A mixed entangled fiber hydrogen storage cylinder forward design method, device, equipment and medium

Abstract

The application relates to the technical field of gas cylinder design, and discloses a mixed-winding fiber hydrogen storage cylinder forward design method, device, equipment and medium, wherein the method comprises the following steps: in response to a plurality of received composite materials containing fibers and resin matrices, performance testing is conducted on the composite materials, a composite material performance database is constructed according to test results, and a preliminary mixed-winding layer scheme is determined in combination with a fiber winding grid theory; the influence law of various design parameters in the preliminary mixed-winding layer scheme on the service performance of the gas cylinder is analyzed, an optimization strategy is established based on key evaluation indexes, the design parameters are iteratively optimized, and optimal winding layer design parameters are obtained; a gas cylinder numerical model is constructed according to the optimal winding layer design parameters, the internal damage of the gas cylinder is determined under a plurality of pressure working conditions, and an optimal mixed-winding layer scheme is determined based on the internal damage of the gas cylinder. The technical scheme provided by the application can realize the lightweight forward design of the fiber mixed-winding gas cylinder and comprehensively optimize the service performance.

Description

Technical Field

[0001] This application relates to the field of gas cylinder design technology, and in particular to a forward design method, apparatus, equipment and medium for a hybrid fiber hydrogen storage gas cylinder. Background Technology

[0002] Safe and efficient hydrogen storage and transportation technology is the core support for the large-scale development of the hydrogen energy industry. Aluminum-lined carbon fiber fully wound hydrogen storage cylinders (hereinafter referred to as Type III cylinders) have been widely used in new energy vehicles, aerospace, and shipbuilding due to their advantages of light weight and high strength. However, the metal material of the Type III cylinder liner is prone to significant deformation under the pressure load of the filling and discharging cycle, leading to fatigue damage, shortening the cylinder's service life, and hindering its further promotion in the pressure vessel field. To meet fatigue life and structural strength requirements, over-winding of the winding layer is often adopted in actual design, but this contradicts the development goal of lightweight cylinders. To address these issues, the field of composite material cylinders has proposed the concept of fiber hybrid winding to overcome the limitations of single-fiber winding methods.

[0003] Therefore, how to achieve a lightweight forward design and optimization method for fiber-entangled Type III bottles and comprehensively optimize their service performance has become a technical problem that needs to be solved. Summary of the Invention

[0004] This application provides a forward design method, apparatus, equipment, and medium for hybrid fiber hydrogen storage cylinders, which solves the problem of how to achieve lightweight forward design and optimization of fiber hybrid type III cylinders, and comprehensively optimizes their service performance, which has become a technical problem that needs to be solved.

[0005] To achieve the above objectives, the main technical solutions adopted in this application include: In a first aspect, embodiments of this application provide a forward design method for a hybrid fiber hydrogen storage cylinder, the method comprising: In response to the received composite materials containing fibers and resin matrices, the performance of the composite materials is tested, a composite material performance database is constructed based on the test results, and a preliminary mixed-layout scheme is determined in combination with the fiber winding mesh theory. The influence of each design parameter in the preliminary mixed-layer layup scheme on the service performance of the gas cylinder is analyzed. An optimization strategy is established based on key evaluation indicators, and the design parameters are iteratively optimized to obtain the optimal winding layer design parameters. A numerical model of the gas cylinder is constructed based on the optimal winding layer design parameters. The internal damage of the gas cylinder is determined under various pressure conditions, and the optimal mixed winding layer scheme is determined based on the internal damage of the gas cylinder.

[0006] This embodiment provides a forward design method for hybrid fiber-wound hydrogen storage cylinders. It constructs a composite material performance database based on received fiber-resin composite material systems and performance testing, and forms a preliminary hybrid layup scheme using fiber winding mesh theory. Based on this, it analyzes the influence of key design parameters such as winding angle, number of winding layers, and layup sequence on the cylinder's burst pressure and fatigue life. An optimization strategy based on multiple evaluation indicators is established to iteratively optimize the design parameters and determine the optimal hybrid layup scheme. This embodiment realizes a forward development process from top-level target decomposition, material data-driven design, multi-parameter decoupling optimization to simulation verification closed loop. It can effectively improve the matching degree of hydrogen storage cylinder load-bearing capacity and durability, while also considering lightweight requirements. It provides a systematic and highly reliable technical path for the engineering design of high-performance composite material wound cylinders. It enables a lightweight forward design and optimization method for fiber-wound Type III cylinders, comprehensively optimizing their service performance.

[0007] In one embodiment, the performance testing of the composite material in response to receiving multiple composite materials comprising fibers and resin matrices includes: Prepare NOL ring specimens and laminate specimens containing single fibers. Based on the fiber, various fiber mixing ratios are set to mix the fiber with the resin matrix, and NOL ring samples and laminate samples containing various fiber mixtures are prepared according to the various fiber mixing ratios. Performance tests were conducted on all NOL ring specimens and laminate specimens to obtain test results.

[0008] This embodiment selects fibers and resin matrices based on two core service parameters: target burst pressure and fatigue life, ensuring compatibility with the operating conditions of the gas cylinder. Subsequently, NOL ring specimens and laminate specimens with single fibers and multiple fiber blends are prepared, strictly adhering to the same process procedures as actual gas cylinder production. Systematic mechanical property testing is used to obtain key data such as the reference strength, modulus, and failure modes of each component and the hybrid system. This embodiment, through standardized specimen preparation and testing procedures, provides accurate and reliable single-component calibration inputs and hybrid effect laws support for the composite material performance database. This lays a solid data foundation for subsequent winding layer thickness design, blending ratio optimization, and overall structural strength verification, effectively improving the rationality of parameter selection and the accuracy of performance prediction in the design stage of composite pressure vessels.

[0009] In one implementation, a preliminary mixed-layer layup scheme is determined by combining fiber-wound mesh theory, including: Based on the ratio of the polar hole radius to the cylinder radius in the composite material performance database, the winding angle is determined by enlarging the hole; The corresponding winding layer thickness is determined based on the selected winding method and the winding angle; The number of winding layers is determined based on the ratio of the winding layer thickness to the thickness of a single layer of winding layer; A preliminary mixed-layout scheme is determined based on the winding angle, the number of winding layers, and the winding method.

[0010] This embodiment, in the composite material winding process, initially determines the theoretical winding angle based on the geometric relationship between the radius of the polar hole and the radius of the cylinder, and adjusts the actual winding angle by appropriately enlarging the hole to alleviate the problems of sudden wall thickness changes and stress concentration caused by fiber accumulation in the polar hole area. Based on this, and considering the load-bearing characteristics of circumferential and helical winding, the thickness of the corresponding winding layer and the required number of layup layers are determined respectively. Then, based on the constraints of multi-angle combinations and the mixing ratio of fibers with different performance characteristics, a preliminary mixed-layup scheme of alternating layup is formed. This initially achieves a reasonable combination of multi-angle helical layers and circumferential layers, effectively dispersing the fiber distribution density in the end cap area, improving the stress-bearing balance in the axial and circumferential directions of the cylinder section. Simultaneously, by utilizing the complementary characteristics of fibers with different moduli and strengths, while ensuring structural safety margins, the comprehensive mechanical properties and process adaptability of the composite pressure vessel in terms of stiffness, strength, and internal pressure stability are significantly improved.

[0011] In one embodiment, determining the corresponding winding layer thickness based on the selected winding method and the winding angle includes: Based on the composite material performance database, the allowable stress of the mixed fiber-resin for each composite material is obtained; The thickness of the winding layer is determined based on a pre-constructed thickness conversion model that characterizes the relationship between the service parameters, the winding method, the winding angle, and the allowable stress of the fiber-resin.

[0012] This embodiment obtains the volume percentage of different fibers in the hybrid system through a composite material performance database, and obtains the fiber-resin allowable stress of the mixed fiber and resin system through weighted superposition. Based on a pre-constructed thickness conversion model, service parameters, winding method, winding angle, and fiber-resin allowable stress are correlated to determine the winding layer thickness of the helical winding layer and the circumferential winding layer, respectively. This embodiment achieves a simplified calculation of the winding layer thickness, ensuring that the stress distribution of each fiber layer is reasonable under internal pressure load and does not exceed the material's safe allowable limit, providing a reliable mechanical basis for subsequent calculation of the number of layups and scheme design.

[0013] In one embodiment, obtaining the allowable fiber-resin hybrid stress of each composite material according to the composite material performance database includes: The tensile strength of a single fiber is determined by multiplying the entangled fiber ratio of the single fiber in the composite material performance database with the longitudinal tensile strength of the corresponding single fiber. The total tensile strength is determined by summing the tensile strengths of each individual fiber. The allowable stress of the fiber-resin is determined by multiplying the total tensile strength by the fiber volume fraction in the composite material performance database.

[0014] This embodiment utilizes a composite material performance database. First, it calculates the effective tensile strength contribution of each individual fiber by multiplying the entanglement ratio of each fiber with its corresponding longitudinal tensile strength. Then, it sums the tensile strengths of all individual fibers to obtain the total tensile strength, reflecting the combined effect of all fiber components according to their actual volume proportions. Finally, it multiplies the total tensile strength by the fiber volume fraction in the database to determine the allowable fiber-resin stress, thus characterizing the maximum tensile stress that the fiber and resin can withstand working together. This embodiment considers the influence of the composition ratio and fiber volume fraction of hybrid fibers on the tensile properties of composite materials, providing accurate and reliable allowable stress values ​​for composite material structural design. This helps optimize material proportions, improve the accuracy of structural strength prediction, and ensure safety margins in engineering applications.

[0015] In one implementation, the influence pattern is represented by a relationship diagram, which includes: an angle service performance relationship diagram, a layer-number service performance relationship diagram, and a sequential service performance relationship diagram. The relationship diagram is obtained as follows: Using the winding method and winding angle in the design parameters as variables, and the other design parameters as quantities, an angle service performance relationship diagram is constructed. Using the winding method, winding layer thickness, and mixing ratio in the design parameters as variables, and the other design parameters as quantities, a layer number service performance relationship diagram is constructed. Using the winding layer layup sequence in the design parameters as a variable and the other design parameters as quantitative parameters, a sequential service performance relationship diagram is constructed.

[0016] This embodiment constructs three service performance relationship diagrams by changing three key variables: winding angle, winding layer thickness and mixing ratio, and layup sequence, while keeping other design parameters quantitative. First, using the winding angle as a variable, an angle-based service performance relationship diagram is constructed to clarify the independent contribution of the angle parameter to the ultimate bearing capacity and cycle durability. Second, using the winding method type, winding layer thickness, and mixing ratio (such as the proportion of two types of fibers) as variables, a layer-based service performance relationship diagram is constructed to reveal the influence of the mixing ratio on the cylinder performance. Finally, using the layup sequence as a variable, a sequence-based service performance relationship diagram is constructed to visually demonstrate the evolution trend of the layup sequence on service performance. This embodiment effectively decouples the coupling effects of multiple parameters, eliminates the confounding interference of non-study factors, provides a quantitative basis for the optimal winding scheme in the design stage of composite gas cylinders, and clarifies the independent action mechanism of each parameter on fatigue life and burst pressure; thus, it can maximize fatigue life while meeting burst pressure requirements, achieving a synergistic design of lightweight and long-life gas cylinders.

[0017] In one implementation, the key evaluation indicators establish an optimization strategy, including: Select the service parameters to be analyzed as evaluation indicators; Based on the aforementioned patterns of influence, the influencing factors and their levels are identified through analysis. An orthogonal array is constructed by arranging the evaluation indicators, influencing factors, and influence levels. Select orthogonal terms according to the orthogonal array; The experimental results are obtained based on the orthogonal terms and compared with the evaluation index to determine the composite material winding layer hybrid layup scheme.

[0018] This embodiment introduces orthogonal experimental design and matrix analysis methods to couple and optimize multiple evaluation indicators with influencing factors and their levels. Through a balanced combination of a limited number of simulation analyses, the sensitivity and weight ranking of each influencing factor can be quantitatively assessed. This embodiment effectively eliminates the mixed interference between multiple parameters, significantly reduces the computational cost of comprehensive testing, and can significantly improve the cyclic durability performance of gas cylinders and achieve lightweight structural design while meeting the ultimate bearing capacity requirements. It provides a precise and efficient optimization path for the mixed-layout scheme of composite material winding layers.

[0019] Secondly, embodiments of this application provide a forward design device for a hybrid fiber hydrogen storage cylinder, the device comprising: The initial design unit is used to respond to a variety of composite materials containing fibers and resin matrices, perform performance tests on the composite materials, construct a composite material performance database based on the test results and the structural parameters, and determine an initial mixed-layout scheme in combination with fiber winding mesh theory. The optimization unit is used to analyze the influence of each design parameter in the preliminary mixed-layer layup scheme on the service performance of the gas cylinder, establish an optimization strategy based on key evaluation indicators, and iteratively optimize the design parameters to obtain the optimal winding layer design parameters. The final design unit is used to construct a numerical model of the gas cylinder based on the optimal winding layer design parameters, determine the internal damage of the gas cylinder under various pressure conditions, and determine the optimal mixed winding layer scheme based on the internal damage of the gas cylinder.

[0020] Thirdly, embodiments of this application provide a computer device, including: The system includes a memory and a processor, which are interconnected. The memory stores computer instructions, and the processor executes these computer instructions to perform the forward design method for entangled fiber hydrogen storage cylinders described above.

[0021] Fourthly, embodiments of this application provide a computer-readable storage medium storing computer instructions, which are used to cause a computer to execute the forward design method for entangled fiber hydrogen storage cylinders described in any of the above claims. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0023] Figure 1 A flowchart illustrating a forward design method for a hybrid fiber hydrogen storage cylinder provided in this application embodiment; Figure 2 A flowchart of step S311 provided in an embodiment of this application; Figure 3 A flowchart of step S331 provided in an embodiment of this application; Figure 4 A flowchart of step S3331 provided in the embodiments of this application; Figure 5 A flowchart of step S33311 provided in the embodiments of this application; Figure 6 An angular service performance relationship diagram provided for embodiments of this application; Figure 7 A diagram showing the service performance relationship of different layers provided in this application embodiment; Figure 8A diagram showing the service performance relationship of different layers provided in this application embodiment; Figure 9 This is a schematic diagram of the service performance of a gas cylinder before adopting an iterative optimization strategy, provided in an embodiment of this application. Figure 10 A schematic diagram of the service performance of a gas cylinder after an iterative optimization strategy for the design parameters of the winding layer of the mixed-wound gas cylinder, which is provided for the embodiments of this application. Figure 11 Damage cloud diagram of the entangled gas cylinder winding layer under rated working pressure provided in the embodiments of this application; Figure 12 Damage cloud map of the entangled gas cylinder winding layer under the hydrostatic cycling test pressure provided in the embodiment of this application; Figure 13 Damage cloud diagram of the entangled gas cylinder winding layer under self-tightening pressure provided in the embodiments of this application; Figure 14 A block diagram of a forward design device for a hybrid fiber hydrogen storage cylinder provided in this application embodiment; Figure 15 This is a schematic diagram of the structure of a computer device provided in an embodiment of this application. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0025] To achieve the above objectives, the main technical solutions adopted in this application include: Firstly, embodiments of this application provide a forward design method for a hybrid fiber hydrogen storage cylinder. Figure 1 A flowchart illustrating a forward design method for a hybrid fiber hydrogen storage cylinder provided in this application embodiment is shown below. Figure 1 As shown, the process includes the following steps: Step S1: In response to the received multiple composite materials containing fibers and resin matrices, the performance of the composite materials is tested, a composite material performance database is constructed based on the test results and structural parameters, and a preliminary mixed-layout scheme is determined in combination with fiber winding mesh theory.

[0026] Specifically, key data such as tensile strength, elastic modulus, shear properties, and fatigue SN curves under different fiber and hybrid ratios are obtained through NOL ring and laminate performance testing, and a composite material performance database is constructed based on this. The composite material performance database also includes service parameters characterizing the service target, such as rated working pressure, hydrostatic cycling test pressure, autotightening pressure, burst pressure, and fatigue life. Structural parameters are derived from the cylinder geometry and liner design output, covering data characterizing the cylinder structure, including cylinder volume, liner section radius (cylinder radius), pole hole radius, liner wall thickness distribution, and end cap curve equation parameters. Based on the target cylinder's application scenario (e.g., vehicle-mounted hydrogen storage, aerospace, or respiratory protection) and corresponding international standards (e.g., ISO 11439, GB / T 35544), these indicators are converted into specific design target values, thus providing clear mechanical boundaries and geometric constraints for subsequent mesh theory layup calculations, fiber selection strength verification, and fatigue life assessment. By further combining the fiber winding mesh theory, and using burst pressure and polar hole radius as inputs, the circumferential and longitudinal layup thickness requirements are calculated, and a preliminary mixed-winding layup scheme that takes into account burst pressure margin and fatigue life is initially determined.

[0027] Step S3: Analyze the influence of each design parameter in the preliminary mixed-layer layup scheme on the service performance of the gas cylinder, establish an optimization strategy based on key evaluation indicators, and iteratively optimize the design parameters to obtain the optimal winding layer design parameters.

[0028] Specifically, addressing the coupled influence of multiple design parameters such as winding angle, winding layer thickness, and layer sequence in the preliminary mixed-layer layup scheme, a service performance relationship graph was constructed by controlling variables one by one to decouple and quantify the independent contribution of each parameter to the cylinder burst pressure and fatigue life. Evaluation indicators were selected based on the service parameters, and orthogonal experimental design and multi-index matrix analysis methods were introduced to achieve a balanced combination and weight ranking of multiple factors and levels within a limited number of simulation iterations. This embodiment effectively eliminates mixed interference, accurately identifies dominant sensitive factors, and obtains the optimal combination of winding layer design parameters that balances high burst margin, long fatigue life, and lightweight design through iterative optimization, providing a scientific basis for subsequent verification and scheme determination.

[0029] Step S5: Construct a numerical model of the gas cylinder based on the optimal winding layer design parameters, determine the internal damage of the gas cylinder under various pressure conditions, and determine the optimal mixed winding layer scheme based on the internal damage of the gas cylinder.

[0030] Specifically, based on the relevant design specifications and usage requirements for hydrogen storage cylinders, the service and structural parameters of the hybrid winding cylinder are defined as follows: rated working pressure is 70 MPa, hydrostatic cycling test pressure is 87.5 MPa, and burst pressure is required to be no less than 157.5 MPa; the nominal volume of the cylinder is 10 L, the total length of the inner liner is 590 mm, the diameter of the inner liner section is 186 mm, the inner liner wall thickness is 5 mm, and the end cap adopts an ellipsoidal structure with a minor semi-axis length of 127.1 mm. A refined finite element model is established based on these parameters. The finite element model is based on finite element analysis software, and the execution process includes: first, constructing a three-dimensional model of the cylinder inner liner; then, based on the composite material performance database, completing the layup definition according to the obtained optimal winding layer design parameters, and applying one or more of the following internal pressure loads: rated working pressure, hydrostatic cycling test pressure, self-tightening pressure, and minimum burst pressure. The analysis process is based on Abaqus finite element analysis software, employing the UMAT subroutine for progressive failure analysis of composite materials. First, the Hashin failure criterion is used to determine if the material is damaged. If damage occurs, the Linde nonlinear reduced stiffness matrix method is used to calculate damage parameters and reduce material properties. The damage calculation results are fed back to Abaqus to assess convergence, and the failure state variable SDV1 is output. Evaluation results are obtained based on finite element contour plots, and the degree of damage is quantified by the SDV1 value: SDV1=0 indicates no damage to the winding fiber; SDV1>0 indicates fiber damage and impending failure; SDV1=1 indicates complete fiber damage and complete failure of load-bearing capacity. The SDV1 values ​​of the mixed-layer gas cylinder are calculated under four operating conditions. Safety requirements stipulate that SDV1=0 must be maintained under rated working pressure, hydrostatic test pressure, and self-tightening pressure conditions, while SDV1 should be less than 1 before the internal pressure reaches the minimum burst pressure. If this safety requirement is not met, the design needs to be readjusted.

[0031] This embodiment provides a forward design method for hybrid fiber-wound hydrogen storage cylinders. It constructs a composite material performance database based on received fiber-resin composite material systems and performance testing, and forms a preliminary hybrid layup scheme using fiber winding mesh theory. Based on this, it analyzes the influence of key design parameters such as winding angle, number of winding layers, and layup sequence on the cylinder's burst pressure and fatigue life. An optimization strategy based on multiple evaluation indicators is established to iteratively optimize the design parameters and determine the optimal hybrid layup scheme. This embodiment realizes a forward development process from top-level target decomposition, material data-driven design, multi-parameter decoupling optimization to simulation verification closed loop. It can effectively improve the matching degree of hydrogen storage cylinder load-bearing capacity and durability, while also considering lightweight requirements. It provides a systematic and highly reliable technical path for the engineering design of high-performance composite material wound cylinders. It enables a lightweight forward design and optimization method for fiber-wound Type III cylinders, comprehensively optimizing their service performance.

[0032] Figure 2 A flowchart for performance testing of composite materials comprising fibers and resin matrices, provided as an embodiment of this application, may include the following steps: Step S111: Prepare NOL ring samples and laminate samples containing a single fiber.

[0033] Specifically, the preparation of NOL ring specimens and laminate specimens containing a single fiber is to obtain the baseline mechanical property parameters of a specific fiber grade combined with a selected epoxy resin system, providing single-component calibration input for subsequent hybrid design and database establishment. For example, a single type of carbon fiber (such as T800S or M46J) is impregnated with a high-toughness epoxy resin using a winding process, and then NOL ring specimens are formed circumferentially on a special mandrel according to ASTM D2291 standard. Experimental results are used to obtain the fundamental elastic constants and interlaminar shear strengths of the unidirectional plate for both the fiber and resin system. The curing regime for all specimens is consistent with the actual production process of the gas cylinder, ensuring that the test data directly reflects the performance level of the wound layer under actual service conditions.

[0034] Step S113: Based on the fiber, set multiple fiber mixing ratios for fiber and resin matrix, and prepare NOL ring samples and laminate samples containing multiple fiber mixtures according to the multiple fiber mixing ratios.

[0035] Specifically, based on the screened single-fiber performance data, further research was conducted on fiber hybridization ratio design and hybrid composite sample preparation. For example, firstly, based on the weighting ratio of gas cylinder strength and fatigue life, multiple fiber hybridization schemes were set: for instance, high-strength fibers and high-modulus fibers were set in multiple ratios between 0% and 100% by volume content or winding layer ratio, such as gradient combinations of 1:1, 2:1, 1:2, etc., or an interlayer hybrid structure of high-modulus inner layer / high-strength outer layer was adopted, followed by impregnation with resin matrix adhesive. For each hybridization ratio, different fiber bundles were alternately laid on a mandrel using a wet winding process to prepare NOL ring samples, ensuring that the fiber tension, adhesive content, and curing regime were completely consistent with the actual gas cylinder process, in order to determine the circumferential tensile strength and failure mode evolution law under hybrid conditions. At the same time, hybrid laminate samples were prepared using an alternating layup molding process, and the samples were processed according to ASTM D3039 standard to test the longitudinal tensile modulus, Poisson's ratio, and the influence of different hybridization ratios on the failure strain of the first layer of the hybrid layup system.

[0036] Step S115: Perform performance tests on all NOL ring specimens and laminate specimens to obtain test results.

[0037] Specifically, systematic mechanical property tests were conducted on all NOL ring specimens and laminate specimens. For the NOL ring specimens, circumferential tensile tests were performed according to ASTM D2291 to obtain data on tensile strength, elastic modulus, and elongation at break in the fiber winding direction. For the laminate specimens, all test results were categorized and archived according to fiber grade and blending ratio, providing accurate allowable strength values, stiffness degradation models, and fatigue life prediction basis for the composite material performance database.

[0038] This embodiment prepared NOL ring specimens and laminate specimens with single fibers and mixed proportions of multiple fibers, strictly adhering to the same process procedures as actual gas cylinder production. Through systematic mechanical property testing, key data such as the reference strength, modulus, and failure modes of each component and the hybrid system were obtained. This embodiment, through standardized specimen preparation and testing procedures, provides accurate and reliable single-component calibration inputs and hybrid effect laws support for the composite material performance database. This lays a solid data foundation for subsequent winding layer thickness design, hybrid ratio optimization, and overall structural strength verification, effectively improving the rationality of parameter selection and the accuracy of performance prediction in the design stage of composite pressure vessels.

[0039] Figure 3 The flowchart for determining a preliminary mixed-layout scheme based on fiber-wound mesh theory provided in this application embodiment may include the following steps: Step S131: Based on the ratio of the polar hole radius to the cylinder radius in the composite material performance database, the winding angle is determined by enlarging the hole.

[0040] Specifically, in the composite material winding process, the design of the winding angle directly affects the load-bearing efficiency of the shell structure and the stability of fiber placement. The winding angle (the angle between the fiber winding direction and the axis of the cylinder) is usually initially determined based on the geometric boundary conditions of the inner liner: when the radius of the inner liner is known... (i.e., the distance from the inner wall of the cylindrical section of the air cylinder to the axis) and the radius of the polar hole When the radius of the opening at the axis of the end caps at both ends of the air cylinder is (), the winding angle is ( ). The expression is: In the actual winding process, if the theoretical winding angle is strictly followed... The winding process leads to a significant fiber thickness accumulation effect near the polar hole. Multiple strands of composite material repeatedly overlap due to converging on the same tangential circumferential path, causing a sharp increase in the local wall thickness at the edge of the polar hole (the circular opening at the center of the top of the end caps at both ends of the inner liner). This not only affects the smooth adhesion of subsequent winding layers but also causes stress concentration and material redundancy after curing. To alleviate excessive accumulation at the polar hole, an enlarged hole method is used to obtain the final winding angle. This involves moderately increasing the winding angle based on the theoretical value, so that the composite material is no longer strictly tangential at the edge of the polar hole during winding, but rather passes around it at a certain offset distance. This shifts the distribution range of the composite material towards the outside of the end cap, dispersing the accumulation area and reducing the local thickness gradient. Based on the geometric parameters and molding experience in the composite material performance database, the winding angle is further gradually increased to 12°, 15°, 20°, 25°, 35°, 40° and 45°. Through multi-angle combination layup design, the fiber distribution uniformity of the end cap section can be effectively controlled, while the load-bearing requirements of the cylinder section in different stress directions can be taken into account, providing a more flexible process window for the comprehensive mechanical performance optimization of pressure vessels.

[0041] Step S133: Determine the corresponding winding layer thickness based on the selected winding method and winding angle.

[0042] Specifically, taking circumferential winding and helical winding as examples, the thickness of the helical winding layer... The representation is as follows: in, The radius of the inner cylinder section is... The burst pressure of the gas cylinder (provided by service parameters from the composite material performance database), and the allowable stress of the fiber-resin. , The spiral winding angle (including the winding angle after hole enlargement) is the main factor. The thickness of the spiral winding layer mainly bears the axial stress and part of the circumferential stress component caused by internal pressure. The thickness of the spiral winding layer increases with the increase of the spiral winding angle, reflecting the impact on load-bearing efficiency when the fibers deviate from the circumferential arrangement. The circumferential winding layer thickness is given by the formula: The calculation of the thickness of both winding layers is based on the burst pressure given in the composite material performance database. This together constitutes the design basis for the thickness of the fiber winding layers of the gas cylinder, ensuring that the stress on each fiber layer is reasonable and does not exceed the allowable limit of the material under the target pressure level.

[0043] Step S135: Determine the number of winding layers based on the ratio of the winding layer thickness to the thickness of a single layer of winding layer.

[0044] Specifically, in the fiber winding process for gas cylinders, a combination of circumferential winding and helical winding is typically used to meet the strength requirements of the internal pressure vessel in both the axial and circumferential principal stress directions. The circumferential winding layer primarily bears the circumferential stress of the cylinder body, while the helical winding layer simultaneously bears both axial stress and part of the circumferential stress, achieving continuous fiber coverage and mechanical transfer in the end cap region.

[0045] When designing the fiber winding layup, the single-layer thickness of different fiber windings in the composite material performance database should be considered. The thickness of a single layer of the winding layer is usually determined in advance by process parameters such as fiber specifications, width, and winding tension.

[0046] The number of winding layers for different winding methods can be determined based on the thickness of a single layer of different fiber winding layers, and its expression is as follows: in, Indicates the number of circumferential winding layers. This indicates the number of spiral winding layers. The obtained number of winding layers usually needs to be rounded up to ensure that the actual winding layer thickness is not less than the minimum load-bearing thickness required by the design, thereby meeting the safety margin of the gas cylinder under working pressure. This embodiment provides a direct quantitative basis for planning the layup sequence of the winding process.

[0047] Step S137: Determine the preliminary mixed-layup scheme based on the winding angle, number of winding layers, and winding method.

[0048] Specifically, in the initial determination of the hybrid layup scheme, three key factors are considered comprehensively: winding angle, number of winding layers, and specific winding method. Taking a fiber volume fraction (Vf) of 70%, and using the hybrid ratio of two types of carbon fibers as an example: the upper limit for the proportion of M-40 high-modulus carbon fiber is 25%, while the lower limit for the proportion of T-700 high-strength carbon fiber is 75%. Furthermore, based on the obtained fiber-resin allowable stress... Based on the cylinder radius With the radius of the polar hole The spiral winding angle is selected as 12.0°, and the total thickness of the spiral layup is... Approximately 6.5 mm, total thickness of circumferential ply The thickness is approximately 9.5mm. The spiral winding angle was measured on a winding machine and determined to be seven gradient angles for hole expansion: 12°, 15°, 20°, 25°, 35°, 40°, and 45°. The measured thickness of a single cured T-700 carbon fiber reinforced polymer (CFRP) layer was 0.214mm, while the thickness of a single M-40 CFRP layer was 0.125mm. This difference in thickness was considered separately in the calculation of the cumulative layup thickness. Based on this, a specific preliminary mixed-layup scheme was defined, expressed as follows: In this designation, the 90° layup represents circumferential winding to withstand circumferential stress caused by internal pressure. Layers marked with "±" (12°, 15°, 20°, 25°, 35°, 40°, and 45°) are helical windings used to balance axial and circumferential load distribution. The subscript numbers for each angle indicate the number of circumferential winding layers at each helical winding angle. Regarding material distribution, only the first layer uses M-40CFRP, with a calculated mixed-winding ratio of 12.4% in the entire layup sequence, meeting the predetermined upper limit requirement of no more than 25%. All other layups use T-700CFRP to ensure that the overall structural strength reserve matches the allowable stress level. Mixed-winding refers to the mixing of different fibers (a mixture of high-modulus and high-strength fibers), and the mixed-winding ratio refers to the volume fraction of high-modulus fibers. The layup sequence can be expressed as the stacking order of fibers with a high modulus ratio and fibers with a high strength ratio.

[0049] This embodiment combines alternating combinations of multi-angle helical layups and circumferential layups, along with the complementary properties of the two types of carbon fibers in terms of modulus and strength, to achieve a reasonable match between stiffness, strength, and internal pressure stability in composite pressure vessels or tubular components.

[0050] This embodiment, in the composite material winding process, initially determines the theoretical winding angle based on the geometric relationship between the radius of the polar hole and the radius of the cylinder, and adjusts the actual winding angle by appropriately enlarging the hole to alleviate the problems of sudden wall thickness changes and stress concentration caused by fiber accumulation in the polar hole area. Based on this, and considering the load-bearing characteristics of circumferential and helical winding, the thickness of the corresponding winding layer and the required number of layup layers are determined respectively. Then, based on the constraints of multi-angle combinations and the mixing ratio of fibers with different performance characteristics, a preliminary mixed-layup scheme of alternating layup is formed. This initially achieves a reasonable combination of multi-angle helical layers and circumferential layers, effectively dispersing the fiber distribution density in the end cap area, improving the stress-bearing balance in the axial and circumferential directions of the cylinder section. Simultaneously, by utilizing the complementary characteristics of fibers with different moduli and strengths, while ensuring structural safety margins, the comprehensive mechanical properties and process adaptability of the composite pressure vessel in terms of stiffness, strength, and internal pressure stability are significantly improved.

[0051] Figure 4 Based on the selected winding method and winding angle, the corresponding winding layer thickness is determined according to the embodiments of this application. This process may include the following steps: Step S1331: Obtain the allowable stress of the mixed fiber-resin for each composite material based on the composite material performance database.

[0052] Specifically, based on the records of each individual fiber in the composite material performance database, the entanglement ratio of that fiber in the total volume of all fibers is first obtained. Then, combined with the inherent longitudinal tensile strength of that fiber, the two are multiplied to obtain the tensile strength of the individual fiber. This calculation process essentially correlates the volume ratio of different fibers with their own mechanical properties, thereby quantifying the actual reinforcing effect that each fiber can play in the hybrid system, providing basic data for subsequent superposition and summation.

[0053] Step S1333: Determine the thickness of the winding layer based on a pre-constructed thickness conversion model that characterizes the relationship between service parameters, winding method, winding angle and fiber-resin allowable stress.

[0054] Specifically, the thickness conversion model is based on the radius of the inner liner of the gas cylinder. The burst pressure provided by the composite material performance database Allowable stress of fiber-resin and winding angle The thickness conversion model is constructed and represented as follows: Spiral winding layer thickness It mainly bears the axial stress and part of the circumferential stress component caused by internal pressure, and its value varies with the helical winding angle. The thickness of the circumferential winding layer increases with the increase of the value; This is used to compensate for the remaining circumferential stress bearing requirements. This embodiment implements the design criteria for the thickness of the winding layer, ensuring that the stress distribution of each fiber layer is reasonable under the target burst pressure and does not exceed the allowable limits of the material.

[0055] This embodiment obtains the volume percentage of different fibers in the hybrid system through a composite material performance database, and obtains the fiber-resin allowable stress of the mixed fiber and resin system through weighted superposition. Based on a pre-constructed thickness conversion model, service parameters, winding method, winding angle, and fiber-resin allowable stress are correlated to determine the winding layer thickness of the helical winding layer and the circumferential winding layer, respectively. This embodiment achieves a simplified calculation of the winding layer thickness, ensuring that the stress distribution of each fiber layer is reasonable under internal pressure load and does not exceed the material's safe allowable limit, providing a reliable mechanical basis for subsequent calculation of the number of layups and scheme design.

[0056] Figure 5 A flowchart for obtaining the allowable stress of the mixed fiber-resin of each composite material based on a composite material performance database, provided for embodiments of this application, may include the following steps: Step S13311: Determine the tensile strength of a single fiber based on the product of the entangled fiber ratio of the single fiber and the longitudinal tensile strength of the corresponding single fiber in the composite material performance database.

[0057] Specifically, the allowable stress of the fiber-resin composite material can be determined by calculating the tensile strength of multiple individual fibers. This involves determining the proportion of each individual fiber in the total fiber volume. (That is, the ratio of the volume of this type of fiber to the total volume of all fibers) and the inherent tensile strength (longitudinal tensile strength) of the corresponding single fiber in the longitudinal tensile load direction. The product operation is represented as follows: The tensile strength of a single fiber characterizes the effective strength share of a single fiber to the overall tensile strength, taking into account the actual fiber hybrid volume ratio.

[0058] Step S13313: Sum the tensile strengths of each individual fiber to determine the total tensile strength.

[0059] Specifically, the tensile strength of the obtained single fiber The expression for linear superposition and summation is: The obtained total tensile strength characterizes the contribution of all fiber components to the total tensile strength of the composite material under a given fiber hybrid volume ratio configuration. It reflects the combined effect of the longitudinal tensile capacity of different types of fibers according to their actual volume ratio, providing the fiber-side strength basis data for subsequently determining the allowable stress of the hybrid fiber-resin composite material.

[0060] Step S13315: Determine the allowable fiber-resin stress based on the product of the total tensile strength and the fiber volume fraction in the composite material properties database.

[0061] Specifically, based on the obtained total tensile strength, and the fiber percentage of the total component recorded in the composite material properties database... Allowable stress of fiber-resin obtained by performing a product operation Its expression is: The obtained fiber-resin allowable stress is used to characterize the maximum tensile stress that the fiber and resin can withstand working together in the composite material at a given fiber volume fraction.

[0062] This embodiment utilizes a composite material performance database. First, it calculates the effective tensile strength contribution of each individual fiber by multiplying the entanglement ratio of each fiber with its corresponding longitudinal tensile strength. Then, it sums the tensile strengths of all individual fibers to obtain the total tensile strength, reflecting the combined effect of all fiber components according to their actual volume proportions. Finally, it multiplies the total tensile strength by the fiber volume fraction in the database to determine the allowable fiber-resin stress, thus characterizing the maximum tensile stress that the fiber and resin can withstand working together. This embodiment considers the influence of the composition ratio and fiber volume fraction of hybrid fibers on the tensile properties of composite materials, providing accurate and reliable allowable stress values ​​for composite material structural design. This helps optimize material proportions, improve the accuracy of structural strength prediction, and ensure safety margins in engineering applications.

[0063] In one optional embodiment, the influence patterns are represented by relationship diagrams, including: angle service performance relationship diagrams, layer-number service performance relationship diagrams, and sequential service performance relationship diagrams. The relationship diagrams are obtained as follows: Step S311: Using the winding method and winding angle in the design parameters as variables and the other design parameters as quantities, construct the angle service performance relationship diagram.

[0064] Specifically, to investigate the comprehensive influence of winding angle parameters on the burst pressure and fatigue life of gas cylinders by composite materials, for example, based on the commonly used winding angle range and the feasibility of variable combinations in engineering, a total of [number] winding angle parameters were set. A set of representative winding angle calculation cases were used, with circumferential winding angle and helical winding angle as independent variables. The former was fine-tuned within a 90° range (e.g., between 89° and 90°) to reflect the sensitivity of the circumferential layer angle. The helical winding angle could be taken between ±12° and ±47.9° to cover typical winding strategies from small-angle axial reinforcement to large-angle circumferential contribution increases. Design parameters such as the thickness of the mixed circumferential winding layer, the thickness of the mixed helical winding layer, the mixing ratio, the layup sequence of the mixed winding layer, and the minimum burst pressure were kept constant to eliminate the confounding interference of non-angle factors on the performance results. Based on this, the performance data corresponding to the obtained 6 sets of angle combinations were used to construct an angle service performance relationship diagram, where the horizontal axis represents the winding angle corresponding to the mixed winding angle, and the vertical axis represents the fatigue life and burst pressure of the service parameters (please refer to the relevant documentation for details). Figure 6 The angle-based service performance relationship diagram can provide a quantitative basis for the selection of winding schemes in the design stage of composite gas cylinders, clarify the independent contribution law of angle parameters to ultimate bearing capacity and cycle durability, and provide reliable data support for subsequent multivariate optimization and response surface modeling.

[0065] Step S313: Using the winding method, winding layer thickness and mixing ratio in the design parameters as variables, and the remaining design parameters as quantities, construct a layer service performance relationship diagram.

[0066] Specifically, this study investigates the combined effects of winding method (circumferential and helical winding), winding layer thickness, and mixing ratio on the burst pressure and fatigue life of composite gas cylinders. Winding method type, circumferential winding layer thickness, and mixing ratio (the proportion of each fiber) are used as variables, with the difference in directly permissible mixing ratios representing the effects. For details, please refer to the winding layer number calculation formula in step 335. All other design parameters are kept quantitative to eliminate the confounding interference of non-layer number and mixing factors on the performance results. Based on this, a layer number-service performance relationship diagram is obtained, taking a composite material with two fibers as an example: the horizontal axis represents the mixing ratio, i.e., the proportion of one fiber, and the vertical axis represents the service parameters of fatigue life (cycles) and burst pressure (MPa), respectively. For details, please refer to... Figure 7 The relationship between the number of winding layers and service performance provides a quantitative basis for optimizing the number of winding layers in the design stage of composite gas cylinders, clarifies the independent contribution of the winding ratio and the winding ratio to the ultimate bearing capacity and cycle durability, and provides reliable data support for subsequent multivariate coupled optimization and surrogate modeling.

[0067] Step S315: Using the winding layer layup sequence in the design parameters as a variable and the other design parameters as quantitative parameters, construct a sequential service performance relationship diagram.

[0068] Specifically, to investigate the comprehensive influence of the winding layer layup sequence on the burst pressure and fatigue life of composite gas cylinders, based on typical layup design schemes and process feasibility, a total of [number] layers were set. Representative layup sequences (sample types H1~H5) were used. The layup sequence of the winding layers (which could be an alternating arrangement of circumferential and helical winding layers, or the relative position of each layer in the thickness direction) was used as the independent variable. For example, different sequence patterns were considered, such as circumferential layers concentrated on the inner liner surface, gradually transitioning to helical layers interspersed, and finally helical layers preferentially adhering to the inner liner. All other design parameters remained quantitative to eliminate confounding interference beyond the sequence factor. Based on this, the performance data corresponding to the five sequence combinations were used to construct a sequential service performance relationship diagram: the horizontal axis represents the sample type (numbered sequentially from H1 to H5), and the vertical axis represents fatigue life (cycles) and burst pressure (MPa), respectively. The sequential service performance relationship diagram can intuitively reveal the influence of layup sequence on service performance, clarify the independent contribution of layer sequence arrangement to ultimate bearing capacity and cyclic durability, and provide reliable data support for subsequent multivariate optimization.

[0069] This embodiment constructs three service performance relationship diagrams by changing three key variables: winding angle, winding layer thickness and mixing ratio, and layup sequence, while keeping other design parameters quantitative. First, using the winding angle as a variable, an angle-based service performance relationship diagram is constructed to clarify the independent contribution of the angle parameter to the ultimate bearing capacity and cycle durability. Second, using the winding method type, winding layer thickness, and mixing ratio (such as the proportion of two types of fibers) as variables, a layer-based service performance relationship diagram is constructed to reveal the influence of the mixing ratio on the cylinder performance. Finally, using the layup sequence as a variable, a sequence-based service performance relationship diagram is constructed to visually demonstrate the evolution trend of the layup sequence on service performance. This embodiment effectively decouples the coupling effects of multiple parameters, eliminates the confounding interference of non-study factors, provides a quantitative basis for the optimal winding scheme in the design stage of composite gas cylinders, and clarifies the independent action mechanism of each parameter on fatigue life and burst pressure; thus, it can maximize fatigue life while meeting burst pressure requirements, achieving a synergistic design of lightweight and long-life gas cylinders.

[0070] In one alternative implementation, the key evaluation metrics establish an optimization strategy, including: Step S331: Select the service parameters to be analyzed as evaluation indicators; Specifically, for the service parameters of mixed-strand gas cylinders, the following four key service parameters can be selected as evaluation indicators for iterative optimization: cylinder fatigue life (reflecting the cylinder's durability under cyclic internal pressure loads), burst pressure (reflecting the cylinder's ultimate load-bearing capacity), both of which are better when the values ​​are higher; cylinder lightweighting, with the goal of minimizing mass; and cylinder fiber utilization rate (the ratio of average fiber stress to fiber tensile strength at burst), with higher values ​​being better. In subsequent analyses, all of the above indicators are treated as positive indicators. If negative indicators exist, a reciprocal transformation is used to satisfy the orthogonal matrix analysis requirement for unidirectional indicators.

[0071] Step S333: Based on the influence patterns, analyze and obtain the influencing factors and their levels.

[0072] Specifically, based on the obtained angle service performance relationship diagram, layer number service performance relationship diagram, and sequential service performance relationship diagram, three design parameters that have a significant regulatory effect on the above four evaluation indicators are selected as influencing factors, and each influencing factor is determined according to engineering feasibility and design boundaries; for example, the spiral winding angle is taken as 15°, 20°, and 25°, the mixing ratio, that is, the volume fraction of high modulus fiber composite material accounts for 40%, 60%, and 80% of the total fiber composite material volume fraction, and the layup sequence is set as [M / H], [H / M], and [M / H / M], respectively, where M represents high modulus fiber and H represents high strength fiber.

[0073] Step S333: Construct an orthogonal array by arranging the evaluation indicators, influencing factors, and influence levels.

[0074] Specifically, orthogonal experimental design was used to construct orthogonal arrays by combining influencing factors and influence levels; Taking three influencing factors, each with three influence levels, as an example, we selected... An orthogonal array requires 27 finite element simulations to achieve a balanced combination and comprehensive coverage of all factors at all levels. The factors are filled into the corresponding columns of the orthogonal array in sequence, and the remaining blank columns are reserved for subsequent error analysis. The parameter combination corresponding to the orthogonal array structure is: helical winding angle 15°, mixing ratio 40%, and layup sequence [H / M]. The parameters corresponding to test number 2 are 20°, 60%, and [M / H], and the parameters corresponding to test number 3 are 25°, 80%, and [M / H / M], and so on until the parameter combination corresponding to test number 27 is: helical winding angle 25°, mixing ratio 40%, and layup sequence [M / H].

[0075] Step S335: Select orthogonal terms based on the orthogonal array.

[0076] Specifically, for example: according to The orthogonal array extracts the specific design parameter combinations corresponding to each row in turn. First, according to the order of the test numbers 1 to 27 in the orthogonal array, the influence level of the influencing factors is read one by one. For example, the parameters corresponding to the first test group are helical winding angle 15°, mixing ratio 40%, and layup sequence [H / M]. The parameter combination corresponding to the 27th test group is helical winding angle 25°, mixing ratio 40%, and layup sequence [M / H].

[0077] Step S337: Obtain experimental results based on orthogonal terms and compare them with evaluation indicators to determine the composite material winding layer hybrid layup scheme.

[0078] Specifically, for the experimental data obtained from simulation analysis using finite element analysis software for orthogonal terms, the mean value of each factor at different levels is first calculated for each evaluation index. ( The number represents the influencing factor. (The number of the level of influence) and its range Taking burst pressure as an example, the influencing factor A (circumferential winding angle) corresponds to the average value of the water level. The range can be obtained through calculation. Influencing factor B (spiral winding angle) corresponds to Extremely poor This process is repeated for all six factors. The magnitude of the range directly reflects the sensitivity of the design parameter to the corresponding service performance indicators, thus allowing for a preliminary ranking of the primary and secondary influencing factors. Based on this, a three-tiered data structure model is established using matrix analysis to transform qualitative influences into quantitative weights: In the first tier, the evaluation index matrix M considers four indicators—fatigue life, burst pressure, reciprocal of lightweighting, and fiber utilization rate—to be as large as possible. If the evaluation index of the test results is also as large as possible, then let... = Conversely, it will make =1 / For the 6-factor, 3-level case, M is an 18×3 diagonal block matrix with the following structure: The second-level influencing factor matrix T is defined as follows: Construct a 6×6 diagonal matrix: The third-level factor matrix S is: Construct column vectors: The weight matrix is ​​obtained by continuously multiplying the above three layers of matrices, that is... Establish a matrix Expanded into an 18×1 weight vector: in, ; , representing the proportion of the mean of the first level of factor A1 to the sum of the mean values ​​of all levels of the factor, comprehensively reflects the absolute influence of the factor level on the indicator and the relative importance of the factor itself. Taking four evaluation indicators as an example, the weight matrix results in a scheme that achieves the evaluation of each item of the indicator, confirming that the service performance of each item has been significantly improved compared to the initial scheme, thus completing the optimization of the composite material winding layer mixed layup scheme.

[0079] This embodiment introduces orthogonal experimental design and matrix analysis methods to couple and optimize multiple evaluation indicators with influencing factors and their levels. Through a balanced combination of a limited number of simulation analyses, the sensitivity and weight ranking of each influencing factor can be quantitatively assessed. This embodiment effectively eliminates the mixed interference between multiple parameters, significantly reduces the computational cost of comprehensive testing, and can significantly improve the cyclic durability performance of gas cylinders and achieve lightweight structural design while meeting the ultimate bearing capacity requirements. It provides a precise and efficient optimization path for the mixed-layout scheme of composite material winding layers.

[0080] The specific implementation process of this invention is described below in conjunction with actual analysis and cloud diagrams.

[0081] Based on the relevant design specifications and usage requirements for hydrogen storage cylinders, the service and structural parameters of the hybrid-layered cylinder are defined as follows: rated working pressure is 70 MPa, hydrostatic cycling test pressure is 87.5 MPa, and burst pressure is required to be no less than 157.5 MPa; the nominal volume of the cylinder is 10 L, the total length of the inner liner is 590 mm, the diameter of the inner liner section is 186 mm, the inner liner wall thickness is 5 mm, and the end cap adopts an ellipsoidal structure with a minor axis length of 127.1 mm. Based on these parameters, a refined finite element model is established, and progressive damage analysis is conducted under working pressure, hydrostatic test pressure, and burst pressure conditions to investigate the influence of different layup sequences and hybridization ratios on the initiation, propagation, and distribution characteristics of internal damage, thereby obtaining the optimal hybrid layup scheme that balances load-bearing capacity and structural integrity. Please refer to the relevant modeling and analysis results. Figures 9 to 13 The results analysis. Among them... Figure 9 The image shows the contour plot of the initial mixed-layup scheme before adopting the iterative optimization strategy. In fatigue life analysis, the red area in the contour plot of the initial mixed-layup scheme corresponds to the minimum lifespan, and the blue area corresponds to the maximum lifespan. The minimum lifespan value of 8396 cycles in the contour plot of the initial mixed-layup scheme is located at the deepest red area, which is also the weakest point determining the lifespan of the entire component. In burst pressure analysis, if the stress distribution in the contour plot of the initial mixed-layup scheme is displayed using a color gradient, the red area corresponds to a higher stress level (close to the material's ultimate strength), and the blue area corresponds to a lower stress level (with a larger safety margin). Burst pressure indicates the ultimate bearing capacity value at 171.8 MPa under a given load condition. When the internal pressure reaches this value, the weakest part of the structure will first experience plastic instability or fracture, leading to overall burst failure (i.e., burst pressure). Figure 10 For the contour plot of the optimal mixed-layup scheme, Figure 9 and Figure 10 The comparison clearly shows that the optimal mixed-layup scheme is significantly better than the initial mixed-layup scheme in terms of both fatigue life and burst pressure. Figure 11 The image shows the damage cloud map of the mixed-layer gas cylinder winding under the rated working pressure. It represents the damage variables of the mixed-layer gas cylinder winding under the rated working pressure. As can be seen from the figure, all values ​​are the minimum acceptable values ​​(blue), indicating that no damage occurred under the given rated working pressure. Figure 12 The image shows the damage cloud map of the mixed-layer gas cylinder winding under the hydrostatic cycling test pressure. It represents the damage variables of the mixed-layer gas cylinder winding under the hydrostatic cycling test pressure. As can be seen from the figure, all values ​​are the minimum acceptable values ​​(blue), indicating that no damage occurred under the given hydrostatic cycling test pressure. Figure 13The image shows the damage cloud map of the mixed gas cylinder winding layer under self-tightening pressure, which represents the damage variables of the mixed gas cylinder winding layer under self-tightening pressure. As can be seen from the figure, all of them are the minimum acceptable cases (blue), indicating that no damage occurred under the given self-tightening pressure.

[0082] Accordingly, please refer to Figure 14 A block diagram of a forward design device for a hybrid fiber hydrogen storage cylinder provided in this application embodiment, the device comprising: The initial design unit 101 is used to respond to a variety of composite materials containing fibers and resin matrices, perform performance tests on the composite materials, construct a composite material performance database based on the test results and structural parameters, and determine the initial mixed-layout scheme by combining the fiber winding mesh theory.

[0083] The optimization unit 103 is used to analyze the influence of various design parameters on the service performance of gas cylinders in the preliminary mixed-layer scheme, establish an optimization strategy based on key evaluation indicators, and iteratively optimize the design parameters to obtain the optimal winding layer design parameters.

[0084] The final design unit 105 is used to construct a numerical model of the gas cylinder based on the optimal winding layer design parameters, determine the internal damage of the gas cylinder under various pressure conditions, and determine the optimal mixed winding layer scheme based on the internal damage of the gas cylinder.

[0085] In some optional implementations, the initial design unit 101 includes: NOL ring specimens and laminate specimens containing single fibers were prepared.

[0086] Based on fibers, various fiber mixing ratios were set to mix fibers with resin matrix, and NOL ring samples and laminate samples containing multiple fiber mixtures were prepared according to the various fiber mixing ratios.

[0087] Performance tests were conducted on all NOL ring specimens and laminate specimens to obtain test results.

[0088] In some optional implementations, the initial design unit 101 includes: The winding angle is determined by expanding the borehole based on the ratio of the polar hole radius to the cylinder radius in the composite material performance database.

[0089] Determine the corresponding winding layer thickness based on the selected winding method and winding angle.

[0090] The number of winding layers is determined based on the ratio of the winding layer thickness to the thickness of a single layer of winding.

[0091] The preliminary mixed-layup scheme is determined based on the winding angle, the number of winding layers, and the winding method.

[0092] In some optional implementations, the initial design unit 101 includes: Based on the composite material performance database, the allowable stress of the mixed fiber-resin for each composite material was obtained.

[0093] The thickness of the winding layer is determined based on a pre-constructed thickness conversion model that characterizes the relationship between service parameters, winding method, winding angle, and fiber-resin allowable stress.

[0094] In some optional implementations, the initial design unit 101 includes: The tensile strength of a single fiber is determined by multiplying the entangled fiber ratio of the single fiber in the composite material performance database with the longitudinal tensile strength of the corresponding single fiber.

[0095] The total tensile strength is determined by summing the tensile strengths of each individual fiber.

[0096] The allowable stress of the fiber-resin is determined by multiplying the total tensile strength by the fiber volume fraction in the composite material properties database.

[0097] In some optional implementations, the optimization unit 103 includes: Using the winding method and winding angle in the design parameters as variables, and the other design parameters as quantities, an angle service performance relationship diagram is constructed.

[0098] Using the winding method, winding layer thickness, and mixing ratio in the design parameters as variables, and the remaining design parameters as quantities, a relationship diagram of the service performance of the number of layers is constructed.

[0099] Using the winding layer layup sequence in the design parameters as a variable and the other design parameters as quantitative parameters, a sequence service performance relationship diagram is constructed.

[0100] In some alternative implementations, the final solution design unit 105 includes: The service parameters to be analyzed are selected as evaluation indicators.

[0101] Based on the patterns of influence, we can analyze and identify the influencing factors and their levels.

[0102] An orthogonal array is constructed by arranging the evaluation indicators, influencing factors, and impact levels.

[0103] Select orthogonal terms based on the orthogonal array.

[0104] Experimental results are obtained based on orthogonal terms and compared with evaluation indicators to determine the composite material winding layer hybrid layup scheme.

[0105] Further functional descriptions of the above modules and units are the same as those in the corresponding embodiments described above, and will not be repeated here.

[0106] In this embodiment, the data security analysis device of the forward design apparatus for a hybrid fiber hydrogen storage cylinder is presented in the form of a functional unit. Here, a unit refers to an ASIC (Application Specific Integrated Circuit) circuit, a processor and memory that execute one or more software or fixed programs, and / or other devices that can provide the above functions.

[0107] Please see Figure 15 , Figure 15 This application provides a schematic diagram of the structure of a computer device, as shown in the embodiment of the present application. Figure 15 As shown, the computer device includes one or more processors 10, memory 20, and interfaces for connecting the components, including high-speed interfaces and low-speed interfaces. The components communicate with each other via different buses and can be mounted on a common motherboard or otherwise installed as needed. The processors can process instructions executed within the computer device, including instructions stored in or on memory to display graphical information of a GUI on external input / output devices (such as display devices coupled to the interfaces). In some alternative implementations, multiple processors and / or multiple buses can be used with multiple memories and multiple memory modules, if desired. Similarly, multiple computer devices can be connected, each providing some of the necessary operations (e.g., as a server array, a group of blade servers, or a multiprocessor system). Figure 15 Take a processor 10 as an example.

[0108] Processor 10 may be a central processing unit, a network processor, or a combination thereof. Processor 10 may further include a hardware chip. The hardware chip may be an application-specific integrated circuit (ASIC), a programmable logic device (PLD), or a combination thereof. The programmable logic device may be a complex programmable logic device (CAMP), a field-programmable gate array (FPGA), a general-purpose array logic (GDA), or any combination thereof.

[0109] The memory 20 stores instructions executable by at least one processor 10 to cause at least one processor 10 to perform the method shown in the above embodiments.

[0110] The memory 20 may include a program storage area and a data storage area. The program storage area may store the operating system and applications required for at least one function; the data storage area may store data created based on the use of the computer device. Furthermore, the memory 20 may include high-speed random access memory and may also include non-transitory memory, such as at least one disk storage device, flash memory device, or other non-transitory solid-state storage device. In some alternative embodiments, the memory 20 may optionally include memory remotely located relative to the processor 10, and these remote memories may be connected to the computer device via a network. Examples of such networks include, but are not limited to, the Internet, intranets, local area networks, mobile communication networks, and combinations thereof.

[0111] The memory 20 may include volatile memory, such as random access memory; the memory may also include non-volatile memory, such as flash memory, hard disk or solid-state drive; the memory 20 may also include a combination of the above types of memory.

[0112] The computer device also includes a communication interface 30 for communicating with other devices or communication networks.

[0113] This application also provides a computer-readable storage medium. The methods described in this application can be implemented in hardware or firmware, or implemented as recordable on a storage medium, or implemented as computer code downloaded over a network and originally stored on a remote storage medium or a non-transitory machine-readable storage medium and subsequently stored on a local storage medium. Thus, the methods described herein can be processed by software stored on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. The storage medium can be a magnetic disk, optical disk, read-only memory, random access memory, flash memory, hard disk, or solid-state drive, etc.; further, the storage medium can also include combinations of the above types of memory. It is understood that computers, processors, microprocessor controllers, or programmable hardware include storage components capable of storing or receiving software or computer code. When the software or computer code is accessed and executed by the computer, processor, or hardware, the methods shown in the above embodiments are implemented.

[0114] The apparatus and units described in the above embodiments can be implemented by a computer chip or physical entity, or by a product with a certain function. A typical implementation device is a computer. Specifically, a computer can be, for example, a personal computer, a laptop computer, a cellular phone, a camera phone, a smartphone, a personal digital assistant, a media player, a navigation device, an email device, a game console, a tablet computer, a wearable device, or any combination of these devices.

[0115] For ease of description, the above devices are described separately by function as various units. Of course, in implementing this application, the functions of each unit can be implemented in one or more software and / or hardware.

[0116] Those skilled in the art will understand that the embodiments of this application can be provided as methods or apparatus. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0117] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatuses, and devices according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0118] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0119] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0120] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0121] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, the apparatus embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions of the method embodiments.

[0122] The above description is merely an embodiment of this application and is not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

[0123] Although embodiments of this application have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of this application, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A method for forward design of a hydrogen storage cylinder with hybrid entangled fibers, characterized in that, The method includes: In response to the received composite materials containing fibers and resin matrices, the performance of the composite materials is tested, a composite material performance database is constructed based on the test results, and a preliminary mixed-layup scheme is determined in combination with the fiber winding mesh theory. The influence of each design parameter in the preliminary mixed-layer layup scheme on the service performance of the gas cylinder is analyzed. An optimization strategy is established based on key evaluation indicators, and the design parameters are iteratively optimized to obtain the optimal winding layer design parameters. A numerical model of the gas cylinder is constructed based on the optimal winding layer design parameters. The internal damage of the gas cylinder is determined under various pressure conditions, and the optimal mixed winding layer scheme is determined based on the internal damage of the gas cylinder. The performance testing of the composite material in response to receiving multiple composite materials comprising fibers and resin matrices includes: Prepare NOL ring specimens and laminate specimens containing single fibers. Based on the fiber, various fiber mixing ratios are set to mix the fiber with the resin matrix, and NOL ring samples and laminate samples containing multiple fiber mixtures are prepared according to the various fiber mixing ratios. All NOL ring specimens and laminate specimens were subjected to performance tests to obtain test results, including tensile strength, elastic modulus, shear properties and fatigue SN curves under different fiber and hybridization ratios.

2. The method of claim 1, wherein, Based on fiber-wound mesh theory, a preliminary mixed-layer layup scheme was determined, including: Based on the ratio of the polar hole radius to the cylinder radius in the composite material performance database, the winding angle is determined by enlarging the hole; The corresponding winding layer thickness is determined based on the selected winding method and the winding angle; The number of winding layers is determined based on the ratio of the winding layer thickness to the thickness of a single layer of winding layer; A preliminary mixed-layout scheme is determined based on the winding angle, the number of winding layers, and the winding method.

3. The method of claim 2, wherein, Determine the corresponding winding layer thickness based on the selected winding method and the winding angle, including: Based on the composite material performance database, the allowable stress of the mixed fiber-resin for each composite material is obtained; The thickness of the winding layer is determined based on a pre-constructed thickness conversion model that characterizes the relationship between service parameters, the winding method, the winding angle, and the allowable stress of the fiber-resin.

4. The method of claim 3, wherein, The step of obtaining the allowable stress of the mixed fiber-resin for each composite material according to the composite material performance database includes: The tensile strength of a single fiber is determined by multiplying the entangled fiber ratio of the single fiber in the composite material performance database with the longitudinal tensile strength of the corresponding single fiber. The total tensile strength is determined by summing the tensile strengths of each individual fiber. The allowable stress of the fiber-resin is determined by multiplying the total tensile strength by the fiber volume fraction in the composite material performance database.

5. The method of claim 1, wherein, The influencing patterns are represented by relationship diagrams, which include: angle service performance relationship diagrams, layer-number service performance relationship diagrams, and sequential service performance relationship diagrams. The relationship diagrams are obtained as follows: Using the winding method and winding angle in the design parameters as variables, and the other design parameters as quantities, an angle service performance relationship diagram is constructed. Using the winding method, winding layer thickness, and mixing ratio in the design parameters as variables, and the other design parameters as quantities, a layer service performance relationship diagram is constructed. Using the winding layer layup sequence in the design parameters as a variable and the other design parameters as quantitative parameters, a sequential service performance relationship diagram is constructed.

6. The method of claim 1, wherein, The optimization strategy for the key evaluation indicators includes: Select the service parameters to be analyzed as evaluation indicators; Based on the aforementioned patterns of influence, the influencing factors and their levels are identified through analysis. An orthogonal array is constructed by arranging the evaluation indicators, influencing factors, and influence levels. Select orthogonal terms according to the orthogonal table; The experimental results are obtained based on the orthogonal terms and compared with the evaluation index to determine the composite material winding layer hybrid layup scheme.

7. A device for forward design of a hybrid fiber hydrogen storage cylinder, characterized in that, The device includes: The initial design unit is used to respond to a variety of composite materials containing fibers and resin matrices, perform performance tests on the composite materials, construct a composite material performance database based on the test results and structural parameters, and determine an initial mixed-layout scheme in combination with fiber winding mesh theory. The optimization unit is used to analyze the influence of each design parameter in the preliminary mixed-layer layup scheme on the service performance of the gas cylinder, establish an optimization strategy based on key evaluation indicators, and iteratively optimize the design parameters to obtain the optimal winding layer design parameters. The final scheme design unit is used to construct a numerical model of the gas cylinder based on the optimal winding layer design parameters, determine the internal damage of the gas cylinder under various pressure conditions, and determine the optimal mixed winding layer scheme based on the internal damage of the gas cylinder. The performance testing of the composite material in response to receiving multiple composite materials comprising fibers and resin matrices includes: Prepare NOL ring specimens and laminate specimens containing single fibers. Based on the fiber, various fiber mixing ratios are set to mix the fiber with the resin matrix, and NOL ring samples and laminate samples containing multiple fiber mixtures are prepared according to the various fiber mixing ratios. All NOL ring specimens and laminate specimens were subjected to performance tests to obtain test results, including tensile strength, elastic modulus, shear properties and fatigue SN curves under different fiber and hybridization ratios.

8. A computer device, comprising: include: The system includes a memory and a processor, which are interconnected. The memory stores computer instructions, and the processor executes the computer instructions to perform a forward design method for a hybrid fiber hydrogen storage cylinder according to any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions for causing the computer to execute a forward design method for a tangled fiber hydrogen storage cylinder according to any one of claims 1 to 6.

Images