A numerical simulation method for hydraulic structures based on multi-field coupling

Abstract

The invention provides a numerical simulation method for hydraulic structures based on multi-field coupling, and relates to the technical field of numerical simulation of hydraulic structures. The method comprises: setting basic parameters of a hydraulic structure model according to a number of basic parameters corresponding to concrete of the hydraulic structure and a curve of change of ambient temperature over time in the environment in which the hydraulic structure is located, and performing temperature field analysis on the hydraulic structure model according to the ambient temperature to obtain the temperature of each pore, and then performing parameter change on ice in each pore according to the temperature and adding corresponding displacement loads for cyclic simulation. The method of the invention fully considers the multi-field coupling effect in the freeze-thaw cycle of concrete, including the interaction between the temperature field and the mechanical field. By introducing a damage model, the damage evolution process of concrete in the freeze-thaw process can be truly reflected, so that the simulation scene is closer to the real scene, thereby improving the accuracy of the numerical value obtained by simulation.

Description

Technical Field

[0001] The invention relates to the technical field of numerical simulation of hydraulic structures, and in particular to a numerical simulation method of hydraulic structures based on multi-field coupling. Background Art

[0002] Hydraulic structures are buildings that control and regulate water flow, prevent and control water disasters, and develop and utilize water resources. They are an important part of water conservancy projects and play a vital role in water conservancy projects. They are not only related to flood control safety, water resource utilization and ecological environmental protection, but also directly affect the development of the national economy and the improvement of people's lives. A comprehensive understanding of the performance parameters of hydraulic structures is of great significance for the monitoring of hydraulic structures. In winter, due to the low temperature, hydraulic structures, which are mainly concrete structures, are often damaged due to freeze-thaw cycles. Therefore, studying the freeze-thaw damage mechanism of concrete is crucial to improving the durability of concrete structures. However, the freeze-thaw damage process of concrete involves the complex coupling of temperature field and mechanical field. Existing models usually use a single field for simulation, and the accuracy of the simulated values ​​is low. Summary of the invention

[0003] In view of the above technical problems, the technical solution adopted by the present invention is:

[0004] According to a first aspect of the present application, a numerical simulation method for hydraulic structures based on multi-field coupling is provided, the method comprising the following steps:

[0005] S100, obtaining several basic parameters of concrete corresponding to the hydraulic structure and a curve QT of the change of the ambient temperature of the environment where the hydraulic structure is located over time;

[0006] S200, obtaining the ambient temperature at the corresponding time on QT at each preset time interval to obtain an ambient temperature list T = (T1, T2, ..., T i ,…,T n ), i=1, 2, …, n; where T i is the i-th ambient temperature obtained, and n is the number of ambient temperatures obtained;

[0007] S300, setting the basic parameters of the hydraulic structure model corresponding to the hydraulic structure to several basic parameters of the concrete corresponding to the hydraulic structure, and establishing a porous medium temperature field analysis model WR corresponding to the hydraulic structure; wherein WR includes several pores;

[0008] S400, according to T, the temperature field analysis of WR is performed to obtain the pore temperature list set A=(A1, A2, ..., A j , …, A m), j = 1, 2, …, m; where A j is the pore temperature list corresponding to the jth pore of WR, m is the number of pores corresponding to WR; A j =(A j，1 , A j，2 , …, A j，i , …, A j，n ); A j，i The jth pore of WR at ambient temperature T i The corresponding pore temperature at

[0009] S500, obtaining a preset value H=1;

[0010] S600, obtain the jth pore at the pore temperature A j，H The corresponding critical pore radius R j，H , enter S700;

[0011] S700, according to R j，H The relationship between the standard pore radius R corresponding to the jth pore, the parameters of the ice in the target pore are changed and the corresponding displacement load is added, and the model is re-run;

[0012] S800, if there is a damage position of the hydraulic structure, the WR is updated according to the damage position and the process goes to S400; otherwise, the process goes to S900;

[0013] S900, if H<n, obtain H=H+1 and enter S600; otherwise, output the distribution and changes of key parameters of hydraulic structures during the freeze-thaw cycle.

[0014] Furthermore, R j，H Obtained through the following steps:

[0015] S610, if A j，H In the temperature rising stage, determine R j，H =0.757+0.0074θ-33.45 / θ; where θ is R j，H The difference between the normal freezing point of water T0; θ = A j，H -T0;

[0016] S620, if A j，H In the temperature drop stage, determine R j，H =0.584+0.0052θ-63.46 / θ.

[0017] Furthermore, step S700 includes the following steps:

[0018] S710, if R j，H>R, it is determined that all the water in the target pores is frozen; otherwise, it is determined that all the water in the target pores is not frozen; where R is the standard pore radius corresponding to the jth pore;

[0019] S720, if all the water in the target pores is frozen, then the volume, density and constitutive relationship of the ice in the target pores are updated;

[0020] S730, confirm R j，H The corresponding displacement load D j，H =ρ2×R j，H 3 / ρ1-R j，H ; Among them, ρ1 is the density of water, ρ2 is the density of ice;

[0021] S740, establish the mechanical field model and add displacement load D to the jth pore j，H .

[0022] Further, step S800 includes the following steps:

[0023] S810, outputting a stress-strain diagram corresponding to the WR, if the stress of the pore in the WR is greater than the tensile strength of the concrete corresponding to the hydraulic structure or the strain of the pore in the WR is greater than the ultimate strain of the concrete corresponding to the hydraulic structure, then the pore is determined to be a damage location;

[0024] S820, remove damaged pores.

[0025] Furthermore, several basic parameters of the concrete corresponding to the hydraulic structure include: initial porosity n 0 ,volume V , elastic modulus E , Poisson's ratio m , Ultimate strain e f and tensile strength s ts .

[0026] Furthermore, the key parameters of the hydraulic structure during the freeze-thaw cycle include: temperature, pore water pressure, stress and damage.

[0027] The present invention has at least the following beneficial effects:

[0028] The numerical simulation method of hydraulic structures based on multi-field coupling of the present invention sets basic parameters of the hydraulic structure model according to several basic parameters corresponding to the concrete of the hydraulic structure and the change curve of the ambient temperature of the environment with time, and performs temperature field analysis on the hydraulic structure model according to the ambient temperature to obtain the temperature of each pore, and then changes the parameters of ice in each pore according to the temperature and adds corresponding displacement loads for cyclic simulation; the method of the present invention fully considers the multi-field coupling effect in the freeze-thaw cycle of concrete, including the interaction between the temperature field and the mechanical field; by introducing a damage model, it can truly reflect the damage evolution process of concrete in the freeze-thaw process, so that the simulation scene is closer to the real scene, thereby improving the accuracy of the numerical value obtained by simulation. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0030] Figure 1 A flowchart of a numerical simulation method for hydraulic structures based on multi-field coupling provided in an embodiment of the present invention;

[0031] Figure 2 A schematic diagram of the volume change of water turning into ice provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0033] It should be noted that, based on the present disclosure, those skilled in the art should understand that an aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number of aspects described herein can be used to implement a device and / or practice a method. In addition, other structures and / or functionalities other than one or more of the aspects described herein can be used to implement this device and / or practice this method.

[0034] The following will refer to Figure 1The flowchart of the numerical simulation method of hydraulic structures based on multi-field coupling is shown, which introduces a numerical simulation method of hydraulic structures based on multi-field coupling.

[0035] The numerical simulation method of hydraulic structures based on multi-field coupling in this embodiment is based on the following theory:

[0036] Consider the phase change (freezing and melting) and migration process of water in the concrete of hydraulic structures, as well as the resulting pore water pressure and ice pressure. Based on the porous media heat transfer theory, a temperature field model is established; the porous elasticity theory and damage mechanics principle are applied to establish a mechanical field model, considering the influence of damage on the mechanical properties of concrete materials. The iterative method is used to solve the temperature field and mechanical field in turn, and the results of each field are used as the input for solving the next field.

[0037] The numerical simulation method of hydraulic structures based on multi-field coupling may include the following steps:

[0038] S100, obtaining several basic parameters of concrete corresponding to the hydraulic structure and a curve QT of the change of the ambient temperature of the environment where the hydraulic structure is located over time.

[0039] In this embodiment, the hydraulic structure can be any hydraulic structure, such as a bridge pier, a gate, etc. After selecting the hydraulic structure to be simulated, several basic parameters of the concrete corresponding to the hydraulic structure can be obtained, including: the initial porosity of the concrete n 0 ,volume V , elastic modulus E , Poisson's ratio m , Ultimate strain e f and tensile strength s ts And other basic parameters.

[0040] It is also possible to obtain historical environmental information of the area where the hydraulic structure is located, thereby determining the curve QT of the ambient temperature change over time of the environment in which the hydraulic structure is located; it should be noted that technical personnel in this field can use the existing method for determining the curve of the ambient temperature change over time to determine the curve QT of the ambient temperature change over time of the environment in which the hydraulic structure is located according to actual needs, which will not be elaborated here.

[0041] Furthermore, according to the actual environmental conditions, boundary conditions such as the external temperature variation law, initial temperature, water content, etc. can be set; nonlinear solution control parameters such as time step, convergence tolerance and maximum number of iterations can be set.

[0042] S200, obtaining the ambient temperature at the corresponding time on QT at each preset time interval to obtain an ambient temperature list T = (T1, T2, ..., T i ,…,T n ), i=1, 2, …, n; where T i is the i-th ambient temperature obtained, and n is the number of ambient temperatures obtained.

[0043] In this embodiment, after obtaining QT, the ambient temperature at the corresponding time on QT can be obtained at every preset time interval to obtain an ambient temperature list T; the preset time can be set according to actual needs, for example: the preset time can be 1 hour, 30 minutes, etc.

[0044] S300, setting basic parameters of the hydraulic structure model corresponding to the hydraulic structure to several basic parameters of the concrete corresponding to the hydraulic structure, and establishing a porous medium temperature field analysis model WR corresponding to the hydraulic structure; wherein the WR includes several pores.

[0045] In this embodiment, a corresponding hydraulic structure model can be established for the hydraulic structure through relevant software, and then the basic parameters of the hydraulic structure model that are the same as the several basic parameters of the hydraulic structure obtained above are set, and a porous medium temperature field analysis model WR corresponding to the hydraulic structure can also be established; when the initial conditions or the results of the iteration step are known, the established porous medium temperature field analysis model is used to perform temperature field analysis to obtain the temperature of each pore of WR.

[0046] S400, according to T, the temperature field analysis of WR is performed to obtain the pore temperature list set A=(A1, A2, ..., A j , …, A m ), j = 1, 2, …, m; where A j is the pore temperature list corresponding to the jth pore of WR, m is the number of pores corresponding to WR; A j =(A j，1 , A j，2 , …, A j，i , …, A j，n ); A j，i The jth pore of WR at ambient temperature T i The corresponding pore temperature.

[0047] In the present embodiment, it can be understood that, when the external ambient temperature is constant, due to the factor of concrete pore distribution, the pore temperature of each pore may be different. Therefore, the temperature field analysis can be performed on WR to obtain the pore temperature list set A corresponding to each temperature in T of WR. It should be noted that those skilled in the art can use the existing temperature field analysis method to perform temperature field analysis on WR according to actual needs to obtain the pore temperature list set A corresponding to each temperature in T of WR, which will not be elaborated here.

[0048] S500, obtaining a preset value H=1.

[0049] S600, obtain the jth pore at the pore temperature A j，H The corresponding critical pore radius R j，H , enter S700.

[0050] In this embodiment, during the freezing and thawing process of concrete, different pore radii have different freezing points. For the jth pore, when the pore temperature is A j，H When the corresponding critical pore radius R is obtained j，H .

[0051] Furthermore, R j，H It can be obtained by following the steps below:

[0052] S610, if A j，H In the temperature rising stage, determine R j，H =0.757+0.0074θ-33.45 / θ; where θ is R j，H The difference between the normal freezing point of water T0; θ = A j，H -T0.

[0053] S620, if A j，H In the temperature drop stage, determine R j，H =0.584+0.0052θ-63.46 / θ.

[0054] In this embodiment, by comparing A j，H The method of determining whether it is in the temperature rising stage by comparing the pore temperature at the last preset moment, if A j，H If the pore temperature is greater than the previous preset time, then A is determined. j，H In the temperature rising stage, otherwise, determine A j，H The temperature is in the stage of falling. The normal freezing point of water, T0, is a known parameter, T0=273.15K.

[0055] S700, according to R j，HThe relationship between the standard pore radius R corresponding to the jth pore, the parameters of the ice in the target pore are changed and the corresponding displacement load is added, and the model is rerun.

[0056] Further, step S700 may include the following steps:

[0057] S710, if R j，H >R, it is determined that all the water in the target pores is frozen; otherwise, it is determined that all the water in the target pores is not frozen; where R is the standard pore radius corresponding to the jth pore.

[0058] In this embodiment, during the freezing process, when the temperature is A j，H When the standard pore radius R corresponding to the jth pore is greater than R j，H , then it is considered that all the water in the pore is frozen; if the standard pore radius R corresponding to the jth pore is less than R j，H , it is considered that all the water in the pores is not frozen. Thus, the water content and ice content of the new concrete are obtained.

[0059] S720: If all the water in the target pores is frozen, the volume, density and constitutive relationship of the ice in the target pores are updated.

[0060] S730, confirm R j，H The corresponding displacement load D j，H =ρ2×R j，H 3 / ρ1-R j，H ; Among them, ρ1 is the density of water and ρ2 is the density of ice.

[0061] S740, establish the mechanical field model and add displacement load D to the jth pore j，H .

[0062] In this embodiment, as water turns into ice, its volume, density and constitutive relationship will change; at the same time, as the volume of water turns into ice, it will squeeze the pore walls of the concrete pores; therefore, it is necessary to modify the basic parameters of the water that turns into ice in the above steps and apply a displacement load to the pore walls of the concrete pores.

[0063] like Figure 2 As shown in the figure, assuming that the concrete voids are spheres and the voids are filled with water or ice, the water or ice in the voids is also a sphere, but the density of water or ice at different temperatures is different, so the volume expansion rate of water turning into ice is not fixed; based on this, the displacement load can be calculated by the volume change of water turning into ice. The specific calculation process is as follows:

[0064] V1ρ1=V2ρ2;

[0065] V1 = (4π / 3) × R1 3 ;

[0066] V2 = (4π / 3) × R2 3 ;

[0067] D = R1-R2;

[0068] R1, V1 and ρ1 are the volume, radius and density of water when the pore temperature is T'1; R2, V2 and ρ2 are the volume and density of ice when the pore temperature is T'2; D is the displacement load; the displacement load D can be calculated based on the known quantities R1, V1, ρ1 and ρ2; based on the above calculation method, D can be calculated j，H .

[0069] S800: If there is a damage location of the hydraulic structure, WR is updated according to the damage location and the process goes to S400; otherwise, the process goes to S900.

[0070] In this embodiment, a mechanical field model is established to add a displacement load D to the jth pore. j，H , run the model, and output the stress-strain cloud diagram of the concrete model.

[0071] Further, step S800 may include the following steps:

[0072] S810, outputting the stress-strain diagram corresponding to WR. If the stress of the pore in WR is greater than the tensile strength of the concrete corresponding to the hydraulic structure or the strain of the pore in WR is greater than the ultimate strain of the concrete corresponding to the hydraulic structure, the pore is determined to be a damaged location.

[0073] S820, remove damaged pores.

[0074] In this embodiment, the damaged concrete can be considered to have no bearing capacity, so according to the concrete damage results in the mechanical field analysis in the above steps, the damaged concrete pores are manually removed. With the removal of the pores, the pores of the concrete model need to be further corrected, that is, the removed pores can be equivalent to new concrete pores, and then return to S400 for temperature field analysis.

[0075] The above iterative relationship constitutes the coupling relationship and solution steps of the temperature field and mechanical field of the freeze-thaw cycle of concrete materials. At each time step, after the results of each field meet the convergence conditions, the next time step analysis is entered.

[0076] S900, if H<n, obtain H=H+1 and enter S600; otherwise, output the distribution and changes of key parameters of hydraulic structures during the freeze-thaw cycle.

[0077] In this embodiment, after the simulation is completed, the distribution and changes of key parameters such as temperature, pore water pressure, stress and damage of the concrete corresponding to the hydraulic structure during the freeze-thaw cycle can be output. According to the simulation results, the freeze-thaw damage law of the concrete of the hydraulic structure under different conditions is analyzed.

[0078] In this embodiment, the basic parameters of the hydraulic structure model are set according to several basic parameters corresponding to the concrete of the hydraulic structure and the change curve of the ambient temperature of the environment with time, and the temperature field analysis of the hydraulic structure model is performed according to the ambient temperature to obtain the temperature of each pore, and then the parameters of the ice in each pore are changed according to the temperature and the corresponding displacement load is added to perform cyclic simulation; the method of the present invention fully considers the multi-field coupling effect during the freeze-thaw cycle of concrete, including the interaction between the temperature field and the mechanical field; by introducing the damage model, it can truly reflect the damage evolution process of concrete during the freeze-thaw process, so that the simulation scene is closer to the real scene, thereby improving the accuracy of the simulated numerical value; at the same time, it provides a basis for the design, construction, maintenance and durability evaluation of buildings such as hydraulic structures with concrete structures as the main body.

[0079] In addition, although the steps of the method in the present disclosure are described in a specific order in the drawings, this does not require or imply that the steps must be performed in this specific order, or that all the steps shown must be performed to achieve the desired results. Additionally or alternatively, some steps may be omitted, multiple steps may be combined into one step, and / or one step may be decomposed into multiple steps, etc.

[0080] An embodiment of the present invention also provides a non-transitory computer-readable storage medium, which can be set in an electronic device to store at least one instruction or at least one program related to implementing a method in a method embodiment. The at least one instruction or the at least one program is loaded and executed by the processor to implement the method provided in the above embodiment.

[0081] The program product may adopt any combination of one or more readable media. The readable medium may be a readable signal medium or a readable storage medium. The readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device or device, or any combination of the above. More specific examples (non-exhaustive list) of readable storage media include: an electrical connection with one or more wires, a portable disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above.

[0082] Computer readable signal media may include data signals propagated in baseband or as part of a carrier wave, in which readable program code is carried. Such propagated data signals may take a variety of forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the above. Readable signal media may also be any readable medium other than a readable storage medium, which may send, propagate, or transmit a program for use by or in conjunction with an instruction execution system, apparatus, or device.

[0083] The program code embodied on the readable medium may be transmitted using any appropriate medium, including but not limited to wireless, wired, optical cable, RF, etc., or any suitable combination of the foregoing.

[0084] Program code for performing the operations of the present application may be written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Java, C++, etc., and conventional procedural programming languages ​​such as "C" or similar programming languages. The program code may be executed entirely on the user computing device, partially on the user device, as a separate software package, partially on the user computing device and partially on a remote computing device, or entirely on a remote computing device or server. In the case of a remote computing device, the remote computing device may be connected to the user computing device through any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computing device (e.g., using an Internet service provider to connect through the Internet).

[0085] An embodiment of the present invention further provides an electronic device, comprising a processor and the aforementioned non-transitory computer-readable storage medium.

[0086] The electronic device is merely an example and should not bring any limitation to the functions and scope of use of the embodiments of the present application.

[0087] The electronic device is presented in the form of a general-purpose computing device. The components of the electronic device may include, but are not limited to: the at least one processor mentioned above, the at least one memory mentioned above, and a bus connecting different system components (including the memory and the processor).

[0088] The memory stores program codes, which can be executed by the processor, so that the processor executes the steps in various embodiments described in this specification.

[0089] The memory may include readable media in the form of volatile memory, such as random access memory (RAM) and / or cache memory, and may further include read only memory (ROM).

[0090] The memory may also include a program / utility having a set (at least one) of program modules, such program modules including but not limited to: an operating system, one or more application programs, other program modules and program data, each of which or some combination may include an implementation of a network environment.

[0091] The bus may represent one or more of several types of bus structures, including a memory bus or memory controller, a peripheral bus, an accelerated graphics port, a processor, or a local bus using any of a variety of bus architectures.

[0092] The electronic device may also communicate with one or more external devices (e.g., keyboards, pointing devices, Bluetooth devices, etc.), may communicate with one or more devices that enable a user to interact with the electronic device, and / or may communicate with any device (e.g., routers, modems, etc.) that enables the electronic device to communicate with one or more other computing devices. Such communication may be performed through an input / output (I / O) interface. Furthermore, the electronic device may also communicate with one or more networks (e.g., local area networks (LANs), wide area networks (WANs), and / or public networks, such as the Internet) through a network adapter. The network adapter communicates with other modules of the electronic device through a bus. It should be understood that, although not shown in the figure, other hardware and / or software modules may be used in conjunction with the electronic device, including but not limited to: microcode, device drivers, redundant processors, external disk drive arrays, RAID systems, tape drives, and data backup storage systems, etc.

[0093] Through the description of the above implementation, it is easy for those skilled in the art to understand that the example implementation described here can be implemented by software, or by software combined with necessary hardware. Therefore, the technical solution according to the implementation of the present disclosure can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (which can be a CD-ROM, a USB flash drive, a mobile hard disk, etc.) or on a network, including several instructions to enable a computing device (which can be a personal computer, a server, a terminal device, or a network device, etc.) to execute the method according to the implementation of the present disclosure.

[0094] An embodiment of the present invention further provides a computer program product, which includes program code. When the program product is run on an electronic device, the program code is used to enable the electronic device to execute the steps of the method according to various exemplary embodiments of the present invention described above in this specification.

[0095] Although some specific embodiments of the present invention have been described in detail by way of example, it should be understood by those skilled in the art that the above examples are only for illustration, not for limiting the scope of the present invention. It should also be understood by those skilled in the art that various modifications may be made to the embodiments without departing from the scope and spirit of the present invention.

Claims

1. A numerical simulation method for hydraulic structures based on multi-field coupling, characterized in that: The method comprises the following steps: S100, obtaining several basic parameters of concrete corresponding to the hydraulic structure and a curve QT of the change of the ambient temperature of the environment where the hydraulic structure is located over time; S200, obtaining the ambient temperature at the corresponding time on QT at each preset time interval to obtain an ambient temperature list T = (T1, T2, ..., T i , …, T n ), i=1, 2, …, n; where T i is the i-th ambient temperature obtained, and n is the number of ambient temperatures obtained; S300, setting the basic parameters of the hydraulic structure model corresponding to the hydraulic structure to several basic parameters of the concrete corresponding to the hydraulic structure, and establishing a porous medium temperature field analysis model WR corresponding to the hydraulic structure; wherein WR includes several pores; S400, according to T, the temperature field analysis of WR is performed to obtain the pore temperature list set A=(A1, A2, ..., A j , …, A m ), j = 1, 2, …, m; where A j is the pore temperature list corresponding to the jth pore of WR, m is the number of pores corresponding to WR; A j =(A j，1 , A j，2 , …, A j，i , …, A j，n ); A j，i The jth pore of WR at ambient temperature T i The corresponding pore temperature at S500, obtaining a preset value H=1; S600, obtain the jth pore at the pore temperature A j，H The corresponding critical pore radius R j，H , enter S700; S700, according to R j，H The relationship between the standard pore radius R corresponding to the jth pore, the parameters of the ice in the target pore are changed and the corresponding displacement load is added, and the model is re-run; S800, if there is a damage position of the hydraulic structure, the WR is updated according to the damage position and the process goes to S400; otherwise, the process goes to S900; S900, if H<n, obtain H=H+1 and enter S600; otherwise, output the distribution and changes of key parameters of hydraulic structures during the freeze-thaw cycle.

2. The numerical simulation method of hydraulic structures based on multi-field coupling according to claim 1 is characterized in that: R j，H Obtained through the following steps: S610, if A j，H In the temperature rising stage, determine R j，H =0.757+0.0074θ-33.45 / θ; where θ is R j，H The difference between the normal freezing point of water T0; θ = A j，H -T0; S620, if A j，H In the temperature drop stage, determine R j，H =0.584+0.0052θ-63.46 / θ.

3. The numerical simulation method of hydraulic structures based on multi-field coupling according to claim 1 is characterized in that: Step S700 includes the following steps: S710, if R j，H >R, it is determined that all the water in the target pores is frozen; otherwise, it is determined that all the water in the target pores is not frozen; where R is the standard pore radius corresponding to the jth pore; S720, if all the water in the target pores is frozen, then the volume, density and constitutive relationship of the ice in the target pores are updated; S730, confirm R j，H The corresponding displacement load D j，H =ρ2×R j，H 3 / ρ1-R j，H ; Among them, ρ1 is the density of water, ρ2 is the density of ice; S740, establish the mechanical field model and add displacement load D to the jth pore j，H .

4. The numerical simulation method of hydraulic structures based on multi-field coupling according to claim 1 is characterized in that: Step S800 includes the following steps: S810, outputting a stress-strain diagram corresponding to the WR, if the stress of the pore in the WR is greater than the tensile strength of the concrete corresponding to the hydraulic structure or the strain of the pore in the WR is greater than the ultimate strain of the concrete corresponding to the hydraulic structure, then the pore is determined to be a damage location; S820, remove damaged pores.

5. The numerical simulation method of hydraulic structures based on multi-field coupling according to claim 1 is characterized in that: Several basic parameters of concrete corresponding to the hydraulic structure include: initial porosity n 0 ,volume V , elastic modulus E , Poisson's ratio μ , Ultimate strain ε f and tensile strength σ ts .

6. The numerical simulation method of hydraulic structures based on multi-field coupling according to claim 1 is characterized in that: The key parameters of the hydraulic structure during the freeze-thaw cycle include: temperature, pore water pressure, stress and damage.

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