High-precision low-stress winding forming process for ultra-large aspect ratio high-temperature-resistant grid cylinder

Abstract

The application discloses a kind of super large slenderness ratio high-temperature-resistant grid cylinder high-precision low-stress winding forming process, comprising: S1 according to the axial dimension of target product, judge whether to carry out secondary reconstruction to grid model: when the axial dimension of target product is greater than 2000mm, secondary reconstruction is carried out to grid model, otherwise, secondary reconstruction is not carried out to grid model;S2 the grid model obtained in step S1 is used to prepare the core mold with circumferential rib grooves and inclined rib grooves on the surface, and the circumferential ribs and inclined ribs are wound using the core mold;S3 the rib after winding is cured and formed to obtain a grid cylinder.The application belongs to the technical field of composite materials, solves the technical problem that the existing method cannot be applied to the winding of super large slenderness ratio high-temperature-resistant grid cylinder, and the obtained grid cylinder can improve the forming precision and mechanical properties of super large slenderness ratio high-temperature-resistant grid cylinder, and has wide application prospect.

Description

Technical Field

[0001] This invention belongs to the field of composite material technology and relates to a low-stress, high-precision, low-stress winding molding process for ultra-large aspect ratio, high-temperature resistant mesh cylinders. Background Technology

[0002] To meet the requirements of lightweight, high load-bearing capacity, and extreme temperature resistance for satellite power supply components, their support structures often adopt a hollow mesh-like cylindrical structure. A composite material mesh cylinder is composed of composite material ribs arranged in different directions, with the ribs intersecting to form a regular diamond-shaped mesh, ensuring the overall rigidity and mechanical properties of the mesh structure.

[0003] Traditional mesh cylinders have a length and diameter not exceeding 2m, an aspect ratio close to 1, and a small thickness-to-width ratio for the ribs. They typically use epoxy resin as the matrix material, with a curing temperature below 180℃ and a long-term operating temperature not exceeding 150℃. Therefore, they experience relatively low stress during molding and have high molding precision. However, to meet future demands, mesh cylinders need to have an ultra-high aspect ratio (reaching 4), a large thickness-to-width ratio (5), and resistance to extremely high temperatures (long-term operating temperature above 300℃). Ordinary epoxy resin matrix cannot meet these requirements, necessitating the use of polyimide resin with a higher curing temperature (320℃). Considering all these conditions, significant stress exists during winding and curing, affecting the overall dimensional accuracy and mechanical properties of the mesh cylinder. Summary of the Invention

[0004] The purpose of this invention is to overcome the above-mentioned defects and solve the technical problem that existing methods cannot be applied to the winding of ultra-high temperature resistant mesh cylinders with ultra-large aspect ratios. This invention provides a low-stress, high-precision winding molding process for ultra-high temperature resistant mesh cylinders with ultra-large aspect ratios, which can improve the molding accuracy and mechanical properties of ultra-high temperature resistant mesh cylinders with ultra-large aspect ratios and has broad application prospects.

[0005] To achieve the above-mentioned objectives, the present invention provides the following technical solution: A high-precision, low-stress winding process for ultra-high aspect ratio, high-temperature resistant mesh cylinders includes: S1 determines whether to perform a secondary reconstruction of the mesh model based on the axial dimensions of the target product: When the axial dimension of the target product is greater than 2000mm, the mesh model is reconstructed twice; otherwise, the mesh model is not reconstructed twice. S2 uses the mesh model obtained in step S1 to prepare a core mold with circumferential rib grooves and oblique rib grooves on the surface, and uses the core mold to wind the circumferential ribs and oblique ribs; S3 solidifies and shapes the wound ribs to obtain a mesh cylinder.

[0006] Furthermore, methods for secondary reconstruction of the mesh model include: Calculate the axial expansion ΔL of the intersection of the diagonal ribs or the ring ribs; Compensation is made for the position of the diagonal rib intersection node or the ring rib based on ΔL; The mesh model is redrawn based on the positions of the compensated diagonal rib intersection nodes and annular ribs, thus completing the secondary reconstruction of the mesh model.

[0007] Furthermore, ΔL = α ΔTL + Δl; Where α is the thermal expansion coefficient of the core mold material, ΔT is the temperature difference during processing, that is, the difference between the highest temperature during the curing process and the room temperature, L is the axial distance from the location of the diagonal rib intersection node or the ring rib to the center point of the mesh model (the key point of the axis connecting the center of the upper bottom surface and the end point of the lower bottom surface), and Δl is the process adjustment amount, with an empirical value of 0.6~1.0.

[0008] Furthermore, the position of the diagonal reinforcement intersections or annular reinforcements is compensated according to the following formula: X = X1 - ΔL; Where X represents the position of the intersection node or ring reinforcement of the diagonal reinforcement after compensation, and X1 represents the position of the intersection node or ring reinforcement of the diagonal reinforcement before compensation.

[0009] Furthermore, assuming the core mold undergoes linear expansion in the axial direction, with the expansion pattern from the center outwards, the expansion amount at each axial position is calculated based on the thermal expansion formula. Then, the distribution of rib positions before curing is deduced based on the expansion amount to achieve dimensional compensation. For circumferential ribs, only the axial expansion of the product is considered, and the rib positions are shifted according to the expansion amount. For diagonal ribs, the expansion amount along the axial direction of the intersection nodes needs to be calculated. The positions of the intersection nodes are then redefined based on the expansion amount at the intersection points, and the diagonal ribs are redrawn. (See attached diagram) Figure 2 (As shown).

[0010] When calculating the axial expansion of the ring-shaped reinforcing bar, select several points on the ring-shaped reinforcing bar and calculate their axial expansion separately. Then, take the average of the axial expansion of the several points on the ring-shaped reinforcing bar to obtain the axial expansion of the ring-shaped reinforcing bar.

[0011] Furthermore, in step S2, during the winding of the reinforcing bars, each cycle consists of 2 circumferential plies and 4 diagonal plies, with each cycle being approximately 0.8 to 1 mm thick. All circumferential reinforcing bars (e.g., 27 circumferential reinforcing bars) are fully wound once to form one circumferential ply, and all diagonal reinforcing bars (e.g., 24 pairs of diagonal reinforcing bars) are fully wound once to form one diagonal ply. The circumferential and oblique ribs are wound using a tension reduction method. Specifically, after every two cycles, the winding tension is reduced by 1-2N, and when the winding tension drops to 20-30N, it is kept constant.

[0012] Furthermore, before the final curing and shaping of the wound reinforcing strips in step S3, a multi-stage pre-curing process is performed, specifically including: Pre-compression in an autoclave is performed every 8-10 mm of winding thickness. The pre-compression regime is adjusted each time, that is, the pressure of each pre-compression needs to be increased by 0.1-0.15 MPa to ensure full compaction. During pre-compression, a silicone rubber strip is placed on the outer surface of the rib, and then felt is wrapped around its outer side for overall encapsulation and pre-compression.

[0013] Furthermore, the curing temperature of the staged pre-curing is lower than the gel point of the high-temperature resistant resin, generally 20~30℃ lower than its gel temperature.

[0014] Furthermore, the pre-compression temperature for staged pre-curing is 180℃~200℃, the time is 2~4h, the pressure is 0.2MPa~0.6MPa, the initial pre-compression pressure is 0.2MPa, and the maximum pre-compression pressure does not exceed 0.6MPa. That is, the pressure of each pre-compression needs to be increased by 0.1~0.15MPa, but remains unchanged after increasing to 0.6MPa.

[0015] Furthermore, in step S3, when the wound reinforcing strip is cured and molded: The curing pressure during the heating stage shall not exceed 1.0 MPa; The curing pressure during the heat preservation stage is 1~2MPa; During the cooling phase, the pressure is released first, and then the temperature is lowered.

[0016] Compared with the prior art, the present invention has at least one of the following advantages: (1) The low-stress high-precision winding molding process of ultra-large aspect ratio high-temperature resistant mesh cylinder of the present invention realizes low-stress and high-precision molding of ultra-large aspect ratio high-temperature resistant mesh, and maintains the dimensional accuracy and high mechanical properties of the product. (2) The present invention adopts a mesh model secondary reconstruction method to realize deformation compensation of ultra-large mesh structure and improve the overall accuracy of mesh structure; (3) The present invention adopts a tension reduction scheme during the winding process to ensure that the tension of each layer is constant and to meet the overall performance of the product; (4) The present invention adopts a phased pre-curing method to ensure that the ribs are dense and free of air bubbles in each stage, thereby improving the overall mechanical properties and reducing the molding stress. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the ultra-high aspect ratio, high-temperature resistant mesh cylinder of the present invention; Figure 2 This is a schematic diagram of the secondary reconstruction of the mesh according to the present invention. Detailed Implementation

[0018] The features and advantages of the present invention will become clearer and more apparent from the following detailed description.

[0019] The term “exemplary” as used herein means “serving as an example, embodiment, or illustration.” Any embodiment illustrated herein as “exemplary” is not necessarily to be construed as superior to or better than other embodiments. Although various aspects of embodiments are shown in the accompanying drawings, the drawings are not necessarily drawn to scale unless specifically indicated otherwise.

[0020] To meet the requirements of lightweight, high load-bearing capacity, and extreme temperature resistance for spacecraft energy supply components, their support structures often employ perforated mesh-like cylindrical structures. Composite material mesh cylinders are composed of composite material ribs arranged in a regular pattern in different directions. The ribs intersect to form a regular diamond-shaped mesh, ensuring the overall stiffness and mechanical properties of the mesh structure. This manufacturing method is primarily used in the field of spacecraft mesh structures, and it has particularly significant application value in spacecraft mesh load-bearing cylinders.

[0021] This invention provides a low-stress, high-precision winding molding process for ultra-large aspect ratio, high-temperature resistant mesh cylinders. These cylinders, serving as the main support structure for spacecraft energy supply components, are primarily composed of circumferential and diagonal ribs. The circumferential and diagonal ribs provide circumferential and longitudinal forces, forming the main structure of the mesh cylinder. To ensure precise control of curing deformation, this invention proposes a lattice curing deformation pre-compensation method. This method uses secondary geometric reconstruction of the mesh unit to offset dimensional deviations caused by thermal expansion of the ultra-large aspect ratio mold at extremely high curing temperatures. During winding, a stepped tension differentiation design is adopted to reduce stress. Furthermore, during curing, staged pre-compression and precise curing parameter design are employed to address the problem of uneven curing of the high aspect ratio ribs, ultimately achieving low-stress, high-precision molding.

[0022] For mesh cylinder structures with ultra-large aspect ratios, the secondary reconstruction of the mesh model is performed before product production. Based on the curing temperature and product size analysis, the final cured size of the mesh structure is calculated. The cured mesh cylinder size is set as the current model requirement size. The model size before curing (before thermal expansion) is calculated in reverse. Then, the model is deformed and compensated (non-uniform scaling). That is, with the central axis of the mesh cylinder as the starting point, the size is reduced more when it is away from the central axis in the length direction and less when it is closer to the central axis, while the circumferential direction is scaled proportionally.

[0023] like Figure 2 Methods for secondary reconstruction of mesh models include: First, the axial dimension of the target product is determined. When the axial dimension is greater than 2000mm, the thermal expansion along the axis exceeds 5mm, and the accuracy of the mesh cylinder nodes cannot be guaranteed. It is necessary to redesign each mesh of the mesh cylinder, reducing the distance between mesh nodes by a certain proportion—this is a secondary mesh reconstruction design. This invention assumes that the thermal expansion of the mesh cylinder itself is zero; the thermal expansion along the axis is due to the steel mandrel. During the curing process, the mandrel expands axially due to heat, causing deformation of the uncured mesh cylinder blank. After complete curing at high temperature, the mesh cylinder blank hardens and solidifies.

[0024] Then, the expansion amount in the axial direction of the intersection of the annular and oblique ribs at each point is calculated using the thermal expansion formula (1) of the mesh cylinder, starting from the center line. Then, the position of the intersection of the annular and oblique ribs after the second reconstruction of the mesh (i.e. deformation compensation) is calculated according to the formula (2). The annular and oblique ribs are redistributed to determine the mesh ribs after compensation.

[0025] ΔL = α ΔTL + Δl (1) Wherein, ΔL is the amount of thermal deformation (i.e., the amount of axial expansion of the diagonal rib intersection node or annular rib), α is the thermal expansion coefficient of the mandrel material, ΔT is the temperature difference during processing, i.e., the difference between the highest temperature during the curing process and room temperature, L is the axial distance from the location of the diagonal rib intersection node or annular rib to the center point of the mesh model, and Δl is the process adjustment amount, with an empirical value of 0.6~1.0.

[0026] X = X1 - ΔL (2) X represents the position of the diagonal rib intersection or ring rib after compensation, with the center line as the starting point (i.e., the center plane perpendicular to the axis as the reference), positive for upward and negative for downward. X1 represents the position of the diagonal rib intersection or ring rib before compensation, with the center line as the starting point, positive for upward and negative for downward. ΔL represents the compensation amount.

[0027] Finally, the mesh cylinder model is redrawn based on the compensated mesh ribs, and then the forming fixture is designed according to the mesh cylinder model to prepare the mesh cylinder.

[0028] The continuous forming tension differentiation design is used for structures with large thickness-to-width ratios, employing variable tension winding. When the rib thickness exceeds 10mm, using fixed tension winding will loosen the inner fibers when winding the outer layer, resulting in a loose inner layer and a tight outer layer, leading to significant defects in the finished product. Therefore, a tension-reducing scheme is adopted during the winding process to ensure consistent tension in each layer and meet the overall product performance requirements.

[0029] For thick ribs with high curing temperatures, staged pre-curing is used. If only one final curing cycle is performed, the resin matrix of different thicknesses will not be heated evenly, resulting in varying degrees of curing. This leads to porous and crumbly textures in the middle of the product, affecting overall mechanical properties. Therefore, staged pre-curing is employed, with autoclave pre-compression every 8-10 mm. The pre-compression regime is adjusted each time, with the curing temperature pre-compressiond at 180℃-200℃ (before the gel point) and the pressure at 0.2MPa-0.6MPa. This ensures that the ribs are dense and bubble-free at each stage, improving overall mechanical properties and reducing molding stress.

[0030] The curing parameters are precisely designed for the ultra-large aspect ratio mesh cylinder structure. During the curing process, the metal mold continuously expands in both length and diameter directions, with a maximum expansion exceeding 25mm. The curing pressure of the resin matrix is ​​1.6MPa. If a certain curing pressure is maintained consistently from heating to cooling according to traditional curing methods, it will lead to product damage. Therefore, the pressure is precisely designed in real time during the curing process. During the heating stage, before the fibers and resin are cured, the pressure does not exceed 1.0MPa to ensure resin fluidity and eliminate air bubbles. During the heat preservation curing stage, the pressure is maintained at 1.6MPa to ensure the compactness of the product. During the cooling stage, the pressure is released first to prevent pressure damage to the mesh cylinder before cooling, achieving high-precision, low-stress molding.

[0031] Specifically, the high-precision, low-stress winding process for ultra-high aspect ratio, high-temperature resistant mesh cylinders includes: (1) Secondary reconstruction of the mesh model The expansion amount of the product is calculated based on the product size and curing temperature. The maximum expansion amount is 25mm. Then, the mesh model is reconstructed with the center of the mesh cylinder as the baseline, and the mesh length and diameter are reduced. The diamond mesh is also scaled accordingly.

[0032] (2) Winding line programming Before winding the mesh cylinder, a winding program is prepared according to the structural characteristics of the mesh cylinder, and the circumferential and oblique ribs are wound evenly through the line design.

[0033] (3) Rib wrapping During the winding process, the fiber is first wound layer by layer along the process ribs in annular shape. Then, the fiber passes through the transition fixture at the end cap, where it is hung on a hanging pin, thus changing the fiber winding angle from annular to oblique ribs. During the winding of the oblique ribs, after the fiber has traveled one core mold length according to the angle of the mold groove, it is hung on the hanging pin of the core mold transition fixture. The hanging pin changes the fiber angle, and then the winding angle is changed, allowing the fiber to enter the mold groove in the opposite direction of the oblique rib angle. This allows the fiber to wind back from the other side of the core mold, and then pass through the hanging pin of the transition fixture back to the previously wound rib angle, completing the alternating winding of oblique ribs with positive and negative angles until one layer is wound. Every two cycles, the winding tension is reduced by 1N, and when the winding tension drops to 20N, it remains constant.

[0034] (4) Preloading After every 10 cycles of layup, a pre-compression in an autoclave is performed. During pre-compression, silicone rubber strips are placed on the upper surface of the ribs to apply pressure, ensuring that the ribs are fully compressed. Finally, felt is wrapped around the outside of the ribs for overall encapsulation and pre-compression.

[0035] (5) Curing After all the reinforcing strips are wound, silicone rubber strips are placed on the upper surface of the reinforcing strips to apply pressure, ensuring that the reinforcing strips are fully pressurized. Finally, felt is wrapped around the outside of the reinforcing strips for overall encapsulation and curing.

[0036] Example 1: The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0037] like Figure 1 As shown, the ultra-high aspect ratio, high-temperature resistant mesh tube is the main structure of the spacecraft's energy supply components. Based on its requirements for lightweight, high performance, and resistance to extremely high temperatures, the ultra-high aspect ratio, high-temperature resistant mesh tube is the best structural form to achieve this function.

[0038] The ultra-high temperature resistant mesh cylinder with an ultra-large aspect ratio is 6.8m long and 1.7m in diameter. It is mainly composed of 27 circumferential ribs and 24 pairs of diagonal ribs that are continuously wound together and finally cured and formed under high temperature and pressure in a hot autoclave.

[0039] The circumferential ribs are 6mm wide and 30mm thick, and are formed by winding fibers along the circumferential groove of the mesh cylinder mold at a 90-degree angle.

[0040] The diagonal ribs are 6mm wide and 30mm thick, and are formed by winding fibers at a 24.5-degree angle along the diagonal groove of the mesh cylinder mold.

[0041] First, calculate the product's expansion based on its dimensions and curing temperature: The axial expansion ΔL of the diagonal rib intersection or annular rib is calculated to be 0~7.3mm (based on the centerline, the expansion of the annular rib and diagonal rib intersection at different positions is within this range) and 0~-7.3mm (positive is upward, negative is downward). The position of the diagonal rib intersection node or annular rib is compensated according to ΔL. After obtaining the compensated position X of the diagonal rib intersection node or annular rib, the mesh model is reconstructed with the center of the mesh cylinder as the baseline, and the mesh length and diameter are reduced. The rhombus mesh is also scaled accordingly.

[0042] Mandrels were prepared based on the reconstructed mesh model. Then, circumferential and oblique ribs were formed using a winding method. During the winding process, the circumferential ribs were first wound layer by layer along the process ribs, and then transitioned at the end section, changing the winding angle to wind the oblique ribs at a fixed angle. A tension reduction method was used to wind the circumferential and oblique ribs. After every 2 layers of circumferential layup and 4 layers of oblique layup, the winding tension was reduced by 2N. The initial winding tension was 100N, and the final winding tension was maintained at 30N. Autoclave pre-compression is performed every 10 cycles of layup. The initial pre-compression pressure is 0.2 MPa, and the pressure for each subsequent pre-compression is increased by 0.2 MPa until it reaches 0.6 MPa, after which it remains constant.

[0043] Finally, after all the reinforcing ribs are wrapped, the entire structure is encapsulated and cured.

[0044] The formed mesh cylinder achieves a spatial dot matrix position accuracy better than Ф0.5 (Ф1700×6800) mm and an angle accuracy better than ±0.15°.

[0045] Example 2: The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0046] like Figure 2 As shown, the ultra-high aspect ratio, high-temperature resistant mesh tube is the main structure of the spacecraft's energy supply components. Based on its requirements for lightweight, high performance, and resistance to extremely high temperatures, the ultra-high aspect ratio, high-temperature resistant mesh tube is the best structural form to achieve this function.

[0047] The ultra-high temperature resistant mesh cylinder with an ultra-large aspect ratio is 5.4m long and 4.28m in diameter. It is mainly composed of 14 circumferential ribs and 36 pairs of diagonal ribs that are continuously wound together and finally cured and formed under high temperature and high pressure in an autoclave.

[0048] The circumferential ribs are 6mm wide and 16mm thick, and are formed by winding fibers along the circumferential groove of the mesh cylinder mold at a 90-degree angle.

[0049] The diagonal ribs are 6mm wide and 16mm thick, and are formed by winding fibers at a 25-degree angle along the diagonal groove of the mesh cylinder mold.

[0050] First, calculate the product's expansion based on its dimensions and curing temperature: The axial expansion ΔL of the diagonal rib intersection or annular rib is calculated to be 0~6mm (based on the centerline, the expansion of the annular rib and diagonal rib intersection at different positions is within this range) and 0~-6mm (positive is upward, negative is downward). The position of the diagonal rib intersection node or annular rib is compensated according to ΔL. After obtaining the compensated position X of the diagonal rib intersection node or annular rib, the mesh model is reconstructed with the center of the mesh cylinder as the baseline, and the mesh length and diameter are reduced. The rhombus mesh is also scaled accordingly.

[0051] Mandrels were prepared based on the reconstructed mesh model. Then, circumferential and oblique ribs were formed using a winding method. During the winding process, the circumferential ribs were first wound layer by layer along the process ribs, and then transitioned at the end section, changing the winding angle to wind the oblique ribs at a fixed angle. A tension reduction method was used to wind the circumferential and oblique ribs. After every 2 layers of circumferential layup and 4 layers of oblique layup, the winding tension was reduced by 1N. The initial winding tension was 40N, and the final winding tension was maintained at 24N. After every 8 cycles of layup, autoclave pre-compression is performed. The initial pre-compression pressure is 0.2 MPa, and the pressure for each subsequent pre-compression is increased by 0.1 MPa until it reaches 0.4 MPa and then remains constant.

[0052] Finally, after all the reinforcing ribs are wrapped, the entire structure is encapsulated and cured.

[0053] The formed mesh cylinder achieves spatial dot matrix position accuracy better than Ф1 (Ф4280×5400) mm and angular accuracy better than ±0.2°.

[0054] The present invention has been described in detail above with reference to specific embodiments and exemplary examples; however, these descriptions should not be construed as limiting the present invention. Those skilled in the art will understand that various equivalent substitutions, modifications, or improvements can be made to the technical solutions and embodiments of the present invention without departing from the spirit and scope of the invention, and all such modifications and improvements fall within the scope of the present invention. The scope of protection of the present invention is defined by the appended claims.

[0055] The contents not described in detail in this specification are common knowledge to those skilled in the art.

Claims

1. A high-precision, low-stress winding molding process for ultra-high aspect ratio, high-temperature resistant mesh cylinders, characterized in that... include: S1 determines whether to perform a secondary reconstruction of the mesh model based on the axial dimensions of the target product: When the axial dimension of the target product is greater than 2000mm, the mesh model is reconstructed twice; otherwise, the mesh model is not reconstructed twice. S2 uses the mesh model obtained in step S1 to prepare a core mold with circumferential rib grooves and oblique rib grooves on the surface, and uses the core mold to wind the circumferential ribs and oblique ribs; S3 solidifies and shapes the wound ribs to obtain a mesh cylinder; Methods for secondary reconstruction of mesh models include: Calculate the axial expansion ΔL of the intersection of the diagonal ribs or the ring ribs; Compensation is made for the position of the diagonal rib intersection node or the ring rib based on ΔL; The mesh model is redrawn based on the positions of the compensated diagonal rib intersection nodes and annular ribs, thus completing the secondary reconstruction of the mesh model; ΔL = α ΔTL + Δl; Where ΔL is in mm and has dimensions [L]; α is the coefficient of thermal expansion of the mandrel material, in °C. -1 Dimensions [Θ] -1 ]; ΔT is the temperature difference during processing, that is, the difference between the highest temperature during the curing process and room temperature, in °C, dimensionless [Θ]. -1 L is the axial distance from the intersection of the diagonal ribs or the location of the annular ribs to the center point of the mesh model, in mm, dimension [L]; Δl is the process adjustment amount, the empirical value of Δl is 0.6~1.0, in mm, dimension [L].

2. The high-precision, low-stress winding molding process for ultra-large aspect ratio, high-temperature resistant mesh cylinders according to claim 1, is characterized in that... The position of the diagonal reinforcement intersection or the ring reinforcement is compensated according to the following formula: X = X1 - ΔL; Where X represents the position of the diagonal rib intersection or annular rib after compensation, in mm, dimension [L]; X1 represents the position of the diagonal rib intersection or annular rib before compensation, in mm, dimension [L].

3. The high-precision, low-stress winding molding process for ultra-large aspect ratio, high-temperature resistant mesh cylinders according to claim 1, is characterized in that... When calculating the axial expansion of the ring-shaped reinforcing bar, select several points on the ring-shaped reinforcing bar and calculate their axial expansion separately. Then, take the average of the axial expansion of the several points on the ring-shaped reinforcing bar to obtain the axial expansion of the ring-shaped reinforcing bar.

4. The high-precision, low-stress winding molding process for ultra-large aspect ratio, high-temperature resistant mesh cylinders according to claim 1, is characterized in that... In step S2, during the winding of the reinforcing bars, each cycle consists of 2 circumferential ply layers and 4 diagonal ply layers. Each cycle is 0.8~1mm thick. All circumferential reinforcing bars are fully wound once to form one circumferential ply, and all diagonal reinforcing bars are fully wound once to form one diagonal ply. The circumferential and oblique ribs are wound using a tension reduction method. Specifically, after every two cycles, the winding tension is reduced by 1-2N, and when the winding tension drops to 20-30N, it is kept constant.

5. The high-precision, low-stress winding molding process for ultra-large aspect ratio, high-temperature resistant mesh cylinders according to claim 1, is characterized in that... Step S3 involves pre-curing the wound reinforcing strips in stages before they are cured and molded. This includes: Pre-compression is performed in an autoclave every 8-10 mm of winding thickness, with the pre-compression regime adjusted each time, specifically by increasing the pressure by 0.1-0.15 MPa each time.

6. The high-precision, low-stress winding molding process for ultra-large aspect ratio, high-temperature resistant mesh cylinders according to claim 5, is characterized in that... The curing temperature of the pre-curing in stages is lower than the gel point of the material used in the mesh tube.

7. The high-precision, low-stress winding molding process for ultra-large aspect ratio, high-temperature resistant mesh cylinders according to claim 5, is characterized in that... The pre-compression temperature for staged pre-curing is 180℃~200℃, the time is 2~4h, the pressure is 0.2MPa~0.6MPa, the initial pre-compression pressure is 0.2MPa, and the maximum pre-compression pressure does not exceed 0.6MPa.

8. The high-precision, low-stress winding molding process for ultra-large aspect ratio, high-temperature resistant mesh cylinders according to claim 1, is characterized in that... When curing and shaping the wound ribs in step S3: The curing pressure during the heating stage shall not exceed 1.0 MPa; The curing pressure during the heat preservation stage is 1~2MPa; During the cooling phase, the pressure is released first, and then the temperature is lowered.

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