Method, system, equipment and medium for predicting fire resistance performance of vehicle-mounted hydrogen storage cylinders

Abstract

The present application provides a method, system, equipment and medium for predicting the fire resistance performance of on-board hydrogen storage cylinders, which belongs to the field of hydrogen storage cylinder application technology. The method includes: establishing a mechanical property degradation model of carbon fiber epoxy resin-based composite materials at high temperature and a mechanical response finite element model of on-board hydrogen storage cylinders under thermal-mechanical coupling; applying the mechanical property degradation model to the mechanical response finite element model, and performing finite element analysis in combination with the cylinder fire failure criterion to obtain a first change curve, which characterizes the relationship between the degree of fire failure of the on-board hydrogen storage cylinder and the gas pressure in the cylinder; obtaining a second change curve, which characterizes the change law of the gas pressure in the cylinder of the on-board hydrogen storage cylinder with the fire time; combining and analyzing the first change curve and the second change curve according to the cylinder fire failure criterion to obtain the bursting pressure and fire resistance time of the on-board hydrogen storage cylinder under fire. The present application can reliably predict the fire resistance performance parameters of on-board hydrogen storage cylinders.

Description

Technical Field

[0001] The present application relates to the technical field of hydrogen storage cylinder applications, and in particular to a method, system, equipment, and medium for predicting the fire resistance of vehicle-mounted hydrogen storage cylinders. Background Art

[0002] In the existing technology, since most vehicle-mounted hydrogen storage cylinders are equipped with pressure relief devices, the high-pressure hydrogen stored in the vehicle-mounted hydrogen storage cylinders can be released in time in the event of fire. Before the vehicle-mounted hydrogen storage cylinders are officially put into use, fire tests are usually carried out on the vehicle-mounted hydrogen storage cylinders and the pressure relief devices to complete the safety performance test. However, this test process does not take into account the situation where the pressure relief device cannot be opened in time, resulting in unreliable fire resistance performance evaluation of the vehicle-mounted hydrogen storage cylinders. Summary of the Invention

[0003] The main purpose of this application is to propose a method, system, equipment and medium for predicting the fire resistance performance of on-board hydrogen storage cylinders, which can perform finite element mechanical modeling analysis based on the structural material properties of the on-board hydrogen storage cylinders themselves, and at the same time combine the cylinder fire failure criteria for evaluation, so as to more reliably predict the fire resistance performance parameters of the on-board hydrogen storage cylinders.

[0004] To achieve the above objectives, one aspect of the present application provides a method for predicting the fire resistance performance of a vehicle-mounted hydrogen storage cylinder, wherein the vehicle-mounted hydrogen storage cylinder includes a composite material layer, and the composite material layer is made of a carbon fiber epoxy resin-based composite material. The method comprises:

[0005] Establishing a mechanical property degradation model of the carbon fiber epoxy resin-based composite material at high temperature and a finite element model of the mechanical response of the on-board hydrogen storage cylinder under thermal-mechanical coupling;

[0006] Applying the mechanical property degradation model to the mechanical response finite element model, and performing finite element analysis in combination with a preset gas cylinder fire failure criterion to obtain a first variation curve, wherein the first variation curve is used to characterize the relationship between the degree of fire failure of the on-board hydrogen storage gas cylinder and the gas pressure in the cylinder;

[0007] Obtaining a second variation curve, where the second variation curve is used to characterize a variation pattern of the gas pressure in the vehicle-mounted hydrogen storage cylinder with the burning time;

[0008] According to the cylinder fire failure criterion, the first change curve and the second change curve are combined and analyzed to obtain the bursting pressure and fire resistance time of the vehicle-mounted hydrogen storage cylinder under fire conditions.

[0009] Furthermore, the mechanical property degradation model is obtained by:

[0010] Acquire multiple sets of first test data, where the multiple sets of first test data are collected when conducting a high-temperature mechanical property test of the carbon fiber-epoxy resin-based composite material, each set of the first test data includes a temperature value and a mechanical property parameter value of the carbon fiber-epoxy resin-based composite material at the temperature value, where the mechanical property parameter value includes a tensile strength value;

[0011] Curve fitting is performed on the multiple groups of first test data to obtain the mechanical property degradation model, which is used to characterize the change pattern of the mechanical property parameters of the carbon fiber epoxy resin based composite material with temperature.

[0012] Furthermore, the mechanical response finite element model is obtained by:

[0013] Establishing a three-dimensional finite element model of the vehicle-mounted hydrogen storage cylinder;

[0014] Setting mechanical analysis conditions, boundary conditions, and mechanical response analysis conditions of the three-dimensional finite element model to form the mechanical response finite element model;

[0015] Among them, the mechanical analysis conditions include the relationship between the stress and strain of the composite material layer and the relationship between the strain and displacement of the composite material layer; the boundary conditions include the load constraints and displacement constraints acting on the three-dimensional finite element model, and the load constraints include the thermal load and internal pressure load of the on-board hydrogen storage cylinder at any fire time; the mechanical response analysis conditions include the load step and the solver type required when performing model finite element analysis.

[0016] Furthermore, the cylinder fire failure criterion records the failure conditions of the on-board hydrogen storage cylinder, and the failure conditions include: at the current fire time, the ratio between the current maximum stress of the composite material layer and the tensile strength of the composite material layer at the current temperature is greater than or equal to 1, and the ratio is the current fire failure degree value of the on-board hydrogen storage cylinder.

[0017] Furthermore, the mechanical performance degradation model is applied to the mechanical response finite element model, and a finite element analysis is performed in combination with a preset gas cylinder fire failure criterion to obtain a first change curve, including:

[0018] Obtaining a plurality of thermal loads and a plurality of internal pressure loads corresponding to the vehicle-mounted hydrogen storage cylinder at a plurality of different fire times;

[0019] For each of the fire times, the thermal load of the on-board hydrogen storage cylinder at the fire time is applied to the mechanical response finite element model for temperature update, and the mechanical property degradation model is used for solution to obtain the tensile strength of the composite material layer at the fire time; the thermal load and internal pressure load of the on-board hydrogen storage cylinder at the fire time are applied to the mechanical response finite element model for solution to obtain the maximum stress of the composite material layer at the fire time; according to the cylinder fire failure criterion and the tensile strength and maximum stress of the composite material layer at the fire time, the fire failure degree value of the on-board hydrogen storage cylinder at the fire time is determined; the internal pressure load of the on-board hydrogen storage cylinder at the fire time is used as the gas pressure in the cylinder, and the fire failure degree value of the on-board hydrogen storage cylinder at the fire time and the gas pressure in the cylinder are combined to form a set of second test data;

[0020] Acquire several groups of second test data corresponding to the vehicle-mounted hydrogen storage cylinder at the several burning times to generate the first change curve.

[0021] Furthermore, the second variation curve is obtained by:

[0022] Acquire multiple sets of third test data, where the multiple sets of third test data are collected by conducting a real fire test or a numerical simulation test of a fire process of the vehicle-mounted hydrogen storage cylinder, each set of the third test data including the fire time and the gas pressure in the vehicle-mounted hydrogen storage cylinder at the fire time;

[0023] The second variation curve is generated according to the multiple sets of third test data.

[0024] Furthermore, the first variation curve and the second variation curve are combined and analyzed according to the cylinder fire failure criterion to obtain the bursting pressure and fire resistance time of the vehicle-mounted hydrogen storage cylinder under fire conditions, including:

[0025] Filtering out the gas pressure in the vehicle-mounted hydrogen storage cylinder corresponding to a fire failure degree value of 1 from the first variation curve, and using the filtered gas pressure in the cylinder as the bursting pressure;

[0026] Converting the first change curve and the second change curve to obtain a third change curve, wherein the third change curve is used to characterize a change pattern of the degree of fire failure of the vehicle-mounted hydrogen storage cylinder as a function of fire time;

[0027] The fire time corresponding to the case where the fire failure degree value of the vehicle-mounted hydrogen storage cylinder is equal to 1 is screened out from the third variation curve, and the screened fire time is used as the fire resistance time.

[0028] To achieve the above objectives, another aspect of the present application provides a fire resistance performance prediction system for a vehicle-mounted hydrogen storage cylinder, wherein the vehicle-mounted hydrogen storage cylinder comprises a composite material layer made of a carbon fiber epoxy resin-based composite material. The system comprises:

[0029] Establishing a module for establishing a mechanical property degradation model of the carbon fiber epoxy resin-based composite material at high temperature and a finite element model of the mechanical response of the on-board hydrogen storage cylinder under thermal-mechanical coupling;

[0030] a first analysis module, configured to apply the mechanical property degradation model to the mechanical response finite element model, and perform finite element analysis in combination with a preset gas cylinder fire failure criterion to obtain a first variation curve, wherein the first variation curve is used to characterize the relationship between the degree of fire failure of the on-board hydrogen storage gas cylinder and the gas pressure in the cylinder;

[0031] an acquisition module, configured to acquire a second variation curve, wherein the second variation curve is used to characterize a variation pattern of the gas pressure in the vehicle-mounted hydrogen storage cylinder with a burning time;

[0032] The second analysis module is used to combine and analyze the first change curve and the second change curve according to the cylinder fire failure criterion to obtain the bursting pressure and fire resistance time of the vehicle-mounted hydrogen storage cylinder under fire conditions.

[0033] To achieve the above-mentioned purpose, another aspect of the present application provides an electronic device, which includes a memory and a processor, wherein the memory stores a computer program, and the processor implements the above-mentioned method when executing the computer program.

[0034] To achieve the above-mentioned purpose, another aspect of the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and the computer program implements the above-mentioned method when executed by a processor.

[0035] The present application includes at least the following beneficial effects: taking into account the high-temperature mechanical property degradation characteristics of carbon fiber epoxy resin-based composite materials, and starting from the structural characteristics of the on-board hydrogen storage cylinder itself, finite element mechanical modeling analysis under thermal-mechanical coupling is carried out, and at the same time combined with the cylinder fire failure criteria for evaluation, the relevant fire resistance performance parameters of the on-board hydrogen storage cylinder itself can be more reliably predicted. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 This is a flow chart of a method for predicting the fire resistance of a vehicle-mounted hydrogen storage cylinder provided in an embodiment of the present application;

[0037] Figure 2is a schematic diagram of a three-dimensional finite element model of a vehicle-mounted hydrogen storage cylinder provided in an embodiment of the present application;

[0038] Figure 3 This is a schematic diagram of a curve showing the relationship between the degree of fire failure of a vehicle-mounted hydrogen storage cylinder and the gas pressure in the cylinder, provided in an embodiment of the present application;

[0039] Figure 4 This is a schematic diagram of a curve showing changes in gas pressure in a vehicle-mounted hydrogen storage cylinder with fire time, provided in an embodiment of the present application;

[0040] Figure 5 Schematic diagram of a curve showing the degree of fire failure of a vehicle-mounted hydrogen storage cylinder as a function of fire time, provided in an embodiment of the present application;

[0041] Figure 6 This is a structural diagram of a fire resistance performance prediction system for a vehicle-mounted hydrogen storage cylinder provided in an embodiment of the present application;

[0042] Figure 7 This is a schematic diagram of the hardware structure of the electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0043] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application is further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the embodiments of the present application. They are merely examples of systems and methods consistent with some aspects of the embodiments of the present application as detailed in the appended claims.

[0044] It will be understood that the terms "first", "second", etc. used in this application may be used herein to describe various concepts, but unless otherwise specified, these concepts are not limited by these terms. These terms are only used to distinguish one concept from another. For example, without departing from the scope of the embodiments of the present application, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Depending on the context, the words "if" and "if" as used herein may be interpreted as "at the time of" or "when" or "in response to determining".

[0045] The terms "at least one", "plurality", "each", "any", etc. used in this application include "at least one", "two" or more, "plurality" or "each", "any" or "any one", "each" or "any one" as used herein.

[0046] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application pertains. The terms used herein are for the purpose of describing the embodiments of this application only and are not intended to limit this application.

[0047] Hydrogen fuel cell vehicles are one of the core applications of the hydrogen energy industry. Currently, hydrogen fuel cell vehicles generally use on-board hydrogen storage cylinders made of carbon fiber epoxy resin-based composite materials to store high-pressure hydrogen. Since the nominal working pressure of on-board hydrogen storage cylinders for storing high-pressure hydrogen is as high as 70MPa, and carbon fiber epoxy resin-based composite materials are flammable, when a hydrogen fuel cell vehicle has an accident and causes a fire, if the high-pressure hydrogen stored in the on-board hydrogen storage cylinder cannot be released in time and explodes, the resulting explosion fireball, shock wave and fragments will pose a serious safety threat to the surrounding environment and pedestrians.

[0048] Currently, regulations and standards require that on-board hydrogen storage cylinders be equipped with pressure relief devices so that the high-pressure hydrogen stored inside the on-board hydrogen storage cylinders can be released promptly in the event of a fire, preventing the on-board hydrogen storage cylinders from exploding. Before on-board hydrogen storage cylinders are officially put into use, it is usually required to conduct a fire test on the on-board hydrogen storage cylinders and the pressure relief device to verify their safety performance in the event of a fire. Therefore, the main results obtained in the standard fire test include the opening time of the pressure relief device and the increase in the temperature and pressure of the hydrogen in the on-board hydrogen storage cylinder with the fire time when the pressure relief device can be opened. However, the standard fire test does not take into account the situation where the pressure relief device cannot be opened in time, which is a very likely situation in actual application scenarios. At this time, if more reliable burst pressure and fire resistance time of the on-board hydrogen storage cylinder itself cannot be obtained, the progress and safety of fire rescue will be affected.

[0049] In view of this, the embodiments of the present application provide a method, system, equipment and medium for predicting the fire resistance performance of on-board hydrogen storage cylinders. This solution takes into account the high-temperature mechanical performance degradation characteristics of carbon fiber epoxy resin-based composite materials, and conducts finite element mechanical modeling analysis under thermal-mechanical coupling based on the structural characteristics of the on-board hydrogen storage cylinders themselves. At the same time, combined with the cylinder fire failure criteria for evaluation, the relevant fire resistance performance parameters of the on-board hydrogen storage cylinders themselves can be more reliably predicted.

[0050] The embodiment of the present application provides a method for predicting the fire resistance performance of an on-board hydrogen storage cylinder, which relates to the field of hydrogen storage cylinder application technology. It can be applied to a terminal, a server, or software running in a terminal or a server. In some embodiments, the terminal can be a smart phone, a tablet computer, a laptop computer, a desktop computer, a smart speaker, a smart watch, and an on-board terminal, etc., but is not limited to this; the server side can be configured as an independent physical server, or as a server cluster or distributed system composed of multiple physical servers, or as a cloud server that provides basic cloud computing services such as cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communications, middleware services, domain name services, security services, CDN, and big data and artificial intelligence platforms. The server can also be a node server in a blockchain network; the software can be an application that implements the above-mentioned method for predicting the fire resistance performance of on-board hydrogen storage cylinders, etc., but is not limited to the above forms.

[0051] The present application can be used in many general or special computer system environments or configurations. For example: personal computers, server computers, handheld or portable devices, tablet devices, multiprocessor systems, microprocessor-based systems, set-top boxes, programmable consumer electronics, network PCs, minicomputers, mainframe computers, distributed computing environments including any of the above systems or devices, and the like. The present application can be described in the general context of computer-executable instructions executed by a computer, such as program modules. Generally, program modules include routines, programs, objects, components, data structures, etc. that perform specific tasks or implement specific abstract data types. The present application can also be practiced in distributed computing environments, in which tasks are performed by remote processing devices connected via a communication network. In a distributed computing environment, program modules can be located in local and remote computer storage media, including storage devices.

[0052] Figure 1 This is an optional flow chart of a method for predicting the fire resistance performance of a vehicle-mounted hydrogen storage cylinder provided in an embodiment of the present application. First, it is explained that the vehicle-mounted hydrogen storage cylinder includes a composite material layer, which is mainly made of a carbon fiber epoxy resin-based composite material. Figure 1 The method may include, but is not limited to, steps S101 to S104:

[0053] Step S101: establishing a mechanical property degradation model of a carbon fiber epoxy resin-based composite material at high temperature and a finite element model of the mechanical response of an on-board hydrogen storage cylinder under thermal-mechanical coupling;

[0054] Step S102: Applying the mechanical property degradation model to the mechanical response finite element model, and performing finite element analysis in combination with a preset cylinder fire failure criterion to obtain a first variation curve, wherein the first variation curve is used to characterize the relationship between the degree of fire failure of the vehicle-mounted hydrogen storage cylinder and the gas pressure in the cylinder;

[0055] Step S103: obtaining a second variation curve, wherein the second variation curve is used to characterize a variation pattern of the gas pressure in the vehicle-mounted hydrogen storage cylinder with the burning time;

[0056] Step S104: According to the cylinder fire failure criterion, the first variation curve and the second variation curve are combined and analyzed to obtain the bursting pressure and fire resistance time of the vehicle-mounted hydrogen storage cylinder in the case of fire.

[0057] Steps S101 to S104 shown in the embodiment of the present application perform finite element mechanical modeling analysis based on the structural material properties of the on-board hydrogen storage cylinder itself, and at the same time evaluate the cylinder fire failure criteria, so as to more reliably predict the fire resistance performance parameters of the on-board hydrogen storage cylinder.

[0058] In step S101 of some embodiments, the mechanical property degradation model of the carbon fiber epoxy resin-based composite material at high temperature mainly characterizes the variation pattern of the mechanical property parameters of the carbon fiber epoxy resin-based composite material with temperature, which is obtained by the following method:

[0059] By conducting high-temperature mechanical property tests on the carbon fiber epoxy resin-based composite material in advance, multiple groups of first test data are collected, each group of first test data includes a temperature value and a mechanical property parameter value of the carbon fiber epoxy resin-based composite material at the temperature value, and the mechanical property parameter value includes a tensile strength value and an elastic modulus, etc.; then, curve fitting is performed on the multiple groups of collected first test data to obtain the mechanical property degradation model, and in this application, a hyperbolic tangent function is preferably used to complete the curve fitting.

[0060] Among them, the principles of the high-temperature mechanical properties test of the carbon fiber epoxy resin-based composite material include: based on the thermogravimetric analysis test of the material, the thermal decomposition process of the material is determined through the thermal weight loss curve of the material at different heating rates; based on the differential thermogravimetric curve of the material at different heating rates, the peak temperature is obtained to determine the temperature range of each decomposition stage; based on the non-isothermal differential thermogravimetric curve and mechanism function of the carbon fiber epoxy resin-based composite material, the thermal decomposition kinetic parameters of the material are determined, and the kinetic parameters include activation energy and pre-exponential factor; prepare unidirectional carbon fiber epoxy resin-based composite laminates; use the ANSYS software thermal analysis module to calculate the heating time required for the unidirectional carbon fiber epoxy resin-based composite laminates to reach a stable thermal equilibrium state; determine the maximum tensile load of the carbon fiber epoxy resin-based composite material at different temperature points under high temperature environment; calculate the tensile strength of the carbon fiber epoxy resin-based composite material in accordance with the standard GB / T 3354-2014 to obtain relevant test values.

[0061] In step S101 of some embodiments, a finite element model of the mechanical response of the vehicle-mounted hydrogen storage cylinder under thermal-mechanical coupling is obtained by:

[0062] A three-dimensional finite element model of the on-board hydrogen storage cylinder is established, and in this application, ANSYS Workbench software is preferably used to implement modeling and analysis, specifically: defining the structural unit type of the composite material layer and setting the geometric size parameters of the on-board hydrogen storage cylinder (including the outer diameter of the bottle body and the thickness of the composite material layer), meshing the preliminarily formed three-dimensional finite element model of the on-board hydrogen storage cylinder, and refining part of the mesh of the head and the bottle mouth; in addition, considering that the on-board hydrogen storage cylinder also includes an inner liner layer, which is mainly made of aluminum alloy material, the structural unit type of the inner liner layer and the thickness of the inner liner layer can also be defined at the same time; then, the mechanical analysis conditions, boundary conditions and mechanical response analysis conditions of the three-dimensional finite element model of the on-board hydrogen storage cylinder are set to form a mechanical response finite element model of the on-board hydrogen storage cylinder under thermal-mechanical coupling.

[0063] The mechanical analysis conditions mainly include the relationship between the stress and strain of the composite material layer and the relationship between the strain and displacement of the composite material layer, which are specifically described as follows:

[0064] The linear elastic analysis method is used to determine that the carbon fiber epoxy resin matrix composite material is an anisotropic material. The composite material layer is a typical winding structure, generally composed of multiple composite material layers with different winding angles. The equilibrium equation of each composite material layer in the cylindrical coordinate system is:

[0065]

[0066] Where r is the radial direction of the cylindrical coordinate system, σ r is the radial stress of a single layer of composite material, σ θ is the hoop stress of a single layer of composite material, which can also be called transverse stress;

[0067] The relationship between the stress and strain of each composite material layer can be expressed as:

[0068]

[0069]

[0070] Where, σ z is the axial stress of a single layer of composite material, also known as longitudinal stress, τ zθ is the shear stress of the composite material single layer, C is the stiffness matrix of the composite material single layer, ε z is the axial strain of the composite material single layer, ε θ is the hoop strain of the composite material single layer, ε r is the radial strain of the composite material single layer, γ zθ is the shear strain of the composite material single layer, η1 is the first thermal expansion coefficient, which mainly characterizes the thermal expansion degree of the carbon fiber epoxy resin-based composite material along the fiber direction, η2 is the second thermal expansion coefficient, which mainly characterizes the thermal expansion degree of the carbon fiber epoxy resin-based composite material in the direction perpendicular to the fiber, η3 is the third thermal expansion coefficient, which mainly characterizes the thermal expansion degree of the carbon fiber epoxy resin-based composite material along the interlayer direction, η6 is the fourth thermal expansion coefficient, which mainly characterizes the thermal expansion degree of the carbon fiber epoxy resin-based composite material in the plane formed by the fiber direction and the direction perpendicular to the fiber, ΔT is the manufacturing temperature difference of the carbon fiber epoxy resin-based composite material, S is the flexible matrix of the composite material single layer, E1 is the longitudinal tensile strength of the carbon fiber epoxy resin-based composite material, E2 is the transverse tensile strength of the carbon fiber epoxy resin-based composite material, ν 12 is the Poisson's ratio generated when the carbon fiber epoxy resin matrix composite material is stretched in the interlaminar direction, ν 23 is the Poisson's ratio generated when the carbon fiber epoxy resin based composite material is stretched in the fiber direction;

[0071] The relationship between the strain and displacement of each composite material layer can be expressed as:

[0072]

[0073] Where u r is the radial displacement of the composite material single layer, u z is the axial displacement of the composite material single layer, z is the axial direction of the cylindrical coordinate system, ε0 is the average strain of the composite material single layer, u θis the circumferential displacement of the composite material single layer, and γ0 is a preset constant.

[0074] In addition, the mechanical analysis conditions may also include a relationship between the stress and strain of the liner layer and a relationship between the strain and displacement of the liner layer, as specifically described below:

[0075] The linear elastic analysis method is used to determine that the aluminum alloy material is an isotropic material. The relationship between the stress and strain of the liner layer under internal pressure and thermal stress can be expressed as:

[0076]

[0077] Where σ' z is the axial stress of the liner layer, σ' θ is the hoop stress of the liner layer, σ r ' is the radial stress of the liner layer, τ' zθ is the shear stress of the liner layer, a, b and c are stiffness coefficients, ε' z is the axial strain of the liner layer, ε' θ is the hoop strain of the liner layer, ε' r is the radial strain of the liner layer, γ' zθ is the shear strain of the liner layer, η1', η'2, η3' and η'6 are the thermal expansion coefficients of the aluminum alloy material, and ΔT' is the manufacturing temperature difference of the aluminum alloy material;

[0078] The relationship between the strain and displacement of the liner layer can be expressed as:

[0079]

[0080] Where u' r is the radial displacement of the liner layer, B is the integral constant, and ε'0 is the equivalent strain.

[0081] Among them, the boundary conditions mainly include load constraints and displacement constraints acting on the three-dimensional finite element model of the on-board hydrogen storage cylinder. The load constraints mainly include the thermal load and internal pressure load of the on-board hydrogen storage cylinder at any fire time. The internal pressure load mainly acts on the inner wall surface of the on-board hydrogen storage cylinder. It should be noted that in the finite element analysis process, the load constraint should be loaded first and then the displacement constraint.

[0082] Among them, the mechanical response analysis conditions include the load step and the solver type required when performing finite element analysis of the model. The solver type preferably adopts an iterative solver. After setting the mechanical response analysis conditions, the mechanical response of the on-board hydrogen storage cylinder under fire conditions can be solved by finite element analysis, including stress, strain, etc.

[0083] In step S102 of some embodiments, the gas cylinder fire failure criterion mainly records the failure conditions of the vehicle-mounted hydrogen storage gas cylinder, and the failure conditions include: at the current fire time, the ratio between the current maximum stress of the composite material layer and the tensile strength of the composite material layer at the current temperature is greater than or equal to 1, and the ratio refers to the current fire failure degree value of the vehicle-mounted hydrogen storage gas cylinder.

[0084] It should be noted that the current maximum stress of the composite material layer includes the current maximum longitudinal stress, the current maximum transverse stress and the current maximum shear stress of the composite material layer. The tensile strength of the composite material layer at the current temperature includes the longitudinal strength, the transverse strength and the shear strength of the composite material layer at the current temperature. The failure condition can be subdivided into a longitudinal failure condition, a transverse failure condition and a shear failure condition, which are specifically described as follows:

[0085] The longitudinal failure condition is: at the current fire time, the ratio between the current maximum longitudinal stress of the composite material layer and the longitudinal strength of the composite material layer at the current temperature is greater than or equal to 1, indicating that the on-board hydrogen storage cylinder has experienced longitudinal failure;

[0086] The transverse failure condition is: at the current burning time, the ratio between the current maximum transverse stress of the composite material layer and the transverse strength of the composite material layer at the current temperature is greater than or equal to 1, indicating that the on-board hydrogen storage cylinder has undergone transverse failure;

[0087] The shear failure condition is: at the current burning time, the ratio between the current maximum shear stress of the composite material layer and the shear strength of the composite material layer at the current temperature is greater than or equal to 1, which indicates that the on-board hydrogen storage cylinder has shear failure.

[0088] Taking into account the winding manufacturing process, stress-strain distribution and actual failure conditions of the vehicle-mounted hydrogen storage cylinder, the lateral stress and shear stress of the composite material layer are very small, and the vehicle-mounted hydrogen storage cylinder basically suffers from longitudinal failure in the event of a fire. Therefore, this application mainly focuses on the longitudinal failure condition.

[0089] In some embodiments, the above step S102 may include, but is not limited to, steps S201 to S203:

[0090] Step S201: Obtain a number of internal pressure loads and a number of thermal loads corresponding to the vehicle-mounted hydrogen storage cylinder at a number of different burning times. The several thermal loads are different from each other. The thermal load refers to the thermal load on the inner and outer walls of the vehicle-mounted hydrogen storage cylinder. The several burning times are gradually increasing, and the corresponding several internal pressure loads are also gradually increasing.

[0091] Step S202: For each fire time, apply the thermal load of the vehicle-mounted hydrogen storage cylinder at the fire time to the mechanical response finite element model for temperature update, and use the mechanical property degradation model to solve to obtain the tensile strength of the composite material layer at the fire time; apply the thermal load and internal pressure load of the vehicle-mounted hydrogen storage cylinder at the fire time to the mechanical response finite element model for solution to obtain the maximum stress of the composite material layer at the fire time; combine the cylinder fire failure criterion and the maximum stress and tensile strength of the composite material layer at the fire time to calculate the fire failure degree value of the vehicle-mounted hydrogen storage cylinder at the fire time; define the internal pressure load of the vehicle-mounted hydrogen storage cylinder at the fire time as the gas pressure in the cylinder, and combine the gas pressure in the cylinder and the fire failure degree value of the vehicle-mounted hydrogen storage cylinder at the fire time to form a set of second test data.

[0092] In this step, the thermal load of the vehicle-mounted hydrogen storage cylinder at the fire time is applied to the mechanical response finite element model to perform temperature update. This can be understood as: the thermal load of the vehicle-mounted hydrogen storage cylinder at the fire time is solved by the heat transfer equation to obtain the thermal distribution of the vehicle-mounted hydrogen storage cylinder, and the mechanical response finite element model performs node temperature update according to the thermal distribution of the vehicle-mounted hydrogen storage cylinder.

[0093] In this step, the internal pressure load of the vehicle-mounted hydrogen storage cylinder at the fire time is applied to the mechanical response finite element model for solution. This can be understood as: the internal pressure load of the vehicle-mounted hydrogen storage cylinder at the fire time is applied to the inner surface of the bottle body in the mechanical response finite element model, and after determining the appropriate load step, the stress distribution of the composite material layer at each load step is solved by finite element analysis.

[0094] It should be noted that, considering that the mechanical properties of the composite material layer continue to deteriorate with the increase of the burning time, the carrying capacity of the on-board hydrogen storage cylinder also gradually decreases. In this step, the mechanical response of the on-board hydrogen storage cylinder at different burning times is mainly solved along the time history and data collection is completed.

[0095] Step S203: Acquire several sets of second test data corresponding to the vehicle-mounted hydrogen storage cylinder at the several burning times obtained by the above step S202, and then generate the first change curve by directly connecting the data points.

[0096] It should be noted that the several groups of second test data should include cases where the fire failure degree value is less than 1 and cases where the fire failure degree value is greater than or equal to 1.

[0097] In step S103 of some embodiments, the second variation curve is obtained by:

[0098] Multiple sets of third test data are collected by conducting numerical simulation tests or actual fire tests on the vehicle-mounted hydrogen storage cylinder in advance, each set of third test data includes the fire time and the gas pressure in the vehicle-mounted hydrogen storage cylinder at the fire time, and then the second change curve is generated by directly connecting the data points.

[0099] In some embodiments, the above step S104 may include, but is not limited to, steps S301 to S303:

[0100] Step S301: Filter out the gas pressure in the vehicle-mounted hydrogen storage cylinder when the fire failure degree value of the vehicle-mounted hydrogen storage cylinder is equal to 1 from the first variation curve, and then define the filtered gas pressure in the cylinder as the bursting pressure of the vehicle-mounted hydrogen storage cylinder in the fire condition;

[0101] Step S302: converting the first change curve and the second change curve to obtain a third change curve, wherein the third change curve mainly represents a change pattern of the degree of fire failure of the vehicle-mounted hydrogen storage cylinder as a function of fire time;

[0102] Step S303: Filter out the fire time corresponding to the case where the fire failure degree value of the vehicle-mounted hydrogen storage cylinder is equal to 1 from the third change curve, and then define the filtered fire time as the fire resistance time of the vehicle-mounted hydrogen storage cylinder under fire.

[0103] The method for predicting the fire resistance performance of on-board hydrogen storage cylinders proposed in the embodiments of the present application takes into account the high-temperature mechanical property degradation characteristics of carbon fiber epoxy resin-based composite materials in order to be more in line with actual fire conditions, and conducts finite element mechanical modeling analysis under thermal-mechanical coupling based on the structural characteristics of the on-board hydrogen storage cylinders themselves. At the same time, combined with the cylinder fire failure criteria for evaluation, the relevant fire resistance performance parameters of the on-board hydrogen storage cylinders themselves can be more reliably predicted.

[0104] The following further describes the solution of the embodiment of the present application with reference to a specific application example, which mainly includes the following steps 1 to 7:

[0105] First of all, it is clear that the on-board hydrogen storage cylinder is a 70MPa aluminum alloy liner carbon fiber fully wrapped composite material hydrogen storage cylinder. The geometric size parameters of the on-board hydrogen storage cylinder are: the outer diameter of the bottle body is 310mm, the thickness of the composite material layer is 25mm, and the thickness of the aluminum alloy liner layer is 4.5mm.

[0106] Step 1: Construct a mechanical property degradation model of carbon fiber epoxy resin based composite materials at high temperature;

[0107] Specifically, by conducting high-temperature mechanical property tests on the carbon fiber epoxy resin-based composite material in advance to collect relevant data, a hyperbolic tangent function was used to complete curve fitting, and then the mechanical property degradation model of the carbon fiber epoxy resin-based composite material at high temperature (20°C to 450°C) was obtained:

[0108] P(T)=2019-180{1+tanh[0.01(T-112)]}-350{1+tanh[0.0167(T-339)]}

[0109] Wherein, T is temperature, P(T) is the longitudinal strength of the carbon fiber epoxy resin based composite material at temperature T, and the longitudinal strength of the carbon fiber epoxy resin based composite material at room temperature is 2019 MPa.

[0110] Step 2: construct a finite element model of the mechanical response of the on-board hydrogen storage cylinder under the action of thermal-mechanical coupling;

[0111] Specifically, ANSYS Workbench software was first used to construct a three-dimensional finite element model of the on-board hydrogen storage cylinder. The structural unit types of the composite material layer and the aluminum alloy liner layer were defined respectively. The structural unit Sol id186 was used to mesh the three-dimensional finite element model of the on-board hydrogen storage cylinder, and the meshes of the head and the bottle mouth were refined. After mesh independence verification, the three-dimensional finite element model of the on-board hydrogen storage cylinder was obtained to have a total of 71,584 units and 314,393 nodes, as shown in the figure. Figure 2 As shown; then, the constitutive relationship of the carbon fiber epoxy resin-based composite material and the aluminum alloy material is constructed, and the mechanical analysis of the composite material layer and the aluminum alloy liner layer is performed; secondly, boundary conditions are applied to the three-dimensional finite element model of the on-board hydrogen storage cylinder, including: obtaining the thermal load of the on-board hydrogen storage cylinder at any fire time and applying it to the bottle body, obtaining the internal pressure load of the on-board hydrogen storage cylinder at the fire time and applying it to the inner wall of the bottle body, and at the same time applying an axial balance load to the annular surface of the bottle mouth, and applying axial displacement constraints and rotation constraints in three directions to the nodes at the vertex of the tail of the bottle body. The rotation constraints in these three directions can be understood as axial rotation constraints, circumferential rotation constraints and radial rotation constraints; finally, the mechanical response analysis conditions of the three-dimensional finite element model of the on-board hydrogen storage cylinder are set, including parameters such as the Iterative solver and the load step to be applied.

[0112] Step 3: Apply the mechanical performance degradation model to the mechanical response finite element model, and perform finite element analysis in combination with the preset cylinder fire failure criterion to obtain a curve showing the relationship between the degree of fire failure of the on-board hydrogen storage cylinder and the gas pressure in the cylinder, as shown in the figure. Figure 3 shown.

[0113] Step 4: After collecting relevant data by conducting a numerical simulation test on the fire process of the vehicle-mounted hydrogen storage cylinder in advance, connect the data points and obtain a curve of the gas pressure in the vehicle-mounted hydrogen storage cylinder changing with the fire time, such as Figure 4 shown.

[0114] Step 5: Based on the fire failure criterion of the gas cylinder, data screening is performed on the curve of the change between the fire failure degree of the vehicle-mounted hydrogen storage cylinder and the gas pressure in the cylinder, and the bursting pressure of the vehicle-mounted hydrogen storage cylinder in the case of fire is obtained to be 95.4 MPa.

[0115] Step 6: Convert the curve of the change between the degree of fire failure of the vehicle-mounted hydrogen storage cylinder and the gas pressure in the cylinder and the curve of the change between the gas pressure in the cylinder and the fire time of the vehicle-mounted hydrogen storage cylinder to obtain the curve of the change between the degree of fire failure of the vehicle-mounted hydrogen storage cylinder and the fire time, as shown in FIG. Figure 5 shown.

[0116] Step seven, based on the cylinder fire failure criterion, data screening is performed on the curve of the fire failure degree of the vehicle-mounted hydrogen storage cylinder versus the fire time, and the fire resistance time of the vehicle-mounted hydrogen storage cylinder under fire conditions is obtained to be 844s.

[0117] See also Figure 6 The present application also provides a schematic structural diagram of a vehicle-mounted hydrogen storage cylinder fire resistance performance prediction system, which can implement the above-mentioned vehicle-mounted hydrogen storage cylinder fire resistance performance prediction method. First, it is explained that the vehicle-mounted hydrogen storage cylinder includes a composite material layer, which is mainly made of a carbon fiber epoxy resin-based composite material. The system includes:

[0118] Establishing module 401, for establishing a finite element model of the mechanical response of the vehicle-mounted hydrogen storage cylinder under the action of thermo-mechanical coupling and a mechanical property degradation model of the carbon fiber epoxy resin-based composite material at high temperature;

[0119] A first analysis module 402 is configured to apply the mechanical performance degradation model to the mechanical response finite element model, and perform finite element analysis in combination with a preset gas cylinder fire failure criterion to obtain a first variation curve, wherein the first variation curve primarily represents the relationship between the degree of fire failure of the vehicle-mounted hydrogen storage gas cylinder and the gas pressure within the cylinder;

[0120] An acquisition module 403 is configured to acquire a second variation curve, wherein the second variation curve mainly represents a variation pattern of the gas pressure in the vehicle-mounted hydrogen storage cylinder with the burning time;

[0121] The second analysis module 404 is used to analyze the first change curve and the second change curve in combination according to the cylinder fire failure criterion to obtain the fire resistance time and bursting pressure of the vehicle-mounted hydrogen storage cylinder in the case of fire.

[0122] It can be understood that the contents of the above method embodiments are all applicable to the present system embodiments, the functions specifically implemented by the present system embodiments are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above method embodiments.

[0123] The present application also provides an electronic device comprising a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement the aforementioned method for predicting the fire resistance performance of an on-board hydrogen storage cylinder. The electronic device may include any smart terminal, such as a tablet computer or an on-board computer.

[0124] It can be understood that the contents of the above method embodiments are applicable to the present device embodiments, the functions specifically implemented by the present device embodiments are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above method embodiments.

[0125] See also Figure 7 , Figure 7 The hardware structure of an electronic device according to another embodiment is shown. The electronic device includes:

[0126] The processor 501 may be implemented using a general-purpose CPU (Central Processing Unit), a microprocessor, an application-specific integrated circuit (ASIC), or one or more integrated circuits, and is configured to execute relevant programs to implement the technical solutions provided in the embodiments of the present application.

[0127] The memory 502 can be implemented in the form of a read-only memory (ROM), a static storage device, a dynamic storage device, or a random access memory (RAM). The memory 502 can store an operating system and other application programs. When the technical solutions provided by the embodiments of the present application are implemented through software or firmware, the relevant program code is stored in the memory 502 and is called by the processor 501 to execute the technical solutions provided by the embodiments of the present application.

[0128] Input / output interface 503, used to implement information input and output;

[0129] Communication interface 504, used to implement communication interaction between this device and other devices, which can be achieved through wired means (such as USB, network cable, etc.) or wireless means (such as mobile network, Wi-Fi, Bluetooth, etc.);

[0130] Bus 505 , which transmits information between various components of the device (e.g., processor 501 , memory 502 , input / output interface 503 , and communication interface 504 );

[0131] The processor 501 , the memory 502 , the input / output interface 503 and the communication interface 504 are connected to each other in communication within the device via a bus 505 .

[0132] An embodiment of the present application also provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, it implements the above-mentioned method for predicting the fire resistance performance of the on-board hydrogen storage cylinder.

[0133] It can be understood that the contents of the above method embodiments are all applicable to the present storage medium embodiment, the functions specifically implemented by the present storage medium embodiment are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above method embodiments.

[0134] The memory, as a non-transient computer-readable storage medium, can be used to store non-transient software programs and non-transient computer executable programs. In addition, the memory may include a high-speed random access memory and may also include a non-transient memory, such as at least one disk storage device, a flash memory device, or other non-transient solid-state storage device. In some embodiments, the memory may optionally include a memory remotely arranged relative to the processor, and these remote memories may be connected to the processor via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0135] The embodiments described in the embodiments of this application are intended to more clearly illustrate the technical solutions of the embodiments of this application and do not constitute a limitation on the technical solutions provided by the embodiments of this application. Those skilled in the art will appreciate that with the evolution of technology and the emergence of new application scenarios, the technical solutions provided in the embodiments of this application are also applicable to similar technical problems.

[0136] Those skilled in the art will understand that the technical solutions shown in the figures do not constitute a limitation on the embodiments of the present application, and may include more or fewer steps than shown in the figures, or a combination of certain steps, or different steps.

[0137] The system embodiment described above is merely illustrative. The units described as separate components may or may not be physically separate, i.e., they may be located in one place or distributed across multiple network units. Some or all of the modules may be selected based on actual needs to achieve the objectives of this embodiment.

[0138] Those skilled in the art will appreciate that all or some of the steps in the methods, systems, and functional modules / units in the devices disclosed above may be implemented as software, firmware, hardware, or appropriate combinations thereof.

[0139] The terms "first", "second", "third", "fourth", etc. (if any) in the specification of the present application and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequential order. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0140] It should be understood that in this application, "at least one (item)" means one or more, and "plurality" means two or more. "And / or" is used to describe the association relationship of associated objects, indicating that three relationships may exist. For example, "A and / or B" can mean: only A exists, only B exists, and A and B exist at the same time, where A and B can be singular or plural. The character " / " generally indicates that the previous and next associated objects are in an "or" relationship. "At least one of the following items" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, c can be single or multiple.

[0141] In the several embodiments provided in this application, it should be understood that the disclosed systems and methods can be implemented in other ways. For example, the system embodiments described above are merely illustrative. For example, the division of the above units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of systems or units, which can be electrical, mechanical or other forms.

[0142] The units described above as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0143] In addition, the functional units in the various embodiments of the present application may be integrated into a single processing unit, or each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0144] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product, which is stored in a storage medium and includes multiple instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of various embodiments of the present application. The aforementioned storage medium includes: various media that can store programs, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0145] The preferred embodiments of the present invention are described above with reference to the accompanying drawings, but are not intended to limit the scope of the present invention. Any modifications, equivalent substitutions, and improvements made by those skilled in the art without departing from the scope and essence of the present invention should be within the scope of the present invention.

Claims

1. A method for predicting the fire resistance performance of a vehicle-mounted hydrogen storage cylinder, wherein the vehicle-mounted hydrogen storage cylinder comprises a composite material layer, wherein the composite material layer is made of a carbon fiber epoxy resin-based composite material, characterized in that: The method comprises: Establishing a mechanical property degradation model of the carbon fiber epoxy resin-based composite material at high temperature and a finite element model of the mechanical response of the on-board hydrogen storage cylinder under thermal-mechanical coupling; Applying the mechanical property degradation model to the mechanical response finite element model, and performing finite element analysis in combination with a preset gas cylinder fire failure criterion to obtain a first variation curve, wherein the first variation curve is used to characterize the relationship between the degree of fire failure of the on-board hydrogen storage gas cylinder and the gas pressure in the cylinder; Obtaining a second variation curve, where the second variation curve is used to characterize a variation pattern of the gas pressure in the vehicle-mounted hydrogen storage cylinder with the burning time; According to the cylinder fire failure criterion, the first change curve and the second change curve are combined and analyzed to obtain the bursting pressure and fire resistance time of the vehicle-mounted hydrogen storage cylinder under fire conditions; The mechanical property degradation model is obtained by: Acquire multiple sets of first test data, where the multiple sets of first test data are collected when conducting a high-temperature mechanical property test of the carbon fiber-epoxy resin-based composite material, each set of the first test data includes a temperature value and a mechanical property parameter value of the carbon fiber-epoxy resin-based composite material at the temperature value, where the mechanical property parameter value includes a tensile strength value; Performing curve fitting on the multiple sets of first test data to obtain the mechanical property degradation model, wherein the mechanical property degradation model is used to characterize the variation pattern of the mechanical property parameters of the carbon fiber epoxy resin-based composite material with temperature; The mechanical response finite element model is obtained by: Establishing a three-dimensional finite element model of the vehicle-mounted hydrogen storage cylinder; Setting mechanical analysis conditions, boundary conditions, and mechanical response analysis conditions of the three-dimensional finite element model to form the mechanical response finite element model; the mechanical analysis conditions include a relationship between stress and strain of the composite material layer and a relationship between strain and displacement of the composite material layer; the boundary conditions include load constraints and displacement constraints acting on the three-dimensional finite element model, and the load constraints include the thermal load and internal pressure load of the on-board hydrogen storage cylinder at any fire time; the mechanical response analysis conditions include a load step and a solver type required when performing finite element analysis of the model; The first variation curve and the second variation curve are combined and analyzed according to the cylinder fire failure criterion to obtain the bursting pressure and fire resistance time of the vehicle-mounted hydrogen storage cylinder under fire conditions, including: Filtering out the gas pressure in the vehicle-mounted hydrogen storage cylinder corresponding to a fire failure degree value of 1 from the first variation curve, and using the filtered gas pressure in the cylinder as the bursting pressure; Converting the first change curve and the second change curve to obtain a third change curve, wherein the third change curve is used to characterize a change pattern of the degree of fire failure of the vehicle-mounted hydrogen storage cylinder as a function of fire time; The fire time corresponding to the case where the fire failure degree value of the vehicle-mounted hydrogen storage cylinder is equal to 1 is screened out from the third variation curve, and the screened fire time is used as the fire resistance time.

2. The method for predicting the fire resistance performance of a vehicle-mounted hydrogen storage cylinder according to claim 1, characterized in that: The cylinder fire failure criterion records the failure conditions of the on-board hydrogen storage cylinder, and the failure conditions include: at the current fire time, the ratio between the current maximum stress of the composite material layer and the tensile strength of the composite material layer at the current temperature is greater than or equal to 1, and the ratio is the current fire failure degree value of the on-board hydrogen storage cylinder.

3. The method for predicting the fire resistance performance of a vehicle-mounted hydrogen storage cylinder according to claim 2, characterized in that: The first variation curve obtained by applying the mechanical performance degradation model to the mechanical response finite element model and performing finite element analysis in combination with a preset gas cylinder fire failure criterion includes: Obtaining a plurality of thermal loads and a plurality of internal pressure loads corresponding to the vehicle-mounted hydrogen storage cylinder at a plurality of different fire times; For each of the fire times, the thermal load of the on-board hydrogen storage cylinder at the fire time is applied to the mechanical response finite element model for temperature update, and the mechanical property degradation model is used for solution to obtain the tensile strength of the composite material layer at the fire time; the thermal load and internal pressure load of the on-board hydrogen storage cylinder at the fire time are applied to the mechanical response finite element model for solution to obtain the maximum stress of the composite material layer at the fire time; according to the cylinder fire failure criterion and the tensile strength and maximum stress of the composite material layer at the fire time, the fire failure degree value of the on-board hydrogen storage cylinder at the fire time is determined; the internal pressure load of the on-board hydrogen storage cylinder at the fire time is used as the gas pressure in the cylinder, and the fire failure degree value of the on-board hydrogen storage cylinder at the fire time and the gas pressure in the cylinder are combined to form a set of second test data; Acquire several groups of second test data corresponding to the vehicle-mounted hydrogen storage cylinder at the several burning times to generate the first change curve.

4. The method for predicting the fire resistance performance of a vehicle-mounted hydrogen storage cylinder according to claim 1, characterized in that: The second variation curve is obtained by: Acquire multiple sets of third test data, where the multiple sets of third test data are collected by conducting a real fire test or a numerical simulation test of a fire process of the vehicle-mounted hydrogen storage cylinder, each set of the third test data including the fire time and the gas pressure in the vehicle-mounted hydrogen storage cylinder at the fire time; The second variation curve is generated according to the multiple sets of third test data.

5. A fire resistance performance prediction system for a vehicle-mounted hydrogen storage cylinder, wherein the vehicle-mounted hydrogen storage cylinder comprises a composite material layer, wherein the composite material layer is made of a carbon fiber epoxy resin-based composite material, characterized in that: The system comprises: Establishing a module for establishing a mechanical property degradation model of the carbon fiber epoxy resin-based composite material at high temperature and a finite element model of the mechanical response of the on-board hydrogen storage cylinder under thermal-mechanical coupling; a first analysis module, configured to apply the mechanical property degradation model to the mechanical response finite element model, and perform finite element analysis in combination with a preset gas cylinder fire failure criterion to obtain a first variation curve, wherein the first variation curve is used to characterize the relationship between the degree of fire failure of the on-board hydrogen storage gas cylinder and the gas pressure in the cylinder; an acquisition module, configured to acquire a second variation curve, wherein the second variation curve is used to characterize a variation pattern of the gas pressure in the vehicle-mounted hydrogen storage cylinder with a burning time; A second analysis module is configured to analyze the first variation curve and the second variation curve in combination according to the cylinder fire failure criterion to obtain a bursting pressure and a fire resistance time of the vehicle-mounted hydrogen storage cylinder under fire conditions; The mechanical property degradation model is obtained by: Acquire multiple sets of first test data, where the multiple sets of first test data are collected when conducting a high-temperature mechanical property test of the carbon fiber-epoxy resin-based composite material, each set of the first test data includes a temperature value and a mechanical property parameter value of the carbon fiber-epoxy resin-based composite material at the temperature value, where the mechanical property parameter value includes a tensile strength value; Performing curve fitting on the multiple sets of first test data to obtain the mechanical property degradation model, wherein the mechanical property degradation model is used to characterize the variation pattern of the mechanical property parameters of the carbon fiber epoxy resin-based composite material with temperature; The mechanical response finite element model is obtained by: Establishing a three-dimensional finite element model of the vehicle-mounted hydrogen storage cylinder; Setting mechanical analysis conditions, boundary conditions, and mechanical response analysis conditions of the three-dimensional finite element model to form the mechanical response finite element model; the mechanical analysis conditions include a relationship between stress and strain of the composite material layer and a relationship between strain and displacement of the composite material layer; the boundary conditions include load constraints and displacement constraints acting on the three-dimensional finite element model, and the load constraints include the thermal load and internal pressure load of the on-board hydrogen storage cylinder at any fire time; the mechanical response analysis conditions include a load step and a solver type required when performing finite element analysis of the model; The first variation curve and the second variation curve are combined and analyzed according to the cylinder fire failure criterion to obtain the bursting pressure and fire resistance time of the vehicle-mounted hydrogen storage cylinder under fire conditions, including: Filtering out the gas pressure in the vehicle-mounted hydrogen storage cylinder corresponding to a fire failure degree value of 1 from the first variation curve, and using the filtered gas pressure in the cylinder as the bursting pressure; Converting the first change curve and the second change curve to obtain a third change curve, wherein the third change curve is used to characterize a change pattern of the degree of fire failure of the vehicle-mounted hydrogen storage cylinder as a function of fire time; The fire time corresponding to the case where the fire failure degree value of the vehicle-mounted hydrogen storage cylinder is equal to 1 is screened out from the third variation curve, and the screened fire time is used as the fire resistance time.

6. An electronic device, characterized in that: The electronic device includes a memory and a processor, the memory stores a computer program, and the processor implements the method according to any one of claims 1 to 4 when executing the computer program.

7. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the method according to any one of claims 1 to 4 is implemented.

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