Concrete fine numerical specimen generation method and system based on fluid-solid coupling analysis

Abstract

The application provides a concrete fine numerical specimen generation method based on fluid-solid coupling analysis, and belongs to the technical field of concrete numerical simulation, and comprises the following steps: a three-dimensional model of gravel aggregate with different diameters is established, and a real aggregate model library is constructed according to different three-dimensional models; the size and quantity of aggregate are determined according to the concrete proportioning and Fuller curve, and the three-dimensional model of gravel aggregate in the real aggregate model library is randomly selected; the mortar is filled in the calculation domain, and the SPH-DEM coupling calculation method is used to simulate the concrete mixing-pouring-vibrating process of the aggregate and the mortar; when the kinetic energy of the calculation domain tends to be zero, the spatial distribution information of the aggregate in the specimen is extracted, and a real numerical concrete fine numerical specimen is obtained. The three-dimensional scanning technology is used to establish the real aggregate model library, and then the fluid-solid coupling analysis method is used to simulate the concrete preparation process, so that the real aggregate shape and its spatial distribution can be determined.

Description

Technical Field

[0001] This invention belongs to the field of concrete numerical simulation technology, specifically relating to a method for generating concrete microstructure numerical specimens based on fluid-structure interaction analysis. Background Technology

[0002] Numerical simulation of concrete micromechanics is an important tool for studying concrete performance. It captures the nonlinear behavior of materials by distinguishing the material properties of cement mortar, aggregates, and the interfacial transition zone between them.

[0003] Numerical specimens for concrete micromechanics are fundamental to micromechanical research, containing information on the shape and spatial distribution of coarse aggregates. Traditional methods for generating microstructure distributions simplify crushed stone aggregates into convex polyhedra, randomly placing them into the concrete specimen. This results in non-intrusive aggregates being generated within the specimen space, with larger aggregates added before smaller ones. Consequently, the specimens fail to accurately reflect the true shape, distribution, and content of the aggregates. These are the three major challenges in generating numerical microstructure specimens, potentially leading to inaccurate micromechanical analysis results. Summary of the Invention

[0004] To address the aforementioned problems, this invention provides a method for generating concrete microstructure numerical specimens based on fluid-structure interaction analysis.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A method for generating concrete mesoscopic numerical specimens based on fluid-structure interaction analysis includes:

[0007] Establish an aggregate rigid body for generating concrete microstructure numerical specimens;

[0008] The Smooth Particle Hydrodynamics (SPH) method and Discrete Element Method (DEM) were used to simulate the mixing, pouring, and vibration process of aggregate rigid bodies and mortar to obtain concrete mixtures. SPH was used to simulate the shear thinning behavior of mortar, and DEM was used to simulate the movement of aggregates in mortar. The interaction forces between aggregate rigid bodies in the concrete mixture at time t during the simulation were calculated. The linear velocity, angular velocity, and centroid position of the aggregate rigid bodies, as well as the velocity, relative density, and position of mortar particles, were obtained through the interaction forces.

[0009] Update the position, pressure, linear velocity, and relative density of fluid for each aggregate rigid body in the concrete mixture within the SPH simulation space. Iterate and calculate the linear velocity, angular velocity, and centroid position of the aggregate rigid body at time t+n, as well as the velocity, relative density, and position of mortar particles, until the mixing-pouring-vibration process is completed.

[0010] Extract the linear velocity, angular velocity, and centroid position of the rigid aggregate in the concrete mixture at time t+n, as well as the spatial distribution information of the velocity, relative density, and position of mortar particles. Based on the spatial distribution information, obtain the true numerical concrete microstructure specimen.

[0011] Preferably, the threshold method is used to calculate the interaction forces between rigid aggregates in the concrete mixture, specifically:

[0012]

[0013] f t (v,t,q)=f e -f c ;

[0014] In the formula, M is the aggregate mass matrix, t is the simulation time, q is the aggregate rigid body coordinates, v is the aggregate rigid body velocity, and f is the aggregate mass matrix. t f is the resultant force of external force and constraint force. e For external force, f c Let L be the interaction force, and L be the linear transformation function.

[0015] Preferably, the interaction forces include the interaction forces between aggregates, the interaction forces between aggregates and SPH particles, and the interaction forces between aggregates and the boundary.

[0016] Preferably, the external force f e The calculation is as follows:

[0017] Considering fluid-rigid body interaction and the linear acceleration dV / dt and angular acceleration dΩ / dt of the rigid body, calculate the linear force F and torque T of the aggregate rigid body, and obtain the external force f from the linear force F and torque T. e .

[0018] Preferably, the process of establishing the aggregate rigid body for generating the concrete microstructure numerical specimen specifically involves:

[0019] Three-dimensional models of crushed stone aggregates with different diameters were established to construct a library of real aggregate models. The quantity of aggregates was calculated based on the concrete mix design information, and three-dimensional models of crushed stone aggregates from the library of real aggregate models were randomly selected as the aggregate rigid bodies based on the quantity of aggregates.

[0020] Preferably, the calculation of aggregate quantity based on concrete mix proportion information specifically involves determining the aggregate quantity using a Fuller curve based on the concrete mix proportion information.

[0021] This invention also proposes a concrete microstructure numerical specimen generation system based on fluid-structure interaction analysis, comprising:

[0022] The model building module is used to create aggregate rigid bodies for generating concrete microstructure numerical specimens;

[0023] The behavior simulation module is used to simulate the mixing, pouring, and vibration process of aggregate rigid bodies and mortar using the Smooth Particle Hydrodynamics (SPH) method and the Discrete Element Method (DEM) to obtain concrete mixtures. SPH is used to simulate the shear thinning behavior of mortar, and DEM is used to simulate the movement of aggregates in mortar. The module calculates the interaction forces between aggregate rigid bodies in the concrete mixture at time t during the simulation process. Through the interaction forces, the linear velocity, angular velocity, and centroid position of the aggregate rigid bodies, as well as the velocity, relative density, and position of mortar particles are obtained.

[0024] The simulation update module is used to update the position, pressure, linear velocity, and relative density of fluid of each aggregate rigid body in the concrete mixture in the SPH simulation space. It iteratively calculates the linear velocity, angular velocity, and centroid position of the aggregate rigid body at time t+n, as well as the velocity, relative density, and position of mortar particles, until the mixing-pouring-vibration process ends.

[0025] The specimen generation module is used to extract the linear velocity, angular velocity, and centroid position of the aggregate rigid body in the concrete mixture at time t+n, as well as the spatial distribution information of the velocity, relative density, and position of mortar particles. Based on the spatial distribution information, a true numerical concrete microstructure specimen is obtained.

[0026] The present invention also provides a computer device, including a memory, a processor, and a computer program stored in the memory, wherein the processor executes the computer program to implement any of the steps in the method for generating concrete microstructure numerical specimens based on fluid-structure interaction analysis.

[0027] The present invention also provides a computer-readable storage medium storing a computer program that, when loaded by a processor, can execute any of the steps in the method for generating concrete microstructure numerical specimens based on fluid-structure interaction analysis.

[0028] The method for generating concrete microstructure numerical specimens based on fluid-structure interaction analysis provided by this invention has the following advantages:

[0029] Beneficial effects:

[0030] This invention employs the Smooth Particle Hydrodynamics (SPH) method and the Discrete Element Method (DEM) to simulate the mixing, pouring, and vibration process of aggregate rigid bodies and mortar, obtaining concrete mixtures. The concrete preparation process is constructed as a rheological problem, and the fluid-structure interaction analysis method is used to realistically simulate the concrete preparation process. During the simulation, the spatial distribution information of the aggregate rigid body used to generate concrete micro-numerical specimens is iteratively calculated by changing the simulation parameters. Based on the spatial distribution information, the true numerical concrete micro-numerical specimens are obtained, thereby determining the true shape and spatial distribution of aggregates. Attached Figure Description

[0031] To more clearly illustrate the embodiments and design schemes of the present invention, the accompanying drawings required for this embodiment will be briefly described below. The drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This is a flowchart of the method for generating concrete microstructure numerical specimens based on fluid-structure interaction analysis in Embodiment 1 of the present invention;

[0033] Figure 2 A flowchart for obtaining spatial distribution information of rigid aggregates;

[0034] Figure 3 This is a schematic diagram illustrating the effect of generating concrete microstructure numerical specimens in an example of the present invention. Detailed Implementation

[0035] To enable those skilled in the art to better understand and implement the technical solutions of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and should not be construed as limiting the scope of protection of the present invention.

[0036] This invention provides a method for generating concrete microstructure numerical specimens based on fluid-structure interaction analysis. From a rheological perspective, it utilizes 3D scanning technology to establish a realistic aggregate model library, completely simulating the real concrete preparation process, and thus generating concrete microstructure numerical specimens. Specifically, as follows... Figure 1 As shown, the method includes the following steps:

[0037] Step 1: Using a 3D scanner, create 3D models of crushed stone aggregates of different diameters, and construct a library of real aggregate models based on these models. Calculate the quantity of aggregates based on the concrete mix design information, and randomly select a 3D model of crushed stone aggregate from the library as the aggregate rigid body based on the quantity of aggregates.

[0038] Step 2: Determine the size and quantity of aggregates according to the concrete mix design and Fuller curve. Based on the size and quantity of aggregates, randomly select a 3D model of crushed stone aggregate from the real aggregate model library as the aggregate rigid body.

[0039] Step 3: The Smooth Particle Hydrodynamics (SPH) method and Discrete Element Method (DEM) are used to simulate the mixing, pouring, and vibration process of aggregate rigid bodies and mortar to obtain concrete mixture. SPH is used to simulate the shear thinning behavior of mortar, and DEM is used to simulate the movement of aggregates in mortar. The interaction forces between aggregate rigid bodies in concrete mixture at time t during the simulation are calculated. The linear velocity, angular velocity, and centroid position of aggregate rigid bodies, as well as the velocity, relative density, and position of mortar particles are obtained through the interaction forces.

[0040] Step 4: Update the position, pressure, linear velocity, and relative density of the fluid in each aggregate rigid body in the concrete mixture within the SPH simulation space. Iteratively calculate the linear velocity, angular velocity, and centroid position of the aggregate rigid body at time t+n, as well as the velocity, relative density, and position of the mortar particles, until the mixing-pouring-vibration process is completed.

[0041] Step 5: Extract the linear velocity, angular velocity, and centroid position of the rigid aggregate in the concrete mixture at time t+n, as well as the spatial distribution information of the velocity, relative density, and position of the mortar particles. Based on the spatial distribution information, obtain the true numerical concrete microstructure specimen.

[0042] The following specific examples further illustrate the method for generating concrete microstructure numerical specimens based on fluid-structure interaction analysis proposed in this invention.

[0043] Example 1

[0044] like Figure 2 As shown, the implementation of the concrete microstructure numerical specimen generation method based on fluid-structure interaction analysis proposed in this embodiment specifically includes the following steps:

[0045] S1. Using a 3D scanner, establish 3D models of real crushed stone aggregates with different gradations and create a real aggregate model library.

[0046] S2. Based on the concrete mix design and Fuller curve, determine the aggregate size and quantity. Randomly select a 3D model of crushed stone aggregate from a real aggregate model library and simulate aggregate movement using the Discrete Element Method (DEM). The method employs a threshold method to calculate the collision contact force.

[0047] The discrete element method (DEM) is used to simulate aggregate movement. Specifically, the threshold method is used to calculate the collision contact force.

[0048]

[0049] f t (v,t,q)=f e -f c (3)

[0050] In the formula, M is the aggregate mass matrix, t is the simulation time, q is the aggregate rigid body coordinates, v is the aggregate rigid body velocity, and f is the aggregate mass matrix. t f is the resultant force of external force and constraint force. e For external force, f c Let L be the interaction force, and L be the linear transformation function.

[0051] S3. Mortar is generated using the Smooth Particle Hydrodynamics (SPH) method, and its shear thinning behavior is simulated. The weak form of the governing equations is:

[0052]

[0053] In the formula, a is the target SPH particle, b is a neighboring particle, m is the mass, ρ is the density, and W is the kernel function. The acceleration of SPH particle a is:

[0054]

[0055] In the formula, v is velocity, t is time, g is gravitational acceleration, and Γ is velocity. a This is the momentum dissipation term, where p is the fluid pressure.

[0056]

[0057] In the formula, c s The velocity of sound is ρ0, the reference fluid pressure is β = 7. The shear force between particles in the shear-thinned mortar is:

[0058]

[0059] In the formula, It is the shear rate tensor, τ y denoted as the fluid yield stress, μ as the fluid viscosity coefficient, and n as the non-Newtonian fluid coefficient.

[0060] S4. Generate a concrete mixture consisting of an SPH-DEM coupled computational domain (specimen), aggregates (DEM aggregate rigid body), and mortar (SPH particles). The specific steps are as follows:

[0061] S41. DualSPHysics calculates the interparticle interactions based on the SPH governing equations, considering fluid-aggregate rigid body interactions as well as the linear acceleration (dV / dt) and angular acceleration (dΩ / dt) of the aggregate rigid body. Subsequently, the velocity and SPH time step are passed to DSPHChronoLib. Linear force (F) and torque (T) are calculated. Finally, DSPHChronoLib transfers F and T to Project Chrono.

[0062] S42, Project Chrono receives F and T as external forces (fe After that, the constraint forces (f) defined by the multibody dynamics model c These are also applied as internal and / or external constraints to the aggregate rigid bodies. The total forces acting on each aggregate rigid body are then calculated. The state of the aggregate rigid body system progresses over time, typically requiring multiple internal integration time steps. This process continues until the cycle exit condition is met. In each Project Chrono substep, constraint forces and contact forces are continuously updated, while the fluid forces exhibit linear interactions. The new system configuration, including the linear velocity (V), angular velocity (Ω), and center-of-mass position (R0) of each aggregate rigid body, is returned to DualSPHysics via DSPHChronoLib.

[0063] S5, DualSPHysics refreshes the position (r), pressure (p), density (ρ), and velocity (v) of each particle in the SPH simulation space. The velocities of boundary particles bound to the aggregate rigid body are calculated using linear and angular momentum calculations provided by Project Chrono. At this stage, the system prepares for the update process and solves for subsequent time steps if necessary.

[0064] S6. Use the mixing blades (DEM aggregate rigid body) to fully mix the aggregate and mortar in the mixture, and input periodic displacement loads at the boundary of the computational domain to simulate the vibration process, so that the mixture is fully compacted.

[0065] S7. Extract the spatial distribution information of aggregates within the specimen to obtain the true numerical concrete microstructure specimen.

[0066] Example 2

[0067] The implementation of the concrete microstructure numerical specimen generation method based on fluid-structure interaction analysis proposed in this embodiment includes the following steps:

[0068] S101. Using a CR-Scan Lizard 3D scanner, a 3D aggregate library was established. In this example, 500 aggregate samples were established, some of which are shown below. Figure 3 As shown.

[0069] S102. Calculate the quantity of aggregates based on the mix proportion information. In this example, the mix proportion of the three-grade concrete is 382 kg of cement ash, 191 kg of water, 810 kg of coarse aggregate, and 788 kg of river sand per cubic meter of concrete. The specimen is a cylinder with a diameter of 100 mm and a height of 100 mm. Based on the Fuller curve, it is calculated that the specimen requires 317 fine aggregates (diameter 0-7.5 mm), 101 medium aggregates (7.5-11.5 mm), and 45 large aggregates (11.5-20 mm).

[0070] S103. Use ProjectChrono to generate coarse aggregate rigid bodies, use DualSPHysic to generate mortar, apply gravity, and form a stockpile.

[0071] S104. The DEM method (Project Chrono) was used to simulate the rigid body motion of coarse aggregate, and the SPH method (Dual SPHysic) was used to simulate the non-Newtonian mortar flow. The rigid body blades of the aggregate were used to mix the coarse aggregate. The material parameters in this example are: rigid body density of aggregate 3150 kg / m³. 3 The stiffness of the aggregate rigid body contact spring is 1e9 N / m. 2 The mortar yield stress is 3.9 Pa, the plastic viscosity is 38.1 Pa·s, and the non-Newtonian fluid coefficient is n = 0.9 (shear thinning).

[0072] S105. Obtain the coarse aggregate distribution within the specimen, which can be used to establish a concrete microstructure specimen with a diameter of 100 mm and a height of 100 mm.

[0073] Based on the same inventive concept, this invention also provides a concrete microstructure numerical specimen generation system based on fluid-structure interaction analysis, comprising:

[0074] The model building module is used to create aggregate rigid bodies for generating concrete microstructure numerical specimens.

[0075] The behavior simulation module is used to simulate the mixing, pouring, and vibration process of aggregate rigid bodies and mortar using the Smooth Particle Hydrodynamics (SPH) method and the Discrete Element Method (DEM) to obtain concrete mixtures. SPH is used to simulate the shear thinning behavior of mortar, and DEM is used to simulate the movement of aggregates in mortar. The module calculates the interaction forces between aggregate rigid bodies in the concrete mixture at time t during the simulation process. Through the interaction forces, the linear velocity, angular velocity, and centroid position of the aggregate rigid bodies, as well as the velocity, relative density, and position of mortar particles are obtained.

[0076] The simulation update module is used to update the position, pressure, linear velocity, and relative density of the fluid in each aggregate rigid body in the concrete mixture within the SPH simulation space. It iteratively calculates the linear velocity, angular velocity, and centroid position of the aggregate rigid body at time t+n, as well as the velocity, relative density, and position of the mortar particles, until the mixing-pouring-vibration process is completed.

[0077] The specimen generation module is used to extract the linear velocity, angular velocity, and centroid position of the aggregate rigid body in the concrete mixture at time t+n, as well as the spatial distribution information of the velocity, relative density, and position of mortar particles. Based on the spatial distribution information, a true numerical concrete microstructure specimen is obtained.

[0078] The modules in the aforementioned concrete microstructure numerical specimen generation system based on fluid-structure interaction analysis can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in the processor of a computer device in hardware form or independent of it, or stored in the memory of the computer device in software form, so that the processor can call and execute the corresponding operations of each module.

[0079] The present invention also provides a computer device, including a memory, a processor, and a computer program stored in the memory. The processor executes the computer program to implement the steps in the embodiment of the method for generating concrete microstructure numerical specimens based on fluid-structure interaction analysis. Specific implementation methods can be found in the method embodiments, and will not be repeated here.

[0080] Furthermore, the present invention also provides a non-transitory computer-readable storage medium containing instructions, on which a computer program is stored. For example, a memory containing instructions that can be executed by a processor of a computer device to perform the above-described method. For example, the non-transitory computer-readable storage medium may be a ROM, random access memory (RAM), CD-ROM, magnetic tape, floppy disk, and optical data storage device, etc. When the computer program is executed by the processor, it can implement the steps in the embodiment of the method for generating concrete microstructure numerical specimens based on fluid-structure interaction analysis. Specific implementation methods can be found in the method embodiments, which will not be repeated here.

[0081] Those skilled in the art will understand that embodiments of the present invention can provide methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0082] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, as well as combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0083] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0084] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0085] It should be noted that the specific embodiments described above enable those skilled in the art to more fully understand the present invention, but do not limit the present invention in any way. Therefore, although the present invention has been described in detail in this specification and embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the present invention; and all technical solutions and improvements that do not depart from the spirit and scope of the present invention are covered within the protection scope of the present invention patent. No reference numerals in the claims should be construed as limiting the scope of the claims. Any simple variations or equivalent substitutions of technical solutions that can be readily obtained by those skilled in the art within the scope of the technology disclosed in the present invention are within the protection scope of the present invention.

Claims

1. A method for generating concrete microstructure numerical specimens based on fluid-structure interaction analysis, characterized in that, include: Establish an aggregate rigid body for generating concrete microstructure numerical specimens; The Smooth Particle Hydrodynamics (SPH) method and Discrete Element Method (DEM) were used to simulate the mixing, pouring, and vibration process of aggregate rigid bodies and mortar to obtain concrete mixtures. SPH was used to simulate the shear thinning behavior of mortar, and DEM was used to simulate the movement of aggregates in mortar. The interaction forces between aggregate rigid bodies in the concrete mixture at time t during the simulation were calculated. The linear velocity, angular velocity, and centroid position of the aggregate rigid bodies, as well as the velocity, relative density, and position of mortar particles, were obtained through the interaction forces. Update the position, pressure, linear velocity, and relative density of fluid for each aggregate rigid body in the concrete mixture within the SPH simulation space. Iterate and calculate the linear velocity, angular velocity, and centroid position of the aggregate rigid body at time t+n, as well as the velocity, relative density, and position of mortar particles, until the mixing-pouring-vibration process is completed. Extract the linear velocity, angular velocity, and centroid position of the rigid aggregate in the concrete mixture at time t+n, as well as the spatial distribution information of the velocity, relative density, and position of mortar particles. Based on the spatial distribution information, obtain the true numerical concrete microstructure specimen. The method employs Smooth Particle Hydrodynamics (SPH) and Discrete Element Method (DEM) to simulate the mixing, pouring, and vibration process of aggregate rigid bodies and mortar, resulting in concrete mixtures. The specific steps include: DualSPHysics calculates interparticle interactions based on the SPH governing equations, considering fluid-aggregate rigid body interactions and the linear acceleration d of the aggregate rigid body. V / d t and angular acceleration d Ω / d t ; Pass the velocity and SPH time step to DSPHChronoLib to calculate the linear force. F and torque T DSPHChronoLib will F , T Transferred to Project Chrono; Project Chrono received F and T As an external force f e Subsequently, the constraint forces defined by the multibody dynamics model f c It is also used as an internal and / or external constraint for aggregate rigid bodies; depending on the external force. f e and constraint f c Calculate the total force acting on each aggregate rigid body; the state of the aggregate rigid body system progresses over time, through multiple internal integration time steps, until the cycle exit condition is met. In each Project Chrono substep, constraint forces and contact forces are continuously updated, while fluid forces exhibit linear interactions, including the linear velocity of each aggregate rigid body. V angular velocity Ω and the position of the center of mass R The new system configuration, including 0, is returned to DualSPHysics via DSPHChronoLib; DualSPHysics refreshes the position of each particle within the SPH simulation space. r ,pressure p ,density ρ and speed v The velocities of boundary particles bound to the aggregate rigid body are calculated using linear and angular momentum calculations provided by Project Chrono. The aggregate and mortar in the mixture are thoroughly mixed using mixing blades. Periodic displacement loads are input at the boundary of the computational domain to simulate the vibration process, thus obtaining the concrete mixture.

2. The method for generating concrete microstructure numerical specimens based on fluid-structure interaction analysis according to claim 1, characterized in that, The threshold method is used to calculate the interaction forces between rigid aggregates in concrete mixtures, specifically: ； ； ； In the formula, For aggregate quality matrix, t To simulate time, Let the coordinates be those of the rigid body aggregate. For the rigid body velocity of the aggregate, The resultant force of external force and constraint force. As an external force, For interaction forces, L It is a linear transformation function.

3. The method for generating concrete microstructure numerical specimens based on fluid-structure interaction analysis according to claim 2, characterized in that, The interaction forces include the interaction forces between aggregates, the interaction forces between aggregates and SPH particles, and the interaction forces between aggregates and the boundary.

4. The method for generating concrete microstructure numerical specimens based on fluid-structure interaction analysis according to claim 3, characterized in that, The external force The calculation is as follows: Considering fluid-rigid body interaction and the linear acceleration of the rigid body dV / dt and angular acceleration dΩ / dt Calculate the linear forces of the aggregate rigid body F and torque T Through linear force F and torque T Get external force .

5. The method for generating concrete microstructure numerical specimens based on fluid-structure interaction analysis according to claim 1, characterized in that, The establishment of the aggregate rigid body for generating concrete microstructure numerical specimens specifically involves: Three-dimensional models of crushed stone aggregates with different diameters were established to construct a library of real aggregate models. The quantity of aggregates was calculated based on the concrete mix proportion information, and three-dimensional models of crushed stone aggregates in the library of real aggregate models were randomly selected as the aggregate rigid bodies according to the quantity of aggregates.

6. The method for generating concrete microstructure numerical specimens based on fluid-structure interaction analysis according to claim 5, characterized in that, The calculation of aggregate quantity based on concrete mix proportion information specifically involves using Fuller curves to determine the aggregate quantity based on the concrete mix proportion information.

7. A system for implementing the method for generating concrete microstructure numerical specimens based on fluid-structure interaction analysis as described in claim 1, characterized in that, include: The model building module is used to create aggregate rigid bodies for generating concrete microstructure numerical specimens; The behavior simulation module is used to simulate the mixing, pouring, and vibration process of aggregate rigid bodies and mortar using the Smooth Particle Hydrodynamics (SPH) method and the Discrete Element Method (DEM) to obtain concrete mixtures. SPH is used to simulate the shear thinning behavior of mortar, and DEM is used to simulate the movement of aggregates in mortar. The module calculates the interaction forces between aggregate rigid bodies in the concrete mixture at time t during the simulation process. Through the interaction forces, the linear velocity, angular velocity, and centroid position of the aggregate rigid bodies, as well as the velocity, relative density, and position of mortar particles are obtained. The simulation update module is used to update the position, pressure, linear velocity, and relative density of fluid of each aggregate rigid body in the concrete mixture in the SPH simulation space. It iteratively calculates the linear velocity, angular velocity, and centroid position of the aggregate rigid body at time t+n, as well as the velocity, relative density, and position of mortar particles, until the mixing-pouring-vibration process ends. The specimen generation module is used to extract the linear velocity, angular velocity, and centroid position of the aggregate rigid body in the concrete mixture at time t+n, as well as the spatial distribution information of the velocity, relative density, and position of mortar particles. Based on the spatial distribution information, a true numerical concrete microstructure specimen is obtained.

8. A computer device, comprising a memory, a processor, and a computer program stored in the memory, characterized in that, The processor executes the computer program to implement the steps of the method according to any one of claims 1 to 6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is loaded by the processor, it is able to perform the steps of the method according to any one of claims 1 to 6.

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