Multi-level virtual-real combination static strength verification method for rail transit composite car body

Abstract

The present invention provides a multi-level virtual-real combined static strength verification method for a rail transit composite vehicle body, determines the allowable material values and environmental load factors, and establishes a virtual model according to the vehicle body size and material parameters; in combination with the allowable material values, establishes a vehicle-level finite element model according to the vehicle body material and structure for initial bearing capacity analysis, and selects the high-load composite material structure area as the key area according to the bearing capacity analysis results; establishes multi-level sub-models at the component, assembly, typical structural member, and element levels according to the key area; according to each static strength load condition of the vehicle body virtual model, uses the sectional force method to extract the load boundary conditions of the component, assembly, typical structural member, and element specimens respectively, and conducts the corresponding specimen tests according to the load boundary conditions; the present invention solves the problem that there is no reliable strength verification method for rail transit vehicles with composite material load-bearing structures, and verifies the strength of the vehicle body with composite material structures without conducting vehicle destructive tests.

Description

Technical Field

[0001] The present invention relates to the technical field of rail transit, and particularly to a multi-level virtual-real combined static strength verification method for a rail transit composite vehicle body, which can be referred to for other rail transit composite structures. Background Art

[0002] The statements in this section merely provide background art related to the present invention and do not necessarily constitute prior art.

[0003] Composite materials replace metal materials with good weight reduction effects and excellent comprehensive properties. Therefore, from interior products to non-load-bearing structures, secondary load-bearing structures, and main load-bearing structures, more and more composite materials are applied to rail transit vehicles. However, since the strength verification of composite structures is different from that of metal structures, the current railway standards are formulated based on metal material vehicle bodies, and the specified load conditions are derived from the old load assumptions of steel bridges in the 1930s. For metal bodies, these design load conditions have been verified by years of railway vehicle production and operation experience.

[0004] However, the inventors found that for new rail transit vehicles with composite structures, these load assumptions are insufficient to ensure the operation safety of railway vehicles and cannot be directly used for the design and verification of structural strength. Instead, additional safety factors need to be considered. The unique heterogeneity and anisotropy of composite materials and other performance characteristics, as well as the process characteristics of simultaneous completion of structural forming and material forming, the variability of material properties, the instability of manufacturing processes, the size effect, and complex failure modes of composite structures all result in different strength verification of rail vehicles containing composite structures from metal structures. Summary of the Invention

[0005] In order to solve the deficiencies of the prior art, the present invention provides a multi-level virtual-real combined static strength verification method for a rail transit composite vehicle body, which solves the problem of the lack of a reliable strength verification method for rail transit vehicles with composite load-bearing structures and verifies the strength of the vehicle body with composite structures without conducting a full-vehicle destructive test.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] The first aspect of the present invention provides a multi-level virtual-real combined static strength verification method for a rail transit composite vehicle body.

[0008] A multi-level virtual-real combined static strength verification method for a rail transit composite vehicle body includes the following processes:

[0009] Determine the material allowable value and the environmental load factor, and establish a virtual model according to the vehicle body size and material parameters;

[0010] Combined with the allowable value of the material, an initial load-bearing capacity analysis is carried out on the vehicle-level finite element model based on the vehicle body material and structure. According to the results of the load-bearing capacity analysis, the high-load composite material structure area is selected as the key area;

[0011] Based on the key area, multi-level sub-models at the component, assembly, typical structural part, and element levels are established;

[0012] According to the static strength load conditions of the vehicle body virtual model, the load boundary conditions of the element-level specimens are extracted by the sectional force method. According to the load boundary conditions of the element-level specimens, element-level specimen tests are carried out, and the element-level virtual model is cross-verified and calibrated;

[0013] According to the static strength load conditions of the vehicle body virtual model, the load boundary conditions of the typical structural parts are extracted by the sectional force method. According to the load boundary conditions of the typical structural parts, typical structural part tests are carried out, and the virtual model is cross-verified and calibrated;

[0014] According to the static strength load conditions of the vehicle body virtual model, the load boundary conditions of the assemblies are extracted by the sectional force method. According to the load boundary conditions of the assemblies, assembly tests are carried out and the virtual model is cross-verified and calibrated;

[0015] Using the ultimate load and the limit load respectively, according to the static strength load conditions of the vehicle body virtual model, the load boundary conditions of the components are extracted by the sectional force method. The limit load is used to verify whether the strength of the metal part of the component meets the requirements. The force transmission form of the structure and the accuracy of the model are verified by comparing the component-level sub-model with the component test;

[0016] Using the ultimate load considering the environmental impact factor, verify whether the strength of the composite material structure part of the component meets the requirements. By comparing the component-level sub-model with the component test, verify the force transmission form of the component structure, the accuracy of the model, and the static strength of the component composite material.

[0017] As an optional implementation method, for the element-level specimens, considering the environmental load factor compensation coefficient, if the physical test fails under the ultimate load, the vehicle body strength does not meet the requirements. Modify the multi-level sub-model, carry out the element-level standard test, and determine the design allowable value of each area.

[0018] As an optional implementation method, for the typical structural part-level specimens, determine the environmental load factor. Considering the environmental load factor compensation coefficient, if the physical test fails under the ultimate load, the vehicle body strength does not meet the requirements. If the physical test does not fail under the ultimate load, continue to increase the load until it fails, and preliminarily determine the non-damage design value.

[0019] As an optional implementation method, the environmental load factor is determined for the assembly-level specimen. Under the condition of considering the environmental load factor compensation coefficient, if the physical test under the extreme load causes damage, the vehicle body strength does not meet the requirements. If the physical test does not cause damage, the load is further amplified to the value of damage to obtain a revised design value as the second design value for the corresponding structure in the area without the second type of damage.

[0020] As an optional implementation, the section force method includes:

[0021] The corresponding loads are applied to the overall virtual model, the boundary node displacements of the corresponding multi-level virtual model are extracted, and equivalent boundary conditions are applied according to the node displacements.

[0022] As a further qualification, a multi-level virtual model approach was used to determine the loads, including:

[0023] Apply corresponding loads in the overall virtual model, extract the force values of the boundary section nodes and their comprehensive section forces of the corresponding hierarchical model, and apply corresponding loads according to the node force values and the comprehensive section forces including force and bending moment.

[0024] As an optional implementation method, the load used for static strength adopts the standard load of the corresponding vehicle type category. The standard loads are all limit loads. When the limit load is used as the external load of the structure, an uncertainty coefficient of 1.5 or a safety factor is used. When the limit load is used to specify the load condition, the safety factor is not used.

[0025] As an optional implementation method, the environmental conditions for static strength verification include: temperature, humidity, environmental corrosion, natural aging, and lightning strikes.

[0026] As a further limitation, the determination of the maximum and minimum temperatures that a vehicle may encounter during its service includes: determining the maximum structural temperature caused by climate based on the high temperature of the climate in the area where the vehicle is intended to be used, plus the maximum possible temperature rise caused by sunlight exposure; determining the minimum structural temperature caused by climate based on the minimum ground temperature.

[0027] As a further qualification, the determination of humidity includes determining the equilibrium moisture absorption amount reached at the end of the service life of the composite structure based on the design service life of the vehicle and the expected use environment.

[0028] As a further limitation, the determination of environmental corrosion conditions and natural aging conditions includes: compiling corrosion and aging spectra of composite structures according to the use and storage environment; using natural exposure or accelerated tests of specimens, components, and typical structural parts and assemblies to verify the corrosion and aging resistance of composite structures; using the test results of corrosion and aging resistance of specimens, components, typical structural parts and assemblies to correct the analysis and test results of full-size components.

[0029] As an optional implementation method, for a single-layer board, the mechanical properties of unidirectional laminates at room temperature in the dry state, low temperature in the dry state, and high temperature in the wet state are given, including:

[0030] The tensile elastic modulus and strength in the 0° or warp direction and 90° or weft direction; the compressive elastic modulus and strength in the 0° or warp direction and 90° or weft direction; the in-plane shear elastic modulus and strength; the principal Poisson's ratio;

[0031] For the sandwich structure, the mechanical properties of the sandwich structure at room temperature in the dry state, low temperature in the dry state, and high temperature in the wet state are given, including: the out-of-plane tensile strength, the out-of-plane compressive strength, and the out-of-plane shear strength;

[0032] For the unnotched laminate, the mechanical properties of the typical ply laminate at room temperature in the dry state, low temperature in the dry state, and high temperature in the wet state are given, including: the tensile elastic modulus and strength, the compressive elastic modulus and strength, the in-plane shear elastic modulus and strength, and the Poisson's ratio;

[0033] For the notched laminate, the tensile and compressive strengths of the open hole and filled hole at room temperature in the dry state, low temperature in the dry state, and high temperature in the wet state are given;

[0034] For the laminate with impact damage, the post-impact compressive strength value and the carpet curve of the laminate in the room temperature dry state environment are given;

[0035] For the mechanical connection extrusion strength, the mechanical connection extrusion strength of the laminate at room temperature in the dry state and high temperature in the wet state is given.

[0036] As an optional implementation method, according to the integrity requirements of the specific structure designed, based on the existing allowable values, specimens representing the typical characteristics of the structure, test results of components, and design and use experience, and according to the test results of the assembly, the design values of different parts of the structure are determined.

[0037] The second aspect of the present invention provides a multi-level virtual-real combined static strength verification system for a rail transit composite vehicle body.

[0038] A multi-level virtual-real combined static strength verification system for a rail transit composite vehicle body includes:

[0039] A virtual model construction module, configured to: determine the material allowable values and environmental load factors, and establish a virtual model according to the vehicle body size and material parameters;

[0040] A key area determination module, configured to: combine the material allowable values, establish a vehicle-level finite element model according to the vehicle body material and structure for initial load-bearing capacity analysis, and select the high-load composite material structure area as the key area according to the load-bearing capacity analysis results;

[0041] Multi - level sub - model acquisition module, configured to: establish multi - level sub - models at the levels of components, assemblies, typical structural parts, and elements according to key areas;

[0042] Element - level specimen verification module, configured to: extract the load boundary conditions of the element - level specimen using the sectional force method according to each static strength load condition of the vehicle body virtual model, conduct element - level specimen tests according to the load boundary conditions of the element - level specimen, and perform mutual verification and calibration on the element - level virtual model;

[0043] Typical structural part verification module, configured to: extract the load boundary conditions of the typical structural part using the sectional force method according to each static strength load condition of the vehicle body virtual model, conduct typical structural part tests according to the load boundary conditions of the typical structural part, and perform mutual verification and calibration on the virtual model;

[0044] Assembly verification module, configured to: extract the load boundary conditions of the assembly using the sectional force method according to each static strength load condition of the vehicle body virtual model, conduct assembly tests according to the load boundary conditions of the assembly, and perform mutual verification and calibration on the virtual model;

[0045] Component verification module, configured to: respectively adopt the ultimate load and the limit load, extract the load boundary conditions of the component using the sectional force method according to each static strength load condition of the vehicle body virtual model, verify whether the strength of the metal part of the component meets the requirements using the limit load, and verify the force - transmission form of the structure and the accuracy of the model through the comparison between the component - level sub - model and the component test; adopt the ultimate load considering the environmental impact factor to verify whether the strength of the composite material structure part of the component meets the requirements, and verify the force - transmission form of the component structure, the accuracy of the model, and the static strength of the component composite material through the comparison between the component - level sub - model and the component test.

[0046] The third aspect of the present invention provides a computer - readable storage medium, on which a program is stored, and when the program is executed by a processor, it implements the steps in the multi - level virtual - real combined static strength verification method for a rail transit composite material vehicle body as described in the first aspect of the present invention.

[0047] The fourth aspect of the present invention provides an electronic device, including a memory, a processor, and a program stored on the memory and executable on the processor. When the processor executes the program, it implements the steps in the multi - level virtual - real combined static strength verification method for a rail transit composite material vehicle body as described in the first aspect of the present invention.

[0048] Compared with the prior art, the beneficial effects of the present invention are:

[0049] 1. The multi-level virtual-real combination static strength verification method for the rail transit composite material car body of the present invention solves the problem that there is no reliable strength verification method for rail transit vehicles with composite material load-bearing structures, and verifies the strength of the car body with composite material structures without conducting a full vehicle destructive test.

[0050] 2. The multi-level virtual-real combination static strength verification method for the rail transit composite material car body of the present invention can provide engineering guidance for the design optimization and verification of composite material equipment based on the characteristics of rail transit and composite materials, effectively shortening the engineering cycle and manufacturing test costs, achieving reliable operation, reducing the probability of failure of the full-scale static strength test of rail transit equipment, and reducing the R & D costs.

[0051] Advantages of additional aspects of the present invention will be partly given in the following description, partly become obvious from the following description, or be understood through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] The specification drawings forming a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention.

[0053] Figure 1 It is a schematic flow chart of the multi-level virtual-real combination static strength verification method for the rail transit composite material car body provided in Embodiment 1 of the present invention.

[0054] Figure 2 It is a schematic diagram of a typical multi-level verification plan for the strength verification of a car body with a composite material load-bearing structure provided in Embodiment 1 of the present invention.

[0055] Figure 3 It is a schematic diagram of a multi-level model provided in Embodiment 1 of the present invention.

[0056] Figure 4 It is a schematic diagram of each node and the total sectional force at the boundary of the multi-level model provided in Embodiment 1 of the present invention.

[0057] Figure 5 It is the first feasible implementation method for static strength verification provided in Embodiment 1 of the present invention.

[0058] Figure 6 It is the second feasible implementation method for static strength verification provided in Embodiment 1 of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0059] The present invention will be further described below in conjunction with the drawings and embodiments.

[0060] It should be noted that the following detailed description is exemplary and is intended to provide further illustration of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention pertains.

[0061] It should be noted that the terms used herein are merely for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they specify the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0062] In the case of no conflict, the embodiments in the present invention and the features in the embodiments may be combined with each other.

[0063] Embodiment 1:

[0064] As Figure 1 shown, Embodiment 1 of the present invention provides a method for verifying the multi-level virtual-real combined static strength of a rail transit composite vehicle body, including the following processes:

[0065] Step 101: Define the requirements and methods for verifying the structural strength of a train vehicle body with a composite material load-bearing structure;

[0066] Step 101-1: For verifying the structural strength of a train vehicle body with a composite material load-bearing structure, one of the following methods can be selected:

[0067] a) Adopt a multi-level structure verification method to verify the composite material structure part, while the full-scale vehicle body test is mainly used to assess the metal structure;

[0068] b) Verify the metal structure and the composite material structure separately with two components;

[0069] c) Adopt other methods that have been applied and proven to be reasonable.

[0070] Step 101-2: Determine the basis for verifying the structural strength of a train vehicle body with a composite material load-bearing structure: The content and scope of the analysis and test of the composite material structure depend on the available design, structural form, test, and use experience of previous similar structures; when there is no experience of similar structures, multi-level structural strength tests should be carried out.

[0071] Step 101-3: Define the requirements for verifying the structural strength of a train vehicle body with a composite material load-bearing structure, mainly including:

[0072] a) Argumentation on the selection of composite materials;

[0073] b) Criteria for determining environmental conditions;

[0074] c) Load determination, including the load spectrum of the static strength load characteristics specified in relevant standards such as EN12663;

[0075] d) Analysis and verification of composite material structures, including analysis and verification of static strength, stiffness, etc.;

[0076] e) Strength verification of train car bodies with composite material load-bearing structures should include verification of specimens, components, typical structural parts, assemblies, and full-scale structures;

[0077] f) The full-scale structure test verification outline should specify test contents, sequence arrangements, load conditions, requirements for test pieces, handling of environmental impacts, introduction of artificial defects / damages, processing of test data, etc.; for some structural integrity requirements that cannot be fully verified by the full-scale component test itself, test items for specimens, components, typical structural parts, and assemblies to supplement the verification of these requirements should also be given.

[0078] Step 101-4: Define the multi-level verification method for the strength of train car bodies with composite material load-bearing structures

[0079] When verifying the strength of rail transit car bodies with composite material load-bearing structures, the composite material structures generally adopt a multi-level verification test with gradually increasing complexity starting from specimens, passing through components (including typical structural parts), assemblies, and finally reaching full-scale components and the whole vehicle. And during this process, each level needs to carry out simulation and calculation for synchronous verification of structural analysis to ensure its structural integrity;

[0080] For static strength verification, if the full-scale component structure or the whole vehicle body verification test is carried out under room temperature and atmospheric environment, it is also necessary to verify that the same failure mode can be obtained under room temperature conditions and humid and hot environments through the multi-level verification test method, and confirm the environmental load factor required for the full-scale test under room temperature and atmospheric conditions, so as to ensure the overall integrity of the static strength verification of the composite material structure;

[0081] For the durability and damage tolerance characteristics of widely used composite material / metal hybrid structures, the multi-level verification test method can be used to complete the verification of the composite material structure part, while the full-scale vehicle test is used to complete the verification of the metal structure part.

[0082] Figure 2 The typical multi-level verification plan for the strength verification of car bodies with composite material load-bearing structures is shown. There is no specific order for Step 101-1 to Step 101-4, but all its contents should be included.

[0083] Step 102: Determine the static strength and environmental conditions of rail transit vehicle car bodies with composite material structures.

[0084] The preferred implementation methods are:

[0085] Step 102-1: Determine the environmental conditions of composite materials. The environmental conditions that should be considered in the design of composite materials for vehicles should be formulated based on the expected service area, operating range, usage mission, structural condition, etc. of the vehicle, mainly including the natural environment (such as temperature, humidity, environmental corrosion and natural aging, lightning strike, etc.) and load environment (such as impact loads and limit loads such as tools, sand and gravel, hail, etc.) that have a significant impact on the integrity of the composite material structure.

[0086] For the material system and structural conditions used, the most severe single and combined environments that the composite material structure may be exposed to should be assessed. The long-term environmental spectrum should also be assessed, including the intensity, frequency, duration and order of occurrence of the environment. When there is test data to prove that a certain environmental factor has no obvious impact, it may not be considered.

[0087] Step 102-2: Determination of temperature. The maximum and minimum temperatures that the vehicle may encounter during its service life are determined according to the following methods: a) Determine the maximum structural temperature caused by climate based on the high temperature of the climate in the area where the vehicle is intended to be used, plus the maximum possible temperature rise caused by sunlight exposure; b) Determine the minimum structural temperature caused by climate based on the minimum ground temperature.

[0088] Step 102-3: Determination of humidity should be based on the design service life of the vehicle and the expected use environment to determine the equilibrium moisture absorption reached at the end of the service life of the composite material structure;

[0089] For known material systems, the designed moisture absorption can be achieved by placing the specimen under an exposure level that simulates the most severe moisture absorption that may be obtained to achieve moisture absorption equilibrium, or the equilibrium moisture absorption under 85% relative humidity conditions can be used;

[0090] Moisture absorption of composite materials is an extremely slow process. In order to shorten the test period, it must be accelerated according to certain principles. The goal of accelerating moisture absorption is to establish an environmental condition (temperature and relative humidity) that produces moisture absorption equivalent to the actual situation in a shorter period of time.

[0091] Step 102-4: Determination of environmental corrosion and natural aging: Take effective protective measures to prevent environmental corrosion and natural aging. When composite materials are used to manufacture parts that are susceptible to sand erosion and rain erosion, verify the effectiveness of their structural protection measures:

[0092] a) Prepare corrosion and aging spectra of composite materials structures according to use and storage environments;

[0093] b) The ability of composite materials to resist corrosion and aging can be verified by natural exposure or accelerated testing of specimens, components, typical structural parts, and assembly test pieces;

[0094] c) The test results of anti-corrosion and anti-aging of available specimens, components, typical structural parts, and assemblies are used to correct the analysis and test results of full-scale components.

[0095] Step 102-5: Evaluate the lightning strike situation suffered by the composite material structure.

[0096] Step 102-6: Determine the static load. The composite material structure of the rail vehicle should be able to withstand the maximum load required for its operation and have a sufficient survival probability. The static load requirements are as follows:

[0097] a) For the load used in static strength, the load corresponding to the corresponding vehicle type category in the corresponding standard such as EN12663 is adopted, and the loads specified therein are all limit loads;

[0098] b) Unless otherwise specified, when the limit load is used as the external load of the structure, a reasonable uncertainty factor of 1.5 or other reasonable safety factors must be adopted; when the ultimate load is used to specify the loading condition, no safety factor is required.

[0099] Step 103: Determine the classification and acquisition methods of the allowable values of materials, the allowable values of structures, and the design values for structural strength verification.

[0100] Step 103-1: Material property values obtained from the test results of single-layer specimens on a probabilistic basis.

[0101] For a single ply, the mechanical properties of the unidirectional laminate at room temperature dry (RTD), cryogenic temperature dry (CTD), and elevated temperature wet (ETW) should be given specifically, including:

[0102] a) Tensile elastic modulus and strength in the 0° (or warp) and 90° (or weft) directions; b) Compressive elastic modulus and strength in the 0° (or warp) and 90° (or weft) directions; c) In-plane shear elastic modulus and strength; d) Major Poisson's ratio;

[0103] For the above properties, the tensile, compressive strength, and in-plane shear strength in the 0° (or warp) and 90° (or weft) directions usually take the B-basis value, and the elastic modulus and major Poisson's ratio take the average value.

[0104] For sandwich structures, the mechanical properties of the sandwich structure at room temperature dry, cryogenic temperature dry, and elevated temperature wet should be given, generally including out-of-plane tensile strength, out-of-plane compressive strength, and out-of-plane shear strength.

[0105] In addition, to meet the requirements of structural design, the basic physical properties of the unidirectional plate that should be given include:

[0106] a) Density; b) Cured monolayer thickness; c) Glass transition temperature; d) Longitudinal and transverse thermal expansion coefficients; e) Longitudinal and transverse moisture expansion coefficients; f) Specific heat capacity; g) Conductivity; The above properties are all taken as average values.

[0107] Step 103-2: Based on probability, the material property values determined from the test data of laminate specimens with typical structural features (such as ply ratio, cut-outs, filled holes, mechanical joints, etc.) are applicable to different structures manufactured by the same manufacturer using the same material system and the same process specifications.

[0108] For unnotched laminates, the typical laminate mechanical properties at room temperature dry (RTD), cryogenic temperature dry (CTD), and elevated temperature wet (ETW) are given, generally including: a) Tensile elastic modulus and strength; b) Compressive elastic modulus and strength; c) In-plane shear elastic modulus and strength; d) Poisson's ratio;

[0109] For notched (including filled holes) laminates, the tensile and compressive strengths of the cut-outs and filled holes at room temperature dry (RTD), cryogenic temperature dry (CTD), and elevated temperature wet (ETW) are given, taking the B-basis value;

[0110] For impact-damaged laminates, the post-impact compressive strength value of the laminate in the room temperature dry environment and the carpet curve are given;

[0111] For the bearing strength of mechanical joints, the bearing strength of the laminate at room temperature dry (RTD) and elevated temperature wet (ETW) is given, taking the B-basis value.

[0112] Step 103-3: Determine the design values. Based on the integrity requirements of the specific structure to be designed (usually strength, stiffness, durability, and damage tolerance, including meeting the requirement of no damage propagation under service conditions), on the basis of existing allowable values (including material allowable values and design allowable values), test results of specimens and components (including typical structural parts) representing typical structural features, and design and usage experience, and also according to the test results of the assembly, determine the design values of different parts of the structure. These values are usually based on the allowable values corrected to consider the actual structural state and are used for analyzing and calculating the safety margin.

[0113] Step 104: Determine the static strength verification requirements for the vehicle body with a composite material load-bearing structure

[0114] Step 104-1: Determine the static strength requirements and verification methods for the vehicle body with a composite material load-bearing structure. The static strength analysis and test verification of composite material structural components (including metal-composite hybrid structural components)

[0115] a) When verifying the static strength of the component structure, ensure that under the action of the limit load, the structure does not produce harmful deformation and damage; under the ultimate load and the corresponding most severe environmental combination conditions, the structure does not undergo overall failure; determine the degree to which the structure complies with the design criteria and the possible potential;

[0116] b) The static strength of the composite material structure should be verified through component tests under the ultimate load. Only when there is experience in dealing with similar designs, material systems, and load conditions can an analytical method supported by subassembly tests or component tests under the limit load be used for verification;

[0117] c) For composite material structures with a large safety margin, verification can be carried out through analysis supported by the test results of specimens, elements, typical structural parts, and subassemblies;

[0118] d) When conducting structural verification according to the determined design values, it is necessary to determine the uncertainty factors, including load uncertainty factors, material uncertainty factors, and fail-safe uncertainty factors. Among them, the material uncertainty factor also needs to consider the possibility of an undesirable deviation in the material property values, the possibility of inaccurate calculation of the cross-sectional impedance of the part or the load-bearing capacity of the structure, the error of geometric parameters, the difference ratio between the material properties of the part and the properties measured on the test specimens, etc. The items to be considered for the material uncertainty factor of the composite material structure and an implementable method are shown in Table 1. The total uncertainty factor is the product of each sub-uncertainty factor; under the condition of proving rationality, the total uncertainty factor can also be the same as that of the metal structure, taking 1.5.

[0119] Table 1: Partial Uncertainty Factors of Composite Materials

[0120]

[0121]

[0122]

[0123] Step 104-2: Determine the test pieces for static strength verification. Except for the test pieces at the specimen and element levels, the test pieces for static strength verification mainly include typical structural parts, subassemblies, and full-scale components; the test pieces should be able to reflect the structural characteristics of the typical parts of the vehicle, and the test pieces should be properly stored to avoid damage during transportation and storage.

[0124] Determine the subassembly. The quantity and type of the subassembly test pieces depend on the assessment and analysis of design risk, schedule, and cost; the test pieces used should include a subassembly that combines one or more key structural characteristics. The key structural characteristics for testing include:

[0125] a) Key connection parts; b) Main load-bearing joints; c) Open reinforcement parts; d) Parts that are prone to out-of-plane loads due to complex loads and structures; e) Other key parts that are difficult to analyze due to complex structures; Determine full-scale components, which should be consistent with the production vehicle model.

[0126] Step 104-3: Determine the verification method for static strength physical tests.

[0127] (1) Determine the boundary conditions. When designing the static strength test fixture, the boundary support conditions of the test piece should be made as close as possible to the actual boundary conditions of the part to be examined.

[0128] When it is difficult to truly simulate the actual boundary conditions of the test piece, the boundary conditions provided by the test fixture should make the test results on the safe side compared with the actual situation. One feasible method is to apply the corresponding load in the overall virtual model, then extract the boundary node displacements of the corresponding multi-level virtual model, and apply equivalent boundary conditions according to the node displacement situation. A schematic diagram of the multi-level model is shown in the appendix. Figure 3 as shown.

[0129] (2) Determine the load application method. The type, direction, magnitude, and application point of the applied load should be as close as possible to the actual working conditions of the part to be examined. For specimen and component-level test pieces, a uniform loading method is adopted. For assembly and full-scale test pieces, a stepped loading method is adopted.

[0130] It should be noted that when using the environmental load factor compensation coefficient method for full-scale structure tests, the maximum load test should be loaded to a value not less than the product of the design ultimate load and the environmental load factor compensation coefficient. One feasible method to determine the load is to use the multi-level virtual model method. First, apply the corresponding load in the overall virtual model, then extract the force values of the boundary section nodes and their combined section forces of the corresponding level model, and apply the corresponding load according to the node force values and combined section forces including forces and moments.

[0131] Appendix Figure 4 is a schematic diagram of the boundary nodes and total section forces of the multi-level model. The boundary point coordinates, node constraint forces, equivalent reaction forces, and moments are shown in Table 2.

[0132] Table 2: Node forces, moments, and total equivalent forces and moments of the virtual model boundary nodes

[0133] Boundary point X Y X Fx Fy Fz Mx My Mz Equivalent reaction force Fr Equivalent bending moment Mr 1 -1734.47 -670.369 29.86666 -1.36E+01 -3.83E+00 1.08E+03 -4.80E+03 -1.60E+02 -3.29E+02 1.08E+03 4.81E+03 2 -1752.49 -635.662 29.86666 -3.69E+00 6.49E-02 4.67E+01 -7.00E+00 -4.85E-01 1.03E+00 4.68E+01 7.10E+00 3 -1732.52 -636.826 29.86666 4.83E-01 5.40E-01 1.65E+02 -2.62E+01 1.83E+00 -8.47E-01 1.65E+02 2.63E+01 4 -1712.55 -637.977 29.86666 3.64E+00 -4.25E-01 4.43E+01 -6.73E+00 1.61E+00 -1.40E+00 4.45E+01 7.06E+00 5 -1760.66 -690.276 29.86666 -2.86E+00 6.19E-01 1.48E+02 1.97E+01 -1.56E+00 -3.17E+01 1.48E+02 3.73E+01 6 -1785.61 -688.799 29.86666 -7.64E+00 1.70E+00 6.46E+01 2.32E+01 -2.43E+00 -1.71E+01 6.50E+01 2.89E+01 7 -1710.75 -693.169 29.86666 -4.80E+00 3.52E-01 1.57E+02 1.46E+01 -7.95E-01 2.35E+01 1.57E+02 2.77E+01 8 -1685.79 -694.586 29.86666 5.94E+00 1.10E+00 6.97E+01 2.46E+01 -1.87E+00 1.30E+01 7.00E+01 2.79E+01 9 -1734.11 -664.299 29.86665 -1.50E-01 -2.89E+00 1.51E+02 -1.31E+00 1.23E+00 -3.98E-01 1.51E+02 1.85E+00 10 -1735.7 -691.732 29.86666 -4.53E+00 -4.89E+00 2.32E+02 2.43E+01 6.79E-01 -4.04E+00 2.32E+02 2.47E+01

[0134] (3) Determine the failure criterion. Comprehensively consider aspects such as the test assessment purpose, product functionality, and structural integrity to determine the failure criterion of the test piece, such as the appearance of initial damage, final fracture, non-linear deformation, stiffness reduction, buckling, etc.

[0135] (4) Determine the environmental impact. The full-scale structural static test is the highest-level test in the building-block test for verifying the static strength of composite material structures. Only when the previous design verification tests have proven that the hygrothermal environment will not lead to new dangerous failure modes can the full-scale structural static test up to the ultimate load amplified by the environmental load factor compensation coefficient be carried out in the room-temperature atmospheric environment. If the criteria for the failure mode cannot be met, the static test specimens must be under hygrothermal conditions or other measures must be taken to ensure this requirement is met. One of the following methods should be used:

[0136] a) Environmental chamber simulation method: The test specimens are subjected to moisture absorption treatment to simulate the most severe hygrothermal environment and are loaded to failure or the design ultimate load under the most severe temperature conditions.

[0137] b) Environmental load factor compensation coefficient method: The test is carried out in the room-temperature atmospheric environment, and the applied load level should not be lower than the product of the design ultimate load and the environmental load factor compensation coefficient. At the same time, the strain measured at the dangerous parts of the composite material structure under the design ultimate load should be lower than the failure strain obtained from the verification test considering the hygrothermal environment under the same design details and load conditions. The verification test should indicate that the same failure mode as the test under hygrothermal environment conditions can be obtained by this method. If the environmental load factor compensation coefficient exceeds 1.10, this method can only be adopted after sufficient demonstration.

[0138] c) Load-strain relationship extrapolation method. This method requires loading the structure to the design ultimate load in the room-temperature atmospheric environment, adding the measured strain data to the additional strain caused by moisture absorption and temperature calculated by structural analysis (including the additional strain caused by the reduction of the material elastic modulus under hygrothermal conditions), and comparing it with the design allowable values considering the hygrothermal effects at each key part. The safety margin should be greater than zero.

[0139] For specimen-level, component-level, and smaller subassembly-level tests, the environmental chamber simulation method is generally used, but the heating and heat preservation time of the test specimens in the environmental chamber must be strictly controlled to avoid damage caused by a large amount of moisture absorption. For larger subassemblies and full-scale components, the environmental load factor compensation coefficient method is recommended.

[0140] Step 105: Conduct multi-level virtual-real combined static strength verification. A feasible implementation method for static strength verification is as shown in Appendix Figure 5 and Appendix Figure 6 .

[0141] Step 1051: Conduct material allowable value tests to determine the material allowable values and environmental load factors. Establish a virtual model based on the specimen size and material parameters and calibrate the virtual model according to the test. The virtual model is established at the smallest size level as shown in Appendix Figure 6 for multi-level model establishment, requiring fine dimensions to accurately capture stress and strain changes.

[0142] Step 1052: Adopt the material allowable values and establish a vehicle-level finite element model based on the vehicle body materials and structure for initial load-bearing capacity analysis.

[0143] Step 1053: According to the load-bearing capacity analysis, select the high-stress and high-strain high-load-bearing composite material structure areas as the key areas.

[0144] Step 1054: Establish multi-level sub-models at the component, assembly, typical structural part, and element levels based on the key areas.

[0145] Step 1055: Extract the load boundary conditions of the element-level specimens using the sectional force method in Step 104-3 for each static strength load condition of the vehicle body virtual model.

[0146] Step 1056: Conduct element-level specimen tests and perform cross-validation calibration on the element-level virtual model according to the load boundary conditions of the element-level specimens. At the same time, considering the environmental load factor compensation coefficient, if the physical test fails under the ultimate load, the vehicle body strength does not meet the requirements, and if necessary, correct each level of the model.

[0147] Step 1057: Conduct element-level standard tests and determine the design allowable values for each area according to Step 103-2.

[0148] Step 1058: Extract the load boundary conditions of the typical structural parts using the sectional force method in Step 104-3 for each load condition of the vehicle body static strength.

[0149] Step 1059: Use the sectional force method in Step 104-3 to conduct typical structural part tests and perform cross-validation calibration on the virtual model according to the load boundary conditions of the typical structural parts. If necessary, correct each level of the model. At the same time, considering the environmental load factor compensation coefficient, if the physical test fails under the ultimate load, the vehicle body strength does not meet the requirements. If the physical test does not fail under the ultimate load, continue to increase the load until it fails to preliminarily determine the non-damage design value of the initial structure.

[0150] Step 10510: Use the sectional force method in Step 104-3 to extract the load boundary conditions of the assemblies for each load condition of the vehicle body static strength.

[0151] Step 10511: Conduct assembly tests and perform cross-validation calibration on the virtual model according to the load boundary conditions of the assemblies. If necessary, correct each level of the model. At the same time, considering the environmental load factor compensation coefficient, if the physical test fails under the ultimate load, the vehicle body strength does not meet the requirements. If the physical test does not fail, continue to increase the load until it fails to revise the design value as the second design value of the corresponding structure in this area without secondary damage.

[0152] Step 10512: Respectively adopt the ultimate load and the limit load, and extract the load boundary conditions of components according to the sectional force method in Step 104-3 for each load condition of the static strength of the car body.

[0153] Step 10513: Use the limit load to verify whether the strength of the metal part of the component meets the requirements. Verify the force transmission form of the structure and the accuracy of the model through the comparison between the component-level sub-model and the component test. Modify the model if necessary. Conduct the ultimate load strength test verification and simulation considering the environmental impact factor.

[0154] Step 10514: Use the ultimate load considering the environmental impact factor to verify whether the strength of the composite material structure part of the component meets the requirements. Verify the force transmission form of the structure, the accuracy of the model, and the static strength of the component composite material through the comparison between the component-level sub-model and the component test. Modify the model if necessary. The material parameters of the metal structure part of the virtual model need to consider the plastic section effect. Under the condition of considering the environmental impact factor, if the composite material structure shows the situation of the failure criterion in Step 104-3 under the ultimate load, the static strength does not meet the requirements.

[0155] Step 10515: Conduct the static strength verification at the vehicle level. Use the static strength test under the limit load to verify the strength of the metal part, and further confirm the reliability of the test model and the simulation model. On the premise of ensuring the reliability, conduct the virtual verification of the ultimate strength of the composite material structure at the vehicle level, and consider the environmental load factor compensation coefficient to further confirm whether the static strength at the vehicle level meets the static strength requirements. The static strength of the composite material structure has been verified in Step 10514, and the vehicle-level virtual verification of the composite material structure in Step 10515 can also be selected not to be conducted.

[0156] Example 2:

[0157] The second embodiment of the present invention provides a multi-level virtual-real combined static strength verification system for a rail transit composite material car body, including:

[0158] A virtual model construction module, configured to: determine the material allowable value and the environmental load factor, and establish a virtual model according to the car body size and material parameters;

[0159] A key area determination module, configured to: combine the material allowable value, establish a vehicle-level finite element model according to the car body material and structure for initial load-bearing capacity analysis, and select the high-load composite material structure area as the key area according to the load-bearing capacity analysis result;

[0160] A multi-level sub-model acquisition module, configured to: establish multi-level sub-models at the component, assembly, typical structural part, and element levels according to the key area;

[0161] The component-level specimen verification module is configured to: according to each static strength load condition of the vehicle body virtual model, extract the load boundary conditions of the component-level specimen by using the sectional force method, conduct component-level specimen tests according to the load boundary conditions of the component-level specimen, and perform mutual verification and calibration on the component-level virtual model;

[0162] The typical structural member verification module is configured to: according to each static strength load condition of the vehicle body virtual model, extract the load boundary conditions of the typical structural member by using the sectional force method, conduct typical structural member tests according to the load boundary conditions of the typical structural member, and perform mutual verification and calibration on the virtual model;

[0163] The assembly verification module is configured to: according to each static strength load condition of the vehicle body virtual model, extract the load boundary conditions of the assembly by using the sectional force method, conduct assembly tests according to the load boundary conditions of the assembly, and perform mutual verification and calibration on the virtual model;

[0164] The component verification module is configured to: respectively adopt the ultimate load and the limit load. According to each static strength load condition of the vehicle body virtual model, extract the load boundary conditions of the component by using the sectional force method, use the limit load to verify whether the strength of the metal part of the component meets the requirements, and verify the force transmission form of the structure and the accuracy of the model through the comparison between the component-level sub-model and the component test; adopt the ultimate load considering the environmental impact factor to verify whether the strength of the composite material structure part of the component meets the requirements, and verify the force transmission form of the component structure, the accuracy of the model, and the static strength of the component composite material through the comparison between the component-level sub-model and the component test.

[0165] The working method of the system is the same as the multi-level virtual-real combined static strength verification method for the rail transit composite material vehicle body provided in Embodiment 1, and will not be elaborated here.

[0166] Embodiment 3:

[0167] Embodiment 3 of the present invention provides a computer-readable storage medium, on which a program is stored, and when the program is executed by a processor, it implements the steps in the multi-level virtual-real combined static strength verification method for the rail transit composite material vehicle body as described in Embodiment 1 of the present invention.

[0168] Embodiment 4:

[0169] Embodiment 4 of the present invention provides an electronic device, including a memory, a processor, and a program stored on the memory and executable on the processor. When the processor executes the program, it implements the steps in the multi-level virtual-real combined static strength verification method for the rail transit composite material vehicle body as described in Embodiment 1 of the present invention.

[0170] Those skilled in the art should understand that the embodiments of the present invention can be provided as a method, a system, or a computer program product. Therefore, the present invention can take the form of a hardware embodiment, a software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present invention can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk memory and optical memory, etc.) that contain computer-usable program code.

[0171] The present invention is described with reference to the flowcharts and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the present invention. It should be understood that each flow and / or block in the flowchart and / or block diagram, and the combination of flows and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, such that the instructions executed by the processor of the computer or other programmable data processing devices generate means for implementing the functions specified in one Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.

[0172] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, such that the instructions stored in the computer-readable memory generate a manufactured article including instruction means that implement the functions specified in one Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.

[0173] These computer program instructions can also be loaded onto a computer or other programmable data processing device, such that a series of operation steps are performed on the computer or other programmable device to generate a computer-implemented process, and thus the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.

[0174] Those of ordinary skill in the art can understand that all or part of the processes of implementing the above-mentioned embodiment methods can be completed by instructing relevant hardware through a computer program. The program can be stored in a computer-readable storage medium. When the program is executed, it can include the processes of the above-mentioned method embodiments. Among them, the storage medium can be a magnetic disk, an optical disk, a read-only memory (ROM), or a random access memory (RAM), etc.

[0175] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A multi-level virtual-real combined static strength verification method for a rail transit composite vehicle body, characterized in that: It includes the following processes: Determine the material allowable value and environmental load factor, and establish a virtual model according to the vehicle body size and material parameters; Combined with the material allowable value, establish a vehicle-level finite element model according to the vehicle body material and structure for initial bearing capacity analysis. According to the bearing capacity analysis results, select the high-bearing composite material structure area as the key area; Establish multi-level sub-models at the component, assembly, typical structural part, and element levels according to the key area; According to each static strength load condition of the vehicle body virtual model, use the sectional force method to extract the load boundary conditions of the element-level specimens. According to the load boundary conditions of the element-level specimens, conduct element-level specimen tests and perform mutual verification and calibration on the element-level virtual model; According to each static strength load condition of the vehicle body virtual model, use the sectional force method to extract the load boundary conditions of the typical structural parts. According to the load boundary conditions of the typical structural parts, conduct typical structural part tests and perform mutual verification and calibration on the virtual model; According to each static strength load condition of the vehicle body virtual model, use the sectional force method to extract the load boundary conditions of the assemblies. According to the load boundary conditions of the assemblies, conduct assembly tests and perform mutual verification and calibration on the virtual model; Respectively use the ultimate load and the limit load. According to each static strength load condition of the vehicle body virtual model, use the sectional force method to extract the load boundary conditions of the components. Use the limit load to verify whether the strength of the metal part of the component meets the requirements. Through the comparison between the component-level sub-model and the component test, verify the force transmission form of the structure and the accuracy of the model; Use the ultimate load considering the environmental impact factor to verify whether the strength of the composite material structure part of the component meets the requirements. Through the comparison between the component-level sub-model and the component test, verify the force transmission form of the component structure, the accuracy of the model, and the static strength of the component composite material.

2. The multi-level virtual-real combined static strength verification method for a rail transit composite vehicle body according to claim 1, characterized in that: For the element-level specimens, when considering the environmental load factor compensation coefficient, if the physical test fails under the ultimate load, the vehicle body strength does not meet the requirements. Modify the multi-level sub-model, conduct element-level standard tests, and determine the design allowable values for each area.

3. The multi-level virtual-real combined static strength verification method for a rail transit composite vehicle body according to claim 1, characterized in that: For the typical structural part-level specimens, determine the environmental load factor. When considering the environmental load factor compensation coefficient, if the physical test fails under the ultimate load, the vehicle body strength does not meet the requirements. If the physical test does not fail under the ultimate load, continue to increase the load until it fails, and preliminarily determine the non-damage design value.

4. The multi-level virtual-real combined static strength verification method for a rail transit composite vehicle body according to claim 1, characterized in that: For assembly-level specimens, the environmental load factor is determined. Taking into account the environmental load factor compensation coefficient, if damage occurs in the physical test under the ultimate load, the vehicle body strength does not meet the requirements. If no damage occurs in the physical test, the load is further amplified until it reaches the value of damage, and a revised design value is obtained as the second design value for the corresponding structure in this area without the second type of damage.

5. The multi-level virtual-real combination static strength verification method for rail transit composite material car body according to claim 1, characterized in that: Section force method, including: The corresponding loads are applied to the overall virtual model, the boundary node displacements of the corresponding multi-level virtual model are extracted, and equivalent boundary conditions are applied according to the node displacements.

6. The method for verifying the multi-level virtual-real combination static strength of a rail transit composite material vehicle body according to claim 5, characterized in that: A multi-level virtual model approach is used to determine the loads, including: Apply corresponding loads in the overall virtual model, extract the force values of the boundary section nodes and their comprehensive section forces of the corresponding hierarchical model, and apply corresponding loads according to the node force values and the comprehensive section forces including force and bending moment.

7. The method for verifying the multi-level virtual-real combination static strength of a rail transit composite material vehicle body according to claim 1, characterized in that: The load used for static strength adopts the standard load of the corresponding vehicle type category. The standard loads are all limit loads. When the limit load is used as the external load of the structure, an uncertainty factor of 1.5 or a safety factor is used. When the limit load is used to specify the loading condition, the safety factor is not used.

8. The multi-level virtual-real combination static strength verification method for rail transit composite material car body according to claim 1, characterized in that: Environmental conditions for static strength verification include: temperature, humidity, environmental corrosion, natural aging, and lightning strikes.

9. The method for verifying the multi-level virtual-real combination static strength of a rail transit composite material vehicle body according to claim 8, characterized in that: The determination of the maximum and minimum temperatures that a vehicle may encounter during its service process includes: determining the maximum structural temperature caused by climate based on the high temperature of the climate in the area where the vehicle is intended to be used, plus the maximum possible temperature rise caused by sunlight exposure; and determining the minimum structural temperature caused by climate based on the minimum ground temperature.

10. The method for verifying the multi-level virtual-real combination static strength of a rail transit composite material vehicle body according to claim 8, characterized in that: Determination of humidity includes: determining the equilibrium moisture absorption reached at the end of the composite material structure's life based on the vehicle's design service life and expected use environment.

11. The method for verifying the multi-level virtual-real combination static strength of a rail transit composite material vehicle body according to claim 8, characterized in that: Determination of environmental corrosion conditions and natural aging conditions includes: compiling corrosion and aging spectra of composite materials structures according to the use and storage environment; using natural exposure or accelerated tests of specimens, components, and typical structural parts and assemblies to verify the corrosion and aging resistance of composite materials structures; using the test results of corrosion and aging resistance of specimens, components, typical structural parts and assemblies to correct the analysis and test results of full-size components.

12. The multi-level virtual and physical combined static strength verification method for the rail transit composite material car body as claimed in claim 1, wherein: For a single-layer board, the mechanical properties of the unidirectional laminate at room temperature dry state, low temperature dry state and high temperature wet state are given, including: Tensile elastic modulus and strength in the 0° or warp direction and 90° or weft direction; compressive elastic modulus and strength in the 0° or warp direction and 90° or weft direction; in-plane or transverse shear elastic modulus and strength; major Poisson's ratio; For a sandwich structure, the mechanical properties of the sandwich structure at room temperature dry state, low temperature dry state and high temperature wet state are given, including: out-of-plane tensile strength, out-of-plane compressive strength and out-of-plane shear strength; For a notch-free laminate, the mechanical properties of the typical ply laminate at room temperature dry state, low temperature dry state and high temperature wet state are given, including: tensile elastic modulus and strength, compressive elastic modulus and strength, in-plane shear elastic modulus and strength, Poisson's ratio; For a laminate with a notch, the tensile and compressive strengths of the open hole and filled hole at room temperature dry state, low temperature dry state and high temperature wet state are given; For a laminate with impact damage, the post-impact compressive strength value and the carpet curve of the laminate in the room temperature dry state environment are given; For the mechanical connection extrusion strength, the mechanical connection extrusion strength of the laminate at room temperature dry state and high temperature wet state is given.

13. The multi-level virtual and physical combined static strength verification method for the rail transit composite material car body as claimed in claim 1, wherein: According to the integrity requirements of the specific structure designed, based on the existing allowable values, test results of specimens and components representing the typical characteristics of the structure, and design and use experience, and according to the test results of the assembly, the design values of different parts of the structure are determined.

14. A multi-level virtual and physical combined static strength verification system for a rail transit composite material car body, wherein: It includes: A virtual model construction module, configured to: determine the material allowable values and environmental load factors, and establish a virtual model according to the car body size and material parameters; A key area determination module, configured to: combine the material allowable values, establish a vehicle-level finite element model according to the car body material and structure for initial bearing capacity analysis, and select the high-load composite material structure area as the key area according to the bearing capacity analysis results; A multi-level sub-model acquisition module, configured to: establish multi-level sub-models at the component, assembly, typical structural part and element levels according to the key area; An element-level specimen verification module, configured to: extract the load boundary conditions of the element-level specimen by using the section force method according to each static strength load condition of the car body virtual model, conduct element-level specimen tests according to the load boundary conditions of the element-level specimen, and perform mutual verification and calibration on the element-level virtual model; A typical structural part verification module, configured to: extract the load boundary conditions of the typical structural part by using the section force method according to each static strength load condition of the car body virtual model, conduct typical structural part tests according to the load boundary conditions of the typical structural part, and perform mutual verification and calibration on the virtual model; The assembly verification module is configured to: according to each static strength load condition of the vehicle body virtual model, extract the load boundary conditions of the assembly by using the sectional force method, and perform assembly tests and mutual verification and calibration on the virtual model according to the load boundary conditions of the assembly; The component verification module is configured to: respectively adopt the ultimate load and the limit load, extract the load boundary conditions of the component by using the sectional force method according to each static strength load condition of the vehicle body virtual model, verify whether the strength of the metal part of the component meets the requirements by using the limit load, and verify the force transmission form of the structure and the accuracy of the model through the comparison between the component-level sub-model and the component test; adopt the ultimate load considering the environmental impact factor to verify whether the strength of the composite material structure part of the component meets the requirements, and verify the force transmission form of the component structure, the accuracy of the model and the static strength of the component composite material through the comparison between the component-level sub-model and the component test.

15. A computer-readable storage medium having a program stored thereon, characterized in that, When the program is executed by the processor, it implements the steps in the multi-level virtual-real combination static strength verification method for the rail transit composite material vehicle body as described in any one of claims 1-13.

16. An electronic device, comprising a memory, a processor, and a program stored on the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the steps in the multi-level virtual-real combination static strength verification method for the rail transit composite material vehicle body as described in any one of claims 1-13.

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