A method and system for constructing a material constitutive adaptive tracking model

Abstract

The invention provides a method and system for constructing a material constitutive adaptive tracking model, which relates to the technical field of tunnel engineering, including carrying out an axial compression test on a concrete specimen without participating in a freeze-thaw cycle to obtain basic mechanical performance index values ​​and basic control parameters of the concrete specimen; establishing mechanical performance index values ​​and control parameters of the concrete specimen under the influence of the freeze-thaw cycle; constructing a material constitutive model of the concrete specimen under the influence of the freeze-thaw cycle from the mechanical performance index values ​​and the control parameters; fitting the mechanical performance index values ​​and control parameters of the concrete specimen under the influence of the freeze-thaw cycle to obtain an initial posterior distribution of material constitutive model parameters; using new data to adaptively update the initial posterior distribution of material constitutive model parameters to obtain a material constitutive adaptive tracking model. The invention establishes a material constitutive adaptive tracking model that can reflect the characteristics of a long service life and a complex service environment, and lays a foundation for the establishment of a long life design theory.

Description

Technical Field

[0001] The present invention relates to the technical field of tunnel engineering, and in particular to a method and system for constructing a material constitutive adaptive tracking model. Background Art

[0002] my country has a vast territory, and tunnels are one of the indispensable and important elements in the structural composition of major transportation infrastructure in the west. The lining materials in tunnels are subject to large differences in service environment, complex coupling effects between loads and the environment, and strong performance variability. For the existing traditional material constitutive models for tunnel engineering, although they can represent and reflect the complex mechanical properties of different material characteristics, due to the microscopic mechanisms of different material constitutive and the defects in the basic theory of the constitutive model, it is not possible to establish a constitutive model that can consider the actual material service performance and material damage over time. As a result, under the conditions of the long-life design theory system and complex service environment, the traditional material constitutive model cannot accurately reflect the stress-strain relationship that can represent the time-history characteristics of material damage accumulation. Summary of the invention

[0003] The purpose of the present invention is to provide a method and system for constructing a material constitutive adaptive tracking model to improve the above problems. In order to achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0004] In a first aspect, the present application provides a method for constructing a material constitutive adaptive tracking model, comprising:

[0005] An axial compression test was carried out on the concrete specimens without freeze-thaw cycles to obtain the basic mechanical performance index values ​​and basic control parameters of the concrete specimens;

[0006] Building a test system, placing a concrete specimen in the test system to carry out an axial compression test under freeze-thaw cycles, and using the basic mechanical performance index values ​​and basic control parameters to establish mechanical performance index values ​​and control parameters of the concrete specimen under the influence of freeze-thaw cycles;

[0007] The material constitutive model of concrete specimens under the influence of freeze-thaw cycles is constructed based on mechanical performance index values ​​and control parameters.

[0008] According to the Bayesian theory, the mechanical performance index values ​​and control parameters of concrete specimens under the influence of freeze-thaw cycles are fitted to obtain the initial posterior distribution of the material constitutive model parameters.

[0009] New data of mechanical property index values ​​of new concrete specimens are obtained, and the initial posterior distribution of material constitutive model parameters is adaptively updated using the new data to obtain a material constitutive adaptive tracking model of the new concrete specimens.

[0010] In a second aspect, the present application also provides a system for constructing a material constitutive adaptive tracking model, comprising:

[0011] The first acquisition module: conduct an axial compression test on the concrete specimen without participating in freeze-thaw cycles to obtain the basic mechanical performance index value and basic control parameters of the concrete specimen;

[0012] The second acquisition module: building a test system, placing the concrete specimen in the test system to carry out an axial compression test under freeze-thaw cycles, and using the basic mechanical performance index values ​​and basic control parameters to establish mechanical performance index values ​​and control parameters of the concrete specimen under the influence of freeze-thaw cycles;

[0013] Model building module: Construct the material constitutive model of concrete specimens under the influence of freeze-thaw cycles based on mechanical performance index values ​​and control parameters;

[0014] Fitting module: According to the Bayesian theory, the mechanical performance index values ​​and control parameters of concrete specimens under the influence of freeze-thaw cycles are fitted to obtain the initial posterior distribution of material constitutive model parameters;

[0015] Update module: obtain new data of mechanical performance index values ​​of new concrete specimens, use the new data to adaptively update the initial posterior distribution of material constitutive model parameters, and obtain a material constitutive adaptive tracking model of the new concrete specimen.

[0016] In a third aspect, the present application also provides a device for constructing a material constitutive adaptive tracking model, comprising:

[0017] Memory for storing computer programs;

[0018] A processor is used to implement the steps of the method for constructing the material constitutive adaptive tracking model when executing the computer program.

[0019] In a fourth aspect, the present application further provides a readable storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the steps of the above-mentioned method for constructing a material constitutive adaptive tracking model are implemented.

[0020] The beneficial effects of the present invention are:

[0021] The present invention establishes a material constitutive adaptive tracking model based on typical characteristics of the regional environment, effectively exploring the service performance and damage accumulation time history characteristics of tunnel lining materials under multi-field coupling. The model can reflect the characteristics of long service life and complex service environment, providing a scientific basis for the long-life design theory of transportation infrastructure such as tunnels, ensuring the accuracy and reliability of the design.

[0022] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or be understood by implementing the embodiments of the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the written description, claims, and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0024] Figure 1 It is a schematic flow chart of a method for constructing a material constitutive adaptive tracking model described in an embodiment of the present invention;

[0025] Figure 2 It is the axial force-chloride salt-extreme temperature three-field coupling system described in the embodiment of the present invention;

[0026] Figure 3 Axial compression tests were carried out after different freeze-thaw cycles under MST conditions;

[0027] Figure 4 The changes in the appearance of concrete after different freeze-thaw cycles under MST conditions;

[0028] Figure 5 Axial compression tests were carried out after different freeze-thaw cycles under ST conditions;

[0029] Figure 6 The changes in the appearance of concrete after different freeze-thaw cycles under ST conditions;

[0030] Figure 7 Comparison between the adaptive tracking model and experimental values ​​for concrete materials;

[0031] Figure 8 Schematic diagram of the system structure for constructing the material constitutive adaptive tracking model described in an embodiment of the present invention;

[0032] Fig. 9 Schematic diagram of the structure of the equipment for constructing the material constitutive adaptive tracking model described in an embodiment of the present invention.

[0033] Markings in the figure:

[0034] 1. Test platform; 2. Axial pressure system; 3. Chloride salt solution pool; 4. Large temperature difference test chamber; 800. Equipment for building material constitutive adaptive tracking model; 801. Processor; 802. Memory; 803. Multimedia component; 804. I / O interface; 805. Communication component. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. The components of the embodiments of the present invention generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0036] It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings. At the same time, in the description of the present invention, the terms "first", "second", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0037] Embodiment 1:

[0038] This embodiment provides a method for constructing a material constitutive adaptive tracking model.

[0039] See also Figure 1 , the figure shows that the method includes:

[0040] S1. Carry out axial compression test on concrete specimens without freeze-thaw cycles to obtain basic mechanical performance index values ​​and basic control parameters of concrete specimens;

[0041] Specifically, when the axial compression test is an axial force-chloride salt-extreme temperature three-field coupling test, step S1 includes:

[0042] S11. Build a material constitutive model, and determine the required basic mechanical performance index values ​​and basic control parameters according to the material constitutive model. The basic mechanical performance index values ​​include basic peak stress and base peak strain ;

[0043] In this embodiment, the constitutive model of concrete material includes an ascending section and a descending section. The ascending section is a cubic polynomial calculation formula, and the descending section is a rational fraction, which are as follows:

[0044] ; (1)

[0045] In formula (1), is the peak stress of the foundation concrete, is the stress of concrete, is the peak strain of concrete, is the strain of concrete, is the control parameter of the rising section of the undamaged concrete material, It is the control parameter of the descending section of the undamaged concrete material.

[0046] S12. Conduct an axial force-chloride-extreme temperature three-field coupled test (MST) on concrete specimens without freeze-thaw cycles to obtain the corresponding stress-strain curve;

[0047] S13. According to the stress-strain curve, the base peak stress, base peak strain and base control parameters of the concrete specimen are obtained by least square fitting or nonlinear fitting, as shown in Table 1:

[0048] Table 1

[0049]

[0050] Specifically, when the axial compression test is a chloride salt-extreme temperature two-field coupling test (ST), step S1 further includes:

[0051] S14. Conduct a chloride-extreme temperature two-field coupled test (ST) on concrete specimens without freeze-thaw cycles to obtain the corresponding stress-strain curve;

[0052] S15. According to the stress-strain curve, the base peak stress, base peak strain and base control parameters of the concrete specimen are obtained by least square fitting or nonlinear fitting, as shown in Table 2:

[0053] Table 2

[0054]

[0055] It can be seen from Tables 1 and 2 that the basic peak stress and basic peak strain of MST and ST are the same.

[0056] Based on the above embodiment, the method further includes:

[0057] S2. Build a test system, place the concrete specimen in the test system to carry out an axial compression test under freeze-thaw cycles, and use the basic mechanical performance index values ​​and basic control parameters to establish the mechanical performance index values ​​and control parameters of the concrete specimen under the influence of freeze-thaw cycles;

[0058] In this embodiment, when the test system is used for the axial force-chloride-extreme temperature three-field coupling test, it is composed of a test platform 1, an axial pressure system 2, a chloride solution pool 3 and a large temperature difference test box 4. Figure 2 As shown, the installation process of the test system is as follows:

[0059] First, fix the axial pressure system 2 in the middle of the test platform 1 and ensure that its measurement range covers the design stress level; secondly, arrange the chloride salt solution pool 3 in the middle of the axial pressure system 2 to ensure that the concrete specimen can be completely immersed in the chloride salt solution pool 3; finally, place the entire structure in a large temperature difference test box 4 to complete the construction of the test system.

[0060] When the test system is used for the chloride-salt-extreme temperature two-field coupling test, it is composed of a test platform, a chloride-salt solution pool, and a large temperature difference test box.

[0061] This test system is suitable for environments with axial compressive stress levels of 0~10MPa, chloride salt concentration adjusted according to experimental requirements, and temperatures as low as -25℃ and as high as room temperature.

[0062] Specifically, step S2 includes:

[0063] S21. Place several concrete specimens in a chloride solution pool of the test system and conduct freeze-thaw cycle tests of different times;

[0064] Specifically, firstly, the designed axial pressure is applied to the concrete specimen and kept constant, and the concrete specimen is placed in a chloride salt solution pool for freeze-thaw cycles. After reaching a preset number of times, the specimen is taken out. In this embodiment, freeze-thaw cycle tests are carried out on the concrete test for 90 times, 120 times, 150 times, 180 times, 210 times, 240 times and 270 times.

[0065] S22. Axial compression tests were carried out on concrete specimens after freeze-thaw cycle tests, and the stress-strain curves of concrete specimens after freeze-thaw cycles were fitted. The appearance changes of lining concrete under MST coupling after the test were as follows: Figure 3 , Figure 4 As shown in Figure 2, the appearance of the lining concrete changes under ST coupling. Figure 5 , Figure 6 As shown;

[0066] In this embodiment, axial compression tests were carried out on concrete specimens under two service environments, MST and ST, and stress-strain curves were statistically analyzed based on the test results.

[0067] S23. According to the stress-strain curve, the relationship model of the peak stress of the concrete specimen under the influence of freeze-thaw cycles relative to the basic peak stress and the number of freeze-thaw cycles, the relationship model of the peak strain relative to the basic peak strain and the number of freeze-thaw cycles, and the relationship model of the control parameters relative to the basic control parameters and the number of freeze-thaw cycles are obtained:

[0068] ; (2)

[0069] In the formula, is the number of freeze-thaw cycles, is the peak compressive stress of the concrete specimen under the influence of freeze-thaw cycles, is the peak compressive strain of the concrete specimen under the influence of freeze-thaw cycles, , They are the rising section parameters and the descending section parameters of the concrete specimen under the influence of freeze-thaw cycles;

[0070] Based on the above embodiment, the method further includes:

[0071] S3. The material constitutive model of concrete specimens under the influence of freeze-thaw cycles is constructed based on the mechanical performance index values ​​and control parameters:

[0072] ; (3)

[0073] In the formula, is the strain of concrete, is the stress of concrete.

[0074] In this embodiment, the above formula can be the material constitutive model of concrete under the two coupling conditions of MST or ST. The material constitutive model under the MST coupling condition can be obtained by numerical calculation using the numerical values ​​in Table 1, and the material constitutive model under the ST coupling condition can be obtained by numerical calculation using the numerical values ​​in Table 2.

[0075] Based on the above embodiment, the method further includes:

[0076] S4. According to the Bayesian theory, the mechanical performance index values ​​and control parameters of the concrete specimens under the influence of freeze-thaw cycles are fitted to obtain the initial posterior distribution of the material constitutive model parameters;

[0077] Specifically, step S4 includes:

[0078] S41. Taking the mechanical property index value and the control parameter as the parameters to be estimated;

[0079] In this embodiment, equation (3) actually describes the stress-strain constitutive model of the concrete specimen under the influence of freeze-thaw cycles, and the independent variable parameter is actually the actual process strain of the concrete under compression. , peak stress , peak strain , Ascending segment parameters And the descending parameters , the dependent variable parameter is the actual compressive stress of concrete , so formula (3) can be simplified to formula (4):

[0080] ; (4)

[0081] In the formula, , , as well as Compared with the formula (2) , , as well as Equivalently, formula (4) represents the relationship between these four variables and the number of freeze-thaw cycles Therefore, , , , As the parameter to be estimated, we get the set to be estimated .

[0082] S42. Mechanical properties and control parameters of concrete specimens under the influence of freeze-thaw cycles , , , As the fitting result of the parameter to be estimated, the prior distribution is obtained :

[0083] S43. Obtain the stress value and corresponding strain value of the stress-strain measurement pair in the freeze-thaw cycle test to construct the likelihood function :

[0084] ; (5)

[0085] In the formula, represents the standard deviation of the measurement noise, The concrete stress in expression (3) is With strain Measurement pair, is the number of data points, i.e. the stress value of the stress-strain measurement pair measured in the experiment, Indicates data points, Indicates the actual measured strain value;

[0086] Among them, the likelihood function Reflects the parameters The degree of fit to the test data.

[0087] S44. Constructing the initial posterior distribution of the material constitutive model parameters based on the prior distribution and likelihood function :

[0088] ; (6)

[0089] Based on the above embodiment, the method further includes:

[0090] S5. obtaining new data of mechanical property index values ​​of the new concrete specimen, and using the new data to adaptively update the initial posterior distribution of material constitutive model parameters to obtain a material constitutive model of the new concrete specimen;

[0091] Specifically, step S5 includes:

[0092] S51. Place the new concrete specimen in the test system and carry out the axial compression test under the preset conditions to obtain the stress value of the new stress-strain measurement pair and strain value ;

[0093] In this embodiment, axial compression tests can be carried out on different concrete specimens under test conditions. Through the new data set obtained through indoor tests, numerical analysis and field tests, the stress-strain curve of the new concrete material under compression under different conditions can be calculated.

[0094] S52. Using the new stress value and strain value Update the likelihood function ;

[0095] S53. The initial posterior distribution As a new prior distribution, a new posterior distribution is constructed by the new prior distribution and the updated likelihood function, and the material constitutive adaptive tracking model of the new concrete specimen is obtained;

[0096] Specifically, the new posterior distribution expression is:

[0097] ; (7)

[0098] The above embodiment can realize the adaptive update of the material constitutive model through the Bayesian principle to obtain a new concrete material.

[0099] Under MST and ST conditions, the material stress-strain curves of new concrete specimens after 270 freeze-thaw cycles are shown in the following figure. Figure 7 shown.

[0100] Under the MST and ST conditions calculated by the adaptive tracking model constructed by the method provided in this embodiment, the results show that compared with the experiment, the maximum calculation error of the adaptive tracking model constructed in this embodiment is 8.3%, and the accuracy is above 90%, indicating that it has good accuracy and can provide a systematic method for the dynamic prediction of concrete properties.

[0101] Embodiment 2:

[0102] like Figure 8 As shown, this embodiment provides a system for constructing a material constitutive adaptive tracking model, the system comprising:

[0103] The first acquisition module: conduct an axial compression test on the concrete specimen without participating in freeze-thaw cycles to obtain the basic mechanical performance index value and basic control parameters of the concrete specimen;

[0104] The second acquisition module: building a test system, placing the concrete specimen in the test system to carry out an axial compression test under freeze-thaw cycles, and using the basic mechanical performance index values ​​and basic control parameters to establish mechanical performance index values ​​and control parameters of the concrete specimen under the influence of freeze-thaw cycles;

[0105] Model building module: Construct the material constitutive model of concrete specimens under the influence of freeze-thaw cycles based on mechanical performance index values ​​and control parameters;

[0106] Fitting module: According to the Bayesian theory, the mechanical performance index values ​​and control parameters of concrete specimens under the influence of freeze-thaw cycles are fitted to obtain the initial posterior distribution of material constitutive model parameters;

[0107] Update module: obtain new data of the mechanical performance index value of the concrete specimen, use the new data to adaptively update the initial posterior distribution of the material constitutive model parameters, and obtain the material constitutive adaptive tracking model.

[0108] Based on the above embodiment, the first acquisition module includes:

[0109] Parameter determination unit: constructing a material constitutive model, and determining required basic mechanical performance index values ​​and basic control parameters according to the material constitutive model, wherein the basic mechanical performance index values ​​include basic peak stress and basic peak strain;

[0110] The first test unit: A three-field coupling test of axial force, chloride salt and extreme temperature without freeze-thaw cycle was carried out on the concrete specimens to obtain the corresponding stress-strain curve;

[0111] The first fitting unit: according to the stress-strain curve, the basic peak stress, basic peak strain and basic control parameters of the concrete specimen are obtained by using the least square fitting method or the nonlinear fitting method.

[0112] Based on the above embodiment, the first acquisition module further includes:

[0113] The second test unit: a chloride salt-extreme temperature two-field coupling test without freeze-thaw cycle was carried out on the concrete specimens to obtain the corresponding stress-strain curve;

[0114] The second fitting unit: according to the stress-strain curve, the basic peak stress, basic peak strain and basic control parameters of the concrete specimen are obtained by using the least square fitting method or the nonlinear fitting method.

[0115] Based on the above embodiments, the model building module includes:

[0116] The second test unit: several concrete specimens are placed in the chloride salt solution pool of the test system to conduct freeze-thaw cycle tests of different times;

[0117] The third test unit: axial compression test is carried out on concrete specimens after freeze-thaw cycle test, and the stress-strain curve of concrete specimens after freeze-thaw cycle is fitted;

[0118] Relationship model building unit: According to the stress-strain curve, the relationship model of the peak stress of the concrete specimen under the influence of freeze-thaw cycles relative to the basic peak stress and the number of freeze-thaw cycles, the relationship model of the peak strain relative to the basic peak strain and the number of freeze-thaw cycles, and the relationship model of the control parameters relative to the basic control parameters and the number of freeze-thaw cycles are obtained.

[0119] Based on the above embodiment, the fitting module includes:

[0120] Select unit: take mechanical property index value and control parameter as parameters to be estimated;

[0121] The third fitting unit: taking the mechanical performance index values ​​and control parameters of the concrete specimen under the influence of freeze-thaw cycles as the fitting results of the parameters to be estimated, and obtaining the prior distribution;

[0122] The first acquisition unit: acquires the stress value and the corresponding strain value of the stress-strain measurement pair in the freeze-thaw cycle test to construct a likelihood function;

[0123] Model building unit: building the initial posterior distribution of material constitutive model parameters by using the prior distribution and likelihood function.

[0124] Based on the above embodiment, the update module includes:

[0125] The fourth test unit: placing the concrete specimen in the test system and carrying out an axial compression test under preset conditions to obtain a new stress-strain measurement pair and a new strain value;

[0126] A first updating unit: updating the likelihood function using the new stress-strain measurement pair and the new strain value;

[0127] The second updating unit: uses the initial posterior distribution as a new prior distribution, constructs a new posterior distribution by the new prior distribution and the updated likelihood function, and obtains a material constitutive adaptive tracking model.

[0128] It should be noted that, regarding the system in the above embodiment, the specific manner in which each module performs operations has been described in detail in the embodiment of the method, and will not be elaborated here.

[0129] Embodiment 3:

[0130] Corresponding to the above method embodiment, this embodiment also provides a device for constructing a material constitutive adaptive tracking model. The device for constructing a material constitutive adaptive tracking model described below and the method for constructing a material constitutive adaptive tracking model described above can refer to each other.

[0131] Fig. 9 8 is a block diagram of a device 800 for constructing a material constitutive adaptive tracking model according to an exemplary embodiment. Fig. 9 As shown, the device 800 for constructing the material constitutive adaptive tracking model may include: a processor 801 and a memory 802. The device 800 for constructing the material constitutive adaptive tracking model may also include one or more of a multimedia component 803, an I / O interface 804, and a communication component 805.

[0132] The processor 801 is used to control the overall operation of the device 800 for constructing the material constitutive adaptive tracking model to complete all or part of the steps in the above-mentioned method for constructing the material constitutive adaptive tracking model. The memory 802 is used to store various types of data to support the operation of the device 800 for constructing the material constitutive adaptive tracking model. These data may include, for example, instructions for any application or method operating on the device 800 for constructing the material constitutive adaptive tracking model, as well as application-related data, such as contact data, sent and received messages, pictures, audio, video, etc. The memory 802 can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic memory, flash memory, disk or optical disk. The multimedia component 803 may include a screen and an audio component. The screen may be, for example, a touch screen, and the audio component is used to output and / or input audio signals. For example, the audio component may include a microphone for receiving external audio signals. The received audio signal may be further stored in the memory 802 or sent via the communication component 805. The audio component also includes at least one speaker for outputting audio signals. The I / O interface 804 provides an interface between the processor 801 and other interface modules, and the above-mentioned other interface modules can be keyboards, mice, buttons, etc. These buttons can be virtual buttons or physical buttons. The communication component 805 is used for wired or wireless communication between the construction device 800 of the material constitutive adaptive tracking model and other devices. Wireless communication, such as Wi-Fi, Bluetooth, Near Field Communication (NFC), 2G, 3G or 4G, or a combination of one or more of them, so the corresponding communication component 805 can include: Wi-Fi module, Bluetooth module, NFC module.

[0133] In an exemplary embodiment, the material constitutive adaptive tracking model construction device 800 can be implemented by one or more application specific integrated circuits (Application Specific Integrated Circuit, referred to as ASIC), digital signal processors (Digital Signal Processing Device, referred to as DSP), digital signal processing devices (Digital Signal Processing Device, referred to as DSPD), programmable logic devices (Programmable Logic Device, referred to as PLD), field programmable gate arrays (Field Programmable Gate Array, referred to as FPGA), controllers, microcontrollers, microprocessors or other electronic components to execute the above-mentioned material constitutive adaptive tracking model construction method.

[0134] In another exemplary embodiment, a computer-readable storage medium including program instructions is also provided, and when the program instructions are executed by a processor, the steps of the method for constructing the material constitutive adaptive tracking model described above are implemented. For example, the computer-readable storage medium may be the memory 802 including the program instructions described above, and the program instructions may be executed by the processor 801 of the device 800 for constructing the material constitutive adaptive tracking model to complete the method for constructing the material constitutive adaptive tracking model described above.

[0135] Embodiment 4:

[0136] Corresponding to the above method embodiment, a readable storage medium is also provided in this embodiment. The readable storage medium described below and the method for constructing a material constitutive adaptive tracking model described above can refer to each other.

[0137] A readable storage medium stores a computer program, which, when executed by a processor, implements the steps of the method for constructing a material constitutive adaptive tracking model of the above method embodiment.

[0138] The readable storage medium may specifically be a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, or other readable storage medium that can store program codes.

[0139] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

[0140] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A method for constructing a material constitutive adaptive tracking model, characterized in that: include: An axial compression test was carried out on the concrete specimens without freeze-thaw cycles to obtain the basic mechanical performance index values ​​and basic control parameters of the concrete specimens; A test system is built, and a concrete specimen is placed in the test system to carry out an axial compression test under freeze-thaw cycles, and the mechanical performance index values ​​and control parameters of the concrete specimen under the influence of freeze-thaw cycles are established by using the basic mechanical performance index values ​​and basic control parameters, including: Several concrete specimens were placed in the chloride salt solution pool of the test system to conduct freeze-thaw cycle tests of different times; Axial compression tests were carried out on concrete specimens after freeze-thaw cycle tests, and stress-strain curves of concrete specimens after freeze-thaw cycle tests were obtained by fitting. According to the stress-strain curve, the relationship model of the peak stress of the concrete specimen under the influence of freeze-thaw cycles relative to the base peak stress and the number of freeze-thaw cycles, the relationship model of the peak strain relative to the base peak strain and the number of freeze-thaw cycles, and the relationship model of the control parameters relative to the base control parameters and the number of freeze-thaw cycles are obtained: Where N is the number of freeze-thaw cycles, σ p is the peak compressive stress of the concrete specimen under the influence of freeze-thaw cycles, σ0 is the peak stress of the base concrete, ε p is the peak compressive strain of the concrete specimen under the influence of freeze-thaw cycles, ε0 is the peak strain of concrete, a and b are the rising section parameters and the descending section parameters of the concrete specimen under the influence of freeze-thaw cycles, respectively, a0 and b0 are the rising section control parameters and the descending section control parameters of the undamaged concrete material; The material constitutive model of concrete specimens under the influence of freeze-thaw cycles is constructed based on the mechanical performance index values ​​and control parameters: Where ε is the strain of concrete and σ is the stress of concrete; According to the Bayesian theory, the mechanical performance index values ​​and control parameters of the concrete specimens under the influence of freeze-thaw cycles are fitted to obtain the initial posterior distribution of the material constitutive model parameters, including: The mechanical property index values ​​and control parameters are used as parameters to be estimated; The mechanical performance index values ​​and control parameters of concrete specimens under the influence of freeze-thaw cycles are used as the fitting results of the parameters to be estimated to obtain the prior distribution. Obtain the stress value and the corresponding strain value of the stress-strain measurement pair in the freeze-thaw cycle test to construct a likelihood function; Constructing an initial posterior distribution of material constitutive model parameters using the prior distribution and likelihood function; New data of mechanical property index values ​​of new concrete specimens are obtained, and the initial posterior distribution of material constitutive model parameters is adaptively updated using the new data to obtain a material constitutive adaptive tracking model of the new concrete specimens.

2. The method for constructing a material constitutive adaptive tracking model according to claim 1, characterized in that , an axial compression test is carried out on the concrete specimen without participating in the freeze-thaw cycle to obtain the basic mechanical performance index value and basic control parameters of the concrete specimen. When the axial compression test is an axial force-chloride salt-extreme temperature three-field coupling test, it includes: Building a material constitutive model, and determining required basic mechanical performance index values ​​and basic control parameters according to the material constitutive model, wherein the basic mechanical performance index values ​​include basic peak stress and basic peak strain; A three-field coupling test of axial force, chloride salt and extreme temperature was carried out on concrete specimens without freeze-thaw cycles, and the corresponding stress-strain curves were obtained. According to the stress-strain curve, the basic peak stress, basic peak strain and basic control parameters of the concrete specimen are obtained by using the least square fitting method or the nonlinear fitting method.

3. The method for constructing a material constitutive adaptive tracking model according to claim 2, characterized in that ,When the axial compression test is a chloride salt-extreme temperature two-field coupling test, it includes: The concrete specimens were subjected to a chloride-extreme temperature two-field coupling test without freeze-thaw cycles, and the corresponding stress-strain curves were obtained. According to the stress-strain curve, the basic peak stress, basic peak strain and basic control parameters of the concrete specimen are obtained by using the least square fitting method or the nonlinear fitting method.

4. A system for constructing a material constitutive adaptive tracking model, used in the method for constructing a material constitutive adaptive tracking model according to any of claims 1 to 3, characterized in that: include: The first acquisition module: conduct an axial compression test on the concrete specimen without participating in freeze-thaw cycles to obtain the basic mechanical performance index value and basic control parameters of the concrete specimen; The second acquisition module: building a test system, placing the concrete specimen in the test system to carry out an axial compression test under freeze-thaw cycles, and using the basic mechanical performance index values ​​and basic control parameters to establish mechanical performance index values ​​and control parameters of the concrete specimen under the influence of freeze-thaw cycles; Model building module: Construct the material constitutive model of concrete specimens under the influence of freeze-thaw cycles based on mechanical performance index values ​​and control parameters; Fitting module: According to the Bayesian theory, the mechanical performance index values ​​and control parameters of concrete specimens under the influence of freeze-thaw cycles are fitted to obtain the initial posterior distribution of material constitutive model parameters; Update module: obtain new data of mechanical performance index values ​​of new concrete specimens, use the new data to adaptively update the initial posterior distribution of material constitutive model parameters, and obtain a material constitutive adaptive tracking model of the new concrete specimen.

5. The system for constructing a material constitutive adaptive tracking model according to claim 4, characterized in that: The first acquisition module includes: Parameter determination unit: constructing a material constitutive model, and determining required basic mechanical performance index values ​​and basic control parameters according to the material constitutive model, wherein the basic mechanical performance index values ​​include basic peak stress and basic peak strain; The first test unit: A three-field coupling test of axial force, chloride salt and extreme temperature without freeze-thaw cycle was carried out on the concrete specimens to obtain the corresponding stress-strain curve; The first fitting unit: according to the stress-strain curve, the basic peak stress, basic peak strain and basic control parameters of the concrete specimen are obtained by using the least square fitting method or the nonlinear fitting method.

6. The system for constructing a material constitutive adaptive tracking model according to claim 5, characterized in that: The first acquisition module also includes: The second test unit: a chloride salt-extreme temperature two-field coupling test without freeze-thaw cycle was carried out on the concrete specimens to obtain the corresponding stress-strain curve; The second fitting unit: according to the stress-strain curve, the basic peak stress, basic peak strain and basic control parameters of the concrete specimen are obtained by using the least square fitting method or the nonlinear fitting method.

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