Systems and methods of forming fiber preforms for manufacturing parts made from composite materials

Abstract

This invention relates to systems and methods for forming fiber preforms for manufacturing parts made of composite materials. This application discloses a method for fabricating a preform for manufacturing parts made of composite materials. The method includes sewing fibers onto a membrane to form a fiber bed in a two-dimensional shape; removing the membrane from the fiber bed; and adjusting the fiber bed into a three-dimensional shape to form the preform.

Description

[0001] Government terms

[0002] This invention was made with government support under U.S. Department of Energy Approval No. DE-EE0009204. The government holds certain rights in this invention.

[0003] introduction

[0004] The information provided in this section is for the purpose of presenting the general context of this disclosure. The work of the currently attributed inventors, to the extent described in this section, and in respect of aspects of that description that may not otherwise be considered as prior art at the time of filing, is neither expressly nor implicitly regarded as prior art to this disclosure. Technical Field

[0005] This disclosure relates to systems and methods for forming fiber preforms for manufacturing parts made of composite materials. Background Technology

[0006] Composite materials are used in buildings, bridges, and structures (such as ship hulls, swimming pool panels, shower rooms, bathtubs, tanks, sinks, and countertops). In the automotive industry, composite materials are used in interior components, structural components, underbody components, and closure parts. Composite materials are also used in components for spacecraft and aircraft.

[0007] Components made from composite materials are manufactured from fiber preforms, which are constructed from yarns or fiber bundles and formed into a three-dimensional (3D) shape. Fiber preforms are typically made using short fiber 3D lay-up or 3D weaving processes, or 3D braiding processes. One or more fiber preforms are inserted into a mold, resin is applied to (or more) fiber preforms, and (or more) fiber preforms and resin are molded into a composite component. Summary of the Invention

[0008] This application discloses a method for fabricating a preform for use in manufacturing components made of composite materials. In a first example, the method includes: sewing fibers onto a membrane to form a fiber bed in a two-dimensional shape; removing the membrane from the fiber bed; and adjusting the fiber bed into a three-dimensional shape to form the preform.

[0009] In one aspect, the method further includes: determining the amount of fiber deformation when the fiber bed is adjusted from a two-dimensional shape to a three-dimensional shape; and determining, based on the amount of fiber deformation, at least one of the following: fiber orientation in the plane of the fiber bed, the number of fibers per unit area of ​​the fiber bed, the material of the sutures securing the fibers to the membrane, the number of stitches per unit area of ​​the fiber bed, and the length of the fiber between a pair of adjacent stitches.

[0010] In one aspect, the method further includes: determining a first region of a fiber bed, wherein the amount of fiber deformation in the first region is greater than the amount of fiber deformation in a second region of the fiber bed; and sewing the fibers onto a membrane such that the fiber length in the first region of the fiber bed is greater than the fiber length in the second region of the fiber bed.

[0011] In one aspect, the method further includes placing a piece of foam onto the membrane in a first region of the fiber bed before sewing the fibers onto the membrane, to increase the fiber length in the first region.

[0012] In one aspect, the method further includes: defining a first region of a fiber bed, in which fiber deformation is greater than that in a second region of the fiber bed; sewing fibers to a membrane using a first set of sutures in the first region of the fiber bed; sewing fibers to a membrane using a second set of sutures in the second region of the fiber bed; and melting the sutures in the first region of the fiber bed after removing the membrane from the fiber bed and before adjusting the fiber bed to a three-dimensional shape. The sutures in the first set are made of a first material, and the sutures in the second set are made of a second material having a higher melting point than the first material.

[0013] In one aspect, the method further includes: defining a first region of a fiber bed in which fiber deformation is greater than that in a second region of the fiber bed; sewing fibers to a membrane in the second region of the fiber bed; and not sewing fibers to a membrane in the first region of the fiber bed.

[0014] In one aspect, the membrane is water-soluble, and the method further includes removing the membrane from the fiber bed by dissolving it.

[0015] In one aspect, the membrane is paper, and the method also includes removing the membrane from the fiber bed by tearing it off.

[0016] In a second example of a method for fabricating a preform for manufacturing a component made of a composite material, the method includes: sewing a first fiber to a first membrane to form a first fiber bed in a first two-dimensional shape having a first dart; forming a tether extending across the first dart; and pulling the tether to close the first dart and adjust the first fiber bed into a first three-dimensional shape.

[0017] In one aspect, the method also includes using a first fiber to form a frenulum.

[0018] In one aspect, the method further includes, after the tether is formed and before the tether is pulled, loosening the suture securing the first fiber to the first membrane along the edge of the first channel.

[0019] In one aspect, the method further includes removing the first membrane after the first fiber is sewn onto the first membrane and before the ties are pulled.

[0020] In one aspect, the method further includes forming the first sluice in a first two-dimensional shape of the first fiber bed by sewing the first fiber to the first membrane in the region surrounding the first sluice and not sewing the first fiber to the first membrane in the region of the first sluice.

[0021] In one aspect, the method further includes determining the stress in the first fiber when the first fiber bed is adjusted from a first two-dimensional shape to a first three-dimensional shape; and forming a first channel in a region of the first fiber bed, in which the fiber stress is greater than the fiber stress in another region of the first fiber bed.

[0022] In one aspect, the method further includes sewing a second fiber onto a second membrane to form a second fiber bed in a second two-dimensional shape having a second channel; closing the second channel in the second fiber bed to adjust the second fiber bed to a second three-dimensional shape; and stacking the first fiber bed and the second fiber bed such that (i) the second fiber bed covers the first channel in the first fiber bed, and (ii) the first fiber bed covers the second channel in the second fiber bed. The first fiber bed and the second fiber bed form a preform.

[0023] In a third example of a method for fabricating a preform for use in manufacturing a component made of a composite material, the method includes: sewing fibers to a membrane to form a fiber bed having a two-dimensional shape; and adjusting the fiber bed to a three-dimensional shape to form the preform. Sewing the fibers to the membrane includes sewing the fibers to the membrane using a first number of suture stitches per unit area in a first region of the fiber bed; and sewing the fibers to the membrane using a second number of suture stitches per unit area in a second region of the fiber bed. The first number is less than the second number.

[0024] In one aspect, the method further includes determining the stress in the fibers when the fiber bed is adjusted from a two-dimensional shape to a three-dimensional shape; and sewing the fibers to a membrane using a first number of suture stitches and a second number of suture stitches per unit area in a first region and a second region of the fiber bed, respectively. The fiber stress in the first region is greater than the fiber stress in the second region.

[0025] In one aspect, the method further includes sewing a third number of fibers per unit area to the membrane in a first region of the fiber bed; and sewing a fourth number of fibers per unit area to the membrane in a second region of the fiber bed. The third number is less than the fourth number.

[0026] In one aspect, the method further includes removing the membrane after the fibers are sewn onto the membrane and before the fiber bed is shaped into a three-dimensional form.

[0027] In one aspect, a first region of the fiber bed corresponds to a sluice in a two-dimensional shape, and the method further includes, after removing the membrane, loosening the seam along the edge of the sluice; and pulling those fibers that extend across the sluice to close the sluice and adjust the fiber bed to a three-dimensional shape.

[0028] This invention includes the following technical solutions:

[0029] Option 1. A method for fabricating a preform for use in manufacturing a component made of a composite material, the method comprising:

[0030] The fibers are sewn onto the membrane to form a fiber bed in a two-dimensional shape;

[0031] Remove the membrane from the fiber bed; and

[0032] The fiber bed is adjusted to a three-dimensional shape to form the preform.

[0033] Option 2. The method according to Option 1 further includes:

[0034] Determine the amount of fiber deformation when the fiber bed is adjusted from the two-dimensional shape to the three-dimensional shape; and

[0035] The following are determined based on the amount of fiber deformation: the orientation of the fibers in the plane of the fiber bed, the number of fibers per unit area of ​​the fiber bed, the material of the sutures that secure the fibers to the membrane, the number of suture stitches per unit area of ​​the fiber bed, and the length of the fiber between a pair of adjacent suture stitches.

[0036] Option 3. The method according to Option 2 further includes:

[0037] A first region of the fiber bed is defined, in which the fiber deformation is greater than that in a second region of the fiber bed; and

[0038] The fibers are sewn onto the membrane such that the fiber length in the first region of the fiber bed is greater than the fiber length in the second region of the fiber bed.

[0039] Option 4. The method according to Option 3 further includes placing a piece of foam onto the membrane in a first region of the fiber bed before sewing the fibers onto the membrane to increase the fiber length in the first region.

[0040] Option 5. The method according to Option 2 further includes:

[0041] A first region of the fiber bed is defined, in which the fiber deformation is greater than that in a second region of the fiber bed;

[0042] The fibers are sewn to the membrane using a first set of sutures in a first region of the fiber bed, wherein the sutures in the first set are made of a first material;

[0043] In a second region of the fiber bed, the fibers are sewn to the membrane using a second set of sutures, wherein the sutures in the second set are made of a second material having a higher melting point than the first material; and

[0044] After the membrane is removed from the fiber bed and before the fiber bed is adjusted to the three-dimensional shape, the sutures in the first region of the fiber bed are melted.

[0045] Option 6. The method according to Option 2 further includes:

[0046] A first region of the fiber bed is defined, in which the fiber deformation is greater than that in a second region of the fiber bed;

[0047] The fibers are sewn onto the membrane in the second region of the fiber bed; and

[0048] The fibers are not sewn onto the membrane in the first region of the fiber bed.

[0049] Option 7. The method according to Option 1, wherein the membrane is water-soluble, and the method further includes removing the membrane from the fiber bed by dissolving the membrane.

[0050] Option 8. The method according to Option 1, wherein the film is paper, and the method further includes removing the film from the fiber bed by tearing off the film.

[0051] Option 9. A method for fabricating a preform for use in manufacturing a component made of a composite material, the method comprising:

[0052] The first fiber is sewn onto the first membrane to form a first fiber bed in a first two-dimensional shape having a first channel;

[0053] Forming a tether that extends across the first provincial highway; and

[0054] Pull the strap to close the first channel and adjust the first fiber bed into a first three-dimensional shape.

[0055] Option 10. The method according to Option 9, further comprising using the first fiber to form the ligament.

[0056] Option 11. The method according to Option 10, further comprising, after forming the tie and before pulling the tie, loosening the seam securing the first fiber to the first membrane along the edge of the first provincial roadway.

[0057] Option 12. The method according to Option 9, further comprising removing the first membrane after the first fiber is sewn onto the first membrane and before the tie is pulled.

[0058] Option 13. The method according to Option 9, further comprising forming the first sluice in a first two-dimensional shape of the first fiber bed by sewing the first fiber to the first membrane in the region surrounding the first sluice and not sewing the first fiber to the first membrane in the region of the first sluice.

[0059] Option 14. The method according to Option 9 further includes:

[0060] Determine the stress in the first fiber when the first fiber bed is adjusted from the first two-dimensional shape to the first three-dimensional shape; and

[0061] The first channel is formed in a region of the first fiber bed, where the fiber stress is greater than that in another region of the first fiber bed.

[0062] Option 15. The method according to Option 9 further includes:

[0063] The second fiber is sewn onto the second membrane, thereby forming a second fiber bed in a second two-dimensional shape with a second channel;

[0064] Close the second channel in the second fiber bed to adjust the second fiber bed to a second three-dimensional shape; and

[0065] The first fiber bed and the second fiber bed are stacked such that (i) the second fiber bed covers the first channel in the first fiber bed, and (ii) the first fiber bed covers the second channel in the second fiber bed, wherein the first fiber bed and the second fiber bed form the preform.

[0066] Option 16. A method for fabricating a preform for use in manufacturing a component made of a composite material, the method comprising:

[0067] Fibers are sewn onto a membrane to form a fiber bed with a two-dimensional shape, wherein sewing the fibers onto the membrane includes:

[0068] In a first region of the fiber bed, the fibers are stitched to the membrane using a first number of suture needle strokes per unit area; and

[0069] In the second region of the fiber bed, the fibers are sewn to the membrane using a second number of suture needle strokes per unit area, wherein the first number is less than the second number; and

[0070] The fiber bed is adjusted to a three-dimensional shape to form the preform.

[0071] Option 17. The method according to Option 16 further includes:

[0072] Determine the stress in the fibers when the fiber bed is adjusted from the two-dimensional shape to the three-dimensional shape; and

[0073] When the fiber stress in the first region is greater than the fiber stress in the second region, the fibers are sewn to the membrane using the first number of suture stitches and the second number of suture stitches per unit area in the first and second regions of the fiber bed, respectively.

[0074] Option 18. The method according to Option 16 further includes:

[0075] In the first region of the fiber bed, a third number of fibers per unit area are sewn to the membrane; and

[0076] In the second region of the fiber bed, a fourth number of fibers per unit area are sewn to the membrane, wherein the third number is less than the fourth number.

[0077] Option 19. The method of Option 16, further comprising removing the membrane after the fibers are sewn to the membrane and before the fiber bed is shaped into the three-dimensional shape.

[0078] Option 20. The method according to Option 16, wherein the first region of the fiber bed corresponds to a channel in the two-dimensional shape, the method further comprising:

[0079] After removing the membrane, loosen the seam along the edge of the provincial channel; and

[0080] Pull those fibers that extend across the province to close the province and adjust the fiber bed to the three-dimensional shape.

[0081] Further applicable areas of this disclosure will become apparent from the detailed description, claims, and drawings. The detailed description and specific examples are intended for illustrative purposes only and are not intended to limit the scope of this disclosure. Attached Figure Description

[0082] This disclosure will be more fully understood from the detailed description and accompanying drawings, in which:

[0083] Figure 1 This is a flowchart illustrating a first example of a method for forming a fiber preform according to the principles of this disclosure;

[0084] Figures 2 to 7 Is Figure 1 Examples of fiber preforms or their shapes at various stages of the method; perspective views and plan views.

[0085] Figure 8 This is a flowchart illustrating a second example of a method for forming fiber preforms according to the principles of this disclosure;

[0086] Figures 9 to 14 Is Figure 8 Examples of fiber preforms or their shapes at various stages of the method; perspective views and plan views.

[0087] Figure 15 This is a flowchart illustrating a third example of a method for forming fiber preforms according to the principles of this disclosure;

[0088] Figures 16 to 20 Is Figure 8 Examples of fiber preforms or their shapes at various stages of the method; and perspective views and plan views;

[0089] Figures 21 to 25 These are perspective and plan views of examples of fiber preforms or their shapes at various stages of a fourth example of a method for forming fiber preforms according to the principles of this disclosure.

[0090] In the accompanying drawings, reference numerals may be reused to identify similar and / or identical elements. Detailed Implementation

[0091] Some fiber preforms are initially formed in a two-dimensional (2D) shape by sewing fiber bundles to a stabilizing fabric to form a fiber bed, and then adjusted to a 3D shape. The stabilizing fabric serves as the base layer to which the fiber bundles are sewn. Stabilizing fabrics are typically plain-weave or non-woven materials that cannot be stretched to match the contours of complex parts. Furthermore, the large number of stitches required to secure the fiber bundles to the material compared to regular, non-crimped or woven fabrics results in high shearing forces on the material. Consequently, it is difficult to shear the material to match the contours of the target part.

[0092] To address this issue, it would be desirable to remove the stitching in the areas requiring cutting. However, once the preform is manufactured, this task becomes difficult for operators because the stitching is located across multiple layers of the preform. Consequently, several preforms are cut off and replaced with larger, more formable patches. This results in inefficient use of reinforcing material, requires preforms to be thicker than necessary, causes racetracking during the molding process, increases overall operational costs, and slows down preform production. Racetracking occurs when the fiber preforms do not uniformly fill the mold, creating gaps that resin races into instead of filling the entire composite part.

[0093] The method for forming fiber preforms according to this disclosure solves the above problems in one or more ways. In one way, the method uses a water-soluble film or an easily removable film (e.g., newsprint) as a base layer to which the fiber bundles are sewn, such that the film can be dissolved or removed from the fiber bed after the fiber bed is formed. Removing the film improves the formability of the fiber preform, making it possible to adjust the fiber preform from its 2D shape to its 3D shape without damaging the fiber preform.

[0094] In another approach, the method modifies one or more parameters in regions of the fiber preform that experience high shear (when the fiber preform is adjusted from its 2D shape to its 3D shape). In one example, the method minimizes the number of stitches used to secure the fiber bundles to the base layer in the high-shear region, avoids stitching the fiber bundles to the base layer in the high-shear region, and / or uses fusible sutures in the high-shear region. In another example, the method reduces the number of fiber bundles traversing the high-shear region, or creates channels or gaps in the high-shear region so that the fiber bundles do not extend across the high-shear region.

[0095] In another example, if the dart is formed in the fiber preform, the method forms a tie extending across the dart, and the method pulls the end of the tie to close the dart and adjust the fiber preform from its 2D shape to its 3D shape. The tie can be formed from fiber bundles. The fiber bundles forming the tie can be sewn to the base layer along the edge of the dart using wider sutures, which have lower thread tension relative to sutures in other areas, allowing the fiber bundles to slide.

[0096] Now for reference Figure 1 ,form Figure 6 The method for the preform 48 shown begins at step 10. At step 12, the method analyzes the shape of the preform 48 to identify areas of high fiber deformation. For example, briefly refer to... Figure 2 and Figure 3The method determines the desired 3D shape 50 of the preform 48 (e.g., a pyramidal truncated cone) and the 2D shape 52 of the preform 48 (e.g., a square), which can be adjusted (e.g., folded, molded) to the desired 3D shape 50. The method then determines the amount of fiber deformation in the preform 48 as it is adjusted from the 2D shape 52 to the 3D shape 50. This determination can be made using finite element analysis (FEA).

[0097] Refer again Figure 1 In step 14, the method determines the desired orientation and desired length of the fibers forming the preform 48 based, for example, on fiber deformation as the preform 48 adjusts from its 2D shape 52 to its 3D shape 50. For example, briefly refer to... Figure 7 In order to form the preform 48 in its 2D shape 52, fiber bundles 54 are sewn to a backing 56 (such as a stabilizing fabric or membrane) to form a fiber bed 58 in a plane defined by the x-axis 60 and the y-axis 62. Each fiber bundle 54 comprises thousands of fibers bundled together.

[0098] The fibers in the fiber bundle 54 may be made of E-glass, S-glass, basalt, carbon, Kevlar®, or combinations thereof. The backing 56 may be made of a water-soluble material (such as polyvinyl alcohol, polyethylene glycol, polyvinyl acetate, polyethylene oxide, or combinations thereof), allowing the backing 56 to be dissolved after the fiber bed 58 is formed. Alternatively, the backing 56 may be made of a material such as newsprint, which is easily torn but stable enough to serve as a substrate for the fiber bundle 54. Furthermore, the backing 56 may be removed from the fiber bed 58 after its formation. Removing the backing 56 improves the formability of the preform 48, enabling the preform 48 to be reshaped from its 2D shape 52 to its 3D shape 50 without damaging the preform 48.

[0099] This method determines the orientation of each fiber bundle 54 in the plane of the fiber bed and the length of each fiber bundle 54 between adjacent stitches securing it to the backing 56. In the example shown, the orientation of each fiber bundle 54 is approximately parallel to the y-axis 60. Furthermore, if each fiber bundle 54 is sewn to the backing 56 at a location 64 where the fiber bundle 54's wiring direction changes, the length of each fiber bundle 54 is equal to the distance 66 between locations 64.

[0100] This method can use, for example, a FEA method to determine the amount of fiber stress associated with multiple possible orientations of each fiber bundle 54, and select the fiber bundle orientation that minimizes fiber stress in regions where the fibers are highly deformed. For example, if the central region 68 of the fiber bed 58 is to be confined or compressed in a recess in a tool to form a preform 48 with its 3D shape 50, the method can select the fiber orientation that minimizes fiber stress in the central region 68. Thus, as shown, orienting the fiber bundles 54 parallel to the y-axis 60 minimizes fiber stress in the central region 68 of the fiber bed 58.

[0101] Similarly, the method can use, for example, FEA to determine the amount of fiber stress associated with a variety of possible lengths of each fiber bundle 54 and select the fiber bundle length that minimizes fiber stress in regions where fibers are highly deformable. If the central region 68 of the fiber bed 58 is to be compressed to form the preform 48 into its 3D shape 50, the method can select the fiber bundle length that minimizes fiber stress in the central region 68. For example, as shown, the method can increase the fiber bundle length in the central region 68 of the fiber bed 58 relative to the fiber bundle lengths in other regions of the fiber bed 58, which can minimize fiber stress in the central region 68.

[0102] Now for reference Figure 1 and Figure 4 In step 16, the method identifies high-shear regions 70 in the fiber bed 58, where seams will be omitted or minimized. When the fiber bed 58 is adjusted from a 2D shape 52 to a 3D shape 50, the amount of fiber deformation (e.g., the amount of fiber bending) in the high-shear regions 70 is greater than the amount of fiber deformation in other regions of the fiber bed 58. The method may use FEA to identify the high-shear regions 70.

[0103] At step 18, the method allows the foam insert 72 to be placed onto the backing 56 in areas of the fiber bed 58 where additional fiber bundle length is required. As discussed above, the method allows for the use of larger fiber bundle lengths in areas of high fiber deformation relative to the fiber bundle lengths used in other areas of the fiber bed 58. Therefore, the method can... Figure 4 As shown, foam inserts 72 are placed in each of the high-shear regions 70 to increase the length of the fiber bundles in the high-shear regions 70. After the fiber bundles 54 are sewn to the backing 56, the foam inserts 72 are placed between the fiber bundles 54 and the backing 56, and thus increase the length of the fiber bundles in the regions(a) of the fiber bed 58 in which the foam inserts 72 are placed.

[0104] At step 20, the method sews the fiber bundles 54 to the backing 56 to form a fiber bed 58, and in doing so, the method uses different stitch densities in the high-shear regions 70 of the fiber bed 58. For example, the method may use a first number of stitches 74 per unit area to sew the fiber bundles 54 to the backing 56 in the high-shear regions 70, while using a second number of stitches 76 per unit area in all other regions of the fiber bed 58. The first number is less than the second number. The first number may be zero, in which case the method does not sew the fiber bundles 54 to the backing 56 in the high-shear regions 70 of the fiber bed 58.

[0105] In addition to adjusting the fiber bundle length and / or stitch density in the high-shear region 70 of the fiber bed 58, the method may adjust one or more of the following (e.g., all): fiber bundle orientation, stitch material, and / or fiber bundle density in the high-shear region 70. For example, in the high-shear region 70, when the fiber bed 58 is adjusted from a 2D shape 52 to a 3D shape 50, the method may orient the fiber bundles 54 perpendicular to the fold line 78 around which the fiber bed 58 is folded. In the remainder of the fiber bed 58, the method may orient the fiber bundles 54 parallel to the vertical or horizontal edges of the fiber bed 58. Furthermore, the method may route the fiber bundles 54 in one layer along a different direction than in another separate layer to accommodate part complexity.

[0106] In another example, the method may form sutures 74 in the high-shear region 70 of fiber bed 58 from a first material, and sutures 76 in all other regions of fiber bed 58 from a second material. The melting point of the first material may be lower than that of the second material, such that sutures 74 can be melted without melting sutures 76. The first material may be low-density polyethylene, poly(ethylene adipate), poly(1-butene), poly(trans-1,4-butadiene), or combinations thereof. The second material may be polyester, polyamide 6, polyamide 66, glass, basalt, carbon, or combinations thereof.

[0107] In another example, the method may stitch a third number of fiber bundles 54 per unit area to the backing 56 in the high-shear region 70, and a fourth number of fiber bundles 54 per unit area to the backing 56 in all other regions of the fiber bed 58. The third number is less than the fourth number. Figure 7 The diagram illustrates this concept, showing that the number of fiber bundles 54 per unit area is less in the central region 68 of the fiber bed 58 compared to the rest of the fiber bed 58. Reducing the fiber bundle density in the central region 68 of the fiber bed 58 allows the fiber bundles 54 to be spaced further apart in the compression direction before becoming tightly packed. This allows the mechanical properties of the final part to remain unaffected in the central region 68.

[0108] Now for reference Figure 1 and Figure 5 At step 22, the method removes the backing 56 from the preform 48, and if the foam insert 72 is placed on the backing 56, the method removes the foam insert 72 from the preform 48. The method removes the backing 56 from the preform 48 by dissolving it in water or tearing it off from the fiber bed 58. At step 24, if the backing 56 has been removed by dissolution, the method dries the preform 48.

[0109] In step 26, the method melts any sutures, such as suture 74, in the high-shear region 70 of the fiber bed 58. In step 28, the method adds an adhesive to the preform 48. This adhesive may be made of an epoxy-based material or a urethane-based material.

[0110] In step 30, the method inserts the preform 48 into the preform mold. In step 32, the method shapes it in its final 3D form (in...). Figure 6 (As shown in the diagram) Molded preform 48. When preform 48 has its final 3D shape, it can be inserted into a final mold and molded into a part made of composite material using, for example, high-pressure resin transfer molding (HP-RTM). Instead of adding an adhesive to preform 48 and inserting it into a preform mold, this method simply inserts preform 48 into the final mold. The method ends at step 34.

[0111] Now for reference Figure 8 ,form Figure 14 The method for the fiber preform 150 shown begins at step 100. At step 102, the method determines the 2D shape (e.g., the shape corresponding to the absence of a spur 154). Figure 10 The 2D shape 152 shown is a rectangle, and this 2D shape can be adjusted to... Figure 9 The preform 150 shown has a desired 3D shape 156. For example, the method can use, for example, computer modeling to flatten the 3D shape 156 into a 2D shape 152.

[0112] At step 104, when the preform 150 is adjusted from its 2D shape to its 3D shape 156, the method analyzes the stress in the preform 150 and removes material from high-stress areas to form a sluice 154 in the 2D shape 152, as... Figure 10As shown in the illustration. For example, the method can form a channel 154 in a region of fiber bed 164 where the fiber stress is greater than that in other regions of fiber bed 164. Although the channel 154 has a triangular shape in the example shown, the channel 154 can have other shapes, such as another polygonal shape or a shape with curved edges. The channel 154 improves the formability of the preform 150, which makes it possible to adjust the preform 150 from its 2D shape 152 to its 3D shape 156 without damaging the preform 150.

[0113] At step 106, if multiple prefabricated parts 150 are needed to cover the gap, the method allows the provincial road 154 to point in different directions. For example, see brief reference. Figure 23 This method allows two of the provincial roads 154 in each preform 150 to point towards a first direction 158 and two of the provincial roads 154 in each preform 150 to point towards a second direction 160 perpendicular to the first direction 158. Furthermore, when the preform 150 is as follows... Figure 24 When the preforms are stacked together as shown, the material of one of the preforms 150 covers the provincial road 154 in the other preform 150.

[0114] Now for reference Figure 8 and Figure 11 In step 108, the method involves placing a bundle of fibers (such as...) Figure 7 The fiber bundles 54 shown are sewn to a removable stabilizing membrane 162, thereby forming a fiber bed 164 in a 2D shape 152. Figure 11 In the example shown, the method places and sews fiber bundles to the stabilizing membrane 162 in the region surrounding the channel 154, but does not place or sew fiber bundles to the stabilizing membrane 162 in the region of the channel 154. Alternatively, the method may place and sew fiber bundles to the stabilizing membrane 162 in the region of the channel 154, but with a lower fiber bundle density in the region of the channel 154 compared to the fiber bundle density in the rest of the fiber bed 164.

[0115] The stabilizing membrane 162 may be made of a water-soluble material (such as polyvinyl alcohol, polyethylene glycol, polyvinyl acetate, polyethylene oxide, or combinations thereof), such that the stabilizing membrane 162 can be dissolved after the fiber bed 164 is formed. Alternatively, the stabilizing membrane 162 may be made of a material such as newsprint, which is easily torn but stable enough to serve as a substrate for the fiber bundles. Furthermore, the stabilizing membrane 162 can be removed from the fiber bed 164 after the fiber bed 164 is formed. Removing the stabilizing membrane 162 improves the formability of the preform 150, making it possible to adjust the preform 150 from its 2D shape 152 to its 3D shape 156 without damaging the preform 150.

[0116] Now for reference Figure 8 and Figure 12 In step 110, the method adds a ties 166 to the province 154 using an adjusted suture width and tension. For example, the suture width for securing the ties 166 to the stabilizing membrane 162 may be 10% to 50% larger than the suture width for securing the fiber bundle to the stabilizing membrane 162. In another example, the suture tension for securing the ties 166 to the stabilizing membrane 162 may be 10% to 50% smaller than the suture tension for securing the fiber bundle to the stabilizing membrane 162. The sutures may be formed of a stitching material such as polyester, polyamide 6, polyamide 66, glass, basalt, carbon, or combinations thereof.

[0117] exist Figure 12 In the example shown, the method forms a tie 166 from a fiber bundle. This is accomplished by extending the fiber bundle across the ditch 154 and at the edge 170 of the ditch 154. Figure 11 The fiber bundle is sewn to the stabilizing membrane 162 at the designated location, but not in the area of ​​the provincial highway 154. Suture material is used only along the edge 170 of the provincial highway 154 to locate the anchor points through which the tether (fiber bundle) can slide. This method does not sew the fiber bundle to the stabilizing membrane 162 in the area of ​​the provincial highway 154 because the stabilizing membrane 162 will be removed, leaving only the tether in the provincial highway area. Figure 13 As shown in the image.

[0118] Now for reference Figure 8 , Figure 12 and Figure 13 In step 112, the method removes the stabilizing membrane 162 from the preform 150. This is done by dissolving the stabilizing membrane 162 in water or by peeling it off from the fiber bed 164. If the stabilizing membrane 162 has been removed by dissolution, the method dries the preform 150.

[0119] Now for reference Figure 8 , Figure 13 and Figure 14 In step 114, the method involves pulling the end 168 of the strap 166 to bring together or overlap the edge 170 of the ditch 154. Figure 11 To close Provincial Highway 154. Pulling the strap 166 can also move the precast component 150 from... Figure 13 The 2D shape 152 shown is adjusted to Figure 14The method then involves attaching the ends 168 of the straps 166 to each other to maintain the preform 150 in its 3D shape 156. After the straps 166 are formed and before the straps 166 are pulled to close the dart 154, the method can loosen the seams securing the straps 166 to the fiber bed 164 along the edge 170 of the dart 154 so that the straps 166 can slide through the seams.

[0120] At step 116, the method adds an adhesive to the preform 150. The adhesive may be made of an epoxy resin-based material or a urethane-based material. At step 118, the method inserts the preform 150 into a preform mold. At step 120, the method shapes it into its final 3D form (in... Figure 14 (As shown in the diagram) Molded preform 150. When preform 150 has its final 3D shape, it can be inserted into a final mold and molded into a part made of composite material using, for example, HP-RTM. Instead of adding adhesive to preform 150 and inserting it into a preform mold, this method simply inserts preform 150 into the final mold. The method ends at step 122.

[0121] Now for reference Figure 15 ,form Figure 20 The method for the fiber preform 250 shown begins at step 200. At step 202, the method determines the 2D shape (e.g., the shape corresponding to the absence of a spur 254). Figure 17 The 2D shape 252 shown is a rectangle, and this 2D shape can be adjusted to... Figure 16 The preform 250 shown has a desired 3D shape 256. This method can, for example, use computer modeling to flatten the 3D shape 256 into a 2D shape 252.

[0122] At step 204, when the preform 250 is adjusted from its 2D shape to its 3D shape 256, the method analyzes the stress in the preform 250 and removes material from high-stress areas to form a channel 254 in the 2D shape 252, as... Figure 17 As shown in the illustration. For example, the method can form a channel 254 in a region of fiber bed 264 where the fiber stress is greater than that in other regions of fiber bed 264. Although the channel 254 has a triangular shape in the example shown, the channel 254 can have other shapes, such as another polygonal shape or a shape with curved edges. The channel 254 improves the formability of the preform 250, which makes it possible to adjust the preform 250 from its 2D shape 252 to its 3D shape 256 without damaging the preform 250.

[0123] At step 206, if multiple prefabricated parts 250 are needed to cover the gap, the method allows the provincial road 254 to point in different directions. For example, see brief reference. Figure 23 This method allows two of the provincial roads 254 in the preform 250 to point towards a first direction 258 and two of the provincial roads 254 in the preform 250 to point towards a second direction 260 perpendicular to the first direction 258. Furthermore, when the preform 250 is as follows... Figure 24 When the preforms are stacked together as shown, the material of one of the preforms 250 covers the provincial road 254 of the other preform 250.

[0124] Now for reference Figure 15 and Figure 18 In step 208, the method stitches the fiber bundle 266 to a removable stabilizing membrane 262, thereby forming a fiber bed 264 in a 2D shape 252. Figure 18 In the example shown, when the fiber bundles 266 are sewn to the stabilizing membrane 262, the method uses fewer stitches per unit area in the region of the channel 254 compared to the number of stitches per unit area used in the rest of the fiber bed 264. Additionally, the method uses fewer fiber bundles 266 per unit area in the region of the channel 254 compared to the number of fiber bundles 266 used in the rest of the fiber bed 264. Each fiber bundle 266 comprises thousands of fibers bundled together.

[0125] The fibers in the fiber bundle 266 may be made of E-glass, S-glass, basalt, carbon, Kevlar®, or a combination thereof. The stabilizing membrane 262 may be made of a water-soluble material (such as polyvinyl alcohol, polyethylene glycol, polyvinyl acetate, polyethylene oxide, or a combination thereof), allowing the stabilizing membrane 262 to be dissolved after the fiber bed 264 is formed. Alternatively, the stabilizing membrane 262 may be made of a material such as newsprint, which is easily torn but stable enough to serve as a substrate for the fiber bundle. Furthermore, the stabilizing membrane 262 may be removed from the fiber bed 264 after its formation. Removing the stabilizing membrane 262 improves the formability of the preform 250, enabling the preform 250 to be reshaped from its 2D shape 252 to its 3D shape 256 without damaging the preform 250.

[0126] The fiber bundles 266 extending across Provincial Highway 254 form a tie on Provincial Highway 254. The fiber bundles 266 forming the tie run along the edge 270 of Provincial Highway 254. Figure 18 The fiber bundle density and suture density in the region of the provincial highway 254 may be 50% to 90% lower than those in all other regions of the fiber bed 264.

[0127] Now for reference Figure 15 , Figure 18 and Figure 19 At step 210, the method removes the stabilizing membrane 262 from the preform 250. This is done by dissolving the stabilizing membrane 262 in water or by tearing it off from the fiber bed 264. If the stabilizing membrane 262 has been removed by dissolution, the method dries the preform 250. At step 212, the method loosens the seams securing the tie 266 to the stabilizing membrane 262 along the edge 270 of the channel 254, allowing the tie 266 to slide through the seams.

[0128] Now for reference Figure 15 , Figure 19 and Figure 20 In step 214, the method closes the dart 254 by pulling the end 268 of the tether 266 to bring together or overlap the edge 270 of the dart 254. The end 268 of the tether 266 is closed by pulling along the cut line 269 on one side of each dart 254. Figure 18 The tie 266 is formed by cutting the fiber bundles that form the tie. Forming the end 268 of the tie 266 in this way ensures that the portion of the tie 266 adjacent to the end 268 can slide after the stabilizing membrane 262 is removed, while the portion of the tie 266 on the other side of the channel 254 is secured. Pulling the tie 266 can also move the preform 250 from... Figure 13 The 2D shape 252 shown is adjusted to Figure 14 The method then uses straps 266 to fasten each other to maintain the preform 250 in its 3D shape 256. After forming the straps 266 and before pulling the straps 266 to close the ditch 254, the method can be used along the edge 270 of the ditch 254. Figure 18 Loosen the stitching that secures the tie 266 to the stabilizing membrane 262 so that the tie 266 can slide through the stitching.

[0129] At step 216, the method adds an adhesive to the preform 250. The adhesive may be made of an epoxy resin-based material or a urethane-based material. At step 218, the method inserts the preform 250 into a preform mold. At step 220, the method shapes it into its final 3D form (in... Figure 20 (As shown in the diagram) Molded preform 250. When preform 250 has its final 3D shape, it can be inserted into a final mold and molded into a part made of composite material using, for example, HP-RTM. Instead of adding adhesive to preform 250 and inserting it into a preform mold, this method simply inserts preform 250 into the final mold. The method ends at step 222.

[0130] Now for reference Figures 21 to 25 The diagram illustrates the formation Figure 25 The method of the fiber preform 300 shown. Figures 21 to 25 The method is illustrated as using a shape similar to Figures 9 to 12 The prefabricated component 150 shown is Figures 15 to 20 The preform 250 shown is a preform. Therefore, the reference numerals for these two preforms and their features are repeatedly used in the description. Figures 21 to 25 The method.

[0131] Figure 21 The desired 3D shape 156 or 256 of the preform 300 is shown. Figure 22 The diagram shows a 2D shape 152 or 252 that can be adjusted to 3D shapes 156 and 256. This method can be referenced above. Figure 8 Steps 102, 104, and 106 or refer to Figure 15 Steps 202, 204, and 206 are used to determine the 2D shape 152 or 252, and to determine where and how the provincial road 154 or 254 is formed therein. Once the 2D shape 152 or 252 is determined, the method references... Figure 8 Steps 108, 110, and 112 or Figure 15 The preform 150 or 250 is formed in the manner described in steps 208, 210 and 212.

[0132] Figure 23 Two prefabricated components 150, two prefabricated components 250, or one prefabricated component 150 and one prefabricated component 250 are shown. As discussed above, prefabricated components 150 and 250 have complementary forms (e.g., provincial roads 154 and 254 in prefabricated components 150 and 250 point in different directions). Figure 24 Two preforms 150 stacked on top of each other, two preforms 250 stacked on top of each other, and preforms 150 and 250 stacked on top of each other are shown. Because preforms 150 and 250 have complementary forms, when preforms 150 or 250 are stacked on top of each other, the material in one of the preforms 150 or 250 covers the gap (e.g., channels 154, 254) in the other preform. This method can be achieved, for example, by pulling straps 166 or 266 before arranging the preforms 150 as stacked on top of each other to adjust the preforms 150 or 250 to their 3D shapes 156, 256.

[0133] Figure 25Two preforms 150, two preforms 250, or preforms 150 and 250 are shown, which together form preform 300 with their 3D shape 156 or 256. To form preform 300, the method may involve adding an adhesive to preforms 150 or 250; inserting preforms 150 or 250 into a preform mold such that preforms 150 or 250 are stacked on top of each other; and then molding preforms 150 or 250 into preform 300. Preform 300 may be inserted into a final mold and molded into a part made of composite material using, for example, HP-RTM.

[0134] The foregoing description is merely illustrative in nature and is not intended in any way to limit this disclosure, its application, or use. The broad teachings of this disclosure can be implemented in various forms. Therefore, while this disclosure includes specific examples, its true scope should not be so limited, as other modifications will become apparent upon studying the drawings, specification, and the following claims. It should be understood that one or more steps within the method may be performed in a different order (or simultaneously) without altering the principles of this disclosure. Furthermore, while each of the embodiments described above is described as having certain features, any one or more of those features described with respect to any embodiment of this disclosure can be implemented in any other embodiment and / or combined with features of any other embodiment, even if such combination is not explicitly described. In other words, the described embodiments are not mutually exclusive, and permutations and combinations of one or more embodiments with each other remain within the scope of this disclosure.

[0135] Spatial and functional relationships between components (e.g., between modules, circuit elements, semiconductor layers, etc.) are described using various terms, including “connection,” “joint,” “link,” “adjacent,” “next to,” “on top of,” “above,” “below,” and “set.” Unless explicitly described as “direct,” when describing the relationship between the first and second components in the above disclosure, the relationship can be a direct relationship in which no other intervening components exist between the first and second components, or it can be an indirect relationship in which one or more intervening components exist between the first and second components (either spatially or functionally). As used herein, at least one of the phrases A, B, and C should be interpreted as referring to the logic (A OR B OR C) using non-exclusive logic OR, and should not be interpreted as referring to “at least one of A, at least one of B, and at least one of C.”

Claims

1. A method for fabricating a preform for use in manufacturing a component made of a composite material, the method comprising: The fibers are sewn onto the membrane to form a fiber bed in a two-dimensional shape; Remove the membrane from the fiber bed; as well as The fiber bed is adjusted to a three-dimensional shape to form the preform.

2. The method according to claim 1, further comprising: Determine the amount of fiber deformation when the fiber bed is adjusted from the two-dimensional shape to the three-dimensional shape; as well as The following are determined based on the amount of fiber deformation: the orientation of the fibers in the plane of the fiber bed, the number of fibers per unit area of ​​the fiber bed, the material of the sutures that secure the fibers to the membrane, the number of suture stitches per unit area of ​​the fiber bed, and the length of the fiber between a pair of adjacent suture stitches.

3. The method according to claim 2, further comprising: A first region of the fiber bed is defined, in which the fiber deformation is greater than that in a second region of the fiber bed; as well as The fibers are sewn onto the membrane such that the fiber length in the first region of the fiber bed is greater than the fiber length in the second region of the fiber bed.

4. The method of claim 3, further comprising placing a piece of foam onto the membrane in a first region of the fiber bed before sewing the fibers onto the membrane to increase the fiber length in the first region.

5. The method according to claim 2, further comprising: A first region of the fiber bed is defined, in which the fiber deformation is greater than that in a second region of the fiber bed; The fibers are sewn to the membrane using a first set of sutures in a first region of the fiber bed, wherein the sutures in the first set are made of a first material; In a second region of the fiber bed, the fibers are sewn to the membrane using a second set of sutures, wherein the sutures in the second set are made of a second material having a higher melting point than the first material; and After the membrane is removed from the fiber bed and before the fiber bed is adjusted to the three-dimensional shape, the sutures in the first region of the fiber bed are melted.

6. The method according to claim 2, further comprising: A first region of the fiber bed is defined, in which the fiber deformation is greater than that in a second region of the fiber bed; The fibers are sewn onto the membrane in a second region of the fiber bed; as well as The fibers are not sewn onto the membrane in the first region of the fiber bed.

7. The method of claim 1, wherein, The membrane is water-soluble, and the method further includes removing the membrane from the fiber bed by dissolving the membrane.

8. The method of claim 1, wherein, The membrane is paper, and the method further includes removing the membrane from the fiber bed by tearing it off.

9. A method for fabricating a preform for use in manufacturing a component made of a composite material, the method comprising: The first fiber is sewn onto the first membrane to form a first fiber bed in a first two-dimensional shape having a first channel; Forming a tether that extends across the first provincial highway; as well as Pull the strap to close the first channel and adjust the first fiber bed into a first three-dimensional shape.

10. The method of claim 9, further comprising using the first fiber to form the ligament.

11. The method of claim 10, further comprising, after forming the ties and before pulling the ties, loosening the seams securing the first fibers to the first membrane along the edge of the first dart.

12. The method of claim 9, further comprising removing the first membrane after the first fiber is sewn onto the first membrane and before the ties are pulled.

13. The method of claim 9, further comprising forming the first sluice in a first two-dimensional shape of the first fiber bed by sewing the first fiber to the first membrane in the region surrounding the first sluice and not sewing the first fiber to the first membrane in the region of the first sluice.

14. The method of claim 9, further comprising: Determine the stress in the first fiber when the first fiber bed is adjusted from the first two-dimensional shape to the first three-dimensional shape; as well as The first channel is formed in a region of the first fiber bed, where the fiber stress is greater than that in another region of the first fiber bed.

15. The method of claim 9, further comprising: The second fiber is sewn onto the second membrane, thereby forming a second fiber bed in a second two-dimensional shape with a second channel; Close the second channel in the second fiber bed to adjust the second fiber bed to a second three-dimensional shape; as well as The first fiber bed and the second fiber bed are stacked such that (i) the second fiber bed covers the first channel in the first fiber bed, and (ii) the first fiber bed covers the second channel in the second fiber bed, wherein the first fiber bed and the second fiber bed form the preform.

16. A method for fabricating a preform for use in manufacturing a component made of a composite material, the method comprising: Fibers are sewn onto a membrane to form a fiber bed with a two-dimensional shape, wherein sewing the fibers onto the membrane includes: In a first region of the fiber bed, the fibers are stitched to the membrane using a first number of suture needle strokes per unit area; and In the second region of the fiber bed, the fibers are sewn to the membrane using a second number of suture needle strokes per unit area, wherein the first number is less than the second number; and The fiber bed is adjusted to a three-dimensional shape to form the preform.

17. The method of claim 16, further comprising: Determine the stress in the fibers when the fiber bed is adjusted from the two-dimensional shape to the three-dimensional shape; as well as When the fiber stress in the first region is greater than the fiber stress in the second region, the fibers are sewn to the membrane using the first number of suture stitches and the second number of suture stitches per unit area in the first and second regions of the fiber bed, respectively.

18. The method of claim 16, further comprising: In the first region of the fiber bed, a third number of fibers per unit area are sewn to the membrane; as well as In the second region of the fiber bed, a fourth number of fibers per unit area are sewn to the membrane, wherein the third number is less than the fourth number.

19. The method of claim 16, further comprising removing the membrane after the fibers are sewn to the membrane and before the fiber bed is shaped into the three-dimensional form.

20. The method of claim 16, wherein, The first region of the fiber bed corresponds to a province in the two-dimensional shape, and the method further includes: After removing the membrane, loosen the seam along the edge of the provincial channel; and Pull those fibers that extend across the province to close the province and adjust the fiber bed to the three-dimensional shape.

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