A simulation method for sealing foam compression amount when a battery pack pressure relief valve is opened

Abstract

This invention relates to a simulation method for the compression of sealing foam when a battery pack pressure relief valve is opened. A finite element model of the battery pack's top cover, side beams, and sealing foam is established. Equivalent models of the rivet bolts are created, and the model is truncated and fully constrained. The contact area is divided into bolt-affected and non-bolt-affected zones, employing both bonded and frictional contact methods to improve simulation realism. A two-step loading method is used: first, bolt pre-tightening is applied to achieve initial foam compression; then, the instantaneous pressure of the explosion-proof valve opening is applied to reproduce the real-world thermal runaway pressure relief condition. The foam displacement field, stress field, and top cover displacement field are obtained through finite element analysis. The residual foam thickness between bolts is extracted, and the compression ratio is calculated. The sealing effectiveness is evaluated based on sealing criteria. This invention accurately reflects the discrete compression and rebound changes of the foam, improving simulation accuracy and computational stability, and providing reliable technical support for battery pack sealing structure design and safety verification.

Description

Technical Field

[0001] This invention relates to the field of battery technology, and specifically to a method for simulating the compression of sealing foam when a battery pack pressure relief valve is opened. Background Technology

[0002] With increasingly stringent safety requirements for power battery packs in new energy vehicles, the sealing reliability of the sealing foam between the battery pack cover and the casing under extreme conditions such as thermal runaway and the opening of the explosion-proof valve has become a core aspect of battery pack structural design and safety verification. When a cell experiences thermal runaway, a large amount of high-temperature, high-pressure gas is rapidly generated inside the battery pack, causing the explosion-proof valve and pressure relief valve to open and release pressure. During this process, the internal gas pressure pushes the cover plate upwards, resulting in a significant reduction in the compression of the sealing foam, which can easily lead to sealing failure and gas leakage, posing safety risks. Therefore, accurately predicting the compression state and sealing effectiveness of the sealing foam when the pressure relief valve opens through simulation during the design phase is of great significance for avoiding failure in thermal runaway tests and improving the intrinsic safety of the battery pack.

[0003] Currently, the simulation and evaluation technology for battery pack sealing foam still has significant shortcomings: Most designs rely on engineers' experience for qualitative judgment, lacking a dedicated simulation method for the typical failure scenario of pressure relief valve opening and internal pressure rising to lift the top cover. This makes it impossible to quantitatively calculate the residual compression of the foam and accurately determine whether the seal is effective.

[0004] Existing simulation technologies are relatively simplified in bolt connection modeling and contact relationship settings, and cannot realistically reproduce the discrete distribution of local compression of foam under the combined action of bolt preload and internal pressure. The simulation accuracy is insufficient and the deviation from the experiment is large.

[0005] Existing methods generally lack the means to back-calculate the minimum thickness of foam after sealing failure, which cannot provide a quantitative basis for foam selection and structural optimization. This leads to design iteration relying on multiple prototype tests, resulting in long cycles and high costs.

[0006] In summary, existing technologies cannot meet the requirements for accurate simulation of sealing foam compression, quantitative assessment of sealing effectiveness, and optimized foam thickness design under the critical safety condition of the pressure relief valve opening in battery packs. Therefore, developing a dedicated simulation method that can accurately simulate the compression behavior of sealing foam when the pressure relief valve opens, and possesses both high precision and engineering practicality, has become an urgent technical problem to be solved in this field. Summary of the Invention

[0007] To address the shortcomings of existing technologies, this invention aims to provide a simulation method for the compression of sealing foam when a battery pack pressure relief valve is opened. This method involves establishing a finite element model including detailed bolt modeling and appropriately segmenting the model. The sealing contact surface is partitioned, and a two-step loading method combining bolt preload and internal pressure load is used for simulation. The residual thickness of the foam in the area between the bolts is extracted, and the compression rate is calculated. Based on sealing criteria, the sealing effectiveness is quantitatively evaluated. This achieves accurate simulation of the foam compression behavior during the opening of the pressure relief valve, improves the reliability of the simulation results, and provides an accurate basis for the design and safety verification of the battery pack sealing structure.

[0008] The solution of the present invention to the above technical problem is as follows: A method for simulating the compression of sealing foam when the battery pack pressure relief valve is opened, comprising: A finite element model of the bolted connection between the battery pack cover and the side beam was established, and the bolts were modeled equivalently using a combination of rbe2-beam-rbe2 elements. Based on the finite element model, the contact relationships between the sealing foam and the top cover plate, and between the sealing foam and the side beam are set. Based on the established contact relationship, boundary constraints are applied to the finite element model, and a two-step loading method is used to simulate the initial compression state of the foam and the actual working condition load history. The finite element model is solved based on boundary constraints and loading conditions to obtain the foam deformation field and the upper cover plate displacement field. Based on the obtained foam deformation field and upper cover plate displacement field, the residual foam thickness in the bolt area is extracted and the residual compression ratio is calculated. The residual compression ratio is compared with the preset minimum residual compression ratio to determine whether the foam seal is effective.

[0009] Preferably, the method further includes: conducting a real thermal runaway test on the battery pack, collecting vertical displacement data at multiple preset feature points on the upper cover, comparing the vertical displacement of the corresponding feature points obtained by simulation with the measured displacement of the thermal runaway test, and determining that the simulation model is reliable when the displacement deviation is within the preset allowable range, and adjusting the finite element model construction parameters, contact relationship parameters or boundary constraint parameters when the displacement deviation exceeds the preset allowable range until the displacement deviation between the simulation result and the test result is within the preset allowable range.

[0010] Preferably, the finite element model is limited to the sealing foam between the side beam and the top cover, and its 20mm upper and lower extension areas.

[0011] The entire battery pack model is cut off to 20mm from the sealing foam on the side beam. Considering that the battery pack body will not deform significantly during thermal runaway, a portion of the battery pack can be fully constrained to reduce the amount of calculation.

[0012] Preferred method: Based on the finite element model, the contact relationships between the sealing foam and the top cover plate, and between the sealing foam and the side beam, are defined, including: In the Abaqus simulation software, the contact area between the upper surface of the foam and the top cover, and the contact area between the lower surface of the foam and the side beam, adopt the contact-general contact form. The self-contact pair form defines the extrusion relationship between the sealing foam and the top cover plate, and between the sealing foam and the side beam, with a contact friction coefficient of 0.2.

[0013] This step simulates the real situation where the compression of the foam, top cover, and side beams is discrete in certain areas during actual thermal runaway, in order to achieve a more realistic correlation with reality.

[0014] Furthermore, the contact area is divided into a bolt-affected area and a non-bolt-affected area; the bolt-affected area uses bonded contact, while the non-bolt-affected area uses frictional contact with a set friction coefficient. The bolt-affected area is a circular region with the center of the bolt hole as the center and a radius of 1 / 4 of the bolt spacing; the non-bolt-affected area is the contact area outside the bolt-affected area.

[0015] Dividing the contact area into bolt-affected and non-bolt-affected zones can accurately reproduce the actual compression characteristics of no slippage near the bolt and local slippage in the middle of the bolt, improving the calculation accuracy of foam deformation and residual thickness, thereby ensuring the accuracy and reliability of subsequent residual compression ratio calculation, sealing effectiveness assessment and thickness back-calculation results.

[0016] Preferably, the step of applying boundary constraints to the finite element model based on the established contact relationship, and simulating the initial compression state and actual working load history of the foam using a two-step loading method, includes: Applying six degrees of freedom full constraints to the side beam cross-section and the middle mounting point can realistically fix the boundary support state of the battery pack, avoid rigid displacement and rotation of the model, ensure stable convergence of simulation calculations, and more closely resemble the actual assembly constraint environment.

[0017] The first step involves applying bolt pre-tightening forced displacement using displacement control to bring the sealing foam to the preset initial compression amount. This method can accurately and stably bring the foam to the designed initial compression amount. Compared with directly applying force load, it is easier to control the uniformity of foam compression and avoid contact non-convergence problems caused by load fluctuations.

[0018] The second step involves applying a stable, uniformly distributed pressure to the inner surface of the top cover plate when the explosion-proof valve is open, creating a load history consistent with actual working conditions. After simulation, the minimum compression of the foam is extracted. This can reproduce the true force form of the internal gas pushing the top cover plate upward during thermal runaway, accurately reflecting the actual change process of the foam gradually rebounding from a compressed state and decreasing compression.

[0019] Furthermore, the timing control of the two-step loading is as follows: the loading time T1 of the first loading step is 0.5~1.0s, and the SmoothStep loading curve is used; after the first loading step is completed, the stabilization time Ts is set to 0.1~0.2s; the loading time T2 of the second loading step is 0.5~1.0s, and the SmoothStep loading curve is also used.

[0020] Preferably, the step of solving the finite element model based on boundary constraints and loading conditions to obtain the foam deformation field and the upper cover plate displacement field includes: Forced displacement is applied to the rbe2 element corresponding to the rivet bolt from the node to set the initial compression of the foam; the initial compression of the foam can be precisely and stably controlled, avoiding load fluctuations and non-convergence of calculations, and improving the accuracy of initial state simulation. The discrete compression of the foam between bolts is simulated based on the bolt preload measured in the experiment, which closely matches the actual non-uniform stress characteristics. Instantaneous pressure under thermal runaway conditions is applied to the inner surface of the upper cover plate to simulate the real-time compression state of the foam between the bolts after the pressure relief valve is opened. Applying instantaneous pressure can realistically reproduce the pressure relief condition and obtain the real-time compression state of the foam. After solving the finite element model, the foam displacement field, stress field, contact pressure distribution, and upper cover plate displacement field are output.

[0021] Preferably, the residual compression ratio is calculated as follows: residual compression ratio = (initial foam thickness - average residual thickness) / initial foam thickness; the preset minimum residual compression ratio is 20%.

[0022] The present invention also provides a device for simulating the compression of sealing foam when the battery pack pressure relief valve is opened, comprising: The finite element model building module is used to create a finite element model of the bolted connection between the battery pack cover and the side beam. The bolts are modeled using a combination of rbe2-beam-rbe2 elements. The contact relationship establishment module is used to set the contact relationship between the sealing foam and the top cover plate, and between the sealing foam and the side beam, based on the finite element model. The boundary constraint setting module is used to apply boundary constraints to the finite element model based on the pre-set contact relationships, and to simulate the initial compression state of the foam and the actual working condition load history using a two-step loading method. The finite element model solving module is used to solve the finite element model based on boundary constraints and loading conditions to obtain the foam deformation field and the upper cover plate displacement field. The foam seal effectiveness verification module is used to extract the residual thickness of the foam in the bolt area and calculate the residual compression ratio based on the obtained foam deformation field and upper cover plate displacement field. It then compares the residual compression ratio with the preset minimum residual compression ratio to determine whether the foam seal is effective.

[0023] The present invention also provides a computer storage medium storing a computer program, which, when executed by a processor, implements the steps of the simulation method for the compression of sealing foam when the battery pack pressure relief valve is opened, as described above.

[0024] The present invention also provides an electronic device, including a memory and a processor: the memory is used to store computer-executable instructions, and the processor is used to execute the computer-executable instructions, wherein when the computer-executable instructions are executed by the processor, the steps of the simulation method for the compression of sealing foam when the battery pack pressure relief valve is opened as described above are implemented.

[0025] The beneficial effects of this invention are as follows: This invention realistically reproduces the foam compression process under battery pack depressurization conditions through refined bolt modeling, zoned contact settings, and a two-step loading method, significantly improving simulation accuracy. The combination of displacement loading and experimental preload accurately reflects the discrete compression characteristics between bolts, avoiding calculation divergence. By setting reasonable boundaries and smoothing the load sequence, the simulation more closely resembles actual stress conditions. This method can accurately obtain foam deformation, stress, and contact pressure, quantitatively assess sealing effectiveness, and provide a reliable basis for battery sealing structure design, demonstrating strong practicality.

[0026] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, the preferred embodiments of the present invention are described in detail below. Specific embodiments of the present invention are given in detail in the following examples. Attached Figure Description

[0027] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this invention, illustrate exemplary embodiments of the invention and are used to explain the invention, but do not constitute an undue limitation of the invention. In the drawings: Figure 1 This is a schematic diagram of a partial finite element model of the battery pack in Example 1; Figure 2 This is a schematic diagram of the interface for setting the contact parameters of the sealing foam in Example 1; Figure 3 This is a schematic diagram illustrating the division of the bolt-affected zone and the non-bolt-affected zone in Example 1; Figure 4 This is a schematic diagram of the initial thickness of the sealing foam in Example 1; Figure 5 This is a schematic diagram of bolt preload forced displacement loading in Example 1; Figure 6 This is a schematic diagram of the pressure load applied when the explosion-proof valve is opened, as shown in Example 1. Figure 7 This is a cloud map showing the compression distribution of foam after bolt pre-tightening in Example 1; Figure 8 This is a cloud map showing the residual compression distribution of foam under the pressure relief condition in Example 1. Detailed Implementation

[0028] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0029] Example 1 This embodiment provides a method for simulating the compression of sealing foam when the battery pack pressure relief valve is opened, including the following steps: S1, such as Figure 1 As shown, a finite element model of the bolted connection between the battery pack top cover and the side beam is established. The bolts are modeled using an RBE2-beam-RBE2 element combination. The entire pack model is limited to the sealing foam of the side beam top cover and its 20mm upper and lower extension areas to reduce the amount of calculation.

[0030] S2, such as Figure 2 As shown, based on the finite element model, the contact relationships between the sealing foam and the upper cover plate, and between the sealing foam and the side beam, are set, including: In the Abaqus simulation software, the contact area between the upper surface of the foam and the top cover, and the contact area between the lower surface of the foam and the side beam, adopt the contact-general contact form. The self-contact pair form defines the extrusion relationship between the sealing foam and the top cover plate, and between the sealing foam and the side beam, with a contact friction coefficient of 0.2.

[0031] The contact area is divided into a bolt-affected zone and a non-bolt-affected zone. The bolt-affected zone uses bonded contact, while the non-bolt-affected zone uses frictional contact with a set friction coefficient. The bolt-affected zone is a circular area with the center of the bolt hole as the center and a radius of 1 / 4 of the bolt spacing; the non-bolt-affected zone is the contact area outside the bolt-affected zone.

[0032] S3. Based on the established contact relationships, apply boundary constraints to the finite element model, and use a two-step loading simulation to model the initial compression state of the foam and the actual working load history, including: like Figure 3 As shown, six degrees of freedom (DOF 1-6) full constraints are applied to the 20mm section of the side beam and the middle mounting point to realistically reproduce the actual constraint state of the battery pack during thermal runaway. The first step involves applying a forced displacement of 1.5mm by pre-tightening the bolts using displacement control, so that the sealing foam reaches the preset initial compression amount of 30%. The second step involves applying a stable, uniformly distributed pressure of 4 kPa, equivalent to the pressure required when the explosion-proof valve is open, to the inner surface of the upper cover plate, thus creating a load history consistent with actual operating conditions. (Both loading steps utilize Contact General contactors for the foam components.) After simulation, the minimum compression amount of the foam is extracted, such as... Figure 1-4 As shown, the initial thickness of the sealing foam is 5mm.

[0033] Furthermore, the timing control of the two-step loading is as follows: the loading time T1 of the first loading step is 0.5~1.0s, and the SmoothStep loading curve is used; after the first loading step is completed, the stabilization time Ts is set to 0.1~0.2s; the loading time T2 of the second loading step is 0.5~1.0s, and the SmoothStep loading curve is also used.

[0034] S4. Solve the finite element model based on boundary constraints and loading conditions to obtain the foam deformation field and the upper cover plate displacement field, including: like Figure 5 As shown, a forced displacement of 1.5 mm is applied to the rbe2 element corresponding to the rivet bolt from the node to set the initial compression of the foam; The discrete compression of the foam between bolts is simulated based on the bolt preload measured in the experiment; like Figure 6 As shown, instantaneous pressure under thermal runaway conditions is applied to the inner surface of the upper cover plate to simulate the real-time compression state of the foam between the bolts after the pressure relief valve is opened. Specifically, the pressure load for opening the explosion-proof valve is set by clicking the analysis panel, clicking pressure, selecting face, and setting a local pressure of 0.004MPa=4KPa.

[0035] After solving the finite element model, the output includes the foam displacement field, stress field, contact pressure distribution, and upper cover plate displacement field.

[0036] S5. Based on the obtained foam deformation field and upper cover plate displacement field, extract the residual foam thickness in the bolt area and calculate the residual compression ratio. Compare it with the preset minimum residual compression ratio to determine whether the foam seal is effective.

[0037] like Figure 7 As shown, after two steps of simulation, including tightening the rivet bolts and applying a 4 kPa pressure relief valve to the critical pressure after opening, the maximum deformation of the upper cover after the explosion-proof valve is opened is 140 mm, which is close to the thermal runaway test. At this time, the upper cover deforms downward and compresses the sealing foam. The next step is to examine the initial compression rate of the foam separately (the foam of the two rivet bolts is pressed and sealed by the upper cover. The compression rate of the sealing foam is less than that near the bolts. Therefore, it is only necessary to examine whether the compression rate of the foam in the middle of the bolts is greater than 20% to define whether the two bolts are completely sealed).

[0038] like Figure 8As shown, after two-step simulation of the rivet bolt clamping force and the critical pressure after the pressure relief valve is opened, since the bolt spacing is relatively uniform, the compression amount of the middle bolt is the smallest after any three bolts are compressed. If the middle compression amount meets the sealing compression rate of 20% sealing criterion, then the compression ratio of the upper cover foam meets the thermal runaway sealing test. Figure 1-8 The average of the three intermediate compression values ​​is taken as D. average =(3.47+3.48+3.69) / 3=3.57mm, compression amount is D compress =D 初始 -D average =5-3.57=1.43mm, compression ratio rate =D compress / D 初始 =28.6%, compression ratio is 20% greater than the effective sealing condition.

[0039] S6. Conduct a real thermal runaway test on the battery pack. Collect vertical displacement data at multiple preset feature points on the upper cover. Compare the vertical displacement of the corresponding feature points obtained from the simulation with the measured displacement of the thermal runaway test. When the displacement deviation is within the preset allowable range, the simulation model is deemed reliable. When the displacement deviation exceeds the preset allowable range, adjust the finite element model construction parameters, contact relationship parameters, or boundary constraint parameters until the displacement deviation between the simulation result and the test result is within the preset allowable range.

[0040] Simulation verification showed that the subsequent airtightness tests of samples B and C both met the airtightness requirements, with the expansion deformation of the top cover measuring approximately 110 mm. This is close to the maximum deformation of the simulated top cover, and the sealing performance is intact.

[0041] Example 2 This embodiment provides a device for simulating the compression of sealing foam when a battery pack pressure relief valve is opened, including: The finite element model building module is used to create a finite element model of the bolted connection between the battery pack cover and the side beam. The bolts are modeled using a combination of rbe2-beam-rbe2 elements. The contact relationship establishment module is used to set the contact relationship between the sealing foam and the top cover plate, and between the sealing foam and the side beam, based on the finite element model. The boundary constraint setting module is used to apply boundary constraints to the finite element model based on the pre-set contact relationships, and to simulate the initial compression state of the foam and the actual working condition load history using a two-step loading method. The finite element model solving module is used to solve the finite element model based on boundary constraints and loading conditions to obtain the foam deformation field and the upper cover plate displacement field. The foam seal effectiveness verification module is used to extract the residual thickness of the foam in the bolt area and calculate the residual compression ratio based on the obtained foam deformation field and upper cover plate displacement field. It then compares the residual compression ratio with the preset minimum residual compression ratio to determine whether the foam seal is effective.

[0042] Example 3 This embodiment provides a computer storage medium storing a computer program. When the computer program is executed by a processor, it implements the steps of the simulation method for the compression of sealing foam when the battery pack pressure relief valve is opened, as described in Embodiment 1.

[0043] Example 4 This embodiment also provides an electronic device, including a memory and a processor: the memory is used to store computer-executable instructions, and the processor is used to execute the computer-executable instructions. When the computer-executable instructions are executed by the processor, they implement the steps of the simulation method for the compression of sealing foam when the battery pack pressure relief valve is opened as described in Embodiment 1.

[0044] The processor can be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it can also be a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components.

[0045] The memory may include random access memory (RAM) or non-volatile memory (NVM), such as at least one disk storage device.

[0046] The memory can be volatile memory, such as random-access memory (RAM); it can also be non-volatile memory, such as read-only memory, flash memory, hard disk drive (HDD), or solid-state drive (SSD); or it can be any other medium capable of carrying or storing desired program code having the form of instructions or data structures and accessible by a computer, but is not limited thereto. The memory can be a combination of the above-described memories. This invention can be implemented wholly or partially by software, hardware, firmware, or any combination thereof. When implemented in software, it can be implemented wholly or partially as a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of this invention are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that integrates one or more available media. The available medium can be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., a solid state disk (SSD)).

[0047] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Those skilled in the art can readily implement the present invention according to the description and above. However, any modifications, alterations, or variations made by those skilled in the art without departing from the scope of the present invention, based on the disclosed technical content, are equivalent embodiments of the present invention. Furthermore, any modifications, alterations, or variations made to the above embodiments based on the essential technology of the present invention are still within the protection scope of the present invention.

Claims

1. A method for simulating the compression of sealing foam when a battery pack pressure relief valve is opened, characterized in that, include: A finite element model of the bolted connection between the battery pack cover and the side beam was established, and the bolts were modeled equivalently using a combination of rbe2-beam-rbe2 elements. Based on the finite element model, the contact relationships between the sealing foam and the top cover plate, and between the sealing foam and the side beam are set. Based on the established contact relationship, boundary constraints are applied to the finite element model, and a two-step loading method is used to simulate the initial compression state of the foam and the actual working condition load history. The finite element model is solved based on boundary constraints and loading conditions to obtain the foam deformation field and the upper cover plate displacement field. Based on the obtained foam deformation field and upper cover plate displacement field, the residual foam thickness in the bolt area is extracted and the residual compression ratio is calculated. The residual compression ratio is compared with the preset minimum residual compression ratio to determine whether the foam seal is effective.

2. The method for simulating the compression of sealing foam when the battery pack pressure relief valve is opened, as described in claim 1, is characterized in that: The method further includes: conducting a real thermal runaway test on the battery pack, collecting vertical displacement data at multiple preset feature points on the upper cover, comparing the vertical displacement of the corresponding feature points obtained by simulation with the measured displacement of the thermal runaway test, and determining that the simulation model is reliable when the displacement deviation is within the preset allowable range. When the displacement deviation exceeds the preset allowable range, the finite element model construction parameters, contact relationship parameters, or boundary constraint parameters are adjusted until the displacement deviation between the simulation result and the test result is within the preset allowable range.

3. The method for simulating the compression of sealing foam when the battery pack pressure relief valve is opened, as described in claim 1, is characterized in that: The finite element model is limited to the sealing foam between the side beam and the top cover, and its 20mm upper and lower extension areas.

4. The method for simulating the compression of sealing foam when the battery pack pressure relief valve is opened, as described in claim 1, is characterized in that: Based on the aforementioned finite element model, the contact relationships between the sealing foam and the top cover plate, and between the sealing foam and the side beams, are defined, including: A general contact algorithm is used to define the frictional and extrusion contact relationship between the sealing foam and the top cover plate, and between the sealing foam and the side beam, with a contact friction coefficient of 0.

2.

5. The method for simulating the compression of sealing foam when the battery pack pressure relief valve is opened, as described in claim 1, is characterized in that... Based on the established contact relationships, boundary constraints are applied to the finite element model, and a two-step loading simulation is used to model the initial compression state of the foam and the actual working load history, including: Apply six degrees of freedom full constraints to the cross-section of the edge beam and the middle mounting point; The first step is to apply bolt pre-tightening forced displacement using displacement control, so that the sealing foam reaches the preset initial compression amount; The second step is to apply a stable and uniformly distributed pressure on the inner surface of the upper cover plate when the explosion-proof valve is opened, forming a load history consistent with the actual working conditions, and then extracting the minimum compression amount of the foam after simulation.

6. The method for simulating the compression of sealing foam when the battery pack pressure relief valve is opened, as described in claim 1, is characterized in that... The finite element model is solved based on boundary constraints and loading conditions to obtain the foam deformation field and the upper cover plate displacement field, including: Forced displacement is applied to the node of the rbe2 element corresponding to the rivet bolt to set the initial compression of the foam; The discrete compression of the foam between bolts is simulated based on the bolt preload measured in the experiment; Instantaneous pressure under thermal runaway conditions is applied to the inner surface of the upper cover plate to simulate the real-time compression state of the foam between the bolts after the pressure relief valve is opened. After solving the finite element model, the foam displacement field, stress field, contact pressure distribution, and upper cover plate displacement field are output.

7. The method for simulating the compression of sealing foam when the battery pack pressure relief valve is opened, as described in claim 1, is characterized in that... The residual compression ratio is calculated as follows: Residual compression ratio = (Initial foam thickness - Average residual thickness) / Initial foam thickness; The preset minimum residual compression ratio is 20%.

8. A device for simulating the compression of sealing foam when a battery pack pressure relief valve is opened, characterized in that, include: The finite element model building module is used to create a finite element model of the bolted connection between the battery pack cover and the side beam. The bolts are modeled using a combination of rbe2-beam-rbe2 elements. The contact relationship establishment module is used to set the contact relationship between the sealing foam and the top cover plate, and between the sealing foam and the side beam, based on the finite element model. The boundary constraint setting module is used to apply boundary constraints to the finite element model based on the pre-set contact relationships, and to simulate the initial compression state of the foam and the actual working condition load history using a two-step loading method. The finite element model solving module is used to solve the finite element model based on boundary constraints and loading conditions to obtain the foam deformation field and the upper cover plate displacement field. The foam seal effectiveness verification module is used to extract the residual thickness of the foam in the bolt area and calculate the residual compression ratio based on the obtained foam deformation field and upper cover plate displacement field. It then compares the residual compression ratio with the preset minimum residual compression ratio to determine whether the foam seal is effective.

9. A computer storage medium storing a computer program, wherein the computer program, when executed by a processor, implements the steps of the method for simulating the compression of sealing foam when the battery pack pressure relief valve is opened as described in any one of claims 1-7.

10. An electronic device, comprising a memory and a processor: the memory for storing computer-executable instructions, the processor for executing the computer-executable instructions, wherein the computer-executable instructions, when executed by the processor, implement the steps of the simulation method for the compression of sealing foam when the battery pack pressure relief valve is opened as described in any one of claims 1-7.

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