CN-121980992-A - Method for obtaining damage deformation damage prediction critical value

Abstract

The invention relates to the technical field of gas hydrate-containing coal bodies, in particular to a method for acquiring a damage deformation damage prediction critical value. The embodiment of the invention provides a damage deformation damage prediction critical value acquisition method which comprises the steps of S1, obtaining a bias stress-strain curve, S2, fitting a nonlinear phase before a peak of the bias stress-strain curve according to a macroscopic damage constitutive relation, inverting to obtain characteristic parameters in the macroscopic damage constitutive relation, namely a shape factor and a scale parameter, S3, determining a damage variable formula according to the shape factor and the scale parameter, S4, obtaining a second derivative of the damage variable formula, taking a zero point value, obtaining critical strain and critical damage, and S5, determining a critical strain ratio according to the critical strain and the peak strain, and obtaining a characteristic damage early warning critical value. The embodiment of the invention provides a method for acquiring a damage deformation damage prediction critical value, which can be used for determining a damage early warning critical value of a gas hydrate-containing coal body.

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. 1. The method for obtaining the damage deformation damage prediction critical value is characterized by comprising the following steps: s1, obtaining a bias stress-strain curve; S2, fitting a nonlinear phase before a peak of a bias stress-strain curve according to the macroscopic damage constitutive relation, and inverting to obtain characteristic parameters, namely shape factors and scale parameters, in the macroscopic damage constitutive relation; s3, determining a damage variable formula according to the shape factor and the scale parameter; S4, obtaining a second derivative of the damage variable formula, and taking a zero value to obtain critical strain and critical damage; And S5, determining a critical strain ratio according to the critical strain and the peak strain to obtain a characteristic damage early warning critical value.
2. 2. The method according to claim 1, wherein in S1, the bias stress-strain curve is obtained by fitting test data obtained by a triaxial compression test or by a gas hydrate-containing coal numerical simulation test.
3. 3. The method of claim 2, wherein the numerical simulation test is based on a gas hydrate-containing coal discrete meta-model comprising a plurality of coal particles and a plurality of rigid clusters, one rigid cluster representing a complete gas hydrate cementitious mass, the strength of the normal/tangential bonds between rigid clusters and between adjacent coal particles being lower than the normal/tangential bonds within the rigid clusters.
4. 4. The method of claim 1, wherein in S2, the macroscopic damage constitutive relationship is as follows: Wherein, the In the event of a stress being applied to the substrate, For initial modulus of elasticity, F 0 is the scale parameter and m is the form factor.
5. 5. The method of claim 1, wherein in S3, the impairment variable formula is: 1-exp(-(col(A)/F 0 )^m) Wherein F 0 is a scale parameter, m is a shape factor, and A is a set fitting parameter.
6. 6. The method of claim 1, wherein in S4, the second derivative of the impairment variable formula is: wherein D is a damage variable, ε is a strain, F 0 is a scale parameter, and m is a shape factor.
7. 7. The method according to claim 1, wherein in S5, the critical strain ratio is: Where ε_peak is the peak strain and ε_c is the critical strain.
8. 8. A damage deformation damage prediction threshold value acquisition device for implementing the method according to any one of claims 1 to 7, the device comprising: An acquisition unit for acquiring a bias stress-strain curve; The fitting unit is used for fitting the nonlinear phase before the peak of the partial stress-strain curve according to the macroscopic damage constitutive relation, and inverting to obtain characteristic parameters in the macroscopic damage constitutive relation, namely shape factors and scale parameters; the calculating unit is used for determining a damage variable formula according to the shape factor and the scale parameter; The deriving unit is used for solving a second derivative of the damage variable formula and taking a zero value to obtain critical strain and critical damage; And the ratio unit is used for determining the critical strain ratio according to the critical strain and the peak strain to obtain the characteristic damage early warning critical value.
9. 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. 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 obtaining damage deformation damage prediction critical value Technical Field The invention relates to the technical field of gas hydrate-containing coal bodies, in particular to a method for acquiring a damage deformation damage prediction critical value. Background Along with the increase of the coal mining depth, dynamic disasters such as coal and gas outburst occur frequently. Early researches show that the gas hydration curing technology can effectively prevent the occurrence of such accidents. Therefore, research on the mechanical properties of the coal body containing the gas hydrate is very important. In the related art, a method for determining a damage early warning critical value of a gas hydrate-containing coal body is lacking. Disclosure of Invention The embodiment of the invention provides a method for acquiring a damage deformation damage prediction critical value, which can be used for determining a damage early warning critical value of a gas hydrate-containing coal body. In a first aspect, an embodiment of the present invention provides a method for obtaining a damage deformation damage prediction threshold, including: s1, obtaining a bias stress-strain curve; S2, fitting a nonlinear phase before a peak of a bias stress-strain curve according to the macroscopic damage constitutive relation, and inverting to obtain characteristic parameters, namely shape factors and scale parameters, in the macroscopic damage constitutive relation; s3, determining a damage variable formula according to the shape factor and the scale parameter; S4, obtaining a second derivative of the damage variable formula, and taking a zero value to obtain critical strain and critical damage; And S5, determining a critical strain ratio according to the critical strain and the peak strain to obtain a characteristic damage early warning critical value. Optionally, in S1, the bias stress-strain curve is obtained by fitting test data obtained by a triaxial compression test or by a discrete element numerical simulation test of a gas hydrate-containing coal body. Optionally, the numerical simulation test is based on 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 adjacent coal particles is lower than that inside the rigid clusters. Optionally, in S2, the macroscopic damage constitutive relation is as follows: Wherein, the In the event of a stress being applied to the substrate,For initial modulus of elasticity, F 0 is the scale parameter and m is the form factor. Optionally, in S3, the damage variable formula is: 1-exp(-(col(A)/F0)^m) Wherein F 0 is a scale parameter, m is a shape factor, and A is a set fitting parameter. Optionally, in S4, the second derivative of the impairment variable formula is: wherein D is a damage variable, ε is a strain, F 0 is a scale parameter, and m is a shape factor. Optionally, in S5, the critical strain ratio is: Where ε_peak is the peak strain and ε_c is the critical strain. In a second aspect, an embodiment of the present invention further provides a device for obtaining a damage deformation damage prediction threshold, including: An acquisition unit for acquiring a bias stress-strain curve; The fitting unit is used for fitting the nonlinear phase before the peak of the partial stress-strain curve according to the macroscopic damage constitutive relation, and inverting to obtain characteristic parameters in the macroscopic damage constitutive relation, namely shape factors and scale parameters; the calculating unit is used for determining a damage variable formula according to the shape factor and the scale parameter; The deriving unit is used for solving a second derivative of the damage variable formula and taking a zero value to obtain critical strain and critical damage; And the ratio unit is used for determining the critical strain ratio according to the critical strain and the peak strain to obtain the characteristic damage early warning critical value. In a third aspect, an embodiment of the present invention further provides an electronic device, including a memory and a processor, where the memory stores a computer program, and when the processor executes the computer program, the method described in any embodiment of the present specification is implemented. In a fourth aspect, embodiments of the present invention also provide a computer-readable storage medium having stored thereon a computer program which, when executed in a computer, causes the computer to perform a method according to any of the embodiments of the present specification. Compared with the prior art, the invention has at least the following beneficial effects: In this embodiment, a specific numerical value of the c