Simulation methods, devices, equipment, media and procedures for true triaxial testing

Abstract

The present application relates to the field of testing and numerical analysis control technology, and in particular to a simulation method, apparatus, equipment, medium, and program for a true triaxial test. The method comprises: obtaining a test target for the true triaxial test; determining a specimen based on the test target and applying a preset axial strain increment to the specimen; collecting the true axial stress value, the true longitudinal stress value, the true transverse stress value, and the axial strain of the specimen; identifying a stress control target and a drainage control target within the test target, calculating a transverse stress target based on the true longitudinal stress value and the true axial stress value, generating a strain control matrix based on the stress control target, the drainage control target, the true axial stress value, the true longitudinal stress value, and the axial strain; and controlling the specimen to apply strain increments in three directions based on the strain control matrix to obtain simulation results of the true triaxial test. This method solves the problem in related arts that the simulation model for true triaxial testing cannot meet the requirements of various drainage conditions, resulting in low applicability and practicality.

Description

Technical Field

[0001] The present application relates to the field of test and numerical analysis control technology, and in particular to a simulation method, device, equipment, medium and program for a true triaxial test. Background Art

[0002] The mechanical behavior of soils is typically studied under fully drained or undrained conditions to reflect factors such as the loading rate and permeability of the soil. However, actual drainage conditions in the field may be neither fully drained nor undrained, but rather partially drained. For example, due to the short duration of seismic events, soil response to seismic loading is often assumed to be undrained, and assuming undrained conditions provides conservative results. However, the increase in pore pressure during a given earthquake shaking event depends significantly on the soil's properties, including its composition, density, and initial stress state. Due to the heterogeneity of soil deposits, significant pressure gradients can develop within the soil during shaking. Positive pressure gradients can lead to contractive volume deformation, while negative pressure gradients can lead to dilatant volume deformation. Furthermore, the accumulation and dissipation of pore water during shaking can further reduce or increase the effective stress in the soil element. The total pore pressure generated in a soil element under these conditions will include shear and volume-induced components, potentially resulting in a more detrimental loading state than under the undrained condition. Therefore, studying soil properties under partially drained conditions is essential. In order to simulate local drainage conditions, proportional strain loading tests can be performed on sand, that is, the ratio of axial strain to volume strain is kept constant throughout the loading process.

[0003] The intermediate principal stress ratio also has a significant impact on the mechanical behavior of soils. For example, strength, dilatancy, friction angle, and failure surface shape are significantly dependent on the intermediate principal stress ratio. At the microscale, the evolution of fabric is significantly affected by the intermediate principal stress ratio.

[0004] In the related art, the simulation of the true triaxial test can only be performed according to one drainage condition, for example, complete drainage, or no drainage at all, which cannot meet the requirements of multiple drainage conditions, resulting in low applicability and practicality. Summary of the Invention

[0005] The present application provides a simulation method, device, equipment, medium and procedure for a true triaxial test to solve the problem that the simulation of the true triaxial test in the related art cannot meet the requirements of various drainage conditions, resulting in low applicability and practicality.

[0006] A first aspect of the present application provides a simulation method for a true triaxial test, comprising the following steps: obtaining a test target for the true triaxial test; determining a specimen according to the test target, and applying a preset axial strain increment to the specimen; collecting the true axial stress value, the true longitudinal stress value, the true transverse stress value, and the axial strain of the specimen; identifying a stress control target and a drainage control target in the test target, calculating a transverse stress target based on the true longitudinal stress value and the true axial stress value, and generating a strain control matrix based on the stress control target, the drainage control target, the true axial stress value, the true longitudinal stress value, and the axial strain; and controlling the specimen to apply strain increments in the three directions according to the strain control matrix until the true triaxial test is completed to obtain a simulation result of the true triaxial test.

[0007] Optionally, the test target includes test materials, test parameters and test conditions, and determining the sample according to the test target includes: identifying the test conditions in the test target; and performing isotropic consolidation according to the test conditions to generate the sample.

[0008] Optionally, the calculation formula for calculating the transverse stress target based on the longitudinal stress true value and the axial stress true value is:

[0009] σ xx(t) =bσ yy +(1-b)σ zz ;

[0010] Where b is the intermediate principal stress ratio, σ yy is the true value of longitudinal stress, σ zz is the true value of axial stress.

[0011] Optionally, generating a strain control matrix based on the stress control target, the drainage control target, the axial stress true value, the longitudinal stress true value and the axial strain includes: calculating corresponding strain increments in three directions according to the axial stress true value, the longitudinal stress true value and the stress control target, and generating a strain control matrix according to the strain increments in the three directions; determining the value of the loading control parameter of the proportional strain loading according to the drainage control target, calculating the target volume strain according to the value of the loading control parameter of the proportional strain loading and the axial strain, and correcting the strain control matrix using the target volume strain.

[0012] Optionally, generating a strain control matrix based on the strain increments in the three directions includes: converting the stress increments into a stress invariant form and obtaining the elastic modulus and Poisson's ratio of the sample; and calculating the strain control matrix using Hooke's law based on the elastic modulus and Poisson's ratio of the sample in the stress invariant form.

[0013] Optionally, before controlling the specimen to apply the strain increments in the three directions according to the lateral stress true value and the lateral stress target, the method includes: identifying a first difference between the axial stress true value and the stress control target, and a second difference between the volume strain true value and the target volume strain; if both the first difference and the second difference are not within the corresponding preset tolerance range, controlling the axial strain increment of the strain matrix to be a preset value; otherwise, calculating the axial strain increment according to the ratio of the specimen axial strain to time and the time step of each adjustment of the servo mode by the servo motor.

[0014] A second aspect of the present application provides a simulation device for a true triaxial test, comprising: an acquisition module for acquiring a test target of the true triaxial test; an application module for determining a specimen according to the test target and applying a preset axial strain increment to the specimen; an acquisition module for acquiring the true axial stress value, the true longitudinal stress value, the true transverse stress value and the axial strain of the specimen; an identification module for identifying a stress control target and a drainage control target in the test target, calculating a transverse stress target based on the true longitudinal stress value and the true axial stress value, and generating a strain control matrix based on the stress control target, the drainage control target, the true axial stress value, the true longitudinal stress value and the axial strain; and a control module for controlling the specimen to apply the strain increments in the three directions according to the strain control matrix until the true triaxial test is completed to obtain a simulation result of the true triaxial test.

[0015] The third aspect of the present application provides an electronic device, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to perform the simulation method of the true triaxial test as described in the above embodiment.

[0016] A fourth aspect of the present application provides a computer-readable storage medium having a computer program stored thereon, which is executed by a processor to perform the simulation method of the true triaxial test as described in the above embodiment.

[0017] The fifth aspect of the present application provides a computer program product, including a computer program or instructions, characterized in that when the computer program or instructions are executed, the simulation method of the true triaxial test as described in the above embodiment is implemented.

[0018] Therefore, this application has at least the following beneficial effects:

[0019] The embodiment of the present application can obtain the test target of the true triaxial test; determine the specimen according to the test target, and apply a preset axial strain increment to the specimen; collect the true axial stress value, longitudinal stress value, transverse stress value and axial strain of the specimen; identify the stress control target and the drainage control target in the test target, calculate the transverse stress target based on the longitudinal stress true value and the axial stress true value, and generate a strain control matrix based on the stress control target, the drainage control target, the axial stress true value, the longitudinal stress true value and the axial strain; control the specimen to apply strain increments in three directions according to the strain control matrix until the true triaxial test is completed to obtain the simulation results of the true triaxial test, thereby being able to meet various drainage condition requirements, achieve precise control of the stress state and flexible control of the drainage conditions, have high applicability and practicality, and improve the accuracy and reliability of the test.

[0020] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0022] Figure 1 This is a flow chart of a simulation method for a true triaxial test provided according to an embodiment of the present application;

[0023] Figure 2 A schematic flow chart of a servo method for applying different drainage conditions under a true triaxial stress state according to an embodiment of the present application;

[0024] Figure 3 A schematic diagram of a servo method for applying different drainage conditions under a true triaxial stress state according to an embodiment of the present application for numerical simulation;

[0025] Figure 4 This is a graph showing the control results of the b value by the servo method that can apply different drainage conditions under the true triaxial stress state provided by an embodiment of the present application;

[0026] Figure 5 This is a graph showing control results of a servo method for applying different drainage conditions to a value under a true triaxial stress state according to an embodiment of the present application;

[0027] Figure 6 This is an example diagram of a simulation device for a true triaxial test provided according to an embodiment of the present application;

[0028] Figure 7 A schematic diagram of the structure of an electronic device provided according to an embodiment of the present application.

[0029] Description of the accompanying drawings: 1 is the sample, 2 is the front wall, 3 is the back wall, 4 is the lower wall, 5 is the upper wall, 6 is the left wall, and 7 is the right wall. DETAILED DESCRIPTION

[0030] The following describes in detail embodiments of the present application, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0031] The following describes the simulation method, device, equipment, storage medium and program of the true triaxial test of the embodiment of the present application with reference to the accompanying drawings. In response to the problem that the simulation of the true triaxial test in the related art mentioned in the background technology center above cannot meet the requirements of various drainage conditions, resulting in low applicability and practicality, the present application provides a simulation method of the true triaxial test, in which the test target of the true triaxial test is obtained; the sample is determined according to the test target, and a preset axial strain increment is applied to the sample; the axial stress true value, longitudinal stress true value, transverse stress true value and axial strain of the sample are collected; the stress control target and the drainage control target in the test target are identified, the transverse stress target is calculated based on the longitudinal stress true value and the axial stress true value, and the strain control matrix is ​​generated based on the stress control target, the drainage control target, the axial stress true value, the longitudinal stress true value and the axial strain; the sample is controlled to apply strain increments in three directions according to the strain control matrix until the true triaxial test is completed to obtain the simulation result of the true triaxial test, thereby being able to meet the requirements of various drainage conditions, realize the precise control of the stress state and the flexible control of the drainage conditions, and has high applicability and practicality, thereby improving the accuracy and reliability of the test. This solves the problem that the simulation of true triaxial tests in related technologies cannot meet the requirements of various drainage conditions, resulting in low applicability and practicality.

[0032] Specifically, Figure 1 A schematic flow chart of a simulation method for a true triaxial test provided in an embodiment of the present application.

[0033] like Figure 1 As shown, the simulation method of the true triaxial test includes the following steps:

[0034] In step S101 , a test target of a true triaxial test is obtained.

[0035] Among them, the test objectives include test materials, test parameters and test conditions.

[0036] It is understandable that the embodiment of the present application can obtain the test objectives of the true triaxial test so as to facilitate the subsequent determination of the specimen according to the test objectives.

[0037] It should be noted that if Figure 2As shown in Figure 2, the test parameters include the intermediate principal stress ratio b and the loading control parameter α of proportional strain loading, where: When α = 0, the specimen is undrained; when α > 0, the specimen is over-drained and the volume shrinks; when α < 0, the specimen is expanded and drained, and the volume expands. At the same time, the various test conditions required for the test specimen must be clearly defined, such as specimen size, relative density, initial confining pressure, etc.

[0038] In step S102, a sample is determined according to a test objective, and a preset axial strain increment is applied to the sample.

[0039] Among them, the preset axial strain increment is a constant value dε zz =vΔt, where v is the shear rate, which is the ratio of the rate of movement of the top seat in physical experiments and the upper wall in numerical simulations to the sample height. Δt refers to the time interval for each servo motor to adjust the servo mode in physical experiments and a time step in numerical simulations.

[0040] It can be understood that the embodiments of the present application can determine the specimen according to the test objectives, apply a preset axial strain increment to the specimen, accurately control the loading path of the specimen, more realistically simulate the loading conditions in actual engineering, improve test efficiency, and reduce manual intervention.

[0041] In an embodiment of the present application, determining a sample according to a test target includes: identifying test conditions in the test target; and performing isotropic consolidation according to the test conditions to generate a sample.

[0042] It can be understood that the embodiments of the present application can identify the test conditions in the test objectives; perform isotropic consolidation to generate specimens according to the test conditions, thereby ensuring that the specimens are in a uniform initial stress state and have a stable structure, thereby improving the reliability and repeatability of the test results.

[0043] It should be noted that if Figure 2 As shown, this application specifies various test conditions required for the test specimens according to the test objectives, such as relative density and initial confining pressure, generates specimens according to the test conditions and performs isotropic consolidation, even if v xx =v yy =v zz .

[0044] Specifically, the sample is first strain-controlled, and an axial strain increment is applied in the z direction, which is a constant value dε zz= vΔt, where v is the shear rate, which is the ratio of the sum of the upper wall's downward displacement rate and the lower wall's upward displacement rate to the specimen height. The magnitude of v must meet regulatory requirements. It is generally accepted that the following steps are reasonable only when v is sufficiently small. Δt is one time step. That is, the ratio of the downward displacement of upper wall 4 per time interval to the specimen's original height is 0.5v, and the ratio of the upward displacement of lower wall 5 per time interval to the specimen's original height is 0.5v.

[0045] In step S103 , the true value of the axial stress, the true value of the longitudinal stress, the true value of the transverse stress and the axial strain of the sample are collected.

[0046] It can be understood that the embodiment of the present application can collect the true value of axial stress, true value of longitudinal stress, true value of transverse stress and axial strain of the sample, so as to facilitate the subsequent generation of a strain control matrix based on the stress control target, drainage control target, true value of axial stress, true value of longitudinal stress and axial strain.

[0047] Specifically, if Figure 3 As shown, the stress on the front wall 2 is the force in the x direction on the front wall divided by the area of ​​the front wall. The strain is the displacement of the front wall 2 in the x-direction divided by the length of the specimen in the x-direction during the time step Δt.

[0048] The stress on the rear wall 3 is the force in the x direction on the front wall divided by the area of ​​the front wall. The strain is the displacement of the back wall 3 in the x-direction divided by the length of the specimen in the x-direction in the time step Δt. Therefore: xx =0.5(σ3-σ2), ε xx =0.5(ε3-ε z ).

[0049] The stress on the left wall 6 is the force in the y direction on the left wall divided by the area of ​​the front wall. The strain is the displacement of the left wall 6 in the x-direction divided by the length of the specimen in the y-direction during the time step Δt.

[0050] The stress on the right wall 7 is the force in the y direction on the front wall divided by the area of ​​the front wall. The strain is the displacement of the front wall in the y direction divided by the length of the specimen in the y direction during the time step Δt. Therefore: yy =0.5(σ7-σ6),ε yy =0.5(ε7-ε6).

[0051] The stress on the lower wall 4 is the force in the z direction on the lower wall divided by the area of ​​the front wall. The strain is the displacement of the lower wall 4 in the z direction divided by the length of the specimen in the z direction during the time step Δt.

[0052] The stress on the upper wall 5 is the force in the z direction on the upper wall divided by the area of ​​the upper wall. The strain is the displacement of the upper wall in the y direction divided by the length of the specimen in the z direction within the time step Δt. Therefore: zz =0.5(σ5-σ4), ε zz =0.5(ε5-ε4).

[0053] In step S104, the stress control target and the drainage control target in the test target are identified, the transverse stress target is calculated based on the longitudinal stress true value and the axial stress true value, and the strain control matrix is ​​generated based on the stress control target, the drainage control target, the axial stress true value, the longitudinal stress true value and the axial strain.

[0054] It can be understood that the embodiments of the present application can identify the stress control target and the drainage control target in the test target, calculate the lateral stress target based on the longitudinal stress true value and the axial stress true value, and generate a strain control matrix based on the stress control target, the drainage control target, the axial stress true value, the longitudinal stress true value and the axial strain. By calculating and applying the strain control matrix, the stress state of the specimen can be accurately controlled to ensure that it meets the expected target stress state, thereby improving the accuracy and reliability of the test results.

[0055] In the embodiment of the present application, the calculation formula for calculating the transverse stress target based on the longitudinal stress true value and the axial stress true value is:

[0056] σ xx(t) =bσ yy +(1-b)σ zz ;

[0057] Where b is the intermediate principal stress ratio, σ yy is the true value of longitudinal stress, σ zz is the true value of axial stress.

[0058] It should be noted that if Figure 2 As shown, actively giving up control σ yy , monitoring σ yy , and according to the principal stress ratio and the stress σ in the y direction obtained by monitoring yy , stress in the z direction σ zz , we can calculate the σ of this time period xx Target value σ xx(t) =bσ yy +(1-b)σ zz , and then monitor the axial stress σ zz , axial strain ε zz , according to the loading control parameters of proportional strain loading and the detected strain ε zz The target volume strain can be calculated and recorded as ε v(t)=α·ε zz .

[0059] In an embodiment of the present application, a strain control matrix is ​​generated based on the stress control target, the drainage control target, the axial stress true value, the longitudinal stress true value and the axial strain, including: calculating the corresponding strain increments in the three directions according to the axial stress true value, the longitudinal stress true value and the stress control target, and generating the strain control matrix according to the strain increments in the three directions; determining the value of the loading control parameter of the proportional strain loading according to the drainage control target, calculating the target volume strain according to the value of the loading control parameter of the proportional strain loading and the axial strain, and correcting the strain control matrix using the target volume strain.

[0060] It can be understood that the embodiments of the present application can calculate the corresponding strain increments in the three directions based on the true value of the axial stress, the true value of the longitudinal stress and the stress control target, and generate a strain control matrix based on the strain increments in the three directions; determine the value of the loading control parameter of the proportional strain loading according to the drainage control target, calculate the target volume strain based on the value of the loading control parameter of the proportional strain loading and the axial strain, and use the target volume strain to correct the strain control matrix. By calculating the strain increment and generating the strain control matrix, it is ensured that the stress of the specimen in the three directions reaches the expected target stress state, thereby improving the accuracy and reliability of the test results.

[0061] Specifically, if Figure 2 As shown, actively giving up control σ yy , detect the stress σ in the y direction yy , stress in the x direction σ xx , that is, do not control the stress on the left wall 6 and the right wall 7, but monitor the stress on the left wall 6 and the right wall 7. Calculate the target stress value of the front wall 2 and the back wall 3 in this time period, that is, σ xx Target value σ xx(t) =bσ yy +(1-b)σ zz . Get the stress control matrix of this time period

[0062] Monitor the stress σ in the z direction zz , strain ε zz The strain ε detected zz The target volume strain can be calculated and recorded as ε v(t) =α·ε zz .

[0063] In an embodiment of the present application, a strain control matrix is ​​generated based on strain increments in three directions, including: converting stress increments into a stress invariant form and obtaining the elastic modulus and Poisson's ratio of the sample; and calculating the strain control matrix using Hooke's law based on the elastic modulus and Poisson's ratio of the sample in the stress invariant form.

[0064] It can be understood that the embodiments of the present application can convert the stress increment into a stress invariant form and obtain the elastic modulus and Poisson's ratio of the sample; the strain control matrix is ​​calculated using Hooke's law based on the elastic modulus and Poisson's ratio of the sample in the stress invariant form. The stress invariant form can greatly simplify complex tensor operations, making the calculation process more intuitive and easy to handle, and more accurately calculate the strain increment, thereby achieving precise control of the sample deformation.

[0065] Specifically, the target stress tensor σ in this time period is known ij(t) and the current stress tensor σ ij In order to achieve the target stress state, a stress increment Δσ needs to be applied to the specimen boundary. ij(t) =σ ij(t) -σ ij For convenience, the stress increment Δσ ij(t) Expressed as stress invariant (Δσ) I (For three-dimensional problems, I = 1, 2, and 3.) The invariant of the strain increment can be obtained from the isotropic elastic stress-strain relationship, namely Hooke's law:

[0066]

[0067] Among them, (Δε) I and (Δα Δε ) I Represent the magnitude and direction of the strain increment respectively. E and v represent the elastic modulus and Poisson's ratio of the specimen respectively. The strain control matrix is ​​calculated as follows:

[0068] The calculated ε v(t) and the actual volume strain ε we monitored v(true) Different, there is a difference ε v(t) -ε v(true) , distribute the difference evenly to dε xx and dε yy , so that the true volume strain ε v(true) Close to the target volume strain ε v(t) , so the corrected strain control matrix is:

[0069]

[0070] In step S105 , the sample is controlled to apply strain increments in three directions according to the strain control matrix until the true triaxial test is completed to obtain the simulation results of the true triaxial test.

[0071] It can be understood that the embodiment of the present application can control the application of strain increments in three directions to the specimen according to the strain control matrix until the true triaxial test is completed to obtain the simulation results of the true triaxial test, thereby being able to meet the requirements of various drainage conditions, achieve precise control of the stress state and flexible control of the drainage conditions, have high applicability and practicality, and improve the accuracy and reliability of the test.

[0072] It should be noted that the three directional strain increments represent the transverse X direction, the longitudinal Y direction, and the axial Z direction, respectively, without specific limitation.

[0073] In an embodiment of the present application, before applying strain increments in three directions to the specimen according to the true value of the lateral stress and the target of the lateral stress, the process includes: identifying a first difference between the true value of the axial stress and the stress control target, and a second difference between the true value of the volume strain and the target volume strain; if both the first difference and the second difference are not within the corresponding preset tolerance range, the axial strain increment of the strain matrix is ​​controlled to be a preset value; otherwise, the axial strain increment is calculated based on the ratio of the strain in the axial direction of the specimen to time and the time step of each adjustment of the servo mode by the servo motor.

[0074] Among them, the preset tolerance range is: The default value can be dε zz =vΔt.

[0075] It can be understood that the embodiment of the present application can identify the first difference between the true value of the axial stress and the stress control target, and the second difference between the true value of the volume strain and the target volume strain; if the first difference and the second difference are not within the corresponding preset tolerance range, the axial strain increment of the strain matrix is ​​controlled to be the preset value, otherwise, the axial strain increment is calculated based on the ratio of the strain in the axial direction of the specimen to the time and the time step of each adjustment of the servo mode by the servo motor, thereby achieving precise control of the servo loading test under the true triaxial stress state.

[0076] Specifically, if Figure 2 As shown, the following formula is used to judge whether the actual mean principal stress ratio and volume strain of the monitored specimen are within the tolerance range by comparing them with the target mean principal stress and volume strain.

[0077]

[0078] If the above two conditions are met at the same time, then dε zz =vΔt, continue to perform servo according to the above steps; if one of the above conditions is not met, then dε zz = 0, first suspend control, let the sample servo until the principal stress ratio and volume strain reach the tolerance range, then continue control. Thus, a new strain control matrix is ​​obtained.

[0079] The obtained strain control matrix Applied to the sample, that is, ε2 = dε xx 、ε3=-dε xx 、ε6=dε yy 、ε7=-dε yy 、ε4=dε zz 、ε5=-dε zz For physical experiments, strain control is applied to the specimen via servo motors in three directions; for numerical simulations, strain control is applied to the specimen by controlling the movement speed of three sets of walls perpendicular to the x, y, and z directions.

[0080] Therefore, see Figure 4 and Figure 5 As can be seen, this application precisely controls the principal stress ratio b, a key parameter in true triaxial testing, and the loading control parameter for proportional strain loading, a key parameter for controlling the drainage state. This is a servo method that can apply different drainage conditions under true triaxial stress conditions.

[0081] According to the simulation method of the true triaxial test proposed in the embodiment of the present application, the test target of the true triaxial test is obtained; the specimen is determined according to the test target, and a preset axial strain increment is applied to the specimen; the true axial stress value, the true longitudinal stress value, the true transverse stress value and the axial strain of the specimen are collected; the stress control target and the drainage control target in the test target are identified, the transverse stress target is calculated based on the true longitudinal stress value and the true axial stress value, and a strain control matrix is ​​generated based on the stress control target, the drainage control target, the true axial stress value, the true longitudinal stress value and the axial strain; the specimen is controlled to apply strain increments in three directions according to the strain control matrix until the true triaxial test is completed to obtain the simulation result of the true triaxial test, thereby being able to meet the requirements of various drainage conditions, realize precise control of the stress state and flexible control of the drainage conditions, have high applicability and practicality, and improve the accuracy and reliability of the test.

[0082] Next, a simulation device for a true triaxial test according to an embodiment of the present application will be described with reference to the accompanying drawings.

[0083] Figure 6 It is a block diagram of a simulation device for a true triaxial test according to an embodiment of the present application.

[0084] like Figure 6 As shown, the simulation device 10 for the true triaxial test includes: an acquisition module 100 , an application module 200 , a collection module 300 , an identification module 400 and a control module 500 .

[0085] Among them, the acquisition module 100 is used to obtain the test target of the true triaxial test; the application module 200 is used to determine the sample according to the test target and apply a preset axial strain increment to the sample; the acquisition module 300 is used to collect the true value of axial stress, true value of longitudinal stress, true value of transverse stress and axial strain of the sample; the identification module 400 is used to identify the stress control target and drainage control target in the test target, calculate the transverse stress target based on the true value of longitudinal stress and the true value of axial stress, and generate a strain control matrix based on the stress control target, drainage control target, true value of axial stress, true value of longitudinal stress and axial strain; the control module 500 is used to control the sample to apply strain increments in three directions according to the strain control matrix until the true triaxial test is completed to obtain the simulation results of the true triaxial test.

[0086] It should be noted that the above explanation of the embodiment of the simulation method of the true triaxial test is also applicable to the simulation device of the true triaxial test of this embodiment, and will not be repeated here.

[0087] According to the simulation device of the true triaxial test proposed in the embodiment of the present application, the test target of the true triaxial test is obtained; the specimen is determined according to the test target, and a preset axial strain increment is applied to the specimen; the true axial stress value, the true longitudinal stress value, the true transverse stress value and the axial strain of the specimen are collected; the stress control target and the drainage control target in the test target are identified, the transverse stress target is calculated based on the true longitudinal stress value and the true axial stress value, and a strain control matrix is ​​generated based on the stress control target, the drainage control target, the true axial stress value, the true longitudinal stress value and the axial strain; the specimen is controlled to apply strain increments in three directions according to the strain control matrix until the true triaxial test is completed to obtain the simulation result of the true triaxial test, thereby being able to meet the requirements of various drainage conditions, realize precise control of the stress state and flexible control of the drainage conditions, have high applicability and practicality, and improve the accuracy and reliability of the test.

[0088] Figure 7 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present application. The electronic device may include:

[0089] Memory 701 , processor 702 , and computer programs stored in the memory 701 and executable on the processor 702 .

[0090] When the processor 702 executes the program, the simulation method of the true triaxial test provided in the above embodiment is implemented.

[0091] Furthermore, the electronic device further includes:

[0092] The communication interface 703 is used for communication between the memory 701 and the processor 702 .

[0093] The memory 701 is used to store computer programs that can be run on the processor 702 .

[0094] The memory 701 may include a high-speed RAM memory, and may also include a non-volatile memory (non-volatile memory), such as at least one disk memory.

[0095] If the memory 701, processor 702, and communication interface 703 are implemented independently, the communication interface 703, memory 701, and processor 702 can be connected to each other via a bus and communicate with each other. The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus. The bus can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Figure 7 Only one thick line is used in the diagram, but this does not mean that there is only one bus or one type of bus.

[0096] Optionally, in a specific implementation, if the memory 701, the processor 702 and the communication interface 703 are integrated on a chip, the memory 701, the processor 702 and the communication interface 703 can communicate with each other through an internal interface.

[0097] The processor 702 may be a central processing unit (CPU), an application specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of the present application.

[0098] An embodiment of the present application further provides a computer-readable storage medium having a computer program or instructions stored thereon. When the computer program or instructions are executed by a processor, the simulation method of the true triaxial test as described above is implemented.

[0099] An embodiment of the present application further provides a computer program product, including a computer program or instructions, characterized in that when the computer program or instructions are executed, the simulation method of the true triaxial test as described above is implemented.

[0100] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or N embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0101] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of technical features indicated. Thus, a feature specified as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of this application, "N" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0102] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, fragment or portion of code comprising one or N executable instructions for implementing a custom logical function or process step, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may be performed in a different order than shown or discussed, including performing functions in a substantially simultaneous manner or in a reverse order depending on the functions involved, which should be understood by those skilled in the art to which the embodiments of the present application pertain.

[0103] It should be understood that various parts of the present application can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiment, the N steps or methods can be implemented using software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented using hardware, as in another embodiment, it can be implemented using any one or a combination of the following technologies known in the art: a discrete logic circuit having a logic gate circuit for implementing a logic function on a data signal, an application-specific integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0104] Those skilled in the art will understand that all or part of the steps in the method of the above embodiment can be completed by instructing related hardware through a program, and the program can be stored in a computer-readable storage medium. When the program is executed, it includes one or a combination of the steps of the method embodiment.

Claims

1. A simulation method for a true triaxial test, characterized in that: The following steps are involved: Obtain the test objectives of true triaxial testing; Determine a specimen according to the test objective, and apply a preset axial strain increment to the specimen; collecting the true value of axial stress, true value of longitudinal stress, true value of transverse stress and axial strain of the sample; identifying a stress control target and a drainage control target in the test target, calculating a transverse stress target based on the longitudinal stress true value and the axial stress true value, and generating a strain control matrix based on the stress control target, the drainage control target, the axial stress true value, the longitudinal stress true value, and the axial strain; The sample is controlled to apply strain increments in three directions according to the strain control matrix until the true triaxial test is completed to obtain a simulation result of the true triaxial test.

2. The true triaxial test simulation method according to claim 1, characterized in that: The test objectives include test materials, test parameters and test conditions. The step of determining the sample according to the test objectives includes: Identify the test conditions within the test objectives; The specimens were generated by isotropic consolidation according to the test conditions.

3. The simulation method of true triaxial test according to claim 2, characterized in that: The calculation formula for calculating the transverse stress target based on the longitudinal stress true value and the axial stress true value is: s xx(t) =bσ yy +(1-b)σ zz ; Where b is the intermediate principal stress ratio, σ yy is the true value of longitudinal stress, σ zz is the true value of axial stress.

4. The simulation method of true triaxial test according to claim 3, characterized in that: The generating of the strain control matrix based on the stress control target, the drainage control target, the axial stress true value, the longitudinal stress true value, and the axial strain includes: Calculate corresponding strain increments in three directions according to the true value of the axial stress, the true value of the longitudinal stress, and the stress control target, and generate a strain control matrix according to the strain increments in the three directions; The value of the loading control parameter of the proportional strain loading is determined according to the drainage control target, the target volume strain is calculated according to the value of the loading control parameter of the proportional strain loading and the axial strain, and the strain control matrix is ​​corrected using the target volume strain.

5. The true triaxial test simulation method according to claim 4, characterized in that: Generating a strain control matrix according to the strain increments in the three directions includes: Converting the stress increment into a stress invariant form and obtaining the elastic modulus and Poisson's ratio of the sample; The strain control matrix is ​​calculated using Hooke's law based on the elastic modulus and Poisson's ratio of the specimen in the form of stress invariants.

6. The true triaxial test simulation method according to claim 4, characterized in that: Before controlling the sample to apply the strain increments in the three directions according to the true transverse stress value and the transverse stress target, the method includes: identifying a first difference between the true value of the axial stress and the stress control target and a second difference between the true value of the volumetric strain and the target volumetric strain; If both the first difference and the second difference are not within the corresponding preset tolerance range, the axial strain increment of the strain matrix is ​​controlled to be the preset value; otherwise, the axial strain increment is calculated based on the ratio of the axial strain of the specimen to time and the time step of each servo mode adjustment of the servo motor.

7. A simulation device for true triaxial testing, characterized in that: include: An acquisition module is used to obtain the test target of the true triaxial test; an applying module, configured to determine a specimen according to the test objective and apply a preset axial strain increment to the specimen; An acquisition module, used for acquiring the true value of the axial stress, the true value of the longitudinal stress, the true value of the transverse stress and the axial strain of the sample; an identification module, configured to identify a stress control target and a drainage control target in the test target, calculate a transverse stress target based on the longitudinal stress true value and the axial stress true value, and generate a strain control matrix based on the stress control target, the drainage control target, the axial stress true value, the longitudinal stress true value, and the axial strain; The control module is used to control the sample to apply strain increments in three directions according to the strain control matrix until the true triaxial test is completed to obtain a simulation result of the true triaxial test.

8. An electronic device, characterized in that: include: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the true triaxial test simulation method according to any one of claims 1 to 6.

9. A computer-readable storage medium having a computer program or instruction stored thereon, characterized in that: When the computer program or instruction is executed by a processor, it is used to implement the simulation method of the true triaxial test according to any one of claims 1 to 6.

10. A computer program product comprising a computer program or instructions, characterized in that When the computer program or instructions are executed, the simulation method of the true triaxial test according to any one of claims 1 to 6 is implemented.

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