim 1, characterized in that, The establishment of the discrete element model for coal containing gas hydrates includes: Define the discrete element model of gas hydrate-containing coal bodies and the hydrate fragmentation event and shear zone germination evolution process.

4. The method according to claim 3, characterized in that, The hydrate breakup event includes: when the external load applied to the rigid cluster exceeds its normal / tangential bond strength, the rigid cluster disintegrates into independent sub-particles by breaking the parallel contact bonds between all particles within the rigid cluster, thus simulating gas hydrate breakup.

5. The method according to claim 3 or 4, characterized in that, The shear band germination and evolution process includes: capturing and tracking the evolution of sample coordination number, porosity, contact force chain and particle rotation field during numerical simulation, defining and identifying the germination location and expansion process of the shear band.

6. The method according to claim 1, characterized in that, After obtaining the shape factor and scale parameters, the following is also included: The shape factor and the scale parameter are assigned to the discrete element model of the gas hydrate-containing coal body, that is, the normal / tangential bond strength in the parallel contact bond model within the rigid cluster is multiplied by a coefficient related to the shape factor and the scale parameter.

7. The method according to claim 6, characterized in that, The coefficient is calculated in the following manner. xishu= F 0 ×(-math.ln(1.0-freq))^(1.0 / m )] Where xishu is a coefficient. m and F 0 The shape factor and the scale parameter.

8. A device for constructing a model of a gas hydrate-containing coal body considering particle fragmentation, characterized in that, The apparatus for implementing the method as described in any one of claims 1-7 comprises: A modeling unit is used to establish a discrete element model of coal containing gas hydrates; wherein, the discrete element model of coal containing gas hydrates includes multiple coal particles and multiple rigid clusters, and a rigid cluster represents a complete gas hydrate cemented agglomerate. The normal / tangential bonding strength between rigid clusters and between them and their adjacent coal particles is set to be lower than the normal / tangential bonding strength inside the rigid cluster. The fitting unit is used to obtain the fitted deviatoric stress-strain curve based on experimental data, and to fit the pre-peak nonlinear stage of the deviatoric stress-strain curve according to the macroscopic damage constitutive relation, and to invert the characteristic parameters in the macroscopic damage constitutive relation: shape factor and scale parameter. The correction unit is used to correct the discrete element model of the gas hydrate-containing coal body using the shape factor and the scale parameter.

9. An electronic device comprising a memory and a processor, wherein the memory stores a computer program, and the processor, when executing the computer program, implements the method as described in any one of claims 1-7.

10. A computer-readable storage medium having a computer program stored thereon, which, when executed in a computer, causes the computer to perform the method of any one of claims 1-7.

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