Stability analysis method of cracked and patched concrete structures based on finite element method

Abstract

The present invention relates to the technical field of numerical simulation of fracture mechanics, and provides a method for analyzing the stability of cracked and patched concrete structures based on the finite element method, including: drawing geometric parameter conditions of a mesh model, drawing geometric parameters of an analysis object, and preset locations of cracks; applying boundary conditions to the finite element mesh model, and performing mesh division. After the mesh division is completed, defining the physical and mechanical parameters representing the concrete structure and the patching paste in the finite element mesh model; defining the actual stress load conditions of the finite element mesh model; simulating the passivation and activation of the mesh area representing the crack through different simulation construction steps, and carrying out finite element calculations; obtaining the cross-sectional internal forces of the cracked area of ​​the concrete structure according to the calculation results, calculating the cross-sectional safety factor, and evaluating its stability. The present invention does not need to use components to detect the stability of concrete on site, and can accurately simulate and analyze the actual stress state and stability of the cracking and patching repair of the concrete structure by electronic calculation.

Description

Technical Field

[0001] The invention relates to the technical field of numerical simulation of fracture mechanics, and in particular to a stability analysis method of cracked and patched concrete structures based on a finite element method. Background Art

[0002] The study of the stability of the fracture section of concrete structures before and after cracking often uses the method of deploying components on site to monitor and analyze the internal forces. However, considering the evaluation cost and the inability to recycle the components after they are buried, this type of method has certain limitations.

[0003] There are the following difficulties in using traditional finite element method or extended finite element method to analyze the stability of cracked concrete structures: first, the traditional finite element method does not take into account the thinning of the structural cross-section after cracking, and the internal force is still calculated based on the original concrete cross-section size; second, the extended finite element method can analyze the size of the internal force of the concrete structure after cracking, but it is impossible to further add an analysis step to analyze the stability of the concrete structure after repair. Summary of the invention

[0004] The purpose of the present invention is to solve at least one technical problem in the background technology and to provide a method for analyzing the stability of cracked and patched concrete structures based on the finite element method.

[0005] To achieve the above object, the present invention provides a method for analyzing the stability of cracked and patched concrete structures based on a finite element method, comprising:

[0006] Create a mesh model to represent the concrete structure;

[0007] An extended finite element mesh model is constructed for the mesh model, including drawing geometric parameter conditions of the mesh model, drawing geometric parameters of the analysis object, and the location of the preset cracks;

[0008] Apply boundary conditions to the finite element mesh model to perform mesh division, and after the mesh division is completed, define physical and mechanical parameters representing the concrete structure and the patching paste in the finite element mesh model;

[0009] Define the actual load conditions of the finite element mesh model;

[0010] Based on the finite element mesh model, finite element calculations are performed by simulating passivation and activation of mesh areas representing cracks through different simulated construction steps;

[0011] The calculation results of the finite element mesh model are used to obtain the cross-sectional internal force of the cracked area of ​​the concrete structure, calculate the cross-sectional safety factor and evaluate its stability.

[0012] According to one aspect of the present invention, when constructing an extended finite element mesh model for the mesh model, the morphology of the actual cracked concrete structure is simplified, the geometric parameters of the crack opening width and crack depth are retained, and the rest of the crack is processed into a regular straight line.

[0013] According to one aspect of the present invention, the meshes of the crack and the surrounding area in the finite element mesh model are encrypted in a manner not greater than 1 / 10 of the outer boundary node density.

[0014] According to one aspect of the present invention, the finite element calculation is performed by simulating the passivation and activation of the mesh area representing the crack through different simulation construction steps, including:

[0015] Simulate the stress of the concrete structure in the uncracked state. In this simulation construction step, the mesh properties of the crack area are defined to be consistent with the concrete mesh properties.

[0016] Simulate the stress of concrete structure in cracked state, and passivate the mesh in the crack area in this simulated construction step;

[0017] To simulate the stress of cracked concrete structure after patching and repair, the mesh of crack area is activated in this simulated construction step, and the activated attribute is the patching attribute.

[0018] According to one aspect of the present invention, the internal force of the cross section of the cracked area of ​​the concrete structure is obtained through the calculation results of the finite element mesh model, the cross section safety factor is calculated and its stability is evaluated as follows:

[0019] After the finite element calculation is completed, the internal forces of the cracked area section in different simulated construction steps are extracted, and the critical stress intensity factor of the section is calculated as the critical value to determine whether the concrete structure is unstable;

[0020] The cross-sectional internal forces include ultimate bearing capacity, lining axial force, ultimate bearing bending moment and lining bending moment;

[0021] The cross-sectional critical stress intensity factor includes a cross-sectional compressive safety factor and a cross-sectional tensile safety factor;

[0022] The cross-section compressive safety factor is the ratio of the ultimate bearing capacity to the lining axial force, and the cross-section tensile safety factor is the ratio of the ultimate bearing bending moment to the lining bending moment.

[0023] To achieve the above object, the present invention also provides a cracked and patched concrete structure stability analysis system based on finite element method, comprising:

[0024] A mesh model building module builds a mesh model representing the concrete structure;

[0025] A finite element mesh model construction module is used to construct an extended finite element mesh model for the mesh model, including drawing geometric parameter conditions of the mesh model, drawing geometric parameters of the analysis object, and the location of the preset cracks;

[0026] A meshing and mechanical parameter definition module applies boundary conditions to the finite element mesh model and performs meshing. After the meshing is completed, the physical and mechanical parameters representing the concrete structure and the patching paste in the mesh model are defined;

[0027] The actual force definition module defines the actual force load conditions of the finite element mesh model;

[0028] A simulation calculation module, based on the finite element mesh model, simulates passivation and activation of mesh areas representing cracks through different simulation construction steps to carry out finite element calculations;

[0029] The stability analysis and evaluation module obtains the cross-sectional internal force of the cracked area of ​​the concrete structure through the calculation results of the finite element mesh model, calculates the cross-sectional safety factor and evaluates its stability.

[0030] To achieve the above-mentioned purpose, the present invention also provides an electronic device, including a processor, a memory, and a computer program stored in the memory and executable on the processor, wherein when the computer program is executed by the processor, the method for analyzing the stability of cracked and patched concrete structures based on the finite element method as described above is implemented.

[0031] To achieve the above objectives, the present invention also provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the method for analyzing the stability of cracked and patched concrete structures based on the finite element method as described above is implemented.

[0032] According to the scheme of the present invention, after mastering the parameters such as the specific crack width and crack depth of the concrete structure crack, the present invention can accurately understand the internal force state and safety and stability of the concrete structure section before cracking, during cracking and after filling based on the analysis of numerical modeling results. The results are intuitive and easy to grasp, and can effectively save monitoring and detection related costs.

[0033] According to the solution of the present invention, there is no need to use components to detect the stability of concrete on site. The computer method can accurately simulate and analyze the cracking of the concrete structure and the actual stress state and stability of the patching repair. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 A flowchart schematically showing a method for analyzing the stability of cracked and patched concrete structures based on the finite element method according to an embodiment of the present invention;

[0035] Figure 2 Schematic representation of the actual cracking morphology of concrete;

[0036] Figure 3 A simplified diagram schematically showing a modeling method for cracking of a concrete structure according to an embodiment of the present invention;

[0037] Figure 4 and Figure 5 They are respectively the stress cloud diagrams in different directions of the concrete structure without cracking;

[0038] Figure 6 and Figure 7 They are respectively the stress cloud diagrams of concrete structure in different directions under the condition of cracking;

[0039] Figure 8 and Fig. 9 They are the stress cloud diagrams in different directions of the concrete structure after being repaired with epoxy resin grouting materials. DETAILED DESCRIPTION

[0040] The present invention will now be discussed with reference to exemplary embodiments. It should be understood that the embodiments discussed are only to enable those skilled in the art to better understand and thus implement the present invention, rather than implying any limitation on the scope of the present invention.

[0041] As used herein, the term “including” and variations thereof are to be interpreted as open-ended terms meaning “including, but not limited to.” The term “based on” is to be interpreted as “based, at least in part, on.” The terms “one embodiment” and “an embodiment” are to be interpreted as “at least one embodiment.”

[0042] Figure 1 The flowchart of the method for analyzing the stability of cracked and patched concrete structures based on the finite element method according to one embodiment of the present invention is schematically shown. Figure 1 As shown, in this embodiment, the cracked and patched concrete structure stability analysis method based on the finite element method includes:

[0043] Create a mesh model to represent the concrete structure;

[0044] The extended finite element mesh model is constructed for the mesh model, including drawing the geometric parameter conditions of the mesh model, drawing the geometric parameters of the analysis object and the location of the preset cracks;

[0045] Apply boundary conditions to the finite element mesh model and perform mesh division. After the mesh division is completed, define the physical and mechanical parameters representing the concrete structure and the embedding paste in the finite element mesh model;

[0046] Define the actual load conditions of the finite element mesh model;

[0047] Based on the finite element mesh model, finite element calculations were carried out by simulating the passivation and activation of the mesh areas representing the cracks through different simulated construction steps;

[0048] Through the calculation results of the finite element mesh model, the internal force of the section in the cracked area of ​​the concrete structure is obtained, the section safety factor is calculated and its stability is evaluated.

[0049] In this embodiment, the finite element software Midas is used to construct a mesh model of concrete and a finite element mesh model, and the finite element mesh model is meshed and various parameter conditions are added. Then, finite element calculations are performed and feasibility verification analysis is performed based on the calculation results.

[0050] In this embodiment, the geometric parameter conditions for drawing the grid model are to draw the length, width and height of the concrete component. The location of drawing the preset crack is the initial location of drawing the crack.

[0051] In this embodiment, the physical and mechanical parameters representing the concrete structure and the patching paste in the finite element mesh model include: the density, elastic modulus, and Poisson's ratio of the concrete; the compressive strength, tensile strength, and bonding strength of the patching paste (such as epoxy resin grouting material).

[0052] In this embodiment, the boundary conditions are constraint conditions of the outer boundaries of the extended finite element mesh model, and the actual force load conditions are external force load conditions applied to the extended finite element mesh model.

[0053] Furthermore, according to an embodiment of the present invention, when constructing an extended finite element mesh model for a mesh model, the morphology of the actual cracked concrete structure is simplified, the geometric parameters of the crack opening width and crack depth are retained, and the rest of the crack is processed as a regular straight line.

[0054] Specifically, Figure 2 As shown in the figure, since the actual cracking morphology of concrete is an irregular geometric shape, in order to facilitate the modeling mesh division and improve the convergence of calculations, the geometric parameters of the crack opening width and crack depth are retained in the process of simplifying the actual cracking concrete structure, and the rest are processed as regular straight lines, which are finally presented as Figure 3 The inverted triangle shown.

[0055] Furthermore, according to an embodiment of the present invention, the mesh of the crack and the surrounding area in the finite element mesh model is encrypted in a manner not greater than 1 / 10 of the outer boundary node density.

[0056] Specifically, the overall model of the finite element mesh model is established using plane units. The meshes for the cracks and surrounding areas should be encrypted, and the density of the nodes should be no greater than 1 / 10 of the outer boundary. In order to ensure the continuity of the mesh without distortion, the inverted triangle area should be evenly divided into meshes using triangular units for adaptive meshing.

[0057] Further, according to an embodiment of the present invention, finite element calculation is performed by simulating passivation and activation of mesh areas representing cracks through different simulation construction steps, including:

[0058] Simulate the stress of the concrete structure in the uncracked state. In this simulation construction step, the mesh properties of the crack area are defined to be consistent with the concrete mesh properties.

[0059] To simulate the stress of concrete structure in cracked state, the mesh in the crack area is passivated (i.e., the mesh is removed) in this simulated construction step;

[0060] To simulate the stress of cracked concrete structure after patching and repair, the mesh of crack area is activated in this simulated construction step (i.e. the mesh removed in the previous step is restored), and the activation attribute is the patching attribute.

[0061] Further, according to an embodiment of the present invention, the internal force of the cross section of the cracked area of ​​the concrete structure is obtained through the calculation results of the finite element mesh model, the cross section safety factor is calculated and its stability is evaluated as follows:

[0062] After the finite element calculation is completed, the internal forces of the cracked area section in different simulated construction steps are extracted, and the critical stress intensity factor of the section is calculated as the critical value to determine whether the concrete structure is unstable;

[0063] Among them, the cross-sectional internal forces include ultimate bearing capacity, lining axial force, ultimate bearing bending moment and lining bending moment;

[0064] The critical stress intensity factor of the section includes the section compressive safety factor and the section tensile safety factor;

[0065] The section compressive safety factor is the ratio of the ultimate bearing capacity to the axial force of the lining, and the section tensile safety factor is the ratio of the ultimate bearing moment to the lining bending moment.

[0066] According to the above scheme of the present invention, after mastering the parameters such as the specific crack width and crack depth of the concrete structure cracks, the present invention can accurately understand the internal force state and safety and stability of the concrete structure section before cracking, during cracking and after filling based on the analysis of numerical modeling results. The results are intuitive and easy to grasp, which can effectively save the related costs of monitoring and detection.

[0067] According to the above scheme of the present invention, the present invention does not need to use components to detect the stability of concrete on site, and can accurately simulate and analyze the cracking of the concrete structure and the actual stress state and stability of the patching repair by electronic calculation.

[0068] Furthermore, in order to achieve the above-mentioned object, the present invention also provides a cracked and patched concrete structure stability analysis system based on finite element method, comprising:

[0069] A mesh model building module builds a mesh model representing the concrete structure;

[0070] A finite element mesh model construction module is used to construct an extended finite element mesh model for the mesh model, including drawing geometric parameter conditions of the mesh model, drawing geometric parameters of the analysis object, and the location of the preset cracks;

[0071] A meshing and mechanical parameter definition module applies boundary conditions to the finite element mesh model and performs meshing. After the meshing is completed, the physical and mechanical parameters representing the concrete structure and the patching paste in the finite element mesh model are defined;

[0072] The actual force definition module defines the actual force load conditions of the finite element mesh model;

[0073] A simulation calculation module, based on the finite element mesh model, simulates passivation and activation of mesh areas representing cracks through different simulation construction steps to carry out finite element calculations;

[0074] The stability analysis and evaluation module obtains the cross-sectional internal force of the cracked area of ​​the concrete structure through the calculation results of the finite element mesh model, calculates the cross-sectional safety factor and evaluates its stability.

[0075] In this embodiment, the finite element software Midas is used to construct a mesh model of concrete and a finite element mesh model, and the finite element mesh model is meshed and various parameter conditions are added. Then, finite element calculations are performed and feasibility verification analysis is performed based on the calculation results.

[0076] In this embodiment, the geometric parameter conditions for drawing the grid model are to draw the length, width and height of the concrete component. The location of drawing the preset crack is to draw the initial location of the crack.

[0077] In this embodiment, the physical and mechanical parameters representing the concrete structure and the patching paste in the finite element mesh model include: the density, elastic modulus, and Poisson's ratio of the concrete; the compressive strength, tensile strength, and bonding strength of the patching paste (such as epoxy resin grouting material).

[0078] In this embodiment, the boundary conditions are constraint conditions of the outer boundaries of the extended finite element mesh model, and the actual force load conditions are external force load conditions applied to the extended finite element mesh model.

[0079] Furthermore, according to an embodiment of the present invention, when constructing an extended finite element mesh model for a mesh model, the morphology of the actual cracked concrete structure is simplified, the geometric parameters of the crack opening width and crack depth are retained, and the rest of the crack is processed as a regular straight line.

[0080] Specifically, if Figure 2 As shown in the figure, since the actual cracking morphology of concrete is an irregular geometric shape, in order to facilitate the modeling mesh division and improve the convergence of calculations, the geometric parameters of the crack opening width and crack depth are retained in the process of simplifying the actual cracking concrete structure, and the rest are processed as regular straight lines, which are finally presented as Figure 3 The inverted triangle shown.

[0081] Furthermore, according to an embodiment of the present invention, the mesh of the crack and the surrounding area in the finite element mesh model is encrypted in a manner not greater than 1 / 10 of the outer boundary node density.

[0082] Specifically, the overall model of the finite element mesh model is established using plane units. The meshes for the cracks and surrounding areas should be encrypted, and the density of the nodes should be no greater than 1 / 10 of the outer boundary. In order to ensure the continuity of the mesh without distortion, the inverted triangle area should be evenly divided into meshes using triangular units for adaptive meshing.

[0083] Further, according to an embodiment of the present invention, finite element calculation is performed by simulating passivation and activation of mesh areas representing cracks through different simulation construction steps, including:

[0084] Simulate the stress of the concrete structure in the uncracked state. In this simulation construction step, the mesh properties of the crack area are defined to be consistent with the concrete mesh properties.

[0085] To simulate the stress of concrete structure in cracked state, the mesh in the crack area is passivated (i.e., the mesh is removed) in this simulated construction step;

[0086] To simulate the stress of cracked concrete structure after patching and repair, the mesh of crack area is activated in this simulated construction step (i.e. the mesh removed in the previous step is restored), and the activation attribute is the patching attribute.

[0087] Further, according to an embodiment of the present invention, the internal force of the cross section of the cracked area of ​​the concrete structure is obtained through the calculation results of the finite element mesh model, the cross section safety factor is calculated and its stability is evaluated as follows:

[0088] After the finite element calculation is completed, the internal forces of the cracked area section in different simulated construction steps are extracted, and the critical stress intensity factor of the section is calculated as the critical value to determine whether the concrete structure is unstable;

[0089] Among them, the cross-sectional internal forces include ultimate bearing capacity, lining axial force, ultimate bearing bending moment and lining bending moment;

[0090] The critical stress intensity factor of the section includes the section compressive safety factor and the section tensile safety factor;

[0091] The section compressive safety factor is the ratio of the ultimate bearing capacity to the axial force of the lining, and the section tensile safety factor is the ratio of the ultimate bearing moment to the lining bending moment.

[0092] According to the above scheme of the present invention, after mastering the parameters such as the specific crack width and crack depth of the concrete structure cracks, the present invention can accurately understand the internal force state and safety and stability of the concrete structure section before cracking, during cracking and after filling based on the analysis of numerical modeling results. The results are intuitive and easy to grasp, which can effectively save the related costs of monitoring and detection.

[0093] According to the above scheme of the present invention, the present invention does not need to use components to detect the stability of concrete on site, and can accurately simulate and analyze the cracking of the concrete structure and the actual stress state and stability of the patching repair by electronic calculation.

[0094] Furthermore, to achieve the above-mentioned purpose, the present invention also provides an electronic device, including a processor, a memory, and a computer program stored in the memory and executable on the processor, wherein when the computer program is executed by the processor, the method for analyzing the stability of cracked and patched concrete structures based on the finite element method as described above is implemented.

[0095] Furthermore, to achieve the above-mentioned purpose, the present invention also provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the stability analysis method of cracked and patched concrete structures based on the finite element method as described above is implemented.

[0096] Furthermore, based on the above-mentioned solution of the present invention, the technical solution of the present invention is described in detail in the form of a specific embodiment in combination with the accompanying drawings.

[0097] Example 1

[0098] In this embodiment, the finite element software Midas is used for modeling. The specific modeling parameters are as follows: the concrete weight is 25 kN / m 3 , elastic modulus 32 GPa, Poisson's ratio 0.3, compressive strength of epoxy resin grouting material 40Mpa, compressive strength 10MPa, and bonding strength 2MPa.

[0099] In this embodiment, the calculation method of the obtained cross-sectional internal force safety factor is as follows: the cross-sectional compressive safety factor is the ultimate bearing capacity N max The ratio of the axial force of the lining, the tensile safety factor of the section is the ultimate bearing moment M max The ratio of the bending moment to the lining.

[0100] Figure 4 and Figure 5 They are stress cloud diagrams in different directions (X direction and Y direction) of the concrete structure without cracking. The compressive safety factor of the section at the actual cracking point is greater than 2.0, and the tensile safety factor of the section is greater than 2.4, so the calculated section of the lining structure is safe.

[0101] Figure 6 and Figure 7 The stress cloud diagrams of the concrete structure in different directions (X and Y directions) when cracking are shown. The compressive safety factor of the crack sections on both sides is greater than 2.0, which is within the safety range. However, the tensile safety factor of the crack sections on both sides is less than 2.4, which does not meet the safety requirements and needs to be reinforced.

[0102] Figure 8 and Fig. 9 These are stress cloud diagrams in different directions (X and Y) of concrete structures after epoxy resin grouting material repair. The stress concentration phenomenon at the crack tip is reduced after reinforcement, and can be obtained by calculating the axial force, bending moment and safety factor of the reinforced section. After grouting and sealing, the cross-section compressive safety factor and cross-section tensile safety factor can reach the specified value and meet the safety conditions, indicating that the lining structure is safe and reliable after reinforcement.

[0103] In this embodiment, Figure 4-Figure 9 The concrete stress is shown in the figure. The concrete stress is converted into structural internal force (bending moment and axial force), and then the bending moment and axial force are used for verification. After verification, check whether the cross-sectional compressive safety factor and cross-sectional tensile safety factor of the interface are greater than 2.0 and 2.4. If they are greater, it is safe. It is worth noting that the two values ​​2.0 and 2.4 are quoted from the first volume of the highway tunnel design specification for civil engineering (JTG 3370.1-2018), and the strength safety factor of reinforced concrete structure is simply calculated.

[0104] Those skilled in the art will appreciate that the modules and algorithm steps described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0105] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the above-described devices and equipment can refer to the corresponding processes in the aforementioned method implementation methods, and will not be repeated here.

[0106] In the embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the modules is only a logical function division. There may be other division methods in actual implementation, such as multiple modules or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or modules, which can be electrical, mechanical or other forms.

[0107] The modules described as separate components may or may not be physically separated, and the components shown as modules may or may not be physical modules, that is, they may be located in one place or distributed on multiple network modules. Some or all of the modules may be selected according to actual needs to achieve the purpose of the embodiments of the present invention.

[0108] In addition, each functional module in the embodiment of the present invention may be integrated into one processing module, or each module may exist physically separately, or two or more modules may be integrated into one module.

[0109] If the functions are implemented in the form of software function modules and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention can be essentially or partly embodied in the form of a software product that contributes to the prior art. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to perform all or part of the steps of the energy-saving signal sending / receiving method of each embodiment of the present invention. The aforementioned storage medium includes: various media that can store program codes, such as USB flash drives, mobile hard disks, ROM, RAM, magnetic disks, or optical disks.

[0110] The above description is only a preferred embodiment of the present application and an explanation of the technical principles used. Those skilled in the art should understand that the scope of the invention involved in the present application is not limited to the technical solution formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the inventive concept. For example, the above features are replaced with the technical features with similar functions disclosed in this application (but not limited to) by each other.

[0111] It should be understood that the size of the serial numbers of each step in the content of the invention and the implementation methods of the present invention does not absolutely mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the implementation methods of the present invention.

Claims

1. A method for analyzing the stability of cracked and patched concrete structures based on the finite element method, characterized in that: include: Create a mesh model to represent the concrete structure; An extended finite element mesh model is constructed for the mesh model, including drawing geometric parameter conditions of the mesh model, drawing geometric parameters of the analysis object, and the location of the preset cracks; Apply boundary conditions to the finite element mesh model to perform mesh division, and after the mesh division is completed, define the physical and mechanical parameters representing the concrete structure and the patching paste in the finite element mesh model; Define the actual load conditions of the finite element mesh model; Based on the finite element mesh model, finite element calculations are performed by simulating passivation and activation of mesh areas representing cracks through different simulated construction steps; The calculation results of the finite element mesh model are used to obtain the internal force of the cross section of the cracked area of ​​the concrete structure, calculate the cross section safety factor and evaluate its stability; When constructing the extended finite element mesh model of the mesh model, the shape of the actual cracked concrete structure is simplified, the geometric parameters of the crack opening width and the crack depth are retained, and the rest of the crack is processed into a regular straight line; Through the calculation results of the finite element mesh model, the internal force of the section in the cracked area of ​​the concrete structure is obtained, the safety factor of the section is calculated and its stability is evaluated as follows: After the finite element calculation is completed, the internal forces of the cracked area section in different simulated construction steps are extracted, and the critical stress intensity factor of the section is calculated as the critical value to determine whether the concrete structure is unstable; The cross-sectional internal forces include ultimate bearing capacity, lining axial force, ultimate bearing bending moment and lining bending moment; The cross-sectional critical stress intensity factor includes a cross-sectional compressive safety factor and a cross-sectional tensile safety factor; The cross-section compressive safety factor is the ratio of the ultimate bearing capacity to the lining axial force, and the cross-section tensile safety factor is the ratio of the ultimate bearing bending moment to the lining bending moment.

2. The method for analyzing the stability of cracked and patched concrete structures based on the finite element method according to claim 1 is characterized in that: The meshes of the crack and the surrounding area in the finite element mesh model are encrypted in a manner not greater than 1 / 10 of the outer boundary node density.

3. The method for analyzing the stability of cracked and patched concrete structures based on the finite element method according to claim 1 is characterized in that: The method of simulating passivation and activating the mesh area representing the cracks through different simulation construction steps and carrying out finite element calculations includes: Simulate the stress of the concrete structure in the uncracked state. In this simulation construction step, the mesh properties of the crack area are defined to be consistent with the concrete mesh properties. Simulate the stress of concrete structure in cracked state, and passivate the mesh in the crack area in this simulated construction step; To simulate the stress of cracked concrete structure after patching and repair, the mesh of crack area is activated in this simulated construction step, and the activated attribute is the patching attribute.

4. The stability analysis system of cracked and patched concrete structures based on finite element method is characterized by: include: A mesh model building module builds a mesh model representing the concrete structure; A finite element mesh model construction module is used to construct an extended finite element mesh model for the mesh model, including drawing geometric parameter conditions of the mesh model, drawing geometric parameters of the analysis object, and the location of the preset cracks; A meshing and mechanical parameter definition module applies boundary conditions to the finite element mesh model and performs meshing. After the meshing is completed, the physical and mechanical parameters representing the concrete structure and the patching paste in the finite element mesh model are defined; The actual force definition module defines the actual force load conditions of the finite element mesh model; A simulation calculation module, based on the finite element mesh model, simulates passivation and activation of mesh areas representing cracks through different simulation construction steps to carry out finite element calculations; The stability analysis and evaluation module obtains the internal force of the section of the cracked area of ​​the concrete structure through the calculation results of the finite element mesh model, calculates the safety factor of the section and evaluates its stability; When constructing the extended finite element mesh model of the mesh model, the shape of the actual cracked concrete structure is simplified, the geometric parameters of the crack opening width and the crack depth are retained, and the rest of the crack is processed into a regular straight line; Through the calculation results of the finite element mesh model, the internal force of the section in the cracked area of ​​the concrete structure is obtained, the safety factor of the section is calculated and its stability is evaluated as follows: After the finite element calculation is completed, the internal forces of the cracked area section in different simulated construction steps are extracted, and the critical stress intensity factor of the section is calculated as the critical value to determine whether the concrete structure is unstable; The cross-sectional internal forces include ultimate bearing capacity, lining axial force, ultimate bearing bending moment and lining bending moment; The cross-sectional critical stress intensity factor includes a cross-sectional compressive safety factor and a cross-sectional tensile safety factor; The cross-section compressive safety factor is the ratio of the ultimate bearing capacity to the lining axial force, and the cross-section tensile safety factor is the ratio of the ultimate bearing bending moment to the lining bending moment.

5. An electronic device, characterized in that The method comprises a processor, a memory and a computer program stored in the memory and executable on the processor, wherein when the computer program is executed by the processor, the method for analyzing the stability of cracked and patched concrete structures based on the finite element method as described in any one of claims 1 to 3 is implemented.

6. A computer-readable storage medium, characterized in that The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the method for analyzing the stability of cracked and patched concrete structures based on the finite element method as described in any one of claims 1 to 3 is implemented.

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