Method for improving vibration and impact resistance of fuel cell engine housing

Abstract

The application provides a fuel cell engine shell vibration impact resistance performance improvement method, comprising the following steps: establishing a finite element mechanics performance simulation model; defining relative constraint position design parameters of the fuel cell engine shell; analyzing responses of the shell and the fuel cell stack finite element model under different test conditions; modifying each defined design parameter and simulating until a model response result set is obtained; combining structure and working characteristics of the fuel cell engine shell and the fuel cell stack, determining a vibration impact resistance performance evaluation index, establishing a link between the response result and the performance; screening to obtain a design parameter range meeting the requirements, determining an optimal design parameter combination according to the fuel cell stack response result; and obtaining a final shell structure after local adjustment of the shell structure. The application can improve the overall vibration impact resistance performance of the fuel cell engine.

Description

Technical Field

[0001] This invention provides a method for improving the vibration and shock resistance of a fuel cell engine housing, belonging to the field of fuel cell housing manufacturing technology and design methods. Background Technology

[0002] Hydrogen fuel cells are widely used in vehicles due to their high energy density and weak infrared characteristics. During vehicle operation, the fuel cell stack installed on the vehicle is inevitably affected by road unevenness, manifesting as mechanical vibration and impact. Such input excitation degrades the performance of the fuel cell stack, and frequent impact vibrations can even lead to irreversible performance degradation and irreparable mechanical structural damage. The ability of a fuel cell stack to resist shock and vibration is commonly referred to as its vibration and shock resistance. How to assess the impact of vibration and shock excitation on the mechanical structural stability of the fuel cell stack, and thus improve the stack's vibration and shock resistance, is one of the key issues in the environmental adaptability technology of automotive fuel cells.

[0003] Current research on the vibration and shock resistance of fuel cell engines mainly involves establishing a mechanical finite element model, analyzing the response results of vibration and shock simulations, and then using experimental design and learning algorithms to find the optimal design parameters. Vibration conditions mainly include random vibration and resonant vibration, while shock conditions involve applying impact excitations in three directions to the fuel cell engine. The response results primarily focus on the stress response within each structure.

[0004] Currently, in the design process of fuel cell engines, the design processes of the casing and fuel cell stack are relatively independent, focusing on improving vibration and shock resistance. When performing vibration and shock simulation analysis on the casing, although the fuel cell stack is assembled inside, the response analysis only considers the casing's own response, without considering the impact of the casing structure design on the vibration and shock resistance of the internal fuel cell stack. However, when the fuel cell engine is subjected to vibration and shock, the fuel cell stack and the casing form a coupled system, with the two mechanisms fixedly connected by a certain structure. Therefore, the response of the fuel cell stack to vibration and shock may be related to many design factors of the casing, such as constraint type and casing thickness. In actual design, it is often necessary to optimize the casing design after the overall design is completed to improve the overall vibration and shock resistance of the fuel cell engine. Such an iterative design process reduces design efficiency and increases design costs.

[0005] CN115169179 provides a method for designing the dimensions of battery pack housing components using stress response analysis, including: S1: establishing a finite element model of the battery pack system; S2: setting the component parameters of the finite element model of the battery pack system; S3: testing the system stress of the finite element model of the battery pack system under different operating conditions; S4: modifying the component parameters of the finite element model of the battery module and returning to S3 until the system stress of several finite element models of the battery pack system is obtained; S5: building a radial basis function neural network model; establishing a training dataset based on the component parameters and system stress of the finite element model of the battery pack system, and training the radial basis function neural network model to obtain a stress prediction model; S6: using the built stress prediction model to predict the stress under all combinations of component parameters of the battery pack system; S7: selecting the combination of component parameters of the battery pack system that meets the preset requirements. This invention uses a radial basis function neural network model to predict the stress response as the dimensions of the housing components change, thereby determining the optimal size design of the housing components, solving the problems of laborious, time-consuming, and complex stress prediction in designing the dimensions of battery pack housing components under different requirements. However, this invention only considers the size of the housing component as a design factor, without considering the influence of other design factors such as wall thickness and constraint form on stress response; in addition, it only analyzes the response results of the housing, without considering the response of the fuel cell stack, and there is still room for improvement in the overall vibration and shock resistance performance of the fuel cell engine.

[0006] CN113722954A provides a lightweight design method for electric vehicle battery pack housings, including: S1: establishing a finite element model of the battery pack housing; S2: establishing verification conditions for the finite element model of the battery pack housing; S3: determining whether the finite element model of the battery pack housing simultaneously meets all verification conditions; if not, regenerating the material properties, wall thickness, and finite element model of each component of the battery pack housing, and returning to S1; if yes, proceeding to S4; the material is high-strength steel; the material properties include material composition, yield strength, tensile strength, elastic modulus, Poisson's ratio, density, and constitutive model; S4: repeating S1 to S3 to obtain a finite element model with multiple material properties and wall thickness combinations; S5: conducting experimental design on the finite element model and optimizing the material properties of each component of the battery pack housing. This invention, by conducting experimental design on finite element models with different material and thickness combinations, obtains material and thickness combinations that meet the target requirements, which helps reduce the number of tests for complex battery pack housing structures in engineering practice, reduces product development costs, and shortens the product development cycle. However, the invention did not take into account the design factors of the constraint form, and did not conduct a more detailed analysis of the response results under vibration and shock conditions, only considering whether the stress response meets the strength requirements.

[0007] CN113704921A provides a lightweight design method for an electric wheel rotor housing, comprising: obtaining relevant parameters affecting the rotor housing based on an optimized rotor housing model, and using an orthogonal experimental method to optimize the relevant parameters affecting the rotor housing to obtain the optimal design scheme for the rotor housing. This invention can achieve the design goal while meeting the requirements of static characteristics, dynamic characteristics, and fatigue durability. However, this invention also does not consider the influence of design factors such as constraint forms, and in terms of response results, it only analyzes stress and displacement.

[0008] CN107819138A provides a structural design method for improving pressure distribution within a fuel cell stack, comprising: S1: measuring initial structural parameters of the battery and obtaining the battery's service conditions; S2: establishing a parameterized equivalent stiffness-mass model based on the measured parameters of the battery structure obtained in S1; S3: calculating the average stress on the membrane electrode assembly and seal under dynamic load and encapsulation force using an equivalent method, and comparing whether the average stress is consistent with the optimal stress tested in the first step; if they are consistent, proceed to S4; if they are inconsistent, change the values ​​of thickness change and encapsulation force in the formula, and recalculate until they are consistent; S4: calculating the cyclic stress amplitude on the membrane assembly and seal, comparing the experimental test results of S1 to determine whether the cyclic stress amplitude on these two components has decreased by more than 30%, calculating whether the stress at the bipolar plate BP boss is less than the yield strength of the bipolar plate BP material, and determining whether the BP boss structure meets the strength verification standard; this invention can efficiently analyze the stress of PEMFC structures, thereby efficiently completing the design of structures such as bosses. However, this invention directly applies external dynamic loads to the fuel cell stack without considering the stack and the outer casing as a whole, thus ignoring the influence of the casing on the vibration and impact response of the fuel cell stack.

[0009] In summary, existing fuel cell casing design methods include optimizing casing materials and component thicknesses based on stress response. This involves establishing a 3D model of the casing and conducting random vibration, constant frequency vibration, fatigue strength testing, and impact simulation experiments using finite element method (FEM) to obtain material properties and wall thickness combinations with good mechanical response. Existing fuel cell unit structural design methods involve establishing an equivalent stiffness model of the fuel cell unit and using FEM to analyze the stress response under static and dynamic loads, optimizing design factors such as seal thickness and static load capacity. However, these methods still have limitations. Existing technologies do not consider design factors such as constraint locations, which can significantly affect the casing's response to vibration and impact. Furthermore, these technologies only improve the casing's own vibration and impact resistance without considering the impact of casing design on the internal stack's vibration and impact resistance. On the other hand, when the fuel cell engine is subjected to vibration and impact, the casing and fuel cell stack form a coupled system. The casing structure affects the fuel cell's vibration and impact resistance. Existing technologies do not consider the transmission of external excitation through the casing; directly applying external excitation to the fuel cell stack reduces the accuracy of the simulation.

[0010] Therefore, if vibration and shock resistance are considered during the casing design process, and the mechanical properties of the internal fuel cell stack are also taken into account during the casing design, a casing design that matches the fuel cell stack can be obtained during the design process, thus determining a fuel cell engine design scheme with better vibration and shock resistance. However, the internal constraint structure of the assembled components of the fuel cell stack and casing is quite complex, and the relationship between the vibration and shock response of the fuel cell stack and its vibration and shock resistance is not intuitive. These issues make it difficult to consider the vibration and shock resistance of the fuel cell stack simultaneously during the casing design process. Summary of the Invention

[0011] In view of the problems in the prior art, the present invention provides a method for improving the vibration and shock resistance of a fuel cell engine casing, in order to solve the following problems:

[0012] 1. Describe the constraint relationships between the shell and the external environment, and between the shell and the fuel cell stack, and optimize the design parameters such as the relative positions of the constraints.

[0013] 2. Based on the structure and operating characteristics of the fuel cell stack, determine the evaluation indicators for the vibration and shock resistance of the shell and the fuel cell stack, and establish the relationship between the vibration and shock response results and mechanical properties of the fuel cell engine.

[0014] 3. During the shell design process, the influence of design parameters on the shell's own response and the fuel cell stack's response is considered simultaneously, aiming to improve the overall vibration and shock resistance of the fuel cell engine.

[0015] The specific technical solution is as follows:

[0016] A method for improving the vibration and shock resistance of a fuel cell engine casing includes the following steps:

[0017] S1. Establish a finite element mechanical performance simulation model based on the fuel cell engine casing and internal stack structure;

[0018] The steps to establish a finite element model include:

[0019] S1.1. Establish a three-dimensional model of the fuel cell stack;

[0020] S1.2. Establish a three-dimensional model of the fuel cell engine casing. The casing components include a lower casing, a top casing cover, a side casing cover, and an internal constraint structure. The lower casing, the top casing cover, and the side casing cover form a cavity. The fuel cell stack is placed in the cavity and connected to the lower casing through the internal constraint structure. The lower casing is connected to the external support. The longitudinal side casing cover has holes for gas and liquid pipelines to pass through.

[0021] S1.3. Set the material properties of the finite element model based on the fuel cell engine casing and stack materials, including Young's modulus, material density, Poisson's ratio, etc.

[0022] S1.4. Simplify the structure of the finite element model and modify the local structure of the model that has little impact on the calculation results but increases the amount of calculation;

[0023] S1.5. In actual installation, an air compressor, intercooler, etc. are also connected to the lower part of the housing. A suspension mass is set at the connection position of the lower component to reflect the influence of the connection on the response during the simulation.

[0024] S1.6. Mesh the simplified finite element model and set the constraints between each component;

[0025] S1.7 Finite element model verification.

[0026] S2. Define the design parameters for the fuel cell engine casing;

[0027] The design parameters of the fuel cell engine housing include:

[0028] 1) Thickness t of each shell component i

[0029] Where i from 1 to 6 represents the lower shell, upper shell cover, front cover, left cover, rear cover, and right cover, respectively;

[0030] 2) The position of the lower shell relative to external constraints, determined by relative position a out To define:

[0031]

[0032] Where n is the number of constraints, a0 is the distance between adjacent constraints, and a1 is the side length of the shell;

[0033] 3) The constraint position between the lower shell and the internal fuel cell stack, determined by the relative position l in To define:

[0034]

[0035] Where l0 is the distance between adjacent constraints, and l1 is the width of the fuel cell stack.

[0036] S3. Analyze the response of the shell and fuel cell stack finite element models under different test conditions;

[0037] The operating conditions include vibration conditions and shock conditions; the vibration conditions adopt the random vibration test standard and harmonic vibration test standard of GB 38031-2020; the shock conditions adopt the test method specified in GB / T 36288-2018.

[0038] The response results include stress response, deformation, strain response in the XYZ directions, and the natural frequencies of the model.

[0039] S4. Modify each of the defined design parameters, and perform simulations on the modified model under different test conditions until the model response result set corresponding to each design parameter is obtained;

[0040] The method for modifying the design parameters is as follows: the design parameters of the casing and fuel cell stack are based on the initial values, and are changed by 5% each time to obtain a set of response results within the range of -25% to +25% of the design parameter changes.

[0041] S5. Analyze the result set obtained in S4, and combine the structural and working characteristics of the fuel cell engine casing and fuel cell stack to determine the vibration and shock resistance performance evaluation indicators such as stress non-uniformity and deformation, and establish the relationship between response results and performance.

[0042] The vibration and shock resistance performance evaluation indicators include:

[0043] 1) The stress response of the shell should be minimized as much as possible, provided that the target requirements are met and the maximum value is lower than the material strength.

[0044] 2) The deformation of the shell, especially at the shell connection boundaries, should be as small as possible;

[0045] 3) Lateral displacement of fuel cell stack: The individual cells of the fuel cell stack are clamped and fixed, and the lateral displacement caused by vibration and impact should be as small as possible;

[0046] 4) Stress non-uniformity of individual cells in a fuel cell stack: After a fuel cell stack is subjected to vibration and impact, the stress distribution inside the components of each individual cell is not uniform. The stress non-uniformity δ of the sealed components is defined as follows:

[0047]

[0048] Where σ imax It is the maximum stress value of the i-th single cell, σ imin It is the minimum stress value of the i-th single cell. The stress non-uniformity should be as small as possible.

[0049] S6. Based on the pre-given target conditions, select the range of design parameters that meet the requirements, and determine the optimal combination of design parameters based on the response results of the fuel cell stack;

[0050] The steps of determining the range of design parameters and determining the optimal combination of design parameters include:

[0051] S6.1. Organize the response results after the change of each design parameter according to the vibration resistance performance evaluation index parameters as described in claim 7;

[0052] S6.2. Select design parameter combinations that meet the target requirements;

[0053] S6.3. Determine the thickness of each component of the housing;

[0054] S6.4. Determine the location of external constraints on the shell;

[0055] S6.5. Determine the constraint positions between the fuel cell stack and the interior of the casing.

[0056] S7. Design the fuel cell casing using the optimal design parameters and make local adjustments to the casing structure.

[0057] The technical effects of this invention are as follows:

[0058] This invention provides a method for improving the vibration and shock resistance of fuel cell engine casings. By simulating various operating conditions of the fuel cell casing and stack, analyzing the response results of the casing and stack, and determining the evaluation index of vibration and shock resistance, and by conducting experimental design on design parameters such as casing thickness and constraint form, the method can reduce the stress response of the casing, as well as the stress response, deformation, and lateral displacement of the fuel cell. At the same time, it can improve the stress distribution inside the single cell, weaken the adverse effects of vibration and shock on the working state of the fuel cell, thereby improving the overall vibration and shock resistance of the fuel cell engine and providing guidance for the structural design of fuel cell casings. Attached Figure Description

[0059] Figure 1 is a schematic diagram of the structure of a fuel cell housing according to a preferred embodiment of the present invention;

[0060] Figure 2 This is a flowchart of the method of the present invention;

[0061] Figure 3 A flowchart for establishing a finite element model;

[0062] Figure 4 This is a schematic diagram showing the relative position of the lower shell and the external fixed constraints;

[0063] Figure 5 This is a schematic diagram showing the relative positions of the lower casing and the fixed constraints of the fuel cell stack.

[0064] Figure 6 The diagram shows the stress non-uniformity of the first 10 individual cells in the fuel cell stack subjected to random vibration.

[0065] In the figure, the lower shell is 1, the upper shell cover is 2, the front cover is 3, the left cover is 4, the rear cover is 5, the right cover is 6, the fuel cell stack is 7, and the internal fixing structure is 8. Detailed Implementation

[0066] The specific technical solutions of the present invention will be further described below with reference to the accompanying drawings and embodiments, but it should not be construed that the scope of the present invention is limited to the following embodiments. Various substitutions and modifications made based on ordinary technical knowledge and common practices in the art without departing from the above-described technical concept of the present invention should be included within the protection scope of the present invention.

[0067] See Figure 1 to Figure 3 A method for improving the vibration and shock resistance of a fuel cell engine casing includes the following steps:

[0068] S1. Establish a finite element mechanical performance simulation model based on the fuel cell engine casing and internal stack structure;

[0069] like Figure 3 As shown, the steps for establishing the finite element model include:

[0070] S1.1. Establish as follows Figure 1b The image shows a 3D model of a fuel cell stack.

[0071] S1.2. Establish a three-dimensional model of the fuel cell engine casing, such as... Figure 1a As shown, the housing components include a lower housing, a top housing cover, a side housing cover, and an internal constraint structure. The lower housing, the top housing cover, and the side housing cover form a cavity. The fuel cell stack is placed inside the cavity and connected to the lower housing through the internal constraint structure. The lower housing is connected to the external support. The longitudinal side housing cover has holes for gas and liquid pipelines to pass through.

[0072] S1.3. Set the material properties of the finite element model based on the fuel cell engine casing and stack materials, including Young's modulus, material density, Poisson's ratio, etc.

[0073] S1.4. Simplify the structure of the finite element model and modify the local structure of the model that has little impact on the calculation results but increases the amount of calculation;

[0074] S1.5. In actual installation, an air compressor, intercooler, etc. are also connected to the lower part of the housing. A suspension mass is set at the connection position of the lower component to reflect the influence of the connection on the response during the simulation.

[0075] S1.6. Mesh the simplified finite element model and set the constraints between each component;

[0076] S1.7 Finite element model verification.

[0077] S2. Define the design parameters for the fuel cell engine casing;

[0078] like Figures 4 to 5 As shown, the design parameters of the fuel cell engine housing include:

[0079] 1) Thickness t of each shell component i

[0080] Where i from 1 to 6 represents the lower shell, upper shell cover, front cover, left cover, rear cover, and right cover, respectively;

[0081] 2) The position of the lower shell relative to external constraints, determined by relative position a out To define:

[0082]

[0083] Where n is the number of constraints, a0 is the distance between adjacent constraints, and a1 is the side length of the shell;

[0084] 3) The constraint position between the lower shell and the internal fuel cell stack, determined by the relative position l in To define:

[0085]

[0086] Where l0 is the distance between adjacent constraints, and l1 is the width of the fuel cell stack.

[0087] S3. Analyze the response of the finite element model of the fuel cell engine under different test conditions;

[0088] The operating conditions include vibration and shock conditions. The vibration test adopts the random vibration test standard and harmonic vibration test standard of GB 38031-2020. The random vibration test applies PSD input with different accelerations in the X, Y, and Z axes. The harmonic vibration test applies harmonic sweep input of 20-200Hz, ±(1.5g~2g). The shock test adopts the test method specified in GB / T36288-2018, with a 5g acceleration in the X, Y, and Z axes and a half-sine waveform shock pulse lasting 15ms.

[0089] The response results include stress response, deformation, strain response in the XYZ directions, and the natural frequencies of the model.

[0090] S4. Modify each of the defined design parameters, and perform simulations on the modified model under different test conditions until the model response result set corresponding to each design parameter is obtained;

[0091] The method for modifying the design parameters is as follows: Each design parameter of the casing and fuel cell stack is changed by 5% each time, based on the initial value, to obtain a set of response results within the range of -25% to +25% for each design parameter change. Tables 1, 2, 3, and 4 show the calculation results of the first ten modes of the fuel cell stack, the equivalent stress response of random vibration of the fuel cell stack at different internal constraint locations, the equivalent stress response of random vibration of the fuel cell stack at different external constraint locations, and the simulation response results of harmonic vibration parameters at different internal encapsulation locations, respectively.

[0092] Table 1 Calculation results of the first ten modes of the fuel cell stack

[0093]

[0094] Table 2 Equivalent stress response of fuel cell stack under random vibration at different internal constraint locations.

[0095]

[0096] Table 3 Equivalent stress response of fuel cell stack under random vibration at different external constraint locations.

[0097]

[0098] Table 4 Simulation response results of harmonic vibration parameters at different internal packaging locations.

[0099]

[0100] S5. Analyze the result set obtained in S4, and combine the structural and working characteristics of the fuel cell engine casing and fuel cell stack to determine the vibration and shock resistance performance evaluation index and establish the relationship between response results and performance.

[0101] The vibration and shock resistance performance evaluation indicators include:

[0102] 1) The stress response of the shell should be minimized as much as possible, provided that the target requirements are met and the maximum value is lower than the material strength.

[0103] 2) The deformation of the shell, especially at the shell connection boundaries, should be as small as possible;

[0104] 3) Lateral displacement of fuel cell stack: The individual cells of the fuel cell stack are clamped and fixed, and the lateral displacement caused by vibration and impact should be as small as possible;

[0105] 4) Stress non-uniformity of individual cells in a fuel cell stack: After a fuel cell stack is subjected to vibration and impact, the stress distribution inside the components of each individual cell is not uniform. The stress non-uniformity δ of the sealed components is defined as follows:

[0106]

[0107] Where σ imax It is the maximum stress value of the i-th single cell, σ imin This represents the minimum stress value of the i-th single cell. Stress non-uniformity should be minimized. For example... Figure 6 The figure shown is a diagram of the stress non-uniformity of the first 10 individual cells in the fuel cell stack subjected to random vibration.

[0108] S6. Based on the pre-given target conditions, select the range of design parameters that meet the requirements, and determine the optimal combination of design parameters based on the response results of the fuel cell stack;

[0109] The steps of determining the range of design parameters and determining the optimal combination of design parameters include:

[0110] S6.1. Organize the response results after the change of each design parameter according to the vibration resistance performance evaluation index parameters as described in claim 7; S6.2. Select the combination of design parameters that meets the target requirements;

[0111] S6.3. Determine the thickness of each component of the housing;

[0112] S6.4. Determine the location of external constraints on the shell;

[0113] S6.5. Determine the constraint positions between the fuel cell stack and the interior of the casing.

[0114] Table 5 shows the random vibration and shock response of the fuel cell stack after the design parameters were optimized.

[0115] Table 5 Random vibration and shock response of fuel cell stack after design parameter optimization

[0116]

[0117] S7. Design the fuel cell casing using the optimal design parameters and make local adjustments to the casing structure.

[0118] The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.

Claims

1. A method for improving the vibration impact resistance of a fuel cell engine housing, characterized by, Includes the following steps: S1. Establish a finite element mechanical performance simulation model based on the fuel cell engine casing and internal stack structure; S2. Define the design parameters for the fuel cell engine casing; The following design parameters are defined: 1) thickness of each housing component wherein 1 to 6 represent lower housing, upper housing cover, front side cover, left side cover, rear side cover, right side cover, respectively 2) the position of the lower housing relative to the external constraint, defined by the relative position : （1） wherein is is the number of constraints, is the distance between adjacent constraints, is the shell side length; 3) the lower housing and the internal fuel cell stack constraint locations, defined by relative positions : （2） wherein is the distance between adjacent constraints, width of the fuel cell stack; S3. Analyze the response of the shell and fuel cell stack finite element models under different test conditions; S4. Modify the design parameters defined in S2, and perform simulations on the modified model under different test conditions until the model response result set corresponding to each design parameter is obtained; S5. Analyze the result set obtained in S4, and combine the structural and working characteristics of the fuel cell engine casing and fuel cell stack to determine the vibration and shock resistance performance evaluation index and establish the relationship between response results and performance. The vibration and shock resistance performance evaluation indicators include: 1) Stress response of the shell; 2) Deformation of the shell; 3) Lateral displacement of the fuel cell stack; 4) stress unevenness of the fuel cell unit, stress distribution in each part inside the unit is not uniform after the fuel cell stack is subjected to vibration and impact, and the stress unevenness of the sealing part is defined : （3） in It is the first The maximum stress of a single cell It is the first Minimum stress of a single cell; S6. Based on the pre-given target conditions, select the range of design parameters that meet the requirements, and determine the optimal combination of design parameters based on the response results of the fuel cell stack; S7. Design the fuel cell casing using the optimal design parameters and make local adjustments to the casing structure.

2. The fuel cell engine case vibration impact resistance performance improvement method according to claim 1, characterized by, S1 specifically includes the following steps: S1.

1. Establish a three-dimensional model of the fuel cell stack; S1.

2. Establish a three-dimensional model of the fuel cell engine casing. The casing components include a lower casing, a top casing cover, a side casing cover, and an internal constraint structure. The lower casing, the top casing cover, and the side casing cover form a cavity. The fuel cell stack is placed in the cavity and connected to the lower casing through the internal constraint structure. The lower casing is connected to the external support. The longitudinal side casing cover has holes for gas and liquid pipelines to pass through. S1.

3. Set the material properties of the finite element model based on the fuel cell engine casing and stack materials; S1.

4. Simplify the structure of the finite element model and modify the local structure of the model that has little impact on the calculation results but increases the amount of calculation; S1.

5. Set a suspension mass at the connection point of the lower component to reflect the influence of the connector on the response during the simulation; S1.

6. Mesh the simplified finite element model and set the constraints between each component; S1.7 Finite element model verification.

3. The fuel cell engine case vibration impact resistance performance improvement method according to claim 1, characterized by, The operating conditions described in S3 include vibration conditions and shock conditions; the vibration conditions adopt the random vibration test standard and harmonic vibration test standard of GB 38031-2020; the shock conditions adopt the test methods specified in GB / T 36288-2018.

4. The fuel cell engine case vibration impact resistance performance improvement method according to claim 1, characterized by, The response results obtained in S4 include stress response, deformation, strain response in the XYZ directions, and the natural frequencies of the model.

5. The fuel cell engine case vibration impact resistance performance improvement method according to claim 1, characterized by, The method for modifying design parameters in S4 is as follows: the design parameters of the casing and fuel cell stack are based on the initial values, and each time they are changed by 5%, resulting in a set of response results within the range of -25% to +25% of the change in each design parameter.

6. The fuel cell engine case vibration impact resistance performance improvement method according to claim 1, characterized by, The pre-given target conditions described in S6 include the stress intensity that the material can withstand, the design target requirements for the shell and fuel cell stack stress, the maximum value of deformation in the XYZ directions, the maximum value of lateral displacement of the fuel cell stack, and the maximum value of deformation at the connection.

7. The fuel cell engine case vibration impact resistance improvement method according to claim 1, characterized by, S6 includes the following steps: S6.

1. The response results after changing the design parameters are sorted according to the vibration resistance performance evaluation index parameters described in S5; S6.

2. The design parameter combinations meeting the target requirement range are screened; S6.

3. The thicknesses of the components of the shell are determined; S6.

4. The external constraint positions of the shell are determined; S6.

5. The constraint positions inside the shell for the fuel cell stack are determined.

8. The fuel cell engine case vibration impact resistance performance improvement method according to claim 1, characterized by, The simulation software for finite element calculation is ANSYS Mechanical.

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