Simulation method, device, equipment, medium and program for true triaxial test

Abstract

The invention relates to the technical field of test and numerical analysis control, in particular to a simulation method, device and equipment for a true triaxial test, a medium and a program.The method comprises the steps that a test target of the true triaxial test is obtained; determining a sample according to a test target, and applying a preset axial strain increment to the sample; collecting an axial stress truth value, a longitudinal stress truth value, a transverse stress truth value and an 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 truth value and the axial stress truth value, and generating a strain control matrix based on the stress control target, the drainage control target, the axial stress truth value, the longitudinal stress truth value and the axial strain; and controlling the sample to apply strain increments in three directions according to the strain control matrix to obtain a simulation result of the true triaxial test. Therefore, the problems of relatively low applicability and practicability and the like caused by the fact that a simulation model of a true triaxial test in related technologies cannot meet various drainage condition requirements are solved.

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 soil is generally studied under fully drained or fully undrained conditions to reflect the loading rate and permeability of the soil. However, the actual drainage conditions in the field may be neither fully drained nor fully undrained, but partially drained. For example, due to the short duration of earthquake events, the response of soil under seismic loads is usually considered to be undrained, and assuming undrained conditions will provide conservative results. However, in an earthquake, the increase in pore pressure during a shaking event at a given location depends largely on the properties of the soil, including its composition, density, and initial stress state. Due to the heterogeneity of soil deposits, significant pressure differences may be generated within the soil during shaking. Positive pressure gradients will lead to contractive volume deformation, and negative pressure gradients will lead to expansive volume deformation. At the same time, the accumulation and dissipation of pore water during shaking will further reduce or increase the effective stress of the soil unit. The total pore pressure generated in a soil unit in this case will include shear and volume induced components, which may lead to a more harmful loading state than the undrained state. Therefore, it is necessary to study the properties of soil under partially drained conditions. In order to simulate local drainage conditions, proportional strain loading tests can be carried out on sand, that is, the ratio of axial strain to volume strain is kept constant during the entire loading process.

[0003] The intermediate principal stress ratio also has an important influence on the mechanical behavior of soil. For example, strength, dilatancy, friction angle and failure surface shape have a significant dependence 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 various drainage conditions and results in low applicability and practicality. Summary of the invention

[0005] The present application provides a simulation method, device, equipment, medium and program 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 of 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 the 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 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.

[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 a loading control parameter of proportional strain loading according to the drainage control target, calculating a 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 according to 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 according to the elastic modulus and Poisson's ratio of the sample in the stress invariant form.

[0013] Optionally, before controlling the sample 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 sample 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] A 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 a simulation method of a 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, the program being executed by a processor to perform the simulation method of a 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 sample according to the test target, and apply a preset axial strain increment to the sample; collect the true value of axial stress, true value of longitudinal stress, true value of transverse stress and axial strain of the sample; 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; 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 result of the true triaxial test, thereby being able to meet various drainage condition requirements, realize precise control of stress state and flexible control of drainage conditions, and having high applicability and practicability, thereby improving 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 the 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 A flowchart of a simulation method for a true triaxial test provided according to an embodiment of the present application;

[0023] Figure 2 It is a 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 numerical simulation that can apply different drainage conditions under a true triaxial stress state provided by an embodiment of the present application;

[0025] Figure 4 This is a graph showing the control result 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 A control result diagram of a servo method for applying different drainage conditions to a value under a true triaxial stress state provided by an embodiment of the present application;

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

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

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

[0030] Embodiments of the present application are described in detail below, and examples of the embodiments 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 simulation method, device, equipment, storage medium and program of the true triaxial test of the embodiment of the present application are described below with reference to the accompanying drawings. In view of the problem that the simulation of the true triaxial test in the related technology mentioned in the background technology center 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, so as 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 the applicability and practicality are high, which improves the accuracy and reliability of the test. As a result, the problem that the simulation of true triaxial test in related technologies cannot meet the requirements of various drainage conditions, resulting in low applicability and practicality, is solved.

[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 embodiments 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 sample is not drained; when α>0, the sample is over-drained and the volume shrinks; when α<0, the sample is expanded and drained, and the volume expands. At the same time, various test conditions required for the test sample are clarified, such as sample 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 adjustment of the servo mode by the servo motor 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 sample according to the test objectives, apply a preset axial strain increment to the sample, accurately control the loading path of the sample, 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 to generate the sample according to the test conditions.

[0042] It can be understood that the embodiments of the present application can identify the test conditions in the test objectives; isotropic consolidation is performed according to the test conditions to generate samples, thereby ensuring that the samples 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. 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 rate at which the upper wall moves downward and the rate at which the lower wall moves upward to the height of the specimen. The size of v must meet the requirements of the specification. It is generally believed that when v is small enough, the following steps are reasonable, and Δt refers to a time step. That is, the ratio of the displacement of the upper wall 4 moving downward at each time interval to the original height of the specimen is 0.5v, and the ratio of the displacement of the lower wall 5 moving upward at each time interval to the original height of the specimen 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 embodiments 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 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 in 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 within 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 previous 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 in 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 within 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 previous wall. The strain is the displacement of the lower wall 4 in the z direction divided by the z direction length of the specimen in 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 previous 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 lateral 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 , monitor σ yy , and according to the intermediate principal stress ratio and the monitored stress σ in the y direction yy , stress in 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 a stress control target, a drainage control target, an axial stress true value, a longitudinal stress true value and an axial strain, including: 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 three directions; determining the value of a loading control parameter of proportional strain loading according to the drainage control target, calculating a 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 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; determine the value of the loading control parameter of the proportional strain loading according to the drainage control target, calculate the target volume strain according to 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, the stress on the left wall 6 and the right wall 7 is not controlled, and the stress on the left wall 6 and the right wall 7 is monitored. The stress target value of the front wall 2 and the rear wall 3 in this time period is calculated, that is, σ xx Target value σ xx(t) =bσ yy +(1-b)σ zz . Get the stress control matrix for this time period

[0062] Monitoring of stress σ in z direction zz , strain ε zz The detected strain ε 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 according to 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 stress increments 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 for 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

[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 equally to dε xx and dε yy , so that the true volume strain ε v(true) Approaching the target volume strain ε v(t) , so the modified 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 result 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 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.

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

[0073] In an embodiment of the present application, before applying strain increments in three directions to the sample according to the true value of the lateral stress and the target of the lateral stress, 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 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 according to the ratio of the strain in the axial direction of the sample to the 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 embodiments 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 actual mean principal stress ratio and volume strain of the sample are monitored and compared with the target mean principal stress and volume strain to determine whether they are within the tolerance range.

[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 to the principal stress ratio and volume strain within the tolerance range and 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 tests, strain control is applied to the specimen by 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] Hence, see Figure 4 and Figure 5 It can be seen that the present application accurately controls the principal stress ratio b among the important parameters of the true triaxial test and the loading control parameter of the proportional strain loading, which is an important parameter for controlling the drainage state. It is a servo method that can apply different drainage conditions under the true triaxial stress state.

[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 the 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 various drainage condition requirements, realize precise control of the stress state and flexible control of the drainage conditions, and has high applicability and practicability, thereby improving 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 of 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 the 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, the drainage control target, the true value of axial stress, the true value of longitudinal stress and the 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 result 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 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 various drainage condition requirements, realize precise control of the stress state and flexible control of the drainage conditions, and has high applicability and practicability, thereby improving the accuracy and reliability of the test.

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

[0089] A memory 701 , a processor 702 , and a computer program 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 comprises:

[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 executed 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, the processor 702 and the communication interface 703 are implemented independently, the communication interface 703, the memory 701 and the processor 702 can be connected to each other through 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 only 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), or 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 also 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" etc. 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 may be combined in any one or N embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0101] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, "N" means at least two, such as two, three, etc., unless otherwise clearly and 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 the steps of a custom logical function or process, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in reverse order depending on the functions involved, which should be understood by technicians in the technical field to which the embodiments of the present application belong.

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

[0104] A person skilled in the art may understand that all or part of the steps in the method for implementing the above-mentioned embodiment may be completed by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium, which, when executed, 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 simulation method of true triaxial test according to claim 1, characterized in that: The test objectives include test materials, test parameters and test conditions, and the step of determining the sample according to the test objectives includes: Identifying 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 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 comprises: 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 simulation method of true triaxial test according to claim 4, characterized in that: The generating of the strain control matrix according to the strain increments in the three directions comprises: 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 simulation method of true triaxial test according to claim 4, characterized in that: Before controlling the sample to apply the strain increments in the three directions according to the true value of the transverse stress 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 according to the ratio of the axial strain of the sample to time and the time step of each adjustment of the servo mode by the servo motor.

7. A simulation device for true triaxial testing, characterized in that: include: An acquisition module is used to acquire the test target of the true triaxial test; An application module, used for determining a sample according to the test target and applying a preset axial strain increment to the sample; A collection module, used for collecting the true value of axial stress, true value of longitudinal stress, true value of transverse stress and axial strain of the sample; an identification module, used for 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 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 the 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 as described in any one of claims 1-6.

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

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