A simulation method for structural detection of hydrogen storage cylinders based on thermal imaging fiber winding

Abstract

The present invention provides a simulation method for detecting the structure of a hydrogen storage cylinder based on thermal imaging fiber winding, establishes a corresponding simulation model according to the cylinder size data and on-site measurement data, performs active thermal excitation infrared thermal imaging simulation on different models, including active thermal excitation infrared thermal imaging simulation on damaged lining models with different laying layers, active thermal excitation infrared thermal imaging simulation on glass fiber epoxy resin ply damage model, and active thermal excitation infrared thermal imaging simulation on carbon fiber epoxy resin ply debonding model, and analyzes the simulation results of active thermal excitation infrared thermal imaging on different models. The method provides a scientific basis for the design, manufacture and detection of hydrogen storage cylinders by simulating and analyzing the effects of different defects on the mechanical properties of hydrogen storage cylinders. Through this method, defects can be discovered and repaired in a timely manner, thereby improving the safety and reliability of hydrogen storage cylinders.

Description

Technical Field

[0001] The invention belongs to the technical field of gas cylinder structure detection simulation, and in particular relates to a simulation method for structure detection of hydrogen storage gas cylinders based on thermal imaging fiber winding. Background Art

[0002] With the popularization of hydrogen energy, hydrogen-powered buses have gradually become mainstream, and the core of their safe use is the hydrogen storage system. Fiber-wound gas cylinders are widely used due to their high strength and good pressure-bearing capacity, but long-term use may be affected by various factors and cause performance degradation. To ensure the safety of gas cylinders, subsequent inspections are essential. This not only ensures the safe operation of hydrogen-powered buses, but also promotes the development of clean energy, improves the urban environment, and improves energy efficiency. Therefore, strengthening the inspection and maintenance of fiber-wound gas cylinders is an important part of the widespread application of hydrogen-powered buses.

[0003] Due to the characteristics of its operating conditions, fiber-wound gas cylinders are subject to long-term alternating loads, and their safety and reliability are extremely important. Therefore, it is urgent to strengthen the risk prevention and control research of hydrogen storage pressure equipment, carry out experimental research on materials, components and products in hydrogen environments, and carry out key technical research such as hydrogen storage equipment inspection and testing. The current problems are as follows: (1) The applicability of the detection method. According to current standards such as GB / T24162-2009 "Periodic Inspection and Assessment of Metal Liner Fiber Ring Wrapped Compressed Natural Gas Cylinders for Automobiles" and TSG21-2016 "Regulations on Safety Technical Supervision of Stationary Pressure Vessels", the periodic inspection of vehicle gas cylinders requires internal and external inspection and water pressure testing of the cylinders after they are disassembled. The periodic inspection of fixed hydrogen pressure vessels sometimes also requires water pressure testing. Due to the special nature of the medium of hydrogen storage pressure vessels and high-pressure hydrogen cylinders, the hydrogen contained must meet the quality requirements of hydrogen fuel cells, with high purity and sealing requirements. Disassembly and assembly of high-pressure hydrogen cylinders may damage their sealing performance, posing a safety hazard. In some hydrogen fuel cell cars, the high-pressure hydrogen cylinders are installed on the chassis of the car, making assembly and disassembly very difficult. In order to meet the hydrogen purity requirements, the inner surfaces of hydrogen storage pressure vessels and hydrogen cylinders have undergone special purification treatment before leaving the factory. The water pressure test during regular inspection will cause contamination or rust on the inner surface, and the inner surface needs to be re-cleaned. Therefore, when revising the relevant safety technical specifications and standards, it is necessary to study and solve the new problems brought about by the regular inspection items and requirements stipulated therein, so as to avoid the above-mentioned safety hazards and unnecessary subsequent treatments.

[0004] (2) Lack of effective detection and evaluation methods. The failure modes and mechanisms of some special structural hydrogen pressure equipment have not been fully understood, and there is a lack of effective detection methods and safety evaluation rules. For example, the inspection of composite high-pressure hydrogen cylinders is limited to appearance inspection and leak detection, and there is no effective method to detect defects inside the cylinder; the connection joint between the valve seat and the inner liner of the cylinder is the weakest link of Type IV high-pressure hydrogen cylinders, but there is a lack of effective non-destructive testing methods and evaluation rules, so research on related technologies should be strengthened. The damage of fiber-wound composite materials has no obvious deformation in the macroscopic morphology, which makes the damage difficult to detect.

[0005] Thermal imaging detection technology is based on the basic principle of infrared radiation. It uses an infrared thermal imager to obtain the change in the surface temperature of the object being tested, and then uses the law of heat transfer to evaluate the defects and damage in the object being tested. The material is made to produce a thermal response through thermal excitation, and the difference in temperature field is recorded by an infrared thermal imager, making the detection of internal defects a reality. For the inspection of fiber-wound gas cylinders, active thermal excitation infrared detection numerical simulation technology is used to test the safety performance of the gas cylinders to achieve the purpose of accurately detecting defects.

[0006] At present, there are few studies on thermal imaging fiber-wound hydrogen storage cylinder structure detection. In order to better study the application of thermal imaging technology in fiber-wound hydrogen storage cylinder structure detection, a simulation method for studying thermal imaging fiber-wound hydrogen storage cylinder structure detection is urgently needed. Summary of the invention

[0007] In view of the problem of thermal imaging filament wound hydrogen storage cylinder structure detection, the present invention provides a simulation method based on thermal imaging filament wound hydrogen storage cylinder structure detection, which is used for research on thermal imaging filament wound hydrogen storage cylinder structure detection.

[0008] The solution adopted by the present invention to solve the technical problem is: a simulation method based on thermal imaging fiber winding hydrogen storage cylinder structure detection, comprising the following steps: Step 1: Establish a lining model based on the cylinder size data and on-site measurement data, and build a 1-8-layer carbon fiber epoxy resin laying layer model based on the lining model; Setting a damaged part at a corresponding position of the lining model to construct a damaged lining model; The eight-layer carbon fiber epoxy resin laying layer model is wrapped and wound on the damaged lining model in sequence to construct the damaged lining model with different laying layers; Two layers of glass fiber epoxy resin plies are arranged on the outer surface of the eighth layer of carbon fiber epoxy resin ply, and corresponding damage locations are arranged on the glass fiber epoxy resin ply to construct a glass fiber epoxy resin ply damage model; Establish debonding models of carbon fiber epoxy resin layup layers at different depths; Step 2: Active thermal excitation infrared thermal imaging simulation is performed on different models, including active thermal excitation infrared thermal imaging simulation of damaged lining models with different laying layers, active thermal excitation infrared thermal imaging simulation of glass fiber epoxy resin ply damage model and active thermal excitation infrared thermal imaging simulation of carbon fiber epoxy resin ply debonding model; Step 3: Analyze the simulation results of active thermal actuation infrared thermal imaging of different models.

[0009] Furthermore, in step one, a 10° liner model is established based on the cylinder size information and on-site measurement data. The material of the liner model is set to aluminum alloy, the thickness of each carbon fiber epoxy resin layer is 1 mm, and the thickness of each glass fiber epoxy resin layer is 1 mm.

[0010] Furthermore, Wound Composite Modeler was used to finely model the hoop- and spirally wound carbon fiber epoxy resin layup layers.

[0011] Furthermore, three carbon fiber epoxy resin ply debonding models were established, namely, a 1-2 layer debonding model, a 4-5 layer debonding model and a 7-8 layer debonding model. The debonding model separately established an infinitely thin solid homogeneous ply between two adjacent carbon fiber epoxy resin ply layers and set the solid homogeneous ply material, wherein the debonded part of the solid homogeneous ply was set to air, and the non-debonded part was set to carbon fiber epoxy resin.

[0012] Furthermore, the simulation of active thermal actuation infrared thermography simulation selected a 100° C. heat source to be applied on each surface of the lining model surface and the damaged area.

[0013] Furthermore, the active thermal excitation infrared thermal imaging simulation of the damaged lining model with different laying layers includes the following steps: S21. Material assignment Create aluminum alloy and carbon fiber epoxy materials based on material thermal properties and add material properties to the corresponding models; S22, set the analysis step The analysis step type is transient heat transfer, the time is set to 10s, the type is automatic, the initial increment step is set to 1, the maximum increment step is set to 1, the minimum increment step is set to 1e-20, the maximum number of increment steps is set to 10000, the maximum temperature change per increment step is set to 2, and the minimum is set to 0.1; S23. Set up interactions The surface film condition is set to simulate heat dissipation. The heat dissipation surface is the outer surface of the gas cylinder, the heat dissipation coefficient is set to 2000, and the ambient temperature is set to 20; S24. Set boundary conditions A heat source of 100°C was applied to the surface of the lining model and the damaged area, and the predefined temperature field of the entire model was set to 20°C as the initial temperature of the entire model; S25. Grid settings Set the element type to DC3D8, which is a linear heat conduction hexahedral element with 8 nodes and describes the temperature distribution based on a linear interpolation function.

[0014] Furthermore, the active thermal excitation infrared thermal imaging simulation of the glass fiber epoxy resin laminate damage model includes the following steps: S31. Material assignment Create a material library based on the thermal properties of the material to add glass fiber epoxy resin material, and add the material properties to the corresponding model; S32, set the analysis step The analysis step type is transient heat transfer, the time is set to 10s, 30s and 60s, the type is automatic, the initial increment step is set to 1, the maximum increment step is set to 1, the minimum increment step is set to 1e-20, the maximum number of increment steps is set to 10000, the maximum temperature change per increment step is set to 2, and the minimum is set to 0.1; S33. Set up interactions The surface film condition is set to simulate heat dissipation. The heat dissipation surface is the outer surface of the gas cylinder, the heat dissipation coefficient is set to 2000, and the ambient temperature is set to 20; S34. Set boundary conditions A 100℃ heat source is applied to the surface of the lining model and each surface of the damaged part, and the predefined temperature field of the entire model is set to 20℃ as the initial temperature of the entire model. The temperature cloud map change at the damaged part is observed by heat dissipation and cooling to judge the damage condition. The predefined temperature field is set to four working conditions of 50℃, 100℃, 150℃ and 200℃, and each working condition is set to three times of 10s, 30s and 60s to observe the temperature cloud map change at the damaged position at different temperatures and different times; S35, Grid Settings Set the unit type to DC3D4, which is a linear heat conduction tetrahedron consisting of four nodes.

[0015] Furthermore, the active thermal excitation infrared thermal imaging simulation of the debonding model of the carbon fiber epoxy resin laying layer used a comparative analysis of the two methods of heating and cooling. The heating method performed a heating simulation by setting a 100°C heat source on the inner surface of the lining model of the fiber-wound hydrogen storage cylinder, and the cooling simulation was performed by setting a predefined temperature field to dissipate heat. The temperature cloud map at the debonding position under heating conditions and cooling conditions was compared and analyzed by heating and cooling. The relationship between the difference and the debonding depth and debonding area was further analyzed.

[0016] Beneficial effects of the present invention: The present invention proposes a method for numerical simulation research on the influence of defects on the structural integrity of filament-wound hydrogen storage cylinders. The method provides a scientific basis for the design, manufacture and inspection of hydrogen storage cylinders by simulating and analyzing the influence of different defects on the mechanical properties of hydrogen storage cylinders. The simulation results show that the presence of defects will significantly reduce the load-bearing capacity and fatigue resistance of hydrogen storage cylinders. Through this method, defects can be discovered and repaired in a timely manner, thereby improving the safety and reliability of hydrogen storage cylinders. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the lining model of the hydrogen storage cylinder; Figure 2 is a schematic diagram of the damaged lining model; Figure 3 This is a schematic diagram of the wrapping and winding of the carbon fiber epoxy resin laying layer; Figure 4 It is a schematic diagram of the glass fiber epoxy resin layup model; Figure 5 It is a schematic diagram of the debonding model of the carbon fiber epoxy resin layup layer; Figure 6 It is a schematic diagram of the heat dissipation surface of the simulation model; Figure 7 It is a schematic diagram of the heat source surface applied by the simulation model; Figure 8 It is a schematic diagram of the material of the debonded pavement; Fig. 9 It is a schematic diagram of the assembly state of the debonded pavement; Fig.10 It is the simulation setting frame view. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be described in detail below.

[0019] Embodiment 1: Finite Element Method (FEM) is a method suitable for solving complex elastic mechanics and structural mechanics problems. The main idea of ​​solving the problem is to discretize the object model and divide the model into a certain number of unit grids, and then use the approximate solution method to approximate the unknown quantity of the simplified model. The ABAQUS finite element calculation platform has outstanding application characteristics when solving nonlinear problems. In view of the thermal properties of the coating layer of the hydrogen storage container, the present invention selects ABAQUS finite element simulation calculation software for simulation.

[0020] The steps of finite element simulation analysis are mainly divided into model pre-processing, model solving and calculation result post-processing. Pre-processing is to convert the engineering research problem into a reasonable model in ABAQUS, which mainly includes: establishing a geometric model, setting material properties, dividing the grid, setting boundary conditions and loads. Model solving requires selecting a suitable solver according to the type of problem to be solved. After the finite element model is solved, the calculation results need to be post-processed, generally including cloud maps and format processing of various output variables. The thermal simulation of the hydrogen storage container of the present invention also follows the above solution process.

[0021] According to the geometric structure and load-bearing characteristics of the carbon fiber composite hydrogen storage container studied in the present invention, in order to improve the calculation efficiency and reduce the amount of calculation, a 10° or 1 / 36 model is selected to replace the full-size model. The lining of this model is 6061 aluminum alloy, and the coating layer is a carbon fiber resin composite material and a glass fiber resin composite material. The carbon fiber resin composite winding layer has a total of 8 layers, each with a thickness of 1mm, and the glass fiber resin protective layer has 2 layers, each with a thickness of 1mm. According to the requirements of the present invention, a total of 3 models of different defect conditions were established, namely the lining damage model, the glass fiber ply damage model and the ply debonding model, and the simulation results of the three models were analyzed.

[0022] For the modeling of carbon fiber composite winding layers, different from the traditional manual modeling method, the present invention selects a special modeling plug-in for hydrogen storage container composite materials (Wound Composite Modeler, WCM) to perform fine modeling of circumferential and spiral winding layers. In WCM, two layers of spiral winding layers with positive and negative angles are defined as one layer. It adopts a layer-by-layer modeling method, with the outer contour of the lining as the modeling reference and combined with the fiber thickness predicted by the cubic spline formula for modeling. During the ply modeling process, the head curve contour is segmented and the discrete thickness value is determined by the coordinate value of the segmentation point. The outer contour points of the corresponding layer thickness are solved in the normal direction of each tangent point, and finally the outer contour points are connected to complete the modeling of the first layer of winding layer that contacts the lining surface. Repeat this process in the future, and the second layer of winding is modeled based on the outer contour of the first layer of fiber winding. Such a ply method can more realistically describe the actual ply state.

[0023] The present invention has created 8 liner damage models with different numbers of layers and 3 different damage depths to compare and analyze the temperature changes of the outer surface of the layers under different numbers of layers, in order to observe the temperature changes of the outer surface of the layers under the condition of heat source boundary conditions, and whether the damage location and damage depth can be determined from the temperature distribution cloud map. These 8 model layers do not contain glass fiber protective layers.

[0024] The liner model is established based on the cylinder size information and on-site measurement data. The damage-free model is as follows: Figure 1 , there is a damage model where the damage location is as follows Figure 2 The damage size from left to right is 20mm×0.5mm×0.5mm, 20mm×0.5mm×1mm, and 20mm×0.5mm×1.5mm respectively. The thickness of each layer of carbon fiber resin winding ply of the above models is 1mm, and the damage position and damage size of each model are fixed.

[0025] like Figure 3 As shown, the present invention establishes 8 different layers of lining damage models to compare and analyze the temperature changes of the outer surface of the layers under different numbers of layers. At the same time, a damaged model with 4 damages on the outer surface of the glass fiber layer is established. The glass fiber layer model is established on the basis of the eight-layer lining damage model. The fiber-wound hydrogen storage cylinder outer layer damage model is established by adding two layers of damaged glass fiber resin layers on the outer surface of the eighth layer of the eight-layer lining damage model. The purpose of establishing this model is to observe whether the damage location and damage depth can be observed through the simulated temperature cloud map when a heat source is applied to the surface of the glass fiber layer.

[0026] A damage model is established on the outer surface of the glass fiber layer. The damage location is as follows: Figure 4 As shown, the damage dimensions from left to right are: 20mm×1mm×2mm in length×width×height, 20mm×1mm×1.4mm, 20mm×1mm×0.8mm, 20mm×1mm×0.2mm.

[0027] Three ply debonding models with different depths were established, namely the 1-2 ply debonding model, the 4-5 ply debonding model and the 7-8 ply debonding model. There are four debonding areas for each ply debonding model. The unit debonding area A is 30×40mm2, and the four debonding areas are 4 times the unit area, 3 times the unit area, 2 times the unit area and 1 times the unit area. The purpose of setting different debonding depths and different debonding areas is to obtain the temperature difference on the surface of the outermost ply of different debonding depths and different debonding area models. This temperature difference can be used to locate the debonding position between the plies of the solid fiber-wound high-pressure hydrogen storage cylinder and estimate the debonding area.

[0028] The debonding model is established on the basis of the damage-free model of the fiber-wound cylinder liner. An infinitely thin solid homogeneous ply is established between two adjacent plies and the ply material is specially set. The material properties of the debonded part of the ply are set to air, and the remaining non-debonded part is set to resin material properties.

[0029] The three debonding models established have similar features except for the debonding depth. Figure 5 shown.

[0030] For the simulation of active thermal excitation infrared thermal imaging of the carbon fiber wrapped gas cylinder liner damage model, a 100°C heat source was applied to the liner surface and each surface of the damage to simulate 100°C hot water. Fig.10 Shown is a simulation setup box view.

[0031] The carbon fiber wrapped gas cylinder liner damage model simulation operation steps include: (1) Material assignment Create relevant materials in the abaqus material library, including 6061 aluminum alloy and carbon fiber epoxy resin materials, and assign them to the model.

[0032] (2) Set the analysis step The analysis step type is transient heat transfer, the time is set to 10s, the type is automatic, the initial increment is set to 1, the maximum increment is set to 1, the minimum increment is set to 1e-20, the maximum number of increments is set to 10000, the maximum temperature change per increment is set to 2, and the minimum is set to 0.1. After the analysis step settings are completed, modify the solver and change IA to 20.

[0033] (3) Set up interactions The present invention uses the setting of surface film condition to simulate heat dissipation, such as Figure 6 As shown, the heat dissipation surface is the outer surface of the gas cylinder, the heat dissipation coefficient is set to 2000, and the ambient temperature is set to 20.

[0034] (4) Setting boundary conditions like Figure 7 As shown, a heat source of 100°C is applied to each surface of the lining surface and the damaged area, and the predefined temperature field of the entire model is set to 20°C as the initial temperature of the entire model.

[0035] (5) Grid settings The unit type is set to DC3D8, which is a linear heat conduction hexahedral unit with 8 nodes, and the temperature distribution is described based on a linear interpolation function. Since the 1-8 ply lining damage model established in the present invention is similar and the model size of the present invention is relatively large, only part of the mesh division of the 8-ply lining damage model is shown.

[0036] For the simulation of active thermal excitation infrared thermal imaging of the glass fiber ply damage model, a cooling method with a predefined temperature field was used. Four predefined temperature fields were set at 50°C, 100°C, 150°C and 200°C, respectively, to observe the changes in the temperature cloud map at the damage position of the glass fiber ply damage model under different predefined temperature field conditions.

[0037] The simulation operation steps of the glass fiber ply damage model include: (1) Material assignment Add glass fiber epoxy resin material to the abaqus material library and assign it to the model.

[0038] (2) Set the analysis step The analysis step type is transient heat transfer, the time is set to 10s, 30s and 60s, the type is automatic, the initial increment is set to 1, the maximum increment is set to 1, the minimum increment is set to 1e-20, the maximum number of increments is 10000, the maximum temperature change per increment is set to 2, and the minimum is set to 0.1. After the analysis step is set, modify the solver and change IA to 20. The specific parameters are as follows Figure 3-6 Different from the analysis step setting of the lining damage model, the simulation of the glass fiber ply damage model sets three time periods of 10s, 30s and 60s for each model to observe the changes in the temperature cloud map at different times.

[0039] (3) Set up interactions This simulation model uses the outer surface of the glass fiber protective layer and the inner surface of the lining as heat dissipation surfaces, and the specific parameter settings are the same as the simulation of the fiber-wound gas cylinder lining damage model.

[0040] (4) Setting boundary conditions The predefined temperature field is set, which is similar to the boundary condition setting of the lining damage model. It should be pointed out that this simulation model uses heat dissipation and cooling to observe the changes in the temperature cloud map at the damaged location to judge the damage situation. This model predefined temperature field has four working conditions of 50℃, 100℃, 150℃ and 200℃, and each working condition has three times of 10s, 30s and 60s, so as to observe the changes in the temperature cloud map at the damaged location at different temperatures and different times.

[0041] (5) Grid division This model is obtained by adding two layers of glass fiber protection on the basis of the 8-ply model, so the mesh type only needs to be set for the two additional layers of glass fiber protection. The mesh type of the two layers of glass fiber protection is set to DC3D4, which is a linear heat conduction tetrahedron composed of four nodes, which can simulate the heat transfer phenomenon, similar to the mesh division of the 8-ply lining damage model.

[0042] (6) Analysis and calculation The present invention sets 12 working conditions for active thermal excitation infrared thermal imaging simulation of fiber-wound gas cylinder glass fiber layer damage. The working condition naming rule is: the first number represents temperature, and the second number represents time. For example, Job-50-10 means that the predefined temperature field is 50°C and the analysis step time is 10s.

[0043] For the active thermal excitation infrared thermal imaging simulation of the ply debonding model, two methods of heating and cooling were used for comparative analysis. The heating method was the same as the method of active thermal excitation simulation of the liner damage model. The heating simulation was performed by setting a 100°C heat source on the inner surface of the liner of the fiber-wound hydrogen storage cylinder, and the cooling simulation was performed by setting a predefined temperature field for heat dissipation. The purpose of using the heating and cooling methods is to compare and analyze the difference in the temperature cloud map of the outermost ply at the debonding position under heating conditions and cooling conditions, and further analyze whether this difference is related to the debonding depth and debonding area.

[0044] The simulation parameter settings of the debonding models at three different depths are the same, and the temperature rise simulation is similar to the lining damage model settings, and the temperature drop simulation is similar to the glass fiber ply damage.

[0045] (1) Material assignment Create and assign air and resin material properties to the debonded plies.

[0046] like Figure 8 In the debonded ply shown, the material properties of the debonded area are air, and the material properties of other areas are resin.

[0047] (2) Model assembly This model is manually assembled, and the liner, 1 ply, debonded ply, and 2-8 plies are assembled together. Fig. 9 shown.

[0048] (3) Set the analysis step The analysis time for heating simulation and cooling simulation of this model is 300s. The heat source of heating simulation is set to 100℃, and the predefined temperature field of cooling simulation is 100℃. Other parameter settings are the same as those of the carbon fiber wrapped gas cylinder liner damage model.

[0049] Through the above method, the model is numerically simulated and analyzed to calculate the mechanical properties of hydrogen storage cylinders under different defects. The simulation analysis should include static analysis and dynamic analysis to comprehensively evaluate the impact of defects on the structural integrity of hydrogen storage cylinders. According to the simulation results, the impact of defects on the structural integrity of hydrogen storage cylinders is analyzed. Focus on the impact of defects on the load-bearing capacity, fatigue resistance and other aspects of hydrogen storage cylinders. According to the analysis results, corresponding improvement measures and suggestions are proposed. Such as repairing defects, optimizing structural design, improving manufacturing process level, etc., to improve the safety and reliability of hydrogen storage cylinders.

[0050] Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other implementation methods obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

Claims

1. A simulation method for structural detection of hydrogen storage cylinders based on thermal imaging fiber winding, characterized in that: The following steps are included: Step 1: Establish a lining model based on the cylinder size data and on-site measurement data, and build a 1-8-layer carbon fiber epoxy resin laying layer model based on the lining model; Setting a damaged part at a corresponding position of the lining model to construct a damaged lining model; The eight-layer carbon fiber epoxy resin laying layer model is wrapped and wound on the damaged lining model in sequence to construct the damaged lining model with different laying layers; Two layers of glass fiber epoxy resin plies are arranged on the outer surface of the eighth layer of carbon fiber epoxy resin ply, and corresponding damage locations are arranged on the glass fiber epoxy resin ply to construct a glass fiber epoxy resin ply damage model; Establish debonding models of carbon fiber epoxy resin layup layers at different depths; Step 2: Active thermal excitation infrared thermal imaging simulation is performed on different models, including active thermal excitation infrared thermal imaging simulation of damaged lining models with different laying layers, active thermal excitation infrared thermal imaging simulation of glass fiber epoxy resin ply damage model and active thermal excitation infrared thermal imaging simulation of carbon fiber epoxy resin ply debonding model; Step 3: Analyze the simulation results of active thermal actuation infrared thermal imaging of different models.

2. The simulation method for detecting the structure of hydrogen storage cylinders based on thermal imaging fiber winding according to claim 1 is characterized in that: In step 1, a 10° lining model is established based on the cylinder size information and on-site measurement data. The material of the lining model is set to aluminum alloy, the thickness of each carbon fiber epoxy resin layer is 1 mm, and the thickness of each glass fiber epoxy resin layer is 1 mm.

3. The simulation method for detecting the structure of hydrogen storage cylinders based on thermal imaging fiber winding according to claim 1 is characterized in that: Wound Composite Modeler was used to model the hoop and spirally wound carbon fiber epoxy resin lay-ups in detail.

4. The simulation method for detecting the structure of hydrogen storage cylinders based on thermal imaging fiber winding according to claim 1 is characterized in that: Three carbon fiber epoxy resin ply debonding models are established, namely, a 1-2 layer debonding model, a 4-5 layer debonding model and a 7-8 layer debonding model. The debonding model separately establishes an infinitely thin solid homogeneous ply between two adjacent carbon fiber epoxy resin ply layers and sets the material of the solid homogeneous ply, wherein the debonded part of the solid homogeneous ply is set to air, and the non-debonded part is set to carbon fiber epoxy resin.

5. The simulation method for detecting the structure of hydrogen storage cylinders based on thermal imaging fiber winding according to claim 1 is characterized in that: The simulation of active thermal actuation infrared thermography simulation selected a 100°C heat source to be applied on each surface of the lining model and the damaged area.

6. The simulation method for detecting the structure of hydrogen storage cylinders based on thermal imaging fiber winding according to claim 1 is characterized in that: The active thermal stimulation infrared thermal imaging simulation of the damaged lining model with different laying layers includes the following steps: S21. Material assignment Create aluminum alloy and carbon fiber epoxy materials based on material thermal properties and add material properties to the corresponding models; S22, set the analysis step The analysis step type is transient heat transfer, the time is set to 10s, the type is automatic, the initial increment step is set to 1, the maximum increment step is set to 1, the minimum increment step is set to 1e-20, the maximum number of increment steps is set to 10000, the maximum temperature change per increment step is set to 2, and the minimum is set to 0.1; S23. Set up interactions The surface film condition is set to simulate heat dissipation. The heat dissipation surface is the outer surface of the gas cylinder, the heat dissipation coefficient is set to 2000, and the ambient temperature is set to 20; S24. Set boundary conditions A heat source of 100°C was applied to the surface of the lining model and the damaged area, and the predefined temperature field of the entire model was set to 20°C as the initial temperature of the entire model; S25. Grid settings Set the element type to DC3D8, which is a linear heat conduction hexahedral element with 8 nodes and describes the temperature distribution based on a linear interpolation function.

7. The simulation method for detecting the structure of hydrogen storage cylinders based on thermal imaging fiber winding according to claim 1 is characterized in that: Active thermal excitation infrared thermal imaging simulation of glass fiber epoxy resin laminate damage model includes the following steps: S31. Material assignment Create a material library based on the thermal properties of the material to add glass fiber epoxy resin material, and add the material properties to the corresponding model; S32, set the analysis step The analysis step type is transient heat transfer, the time is set to 10s, 30s and 60s, the type is automatic, the initial increment step is set to 1, the maximum increment step is set to 1, the minimum increment step is set to 1e-20, the maximum number of increment steps is set to 10000, the maximum temperature change per increment step is set to 2, and the minimum is set to 0.1; S33. Set up interactions The surface film condition is set to simulate heat dissipation. The heat dissipation surface is the outer surface of the gas cylinder, the heat dissipation coefficient is set to 2000, and the ambient temperature is set to 20; S34. Set boundary conditions A 100℃ heat source is applied to the surface of the lining model and each surface of the damaged part, and the predefined temperature field of the entire model is set to 20℃ as the initial temperature of the entire model. The temperature cloud map change at the damaged part is observed by heat dissipation and cooling to judge the damage condition. The predefined temperature field is set to four working conditions of 50℃, 100℃, 150℃ and 200℃, and each working condition is set to three times of 10s, 30s and 60s to observe the temperature cloud map change at the damaged position at different temperatures and different times; S35, Grid Settings Set the unit type to DC3D4, which is a linear heat conduction tetrahedron consisting of four nodes.

8. The simulation method for detecting the structure of hydrogen storage cylinders based on thermal imaging fiber winding according to claim 1 is characterized in that: The active thermal excitation infrared thermal imaging simulation of the debonding model of the carbon fiber epoxy resin laying layer used two methods of heating and cooling for comparative analysis. The heating method performed a heating simulation by setting a 100°C heat source on the inner surface of the lining model of the fiber-wound hydrogen storage cylinder, and the cooling simulation was performed by setting a predefined temperature field for heat dissipation. The temperature cloud map at the debonding position under heating conditions and cooling conditions was compared and analyzed by heating and cooling. The relationship between the difference and the debonding depth and debonding area was further analyzed.

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