A method for making a 3D printed model of a damaged structure of a highway tunnel after a fire

Abstract

The present invention discloses a method for making a 3D printed model of a damaged structure of a highway tunnel after a fire, including: using knowledge graphs and field data analysis to organize and extract damage information of the tunnel structure; based on damage reports and similarity criteria, establishing a 3D printed damaged structure model with stiffness changes to simulate actual damage conditions; verifying and optimizing the accuracy of the 3D printed model and adjusting model parameters through modeling analysis; using 3D printing technology to make an optimized structural model to reproduce the details and complexity of tunnel damage; performing mechanical property testing and calibration on the 3D printed model to verify its mechanical response under different loads, ensuring that the model meets expectations in terms of mechanical properties and geometric accuracy, and providing guidance for post-disaster tunnel structure damage model tests. The present invention can propose a post-fire equivalent stiffness tunnel damage model based on 3D printing technology through post-disaster tunnel deformation and structural characteristics, providing practical guidance for model tests of post-fire tunnel structures.

Description

Technical Field

[0001] The present invention relates to the technical field of post-disaster highway tunnel structure safety, and more specifically, to a method for making a 3D printed model of a damaged structure of a highway tunnel after a fire. Background Art

[0002] Tunnel engineering is a key control project on highways, and its overall structural performance and safety status after a fire are crucial to tunnel repair work. Therefore, it is particularly important to develop a more accurate and efficient tunnel damage model after a fire, and use a more accurate and practical model in model tests to accurately analyze the damage degree of the tunnel structure after the disaster.

[0003] As the scale of tunnel construction continues to expand, the risk of tunnel fire accidents has also increased significantly. Tunnel fires not only cause serious damage to vehicles, personnel and electromechanical equipment inside, but also cause significant damage to the tunnel lining structure, significantly reducing its bearing capacity and safety performance. The high temperature of the fire will cause the segment concrete to burst and peel off, and the steel bars to be exposed, which will greatly damage the integrity and safety of the highway tunnel lining structure and significantly reduce the bearing capacity of the structure.

[0004] Tunnel fires seriously affect the safety and applicability of structures, and the repair cost is high and time-consuming. However, in actual engineering applications, there are relatively few studies on the damage of shield tunnels after fire. At present, engineers rely on advanced detection technology and numerical simulation tools to evaluate the impact of fire on tunnels, but the existing tools and technologies have limitations in simulating tunnel damage after fire and cannot fully and accurately reflect the actual situation. It is difficult to establish finite element numerical models and damage model test models of damaged tunnels. It is difficult to accurately consider the strength, stability and durability of the lining structure and reflect the impact of fire on the stiffness of the tunnel structure. Fire has a serious impact on the destruction of tunnel structures, so it is very important to study the tunnel structure after fire. The traditional test model making method is inefficient and the accuracy is difficult to guarantee. There are obvious deficiencies in existing research, especially in the deformation characteristics and stiffness change functions of highway tunnels after disasters. The existing models fail to combine on-site post-disaster tunnel data, making it difficult to provide strong theoretical support for the evaluation of mechanical properties and repair of post-disaster tunnels.

[0005] To solve the above problems, the present invention proposes a method for making a 3D printed model of a damaged structure of a highway tunnel after a fire. The deformation and local elastic modulus parameters of the tunnel lining structure after the disaster are obtained by using knowledge graph technology, and the stiffness of the damaged tunnel structure is quantified by combining on-site monitoring data. A refined model is established by 3D printing technology, and the change in tunnel stiffness is simulated by the change in model thickness, providing practical guidance for model tests of tunnel structures after fires. Summary of the invention

[0006] The present invention aims to overcome at least one defect in the prior art and provide a method for making a 3D printed model of a damaged structure of a highway tunnel after a fire. The model solves the problem in the prior art that the strength of the lining structure cannot be quantified and the test cannot reflect the real structure after a fire in a highway tunnel, overcomes the shortcomings of the traditional test model making method, and improves the efficiency and accuracy of the tunnel structure model test after a fire.

[0007] The technical solution adopted by the present invention is a 3D printing model of a damaged structure of a highway tunnel after a fire, which mainly includes the following steps:

[0008] S101: Obtain tunnel structure damage report through knowledge graph and field data analysis;

[0009] S102: Establishing a 3D printed damaged structure model with varying stiffness based on damage reports and similarity criteria;

[0010] S103: Verify the accuracy of the 3D printing model through FEA modeling analysis and adjust the model parameters for optimization;

[0011] S104: Produce an optimized model through 3D printing technology;

[0012] S105: Perform mechanical property testing and calibration on the 3D printed model;

[0013] S106: Use 3D printed models to guide model making for post-fire tunnel structure model tests.

[0014] The present invention provides a method for producing an accurate and efficient 3D printed model of a damaged structure of a highway tunnel after a fire, which can truly reflect the damage of the tunnel after the disaster and provide strong theoretical and practical support for post-disaster tunnel repair.

[0015] In step S101, the specific operations are as follows:

[0016] S11: Establish nodes for various types of tunnel damage after disasters, damage levels, locations, historical cases, and existing cases;

[0017] S12: Define and construct the relationship between each data node, including the relationship between damage type and location, comparative analysis of historical cases and existing cases, etc.;

[0018] S13: Organize and classify historical cases and existing case data, and integrate them into a unified knowledge base to form a knowledge graph database retrieval system that can be queried and called.

[0019] S14: Laser scanning and high-precision photography are used to obtain field data of the tunnel lining structure. Laser scanning provides high-precision 3D point cloud data, and high-precision photography provides detailed surface image information.

[0020] S15: The acquired field data is integrated with the historical cases and existing case data in the knowledge graph to comprehensively analyze the damage of the tunnel lining structure.

[0021] S16: Based on the fused data, the damage elastic modulus function of the post-disaster tunnel lining structure is retrieved to further determine the stiffness of the structural lining.

[0022] S17: Comprehensively analyze the knowledge graph and field data to generate a detailed damage report.

[0023] The report content includes: damage location (specific location of the damage in the tunnel lining structure), damage type (specific type of damage, such as cracks, spalling, leakage, etc.), and damage degree.

[0024] Through the above steps, it is ensured that the tunnel lining structure damage report generated in step S101 has high accuracy and high reliability, providing a scientific basis and data support for post-disaster tunnel repair.

[0025] The knowledge graph is used to systematically organize and extract data from related fields, analyze and obtain the damage elastic modulus function of the tunnel lining structure, and determine the stiffness of the damaged part based on this, providing data support for the subsequent production of 3D printing models. At the same time, combined with field surveys and test data, the damage and impact of each part of the tunnel are described in detail.

[0026] In step S102, the establishment of the 3D printing model specifically includes the following steps:

[0027] S21: Based on the damage report analysis and the post-fire lining elastic modulus reduction formula, the elastic modulus of the tunnel structure lining after the fire is obtained, and the stiffness of the tunnel lining is obtained accordingly;

[0028] S22: Based on the similarity criterion, a 3D printing model with different lining thicknesses reflecting different lining stiffnesses of the tunnel was established using CAD software.

[0029] Wherein, in step S21, it also includes reducing the elastic modulus of the material based on the degree of loss of the tunnel lining structure after the disaster, and the formula is: .

[0030] in, is the reduced elastic modulus, is the reduction factor of the elastic modulus of the tunnel concrete lining after the disaster, is the elastic modulus of concrete, is the elastic modulus of the steel bar.

[0031]

[0032] The 3D printing model uses homogeneous materials. Different stiffnesses are simulated according to the thickness of the model. The thickness reduction factor is: ,in, is the thickness of the tunnel lining after the disaster, is the thickness of the tunnel lining before the disaster, is the elastic modulus of the tunnel lining before damage.

[0033] In step S103, the accuracy of the proposed 3D printing model is analyzed through FEA modeling, including the refined model and the proposed model, and the stress, strain distribution and specific structural damage of the two models under load are compared and analyzed. Based on the results, the proposed 3D printing model is iteratively adjusted multiple times to optimize the model parameters to make it closer to the actual situation.

[0034] In step S104, the preparation of the 3D printing model further includes the following steps:

[0035] S41: converting the optimized 3D printing model into a 3D printer readable format and selecting PLA as the printing material;

[0036] S42: Use the 3D printer to print the model layer by layer, monitor the printing process in real time, and adjust the printing parameters;

[0037] S43: performing post-processing such as grinding and polishing on the printed model.

[0038] In step S105, the 3D printed model is subjected to mechanical property testing and calibration, and the specific steps include:

[0039] S51: Compression, tension and bending tests are performed on the printed 3D models to fully evaluate their mechanical properties under different loads;

[0040] S52: Adjust and calibrate the model parameters based on the detailed results of the mechanical properties test. This includes analyzing the differences between the model responses observed in the experiment and the expected ones, and adjusting the material constitutive parameters and geometry to ensure that the model can accurately reflect the complex damage and mechanical properties of the actual tunnel;

[0041] S53: Perform final model calibration to confirm that the model meets expectations in terms of mechanical properties and geometric accuracy.

[0042] In step S106, the test model of the post-disaster damaged tunnel is prepared according to the optimized 3D printing model obtained in S105. The specific process is as follows:

[0043] S61: Based on the detailed data of the optimized 3D printing model, adjust the parameters of the printing material to ensure that the material used can truly reproduce the damage characteristics of the tunnel after the fire. This includes selecting suitable printing materials and adjusting their density, elastic modulus and thermal treatment characteristics to match the changes in the tunnel structure after the fire.

[0044] S62: Control the speed of the 3D printing machine and other printing conditions, such as temperature and layer thickness, to achieve high-precision model manufacturing. During this process, the machine settings need to be carefully adjusted to ensure that the printed model has a high degree of geometric accuracy and surface finish, accurately reflecting the damage state of the actual tunnel. In order to further improve the accuracy and durability of the model, necessary post-processing is carried out after printing, including surface grinding, coating and structural reinforcement to eliminate errors and defects in the printing process and enhance the stability and strength of the model.

[0045] S63: The adjusted and post-processed test model will be used for actual post-disaster damage assessment. Through detailed inspection and testing of the model, its performance data under simulated post-disaster conditions, such as deformation, stress response and failure mode, will be recorded. This data will be used to verify and optimize the post-fire tunnel structure design and provide a scientific basis for actual repair.

[0046] Compared with the prior art, the present invention has the following advantages and technical achievements:

[0047] This technological innovation significantly improves the efficiency and accuracy of post-disaster tunnel structure assessment and repair through a series of key steps (S101 to S106). First, by using knowledge graphs and field data analysis (S101), the damage information of the tunnel structure can be systematically sorted and extracted to provide basic data for subsequent work. Based on the damage report and similarity criteria (S102), a 3D printed damaged structure model with varying stiffness was established, which effectively simulated the actual damage situation.

[0048] The accuracy of the 3D printed model was verified and optimized through finite element analysis (FEA) modeling analysis (S103), and the model parameters were adjusted through multiple iterations to ensure that it was consistent with the actual tunnel damage. Using advanced 3D printing technology (S104), an optimized complex structure model was produced, accurately reproducing the details and complexity of the tunnel damage.

[0049] Subsequently, the 3D printed model is subjected to mechanical property testing and calibration (S105) to verify its mechanical response under different loads and ensure that the model meets expectations in terms of mechanical properties and geometric accuracy. Finally, the optimized 3D printed model is used to provide guidance for the post-disaster tunnel structure damage model test and to provide quantifiable guidance for modeling of damaged structures for model tests. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] The drawings of the present invention are only used for illustrative purposes and should not be construed as limiting the present invention. In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for describing the embodiments are briefly introduced below. 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.

[0051] Figure 1 The present invention is a flow chart of a method for making a 3D printed model of a damaged structure of a highway tunnel after a fire.

[0052] Figure 2 This is a schematic diagram of a damage report generated based on the index spectrum and field data in the present invention.

[0053] Figure 3 Schematic diagram of the 3D printed model based on damage reports and similarity criteria.

[0054] Figure 4 Schematic diagram of the process of establishing the 3D printing model of tunnel structure damage in the present invention.

[0055] Figure 5 It is a schematic diagram of iterative optimization of the 3D printing model in FEA finite element simulation in the present invention. DETAILED DESCRIPTION

[0056] 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 ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0057] like Figure 1 As shown, the method for making a 3D printed model of a damaged structure of a highway tunnel after a fire provided by the present invention comprises:

[0058] Step S101, retrieve the elastic modulus function of the post-disaster tunnel lining structure damage through the knowledge graph, further determine the stiffness of the structural lining based on the function, and obtain a tunnel structure damage report in combination with on-site data analysis;

[0059] Step S102, according to the damage report and similarity criteria, by changing the lining thickness of the model tunnel to reflect the change in tunnel structure stiffness, using computer-aided design software CAD to establish a preliminary 3D printing model, and introducing the thermodynamic and mechanical properties of the tunnel material;

[0060] Step S103, optimizing the initially established 3D printing model, and verifying the model accuracy through FEA modeling analysis based on the model, and adjusting the model parameters through multiple iterations;

[0061] Step S104, inputting the optimized 3D model into the 3D printer, selecting PLA material to ensure the strength and durability of the printed model, and monitoring and adjusting the printing parameters in real time during the printing process to ensure the quality and accuracy of the model;

[0062] Step S105, performing various mechanical property tests on the printed 3D model, and calibrating the model according to the test results to ensure that it can accurately reflect the actual damage of the tunnel;

[0063] Step S106, guiding the production of a model for a post-fire tunnel model test based on the proposed 3D printing model, and analyzing the impact of the fire on the tunnel structure.

[0064] The present invention provides a precise and efficient method for producing a 3D printed model of a damaged structure of a highway tunnel after a fire, which can truly reflect the damage of the tunnel after the disaster and provide guidance for model production of a model test of the tunnel structure after the disaster.

[0065] In particular, in step S101, Figure 2 As shown in the figure, firstly, data nodes such as the elastic modulus of the damaged structure, damage type, damage degree, and damage location are constructed, and the relationship between the nodes is established to comprehensively describe and analyze the tunnel damage. By integrating historical cases and existing case data into a unified knowledge base, an efficient knowledge graph database retrieval system is formed. Laser scanning and high-precision photography are used to generate high-precision three-dimensional point cloud data and detailed surface image information, so as to fully capture the current status of the tunnel lining structure and analyze and process the acquired field data. Then, the field data is fused and analyzed with the knowledge graph data, and the damage elastic modulus function is retrieved to determine the structural stiffness, and a detailed damage report is generated. The report content includes the damage location, damage type and damage degree, providing a scientific basis and data support for the post-disaster tunnel model test parameters.

[0066] In step S102, Figure 3As shown in the figure, first, according to the damage report and similarity criteria, the tunnel-related parameters including damage location, damage type, damage degree, lining thickness, material properties, etc. are input. These parameters will serve as the basic data for model optimization. Through the similarity criteria, the various parameters of the model tunnel, especially the changes in lining thickness, are adjusted and optimized to accurately reflect the changes in the stiffness of the tunnel structure. After the parameter optimization is completed, a preliminary 3D printing model is established based on the optimized parameters using computer-aided design software (CAD). In the process of establishing the 3D model, the thermodynamic and mechanical properties of the tunnel material are comprehensively considered, including the strength, elastic modulus, thermal expansion coefficient, etc. of the material, to ensure that the 3D printing model can truly reflect the physical properties of the actual tunnel. The generated 3D printing model can more accurately reflect the damage of the tunnel structure and ensure the accuracy of the model.

[0067] In particular, in step S22, the thickness of the model lining is changed to simulate the stiffness change of the post-disaster model due to damage, such as Figure 4 As shown in the figure, through the comprehensive analysis of knowledge graph and field data, the detailed damage report of the tunnel is retrieved to determine the location, type and degree of damage, thereby generating a post-disaster site map, and the tunnel within a certain range is equivalent to a damaged curved beam. According to the local equivalence, the local damage is processed into a curved beam model with varying thickness. In this process, special attention is paid to the effect of thickness changes at each damage location on the overall stiffness of the tunnel. All the damage details in the section are superimposed together, and the thickness changes at each damage point are accurately simulated, and finally a refined 3D printed model is formed. This model not only accurately reflects the actual damage of the tunnel lining, but also intuitively shows the effect of damage on the stiffness of the tunnel structure. In the process of modeling, CAD software ensures that every detail is accurately reflected, which can provide a highly realistic physical model for post-disaster tunnel repair.

[0068] In step S103, Figure 5 As shown, the initial model is first established using finite element analysis (FEA). The establishment of the initial model is based on the refined 3D printing model established in S22 to determine the key parameters of the model, such as the geometry, material properties, and boundary conditions. By analyzing the initial results, the model thickness is adjusted. This adjustment process needs to comprehensively consider the complexity of the actual tunnel damage and the feasibility of 3D printing technology to ensure that each adjustment is close to the actual situation. The optimized model is analyzed by FEA again, and by comparing the new results with the previous results, it is evaluated whether the adjusted model is closer to the actual situation. If the new model results meet expectations, the optimized model thickness and other adjustment parameters are recorded for use in subsequent steps. If the results still do not meet expectations, the model thickness is further adjusted.

[0069] This process usually requires multiple iterations, each of which leads to finer adjustments and more accurate analysis. Each modeling and analysis provides valuable data and experience accumulation for the optimization of the final model. By repeating this process, the accuracy and reliability of the model gradually improve, and eventually it can accurately reproduce the damage of the actual tunnel.

[0070] In step S104, the model parameters optimized by finite element analysis (FEA) are first imported into the CAD software to generate a high-precision model. Next, the processed CAD model is converted into the STL file format, and the converted model file is uploaded to the control software of the 3D printer for final preparation before printing. During the printing process, various parameters of the 3D printer are strictly controlled, including printing speed, layer thickness, printing temperature, etc. In addition, in order to further improve the accuracy of the model, necessary post-processing steps are performed after printing, including removing support structures, surface grinding, coating treatment, etc., to ensure that every detail of the model is as close to the actual situation as possible.

[0071] In step S105, the 3D printed model is subjected to mechanical property testing and calibration to ensure that the model can accurately reflect the complex damage and mechanical properties of the actual tunnel. First, the model will undergo a series of detailed mechanical property tests, including compression, tension and bending tests. In the compression test, the model is placed in a compression tester, and vertical loads are gradually applied to record the deformation and bearing capacity under different loads, and the compressive performance of the model under axial load is evaluated to ensure that it can simulate the behavior of the tunnel under geological pressure. The tensile test uses a tensile tester to stretch the model to fracture, and record the stress-strain curve of the model during the stretching process to determine the tensile strength and ductility of the model to ensure that its performance under tension is consistent with the actual situation. The bending test applies a bending load through a bending test device, records the response of the model at different bending angles, and evaluates the bending resistance of the model, especially the resistance of the tunnel structure under bending stress. In each test, high-precision sensors and data acquisition systems record mechanical performance data, including key parameters such as load, displacement, stress, and strain, to ensure the accuracy and integrity of the test data.

[0072] Next, according to the results of the mechanical properties test, the model parameters are adjusted and calibrated. First, the test results are analyzed in detail, and the constitutive parameters of the model material, such as elastic modulus, yield strength, Poisson's ratio, etc., are adjusted to more accurately reflect the performance of the actual material. The optimization of the geometric shape is equally important. According to the geometric deformation and local failure found in the experiment, the geometric shape of the model is optimized, such as adding local reinforcement structures and adjusting thickness, so as to improve the stability and accuracy of the model under stress and make it closer to the stress mode of the actual tunnel. Then, the adjusted parameters and optimized geometry are re-imported into the finite element analysis (FEA) software for a new simulation analysis to verify the performance of the adjusted and optimized model in the virtual environment and ensure that it can accurately reproduce the actual situation. Compression, tension and bending tests are carried out again using the adjusted and optimized model, and new mechanical properties data are recorded to confirm whether the performance of the adjusted model in the actual mechanical properties test meets expectations. The final test results are compared in detail with the expected results to evaluate the consistency of the model in mechanical properties and geometric accuracy, to ensure that all mechanical performance indicators and geometric accuracy meet the design requirements and can accurately reflect the damage and mechanical properties of the tunnel. Comprehensively analyze all test data and simulation results to confirm whether the performance of the model in various indicators meets expectations. If it meets expectations, record the final model parameters and design; if it does not meet expectations, continue to adjust and optimize until all requirements are met. Through these refined steps, the final confirmed 3D printed model can fully and accurately reflect the complex damage and mechanical properties of the tunnel, providing a scientific basis for the evaluation and maintenance of tunnel projects.

[0073] In step S106, the test model of the post-disaster damaged tunnel is prepared according to the optimized 3D printing model obtained in S105. The specific process is as follows:

[0074] First, based on the detailed data of the optimized 3D printed model, the parameters of the printing material are adjusted to ensure that the material used can truly reproduce the damage characteristics of the tunnel after the fire. This includes selecting a suitable printing material and adjusting its density, elastic modulus and thermal treatment characteristics to match the changes in the tunnel structure after the fire.

[0075] Next, the speed of the 3D printer and other printing conditions, such as temperature and layer thickness, are controlled to achieve high-precision model manufacturing. During this process, the machine settings need to be carefully adjusted to ensure that the printed model has a high degree of geometric accuracy and surface finish, accurately reflecting the damage state of the actual tunnel. In order to further improve the accuracy and durability of the model, necessary post-processing is carried out after printing, including surface grinding, coating and structural reinforcement, to eliminate errors and defects in the printing process and enhance the stability and strength of the model.

[0076] Finally, the adjusted and post-processed test model will be used for actual post-disaster damage assessment. Through detailed inspection and testing of the model, its performance data under simulated post-disaster conditions, such as deformation, stress response and failure mode, will be recorded. This data will be used to verify and optimize the post-fire tunnel structure design and provide a scientific basis for actual repair. This process ensures that the test model produced is not only highly accurate, but also can truly reproduce the damage of the post-disaster tunnel, providing reliable support for subsequent structural analysis and repair plans.

[0077] The preferred embodiments of the present invention disclosed above are only used to help explain the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to specific implementation methods. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A method for making a 3D printed model of a damaged structure of a highway tunnel after a fire, characterized in that: The following steps are involved: Step S101: Obtaining a tunnel structure damage report through knowledge graph and field data analysis; Step S102: Establishing a 3D printed damaged structure model with stiffness variation based on the tunnel structure damage report and similarity criteria; Step S103: Verifying the accuracy of the model through FEA modeling analysis and adjusting model parameter optimization; Step S104: Producing an optimized model through 3D printing technology; Step S105: Testing and calibrating the mechanical properties of the 3D printed model; Step S106: Using the 3D printed model to guide model making for a post-fire tunnel structure model test; In step S102, the 3D printing of the damaged structure model includes: generating a post-disaster site map according to the knowledge graph and the site data, and equating the tunnel within a predetermined range to a damaged curved beam; processing the local damage into a curved beam model with thickness variation according to local equivalence; superimposing all the damage details in the segment, simulating the thickness variation of each damage point, and forming a 3D printing damaged structure model; The step S102 comprises: obtaining the elastic modulus of the tunnel structure after the fire and the stiffness of the tunnel lining according to the analysis of the tunnel structure damage report and the lining elastic modulus reduction formula after the fire; and establishing the 3D printed damaged structure model reflecting different lining stiffness of the tunnel with different lining thicknesses using CAD software according to the similarity criterion; In step S102, the lining elastic modulus reduction formula is as follows: is the reduced elastic modulus, is the reduction factor of the elastic modulus of the tunnel concrete lining after the disaster, is the elastic modulus of concrete, is the elastic modulus of the steel bar, and the unit of the elastic modulus is GPa; is the elastic modulus of concrete at different fire temperatures, The temperature of the tunnel lining when it encounters a fire, in °C; In step S102, the relationship between different lining stiffnesses of the tunnel reflected by different lining thicknesses is as follows: ξ is the thickness reduction factor, is the thickness of the tunnel lining after the disaster, is the thickness of the tunnel lining before the disaster, is the elastic modulus of the tunnel lining before the disaster, is the initial section inertia moment of the tunnel lining, is the moment of inertia of the tunnel lining section after the disaster. The moment of inertia is calculated according to the following formula: y is from the neutral axis to the small area unit The distance It is a tiny area unit.

2. The method for making a 3D printed model of a damaged structure of a highway tunnel after a fire according to claim 1, characterized in that: The step S101 includes establishing the knowledge graph: establishing nodes of damage type, damage degree, damage location, historical cases and existing cases of the post-disaster tunnel, and defining the relationship between the nodes, sorting and classifying the data of the historical cases and the existing cases, integrating them into the knowledge base, and forming a knowledge graph database retrieval system; including obtaining the field data of the tunnel lining structure through laser scanning and photography technology; fusing the field data, the historical cases and the existing case data, analyzing the damage condition of the tunnel lining structure and generating the tunnel structure damage report.

3. The method for making a 3D printed model of a damaged structure of a highway tunnel after a fire according to claim 2, characterized in that: The tunnel structure damage report includes: the damage location, the damage type and the damage degree.

4. The method for making a 3D printed model of a damaged structure of a highway tunnel after a fire according to claim 3, characterized in that: The step S103 includes an iterative optimization process, specifically: first, a model is established using FEA, and the establishment of the FEA model is based on the 3D printed damage structure model to determine the key parameters of the model's geometry, material properties, and boundary conditions; the thickness of the FEA model is adjusted by analyzing the initial results; the FEA analysis is performed again on the optimized FEA model, and the new results are compared with the previous results to evaluate whether the optimized model is closer to the actual situation; if the results of the optimized FEA model meet expectations, the thickness and other adjustment parameters of the optimized FEA model are recorded for use in subsequent steps; if the results still do not meet expectations, the thickness of the optimized FEA model is further adjusted.

5. The method for making a 3D printed model of a damaged structure of a highway tunnel after a fire according to claim 4, characterized in that: In the step S104, the optimized model is produced by the 3D printing technology, specifically: the parameters of the FEA optimized model are imported into the CAD software, the processed CAD model is converted into an STL file format, and the converted model file is uploaded to the control software of the 3D printer; During the printing process, control the parameters of the 3D printer; Post-processing steps after printing include support structure removal, surface grinding and coating.

6. The method for making a 3D printed model of a damaged structure of a highway tunnel after a fire according to claim 5, characterized in that: In the step S105, the mechanical property test and calibration of the 3D printed model includes: performing compression, tension and bending tests on the 3D printed model, and using sensors and data acquisition systems to record key parameters of load, displacement, stress and strain; adjusting parameters and calibrating the 3D printed model according to the mechanical property test results; analyzing the test results, adjusting the constitutive parameters and geometric shape of the model material, and re-importing the optimized 3D printed structural model into the FEA software to perform a new simulation analysis; using the 3D printed model adjusted and optimized by FEA to perform compression, tension and bending tests again, recording new mechanical property data, and confirming whether the performance of the 3D printed model in terms of indicators meets expectations; if the expectations are met, recording the final 3D printed model parameters and design; if the expectations are not met, continuing to adjust and optimize until the expected results are met.

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