CN-121980993-A - Method for constructing gas hydrate-containing coal model by considering particle breakage

CN121980993ACN 121980993 ACN121980993 ACN 121980993ACN-121980993-A

Abstract

The invention relates to the technical field of gas hydrate-containing coal bodies, in particular to a method for constructing a gas hydrate-containing coal body model by considering particle breakage. The method comprises the steps of establishing a gas hydrate-containing coal discrete element model, setting a normal/tangential bonding strength between the normal clusters and adjacent coal particles to be lower than that in the normal clusters, obtaining a bias stress-strain curve according to experimental data, fitting a nonlinear phase before peaks of the bias stress-strain curve according to a macroscopic damage constitutive relation, inverting to obtain characteristic parameters in the macroscopic damage constitutive relation, and correcting the gas hydrate-containing coal discrete element model by using the shape factors and the scale parameters. A method for constructing a gas hydrate-containing coal model by considering particle breakage can provide a method capable of finely simulating the crushability of gas hydrate.

Inventors

ZHANG BAOYONG
WANG NANNAN
GAO XIA
WU QIANG

Assignees

黑龙江科技大学

Dates

Publication Date: 20260505
Application Date: 20251230

Claims (10)

1. The method for constructing the gas hydrate-containing coal body model by considering particle breakage is characterized by comprising the following steps of: establishing a gas hydrate-containing coal discrete element model, wherein the gas hydrate-containing coal discrete element model comprises a plurality of coal particles and a plurality of rigid clusters, one rigid cluster represents a complete gas hydrate cementing block, and the normal/tangential bonding strength between the rigid clusters and between the adjacent coal particles is lower than that inside the rigid clusters; Acquiring a fitted partial stress-strain curve according to experimental data, fitting a nonlinear stage before a peak of the partial stress-strain curve according to a macroscopic damage constitutive relation, and inverting to obtain characteristic parameters, namely shape factors and scale parameters, in the macroscopic damage constitutive relation; and correcting the gas hydrate-containing coal discrete meta-model by using the shape factor and the scale parameter.
2. The method of claim 1, wherein the creating a gas hydrate-containing coal discrete meta-model comprises: the method comprises the steps of generating randomly distributed coal particles and gas hydrate particles in a rigid body, adopting an anti-rolling contact bonding model among the coal particles to represent the influence of the shape of the coal particles, and endowing parallel contact bonding models with contact among the hydrate particles and adjacent particles to represent the cementing effect of the gas hydrate; establishing a circular wall body, and randomly generating a plurality of particles which are in parallel contact with the bonding model in the circular wall body to obtain a rigid cluster; and replacing the gas hydrate particles in the rigid body with the rigid clusters by adopting an equal-area method.
3. The method of claim 1, wherein the creating a gas hydrate-containing coal discrete meta-model comprises: And defining a gas hydrate-containing coal discrete element model hydrate crushing event and a shear band germination evolution process.
4. The method of claim 3, wherein the hydrate crushing event comprises breaking the rigid clusters into individual sub-particles by breaking parallel contact bond bonds between all particles within the rigid clusters when an external load on the rigid clusters exceeds its normal/tangential bond strength to simulate gas hydrate crushing.
5. The method according to claim 3 or 4, wherein the shear band germination evolution process comprises the steps of defining and identifying the germination position and the expansion process of the shear band through the evolution rules of sample coordination number, porosity, contact force chain and particle rotation field evolution in the process of capturing and tracking numerical simulation.
6. The method of claim 1, further comprising, after obtaining the form factor and the scale parameter: Assigning said form factor and said scale parameter to said discrete metamodel of gas hydrate-containing coal, i.e. multiplying the normal/tangential bond strength in a parallel contact bond model within a rigid cluster by a factor relating to said form factor and said scale parameter, respectively.
7. The method of claim 6, wherein the coefficients are calculated by xishu=F 0 ×(-math.ln(1.0-freq))^(1.0/m)] Wherein xishu is the coefficient, m and F 0 the shape factor and the scale parameter.
8. A gas hydrate-containing coal model construction device taking into account particle breakage, for implementing the method according to any one of claims 1-7, the device comprising: The modeling unit is used for establishing a gas hydrate-containing coal discrete element model, wherein the gas hydrate-containing coal discrete element model comprises a plurality of coal particles and a plurality of rigid clusters, one rigid cluster represents a complete gas hydrate cementing block mass, and the normal/tangential bonding strength between the rigid clusters and between adjacent coal particles is lower than that in the rigid clusters; the fitting unit is used for obtaining and fitting out a bias stress-strain curve according to experimental data, fitting a nonlinear phase before a peak of the bias stress-strain curve according to a macroscopic damage constitutive relation, and inverting to obtain characteristic parameters in the macroscopic damage constitutive relation, namely a shape factor and a scale parameter; and the correction unit is used for correcting the gas hydrate-containing coal discrete meta-model by using the shape factor and the scale parameter.
9. An electronic device comprising a memory and a processor, the memory having stored therein a computer program, the processor implementing the method of any of claims 1-7 when the computer program is executed.
10. A computer readable storage medium having stored thereon a computer program which, when executed in a computer, causes the computer to perform the method of any of claims 1-7.

Description

Method for constructing gas hydrate-containing coal model by considering particle breakage Technical Field The invention relates to the technical field of gas-containing hydrates, in particular to a method for constructing a gas-containing hydrate coal model by considering particle breakage. Background The hydrate solidification technology becomes an effective way for preventing and controlling the dynamic disasters by strengthening the physical characteristics of coal. Research shows that the generation of the gas hydrate can obviously improve the macroscopic mechanical properties of the coal body and enhance the strength and rigidity of the coal body sample, however, the gas hydrate is very easy to damage as a weak link in the actual loading process, and the broken gas hydrate not only can reduce the strength of a local area, but also can promote the germination and expansion of a shearing band, further the change of the coal physical properties due to the recombination of the system structure is caused, so that the sample is unstable and damaged, and finally disasters such as gas protrusion and the like can be possibly caused. In the prior art, in discrete element simulation of porous media containing hydrates, the hydrates are often reduced to small diameter particles or static bond contacts. However, the method is a complete process of deformation-crushing-disintegration-system structure recombination (shear band formation) of the true gas hydrate in the loading process, which cannot be reduced in the numerical simulation loading process, and the mechanical response of the particle material is difficult to accurately reflect. Most importantly, the existing research is only in the microscopic phenomenon simulation level, and a quantifiable critical criterion capable of early warning the initiation of macroscopic damage cannot be extracted from the microscopic crushing evolution process, so that a digital model is difficult to apply to engineering safety early warning. Therefore, the development of the method capable of finely simulating the crushability of the gas hydrate has great theoretical value and engineering significance for revealing the catastrophe mechanism of the gas hydrate-containing coal body and realizing advanced early warning. Disclosure of Invention The embodiment of the invention provides a method for constructing a gas hydrate-containing coal model by considering particle crushing, which can be used for finely simulating the crushability of gas hydrate. In a first aspect, an embodiment of the present invention provides a method for constructing a gas hydrate-containing coal body model in consideration of particle breakage, including: establishing a gas hydrate-containing coal discrete element model, wherein the gas hydrate-containing coal discrete element model comprises a plurality of coal particles and a plurality of rigid clusters, one rigid cluster represents a complete gas hydrate cementing block, and the normal/tangential bonding strength between the rigid clusters and between the adjacent coal particles is lower than that inside the rigid clusters; Acquiring a fitted partial stress-strain curve according to experimental data, fitting a nonlinear stage before a peak of the partial stress-strain curve according to a macroscopic damage constitutive relation, and inverting to obtain characteristic parameters, namely shape factors and scale parameters, in the macroscopic damage constitutive relation; and correcting the gas hydrate-containing coal discrete meta-model by using the shape factor and the scale parameter. Optionally, the establishing a gas hydrate-containing coal discrete meta-model includes: the method comprises the steps of generating randomly distributed coal particles and gas hydrate particles in a rigid body, adopting an anti-rolling contact bonding model among the coal particles to represent the influence of the shape of the coal particles, and endowing parallel contact bonding models with contact among the hydrate particles and adjacent particles to represent the cementing effect of the gas hydrate; establishing a circular wall body, and randomly generating a plurality of particles which are in parallel contact with the bonding model in the circular wall body to obtain a rigid cluster; and replacing the gas hydrate particles in the rigid body with the rigid clusters by adopting an equal-area method. Optionally, the establishing a gas hydrate-containing coal discrete meta-model includes: And defining a gas hydrate-containing coal discrete element model hydrate crushing event and a shear band germination evolution process. Alternatively, the hydrate fracture event comprises breaking the rigid clusters into individual sub-particles by breaking parallel contact bond bonds between all particles within the rigid clusters when the external load on the rigid clusters exceeds its normal/tangential bond strength, to simulate gas hydrate fracture. Optionally, the shear band