Preparation method of n-shaped composite material workpiece

Abstract

The invention discloses a preparation method of an n-shaped composite material workpiece, and the method comprises the following steps: unfreezing a prepreg, and cutting to obtain a material sheet; the material pieces are laid on the basis of the n-shaped male mold tool with the optimized structure, and an n-shaped composite material laying piece is obtained; the composite material laying piece shaped like the Chinese character'ji 'is subjected to pre-compaction and packaging; the packaged n-shaped composite material laying piece is cured, and an n-shaped composite material workpiece pre-finished product is obtained; and cooling and demolding the pre-finished product of the n-shaped composite material workpiece to obtain the n-shaped composite material workpiece. According to the method, the n-shaped composite material workpiece with high precision, high quality and good mechanical property can be obtained.

Description

Technical Field

[0001] The present application belongs to the technical field of material preparation, and in particular relates to a method for preparing an X-shaped composite material workpiece. Background Art

[0002] In the prior art, such as Figure 1 and Figure 2 The "J"-shaped composite workpiece shown has the following defects under traditional manufacturing processes due to its special structure (containing two female R corners and two male R corners, and the curvature of the R zone is relatively large): First, the R corner size is set only with reference to the sheet metal standard during the design phase, and the feasibility of composite material molding is not fully considered. The overly small R corner design greatly increases the manufacturing difficulty, resulting in the inability to achieve effective molding of the R zone during the stacking and curing process; second, the complex geometric structure (especially the alternating female and male R corners) makes it difficult to fully compact the R corner area during prepreg stacking; finally, during the vacuum bag packaging and curing stage, the traditional process causes uneven force on the workpiece due to the multiple R corner structure - the pressure on the female R zone is significantly lower than that on the male R zone, which in turn causes quality problems such as R zone bridging (pores), resin enrichment / poor, and fiber wrinkles. In severe cases, the workpiece is scrapped and high economic losses are caused.

[0003] The above-mentioned systematic defects expose the shortcomings of existing methods in material property evaluation, process adaptability and special control technology. Summary of the Invention

[0004] In order to overcome the deficiencies of the prior art, the purpose of this application is to provide a method for preparing an X-shaped composite workpiece, and the purpose of this application is to obtain an X-shaped composite workpiece with high precision, high quality and good mechanical properties.

[0005] To achieve the above objectives, this application provides the following technical solutions: A method for preparing an "X"-shaped composite workpiece comprises: thawing a prepreg and then cutting it to obtain a sheet; stacking the sheet based on a structurally optimized "X"-shaped male mold tooling to obtain an "X"-shaped composite layup; pre-compacting and packaging the "X"-shaped composite layup; curing the packaged "X"-shaped composite layup to obtain an "X"-shaped composite workpiece pre-finished product; cooling and demoulding the "X"-shaped composite workpiece pre-finished product to obtain an "X"-shaped composite workpiece.

[0006] Optionally, the stacking of the sheet materials based on the structurally optimized "X"-shaped positive mold tooling includes: uniformly coating a release agent on the surface of the positive mold tooling; fixing the positive mold tooling coated with the release agent on the working area of ​​the laser projector to project a layup contour on the tooling surface; stacking the sheet materials layer by layer on the layup contour to obtain an "X"-shaped composite material layup; and covering the surface of the "X"-shaped composite material layup with a peelable cloth and a non-porous isolation film.

[0007] Optionally, the stacking of the sheets based on the structurally optimized "X"-shaped male mold tooling further includes: laying a custom pressure pad on the non-porous isolation membrane.

[0008] Optionally, the coating range of the release agent exceeds a preset range of the ply profile.

[0009] Optionally, stacking the sheets layer by layer on the ply contour includes: using a vacuum press to compact each layer of the sheets during the stacking process.

[0010] Optionally, stacking the sheets layer by layer on the ply contour further includes: laying edge breathable felt on the edge of each layer of sheet while compacting each layer of sheet using a vacuum press.

[0011] Optionally, the compacting and packaging of the stacked sheets includes: wrapping the "X"-shaped composite material stack with a vacuum bag; sealing the vacuum bag with a rubber strip around it, and fixing the vacuum bag with a putty strip.

[0012] Optionally, curing the packaged I-shaped composite layup to obtain an I-shaped composite workpiece pre-finished product includes: heating the packaged I-shaped composite layup; and maintaining pressure on the heated I-shaped composite layup.

[0013] Optionally, cooling and demolding the pre-finished "X"-shaped composite workpiece to obtain the "X"-shaped composite workpiece includes: cooling the pre-finished "X"-shaped composite workpiece; and demolding the cooled "X"-shaped composite workpiece pre-finished product to obtain the "X"-shaped composite workpiece.

[0014] Optionally, the negative R zone of the X-shaped composite material workpiece adopts a pure layer structure, and the edge of the negative R zone is no more than 10 mm away from the R corner.

[0015] The beneficial effects of this application are: The present application optimizes the structure of the "J"-shaped male mold tooling and accurately controls the entire process of stacking, compacting, packaging, curing, cooling and demolding, thereby effectively solving the problems of uneven pressure in complex R-angle areas, high porosity, uneven resin distribution and large thermal deformation in traditional processes, achieving uniform pressure distribution, improved molding accuracy and dimensional stability, enhanced mechanical properties and improved surface quality, thereby obtaining an "J"-shaped composite material workpiece with high precision, high quality and excellent mechanical properties in one molding. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a front view of the existing "X"-shaped male mold tooling; Figure 2It is a side view of the existing "X"-shaped male mold tooling; Figure 3 This is a schematic flow chart of a method for preparing an X-shaped composite material workpiece provided by the present application; Figure 4 It is a front view of the male mold tooling provided by this application; Figure 5 It is a side view of the male mold tooling provided by this application; Figure 6 This is a schematic diagram of the stacking process of an X-shaped composite material workpiece provided by this application. DETAILED DESCRIPTION

[0017] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0018] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0019] In the present invention, unless otherwise specified or limited, the terms "connection" and "fixation" should be understood in a broad sense. For example, "fixation" can mean fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; internal communication between two elements or interaction between two elements, unless otherwise specified. Those skilled in the art will be able to understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0020] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or suggesting their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of such features. In addition, the meaning of "and / or" appearing throughout the text includes three parallel schemes. Taking "A and / or B" as an example, it includes scheme A, or scheme B, or a scheme in which A and B are satisfied at the same time. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0021] Figure 3 This is a method for preparing a X-shaped composite material workpiece provided in an embodiment of the present application, such as Figure 3 As shown, the method includes the following steps: S100: The prepreg (reinforcement fiber pre-impregnated with resin) is taken out of the freezer and placed in a constant temperature and humidity clean room for thawing. After thawing, it is cut by an automatic blanking machine to obtain sheets; S200: Laying up the sheets based on the structurally optimized "X"-shaped male mold tooling to obtain an "X"-shaped composite layup; S300: Vacuum pre-compacting and bagging of the "X"-shaped composite layup; S400: sending the packaged "X"-shaped composite layup into an autoclave device and curing it according to a preset curing program to obtain an "X"-shaped composite workpiece pre-finished workpiece; S500: Cooling the pre-finished workpiece of the "X"-shaped composite material workpiece, sending it to a release agent preparation box for demoulding after it is completely cooled, and then sending it to a grinding room for external dimension processing and trimming to obtain an "X"-shaped composite material workpiece.

[0022] In another exemplary embodiment, in step S200, stacking the sheets based on the structurally optimized "X"-shaped male mold tooling includes the following steps: S201: Apply 3 to 4 layers of release agent evenly on the surface of the male mold tooling. After each layer of release agent is dried and solidified, apply the next layer of release agent by brushing, and apply the layers in opposite directions and in an alternating manner. In this step, it should be noted that the coating range of the release agent needs to exceed the preset range of the stacking contour (for example, 25mm). The reasons are: First, the area where the release agent is coated needs to cover all contact surfaces of the male mold tooling, including the part outside the stacking area. If it is only coated in the stacking area, the male mold tooling and the composite material may adhere during demolding, thereby affecting the integrity and quality of the workpiece; second, the composite material will undergo slight expansion or deformation during the curing process. The release agent coating exceeds the range of 25mm in the stacking area to ensure that the contact between the outer edge of the tooling and the composite material is unrestricted, thereby avoiding problems during demolding; third, it can prevent the resin from flowing to unnecessary areas during the curing process, reduce resin leakage or accumulation, and ensure that the size and shape of the workpiece meet the requirements.

[0023] S202: fixing the male mold tooling coated with a release agent to the working area of ​​the laser projector to project a layup profile on the tooling surface; During this step, a laser projector uses a laser beam to precisely project the layup contours onto the surface of the male tooling. The projected layup contours provide clear guidance to the operator, ensuring that each layer of material is precisely aligned with the preset path. These projected contours not only accurately identify the location of the target layup area, but also help the operator avoid material misalignment or uneven laying during the layup process. The laser projector's precise projection allows the composite material to be precisely aligned according to these contours even when faced with complex geometries, avoiding material accumulation or uneven laying. In addition, these projected marks typically cover the entire area of ​​the tooling surface, including those with complex geometries, ensuring that the composite material is laid in accordance with the design requirements. After the laser projection is completed, the operator lays the material layer by layer according to the projected layup contours. Each layer must be aligned with the laser contours, while ensuring flatness and uniform compaction between the sheets, ultimately ensuring the accuracy and quality of the composite workpiece.

[0024] S203: Laying up the sheets layer by layer on the layup contour to obtain an X-shaped composite layup; In this step, as the sheets are stacked layer by layer, each layer must be pre-compacted using a vacuum compactor of no less than 0.75 bar to ensure close contact between the sheet and the surface of the male mold tooling. Pre-compacting not only effectively removes the air in the sheet, but also reduces the voids and uneven resin distribution that may exist in the material. Air can cause the formation of bubbles, which can cause structural defects in the workpiece during the curing process, such as porosity and cracks. In severe cases, it may also cause the workpiece to fail to meet the expected performance requirements. Therefore, vacuum compaction can ensure that each layer of sheet is uniform, tight, and free of bubbles.

[0025] In addition, while the sheets are being vacuum compacted, a layer of edge breathable felt is laid along the edge of each sheet. This measure effectively guides the discharge of bubbles and prevents their accumulation at the edge of the ply. The accumulation of bubbles not only affects the flatness of the composite material, but can also lead to uneven resin distribution at the edges, thus affecting the quality of the entire workpiece. Through the guidance of the breathable felt, bubbles can be discharged smoothly, effectively reducing bubble formation and ensuring uniformity during sheet laying, thereby reducing the porosity percentage of the product during non-destructive testing. More importantly, the breathable felt can prevent resin from concentrating in certain areas during the curing process, resulting in resin enrichment or depletion, avoid uneven material thickness, and ensure the stability and consistency of the final composite material in terms of strength, hardness, etc.

[0026] S204: Covering the surface of the "X"-shaped composite layup with a peelable cloth and a non-porous isolation film, and laying a custom pressure pad on the non-porous isolation film.

[0027] In this step, if Figure 6 As shown, the primary surface of the "X"-shaped composite workpiece is covered with a peelable cloth and a non-porous isolation film, and the custom pressure pad is laid on the isolation film. The main purpose is to ensure that the surface of the composite material remains flat and is subjected to uniform pressure during the subsequent curing process. Among them, the non-porous isolation film can effectively prevent the resin from being lost or diffused during the curing process, ensuring that the resin is distributed only in the required area, thereby maintaining the uniformity and dimensional accuracy of the material. At the same time, by laying the custom pressure pad on the isolation film, uniform pressure can be applied during the vacuum pressing and curing process, ensuring that the compaction degree of each layer of sheet is consistent across the entire surface, avoiding problems such as bubbles, voids or uneven material thickness caused by insufficient local pressure. In this way, the surface quality of the composite workpiece is improved, and the final formed workpiece is more stable, with better mechanical properties and a higher finished product qualification rate.

[0028] It should be noted that, in this embodiment, before the lay-up, the present application optimizes the surface of the male mold tooling in the following aspects through finite element simulation: First, in the manufacturing process of the "J"-shaped workpiece, the negative R area is prone to uneven pressure during the vacuuming process due to its complex geometric shape. In order to solve this problem, the present application designs the negative R area as a pure laminate structure (composed of multiple layers of reinforced fiber and resin materials alternately stacked, and each layer of material has different directions, which is beneficial to improving the strength and rigidity of the overall structure), rather than a traditional sandwich structure. Due to the presence of sandwich pores, the pressure during vacuuming and tank pressing is relatively small, resulting in uneven pressure in this area, inability to effectively compact, and prone to structural defects. In contrast, the laminate structure has no internal cavities or gaps, which can ensure uniform pressure during the vacuum and curing process, thereby avoiding the problem of insufficient compaction. The design of the laminate structure effectively improves the compaction of the negative R area, reduces the porosity, and enhances the density and strength of the workpiece. At the same time, due to the high stability of the laminate structure, it avoids the local weaknesses that may occur in the sandwich structure, and improves the stability and durability of the overall structure. Normally, the design requires that the edge of the negative R zone should not exceed 10mm from the R corner to ensure that the area can be fully compacted, thereby ensuring the quality and mechanical properties of the workpiece.

[0029] Secondly, finite element analysis was used to predict the thermal deformation of the workpiece. Based on this analysis, the tooling surface was modified to compensate for the thermal deformation during the molding process. Specifically, the edge of the negative R-shaped area (concave arc area) of the tooling was kept no more than 10mm from the R-shaped corner. This ensured that the porosity in the negative R-shaped area did not exceed 30% when the R-shaped corner was less than 10mm. This ensured sufficient compaction in this area during the molding process and avoided structural weaknesses caused by an excessively small R-shaped corner. Specifically, if the edge of the negative R-shaped area exceeds 10mm from the R-shaped corner, uneven force would be applied to this area during vacuum compaction, resulting in insufficient compaction. This would lead to the formation of bubbles and porosity, reducing the density and strength of the workpiece. Therefore, limiting the distance between the R-shaped corner edges ensures uniform pressure in this area during compaction, avoiding problems such as uneven compaction and high porosity. Furthermore, during the composite molding process, the degree of compaction in the negative R-shaped area directly affects the porosity. If the R-shaped corner is too small, the material may not fully fill the R-shaped area, resulting in porosity or bubbles. By controlling the length of the edge distance from the R angle to within 10mm, it can be effectively ensured that the material in this area can be fully compacted during the molding process, reducing the formation of voids and bubbles, thereby keeping the porosity below 30%. This can ensure that the workpiece is more stable in mechanical properties and avoid the reduction in strength due to excessive porosity. This application can ensure that the negative R area can obtain a uniform pressure distribution through finite element analysis and reverse compensation mold repair of the tooling surface. This allows the resin to be evenly penetrated and distributed in this area during the curing process, avoiding resin loss or aggregation, reducing thermal deformation, and improving the mechanical properties and overall quality of the final workpiece.

[0030] In addition, the tooling adopts an integrated male (punch) design, and its outer surface contour matches the contour of the workpiece, ensuring that the shape of the tooling and the workpiece are consistent.

[0031] Secondly, this embodiment also uses finite element simulation analysis to evaluate the shape, material, number of layers and angle of the workpiece, predict the deformation trend and deformation amount during the workpiece manufacturing process, and Figure 4 and Figure 5 The tooling profile [2] area shown in the figure is subjected to necessary adaptive mold adjustments to reduce the workpiece solidification deformation and improve the manufacturing surface accuracy. In terms of heat conduction of the tooling, in order to improve the heat conduction efficiency, the tooling [3] area avoids the use of a complex support frame (usually the support frame is relatively high, about 800mm), and instead adopts a 50mm thick reinforced hollow plate design. This design can effectively improve the heat conduction performance of the tooling and ensure the temperature uniformity and overall quality of the workpiece during the molding process.

[0032] In summary, this application uses the above optimization and finite element simulation analysis to accurately design the surface of the male mold tooling, which can effectively solve the problem that the negative R area of ​​the "J"-shaped workpiece is difficult to be evenly pressurized during the vacuum process, ensure uniform pressure distribution, and avoid molding defects caused by uneven pressure. By designing this area as a pure layer structure and controlling the length of the edge distance from the R angle, a higher degree of compaction is guaranteed, the porosity is reduced, and the density and strength of the workpiece are improved. Furthermore, through thermal deformation prediction and reverse compensation and mold repair of the tooling surface, the molding process of the workpiece is optimized, the consistency of the tooling and the workpiece shape is ensured, and the heat conduction efficiency is improved through a carefully designed heat conduction structure, ensuring temperature uniformity during the molding process. The above optimizations can effectively reduce thermal stress and deformation, enhance the dimensional accuracy and mechanical properties of the workpiece, and thus improve the overall quality and reliability of the composite workpiece.

[0033] In another exemplary embodiment, in step S300, the pre-compacting and packaging the stacked sheets includes the following steps: S301: Use vacuum bags to wrap the "X"-shaped composite layup; The main purpose of using vacuum bags to wrap the "X"-shaped composite layup in this step is to provide uniform pressure during the curing process and effectively remove air and bubbles. Through vacuum extraction, the vacuum bag ensures that the surface of the composite workpiece layup is evenly pre-compacted, preventing the formation of bubbles and avoiding uneven resin distribution or enrichment, thereby ensuring the density, strength, and uniformity of the material. In addition, the use of vacuum bags can also improve the overall quality of the workpiece, reduce material waste and scrap rate, and ultimately ensure that the composite workpiece has better mechanical properties and a higher qualified finished product rate.

[0034] S302: Seal the vacuum bag with rubber strips around it and fix the vacuum bag with putty strips.

[0035] During this step, as the curing temperature rises, the "X"-shaped composite layup undergoes a transition from solid to liquid. As the temperature rises, the resin contained within it becomes liquid and begins to flow. To prevent resin loss during the curing process and the resulting impact on workpiece quality, the use of rubber strips is an effective measure. These strips prevent the adhesive from flowing beyond the workpiece's clear edges, ensuring that the resin is distributed only within the required area of ​​the workpiece. This prevents insufficient edge material due to adhesive loss, which can lead to uneven thickness of the workpiece after curing, ensuring that the finished product meets the required dimensions and strength.

[0036] Furthermore, multiple stoppers distributed throughout the putty strips play a crucial role in ensuring the workpiece maintains its correct position and shape during the curing process. These stoppers effectively prevent movement of the workpiece when it is not fully secured, thus avoiding deformation or asymmetry caused by unstable positioning. This design ensures that the composite workpiece maintains its correct position during the curing process, thereby improving workpiece precision and quality, reducing scrap due to process defects, and ensuring the structural stability, dimensional accuracy, and mechanical properties of the final product.

[0037] In this embodiment, the effective cooperation between the rubber strip and the putty strip makes the workpiece forming and curing process controllable, which is beneficial to improving the qualification rate and overall quality of the workpiece.

[0038] In another exemplary embodiment, in step S400, curing the packaged "X"-shaped composite layup to obtain an "X"-shaped composite workpiece pre-finished product includes the following steps: S401: performing a temperature raising process on the packaged "X"-shaped composite layup; In this step, the encapsulated "X"-shaped composite layup is first transferred from an autoclave into a heating zone for heating. The heating rate is controlled at 2°C / min, slowly increasing the temperature to the resin's liquefaction point (approximately 120°C). This slow heating phase ensures uniform heating of the resin and ensures adequate resin flow, especially in complex R-angle areas. This ensures that the resin can fully fill these hard-to-reach areas, preventing insufficient resin flow that could cause voids or bubbles.

[0039] S402: Maintaining pressure on the heated "X"-shaped composite layup.

[0040] In this step, once the X-shaped composite layup reaches the resin liquefaction point, the pressure is maintained at 0.6 to 0.8 MPa for 90 minutes. This pressure ensures full penetration and bonding between the composite's fibers and the resin, further enhancing the overall strength and uniformity of the material. Furthermore, the resin has fully liquefied and permeated the fiber structure, improving the composite's mechanical properties.

[0041] In another exemplary embodiment, in step S500, the step of cooling and demoulding the pre-finished "X"-shaped composite material workpiece to obtain the "X"-shaped composite material workpiece includes the following steps: S501: Cooling down the pre-finished product of the "X"-shaped composite material workpiece; During this step, the composite material undergoes a transition from high to low temperatures during the curing process. Materials expand and contract to varying degrees at different temperatures. If the temperature changes too rapidly, different regions within the material will expand and contract at different rates, generating thermal stresses. Excessive thermal stresses can cause cracks on the surface or within the material, or even warp or deform. In this embodiment, the cooling rate is controlled at 3°C / min. By limiting the cooling rate to 3°C / min, the temperature changes in each part of the composite material are relatively gradual throughout the cooling process, helping to reduce the temperature difference between the material's interior and surface, thereby alleviating the accumulation of thermal stress. Furthermore, if the cooling rate is too fast (for example, 5°C / min), some parts of the composite material (such as thicker or more complex areas) may cool more slowly or more quickly than others, resulting in inconsistent expansion and contraction in these areas, which can lead to cracks. If the cooling rate is too slow (for example, 2°C / min), the curing process will be prolonged, increasing the production cycle time. Furthermore, the equipment will require longer to maintain a low temperature, increasing energy consumption and, in turn, production costs.

[0042] S502: Demolding the cooled pre-finished "X"-shaped composite material workpiece to obtain an "X"-shaped composite material workpiece.

[0043] In this step, first, remove the items covering the workpiece for fixing, supporting or assisting curing, such as vacuum bags and sealing strips, and pay attention to protecting the workpiece surface during the removal process; second, use a wooden or plastic wedge to insert between the workpiece and the tooling, and peel the workpiece from the tooling by gradually applying appropriate external force around the workpiece. Based on the above method to obtain the "X" shaped composite material workpiece, this application is aimed at Figure 1 The prior art X-shaped workpiece shown and Figure 4The X-shaped workpiece shown in this application was subjected to comparative testing. The testing method includes non-destructive scanning using ultrasonic A-scan and phased array equipment, as well as physical and chemical performance testing commissioned by a qualified laboratory. The results show that the internal fault diameter of the X-shaped workpiece obtained by the method described in this application is ≤6mm, the internal porosity is ≤2%, the laminate bending strength is ≥70 MPa, and the interlaminar shear strength is ≥1200 MPa; in comparison, Figure 1 The workpiece's internal fault diameter is ≤15 mm, porosity is ≤6%, laminate bending strength is ≥50 MPa, and interlaminar shear strength is ≥900 MPa. This demonstrates that the product in this application has achieved significant improvements in both internal defect control and mechanical properties.

[0044] Through the comparison of the above data, it can be seen that the "J"-shaped composite material workpiece prepared by this application is superior to the existing technology in all key performance indicators: the internal fault diameter is reduced by about 60%, and the porosity is reduced to one-third of the original, which significantly improves the density and internal quality of the material; the bending strength of the laminate is increased by 40%, and the interlaminar shear strength is increased by about 33%, indicating that the interfacial bonding force between the fiber and the resin and the overall bearing capacity are significantly enhanced. These performance improvements are due to the structural optimization of the male mold tooling design, finite element simulation reverse compensation, layer-by-layer vacuum compaction, and uniform pressure-maintaining curing process control, which enables this application to obtain a high-precision, high-quality, excellent mechanical property and good batch consistency "J"-shaped composite material workpiece in one molding.

[0045] Finally, it should be noted that the above description is merely an optional example of the present application and is not intended to limit the present application. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art may still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein with equivalents. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A method for preparing an "X"-shaped composite material workpiece, characterized in that: The method comprises: Thawing the prepreg and cutting it to obtain sheets; Laying up the sheets based on the structurally optimized "X"-shaped male mold tooling to obtain an "X"-shaped composite layup; Pre-compacting and packaging the X-shaped composite layup; curing the packaged "X"-shaped composite material layup to obtain an "X"-shaped composite material workpiece pre-finished product; The pre-finished product of the "X"-shaped composite material workpiece is cooled and demoulded to obtain the "X"-shaped composite material workpiece.

2. The method according to claim 1, characterized in that The stacking of the sheets based on the structurally optimized "X"-shaped male mold tooling includes: Evenly apply release agent on the surface of the male mold tooling; Fixing a male mold tool coated with a release agent to the working area of ​​a laser projector to project the layup profile on the tool surface; Laying up the sheets layer by layer on the layup contour to obtain an X-shaped composite layup; The surface of the "X"-shaped composite layup is covered with a peelable cloth and a non-porous isolation film.

3. The method according to claim 1, characterized in that The stacking of the sheets based on the structurally optimized "X"-shaped male mold tooling further includes: A custom pressure pad is placed on a non-porous release membrane.

4. The method according to claim 2, characterized in that The coating range of the release agent exceeds the preset range of the ply profile.

5. The method according to claim 2, characterized in that The step of stacking the sheets layer by layer on the ply profile comprises: During the layup process, a vacuum press is used to compact each layer of web.

6. The method according to claim 5, characterized in that The step of stacking the sheets layer by layer on the ply profile further includes: While each layer of material is being compacted using a vacuum press, edge breathable felt is laid on the edge of each layer of material.

7. The method according to claim 1, characterized in that The compacting and packaging of the stacked sheets comprises: Use vacuum bags to wrap the "X"-shaped composite layup; Seal the vacuum bag with rubber strips around it and fix it with putty strips.

8. The method according to claim 1, characterized in that The method of curing the packaged "X"-shaped composite material layup to obtain an "X"-shaped composite material workpiece pre-finished product includes: Performing a temperature raising treatment on the packaged "X"-shaped composite layup; The heated "X"-shaped composite layup is pressure maintained.

9. The method according to claim 1, characterized in that The step of cooling and demoulding the pre-finished product of the "X"-shaped composite material workpiece to obtain the "X"-shaped composite material workpiece comprises: Cooling down the pre-finished product of the "X"-shaped composite material workpiece; The cooled pre-finished product of the "X"-shaped composite material workpiece is demoulded to obtain the "X"-shaped composite material workpiece.

10. The method according to claim 9, characterized in that The negative R zone of the X-shaped composite material workpiece adopts a pure layer plate structure, and the edge of the negative R zone is no more than 10 mm away from the R corner.

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