Composite material dot matrix curved surface interlayer shell and preparation method thereof

Abstract

The invention provides a composite material lattice curved surface interlayer shell and a preparation method thereof. The shell comprises an upper curved surface layer, a lower curved surface layer and a middle lattice interlayer, the middle dot matrix interlayer is positioned between the upper curved surface layer and the lower curved surface layer; the upper curved surface layer and the lower curved surface layer are of a woven net-shaped structure; the middle dot matrix interlayer is composed of periodical dot matrix structures which are vertically woven in a penetrating and inserting mode. The method is reasonable in conception, the composite material dot matrix is prepared through the wet-process interspersing weaving technology on the basis of the curved surface structure, the dot matrix can meet the requirement for the curved surface configuration on the basis of meeting the mechanical property, face-core integrated forming is easier to achieve, and the method has the larger technological advantage for improving the shear resistance of the dot matrix; and the overall structural design is relatively free, the cost is lower, a multi-layer complex structure can be formed, the size parameter change is large, and the method is suitable for application and popularization.

Description

Technical Field

[0001] The present invention belongs to the technical field of composite materials, and particularly relates to a composite material lattice curved surface sandwich shell and a preparation method thereof. Background Art

[0002] Composite material lattices have the advantages of light weight, high efficiency and multi-functional integration, and the internal open space structure can be filled with various multi-functional materials, which are widely used in the aerospace field. At present, the preparation of composite material lattices mostly focuses on flat lattice structures, and there are still great difficulties in the research on the preparation of curved surface lattices. Summary of the Invention

[0003] In view of the technical problems existing in the above background art, the present invention provides a method for preparing a composite material lattice on the basis of a curved surface structure by using a wet interpenetrating weaving technique, which can enable the lattice to meet the requirements of the curved surface configuration while satisfying the mechanical properties, is more likely to realize the integral forming of the surface and the core, has relatively greater process advantages in improving the shear resistance of the lattice, and has a relatively free overall structural design, lower cost, can form multi-layer complex structures, and has large changes in size parameters. A composite material lattice curved surface sandwich shell and a preparation method thereof are provided.

[0004] To solve the above technical problems, a composite material lattice curved surface sandwich shell provided by the present invention includes an upper curved surface layer, a lower curved surface layer and an intermediate lattice sandwich layer; the intermediate lattice sandwich layer is located between the upper curved surface layer and the lower curved surface layer; the upper curved surface layer and the lower curved surface layer are woven mesh structures; the intermediate lattice sandwich layer is composed of a periodically lattice structure vertically interwoven.

[0005] For the composite material lattice curved surface sandwich shell, wherein: the materials of the upper curved surface layer and the lower curved surface layer are both glass fibers impregnated with phenolic resin.

[0006] For the composite material lattice curved surface sandwich shell, wherein: the material of the intermediate lattice sandwich layer is glass fiber impregnated with phenolic resin.

[0007] For the composite material lattice curved surface sandwich shell, wherein: the intermediate lattice sandwich layer is any one of a periodic pyramid lattice structure and a tetrahedron lattice structure, and is used to withstand the compression and shear loads applied to the structure.

[0008] For the composite material lattice curved surface sandwich shell, wherein: the space inside the lattice structure unit cell itself and between the cell units of the intermediate lattice sandwich layer can be filled with a multi-functional material by perfusion.

[0009] The preparation method of the composite material lattice curved surface sandwich shell mainly includes the following steps:

[0010] 1) Prepare a curved surface mold and coat a composite material release agent on the forming surface of the curved surface mold;

[0011] 2) Fabricate the intermediate plates required for the upper and lower curved surface layers and the upper and lower bottom plates for fixing the interpenetrating woven composite material lattice fiber rods;

[0012] 3) Place the intermediate plate on the curved surface mold, cut the composite material fibers, weave a net structure on the intermediate plate and lay it on the corresponding grooves of the curved surface mold and fix it;

[0013] 4) Prepare the resin glue solution and pour it into the encapsulated mold to complete the resin infiltration of the composite material curved surface layer;

[0014] 5) Remove the excess resin after the composite material is impregnated and formed, adjust the excess fibers of the composite material fiber layer formed on the mold on the curved surface mold, and cure to obtain a single upper or lower curved surface layer;

[0015] 6) Arrange the cured upper and lower curved surface layers vertically and neatly and fix them to each other by screws with nuts. Arrange the upper and lower bottom plates at both ends of the screws, cut the composite material fibers, and complete the weaving of the intermediate lattice sandwich;

[0016] 7) Adjust the distance between the upper and lower curved surface layers to complete the overall weaving of the composite material lattice curved surface sandwich shell structure;

[0017] 8) Refer to the method in step 4) above to complete the resin infiltration of the fibers of the composite material lattice curved surface sandwich shell, remove the excess resin, and complete the curing of the composite material lattice curved surface sandwich shell structure after heating;

[0018] 9) Remove the intermediate plate and the upper and lower bottom plates, and trim the shape of the composite material lattice curved surface sandwich shell structure to meet the design requirements.

[0019] For the preparation method of the composite material lattice curved surface sandwich shell, wherein: the curved surface mold is made of polytetrafluoroethylene and has a radius of curvature of 940 mm; the lattice cell size corresponding to the curved surface mold is 7 mm × 7 mm × 7 mm.

[0020] For the preparation method of the composite material lattice curved surface sandwich shell, wherein: in step 3), the composite material fibers are cut into a circular profile with a diameter of 800 mm.

[0021] For the preparation method of the composite material lattice curved surface sandwich shell, wherein: in step 5), it is cured at a temperature of 150°C to 180°C to obtain a single upper or lower curved surface layer.

[0022] The preparation method of the composite material lattice curved surface sandwich shell, wherein: in the step 6), composite material fibers with a number four times that of the lattice unit cells are cut, with a length of 800 mm, and are interwoven with single fibers. One fiber represents one column of the lattice unit cell. The four composite material fibers interwoven around the node form a lattice unit cell. Repeating the interweaving of single fibers can complete the weaving of the middle lattice sandwich layer (3).

[0023] The preparation method of the composite material lattice curved surface sandwich shell, wherein: the heating temperature in the step 8) is also 150°C to 180°C.

[0024] Adopting the above technical solution, the present invention has the following beneficial effects:

[0025] The structure design of the composite material lattice curved surface sandwich shell of the present invention is simple and reasonable. The curved surface layer can improve the bending resistance of the composite material lattice. The middle lattice sandwich layer is a periodic pyramid lattice structure or a tetrahedral lattice structure, which can be used to bear the compression and shear loads applied to the structure; the middle lattice sandwich layer is a periodic three-dimensional composite material lattice structure, having good compressive resistance and the ability to resist shear deformation; the middle lattice sandwich layer adopts an open space structure, and various multifunctional materials can be filled and poured inside, which can meet the design requirements of lightweight and multifunctional integration, and is more adaptable to complex service environments. Therefore, it has important application value in practical engineering.

[0026] The preparation method of the composite material lattice curved surface sandwich shell of the present invention is reasonably conceived, and the curved surface configuration can be realized without affecting the structural mechanical properties; on the basis of the curved surface structure, the wet interweaving technology is used to prepare the composite material lattice structure, which can enable the lattice to meet the requirements of the curved surface configuration while meeting the mechanical properties. This preparation process is easier to realize the integrated forming of the lattice core layer and the panel, has greater process advantages for improving the shear resistance of the composite material lattice, and the overall structure design is relatively free, with lower costs, can form multilayer complex structures, and has large changes in size parameters and can form multilayer complex structures. Description of the Drawings

[0027] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained according to these drawings without creative efforts.

[0028] Figure 1 It is the overall structure schematic diagram of the composite material pyramid lattice curved surface sandwich shell of the present invention;

[0029] Figure 2 It is the top view of the composite material pyramid lattice curved surface sandwich shell of the present invention;

[0030] Figure 3 It is the side view of the composite material pyramid lattice curved surface sandwich shell of the present invention;

[0031] Figure 4 It is the structural schematic diagram of the auxiliary tooling required for the preparation involved in the preparation method of the composite material pyramid lattice curved surface sandwich shell of the present invention;

[0032] Figure 5 It is the schematic diagram of the preparation process of the preparation method of the composite material pyramid lattice curved surface sandwich shell of the present invention. Specific embodiments

[0033] Next, the technical solutions of the present invention will be described clearly and completely in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative work shall fall within the protection scope of the present invention.

[0034] Next, the present invention will be further explained and described in conjunction with specific embodiments.

[0035] As Figures 1-3 shown, a composite material lattice curved surface sandwich shell provided in this embodiment includes an upper curved surface layer 1, a lower curved surface layer 2, and an intermediate lattice sandwich layer 3.

[0036] The intermediate lattice sandwich layer 3 is located between the upper curved surface layer 1 and the lower curved surface layer 2; wherein, the material of the intermediate lattice sandwich layer 3 is glass fiber impregnated with phenolic resin; the upper curved surface layer 1 and the lower curved surface layer 2 can improve the bending resistance of the composite material lattice.

[0037] The upper curved surface layer 1 and the lower curved surface layer 2 are reticular structures woven according to certain rules; wherein, the materials of the upper curved surface layer 1 and the lower curved surface layer 2 are glass fiber impregnated with phenolic resin.

[0038] The intermediate lattice sandwich layer 3 is composed of a periodically lattice structure woven vertically; wherein, the core layer of the intermediate lattice sandwich layer 3 has periodically dense composite material lattice fiber rods vertically.

[0039] The intermediate lattice sandwich layer 3 is a periodic pyramid lattice structure or a tetrahedral lattice structure, used to bear the compression and shear loads applied to the structure; and the open space structure (the space structure of the lattice structure cell itself and between cells) of the intermediate lattice sandwich layer 3 can be filled with multifunctional materials by perfusion to achieve the design requirements of lightweight and multifunctional integration.

[0040] The intermediate lattice sandwich layer 3 has a curved surface configuration.

[0041] As Figures 4-5 shown, the preparation method of the composite material lattice curved surface sandwich shell of the present invention mainly includes the following steps:

[0042] (1) Prepare a polytetrafluoroethylene curved surface mold with corresponding dimensions according to the curvature of the required structure and the lattice cell size in the design requirements, and coat a composite material release agent on the forming surface of the mold;

[0043] (2) Design and manufacture the intermediate plates required for the upper curved surface layer 1 and the lower curved surface layer 2 and the upper and lower bottom plates used to fix the interpenetrating woven composite material lattice fiber rods according to the lattice cell size (cell size 7mm×7mm×7mm) required in the design requirements;

[0044] (3) Place the intermediate plate on the polytetrafluoroethylene curved surface mold, cut the composite material fibers with corresponding dimensions (circular contour with a diameter of 800mm) according to the design requirements, perform up-and-down weaving on the intermediate plate according to the rules to form the required mesh structure, and lay it on the corresponding grooves of the curved surface mold for fixation;

[0045] (4) Configure the resin glue solution according to the mass of phenolic resin required for the composite material curved surface layer, and introduce the mixed resin glue solution into the sealed mold through a vacuum bag to complete the resin infiltration of the composite material curved surface layer;

[0046] (5) Remove the excess resin after the composite material is impregnated and formed, adjust the excess fibers of the composite material fiber layer formed on the curved surface mold, and cure at a temperature of 150°C to 180°C according to the properties of the phenolic resin to obtain a single upper curved surface layer 1 or lower curved surface layer 2;

[0047] (6) Arrange the cured upper curved surface layer 1 and the lower curved surface layer 2 vertically and neatly with a certain interval, connect and fix them with screws and nuts, arrange the upper and lower bottom plates at both ends of the screws, cut the composite material fibers with four times the number of lattice cells, with a length of 800mm, perform interpenetrating weaving with single fibers, one fiber represents one column of the lattice cell, and the 4 composite material fibers interpenetrating and weaving around the node form a lattice cell. Repeating the interpenetrating weaving of single fibers can complete the weaving of the intermediate lattice sandwich layer 3;

[0048] (7) Adjust the spacing between the upper curved surface layer 1 and the lower curved surface layer 2 according to the lattice cell height (lattice cell height is 7mm) specified in the design requirements to complete the overall weaving of the composite material lattice curved surface sandwich shell structure;

[0049] (8) Complete the resin infiltration of the fibers of the composite lattice curved surface sandwich shell by referring to the method in step (4) above, remove the excess resin, and after heating at a temperature of 150°C to 180°C, complete the curing of the composite lattice curved surface sandwich shell structure;

[0050] (9) Remove the middle plate and the upper and lower bottom plates, and trim the shape of the composite lattice curved surface sandwich shell structure to meet the design requirements.

[0051] Among them, the curvature radius of the above-mentioned curved surface mold is 940 mm, and the lattice cell size corresponding to the curved surface mold is 7 mm × 7 mm × 7 mm.

[0052] The concept of the present invention is reasonable. Based on the curved surface structure, the composite lattice is prepared by using the wet interweaving technology, which can make the lattice meet the requirements of the curved surface configuration while satisfying the mechanical properties, is more likely to realize the integrated forming of the surface and the core, has relatively greater process advantages in improving the shear resistance of the lattice, and the overall structural design is relatively free, with lower costs, can form multi-layer complex structures, has large changes in size parameters, and is suitable for popularization and application.

[0053] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A composite material lattice curved surface sandwich shell, characterized in that: The housing includes an upper curved surface layer (1), a lower curved surface layer (2), and an intermediate lattice sandwich layer (3); the intermediate lattice sandwich layer (3) is located between the upper curved surface layer (1) and the lower curved surface layer (2); the upper curved surface layer (1) and the lower curved surface layer (2) are woven mesh structures; the intermediate lattice sandwich layer (3) is composed of a periodically lattice structure woven vertically and interspersed.

2. The composite material lattice curved surface sandwich shell according to claim 1, characterized in that: The materials of the upper curved surface layer (1) and the lower curved surface layer (2) are both glass fibers impregnated with phenolic resin.

3. The composite material lattice curved surface sandwich shell according to claim 1, characterized in that: The material of the intermediate lattice sandwich layer (3) is glass fibers impregnated with phenolic resin.

4. The composite material lattice curved surface sandwich shell according to claim 1, characterized in that: The intermediate lattice sandwich layer (3) is any one of a periodic pyramid lattice structure and a tetrahedral lattice structure, and is used to bear the compression and shear loads applied to the structure.

5. The composite material lattice curved surface sandwich shell according to claim 1, wherein: Functional materials can be poured and filled in the space within the lattice structure unit cells of the intermediate lattice sandwich layer (3) itself and between the cells.

6. The preparation method of the composite material lattice curved surface sandwich shell according to claim 1, characterized in that, The preparation method mainly includes the following steps: 1) Prepare a curved surface mold and coat a composite material release agent on the forming surface of the curved surface mold; 2) Manufacture the intermediate plates required for the upper curved surface layer (1) and the lower curved surface layer (2), and the upper and lower bottom plates for fixing the vertically interwoven composite material lattice fiber rods; 3) Place the intermediate plate on the curved surface mold, cut the composite material fibers, weave a mesh structure on the intermediate plate and lay it on the corresponding grooves of the curved surface mold for fixation; 4) Configure the resin glue solution and introduce it into the sealed mold to complete the resin infiltration of the composite material curved surface layer; 5) Remove the excess resin after the composite material is impregnated and formed, adjust the excess fibers of the composite material fiber layer formed on the mold on the curved surface mold, and cure to obtain a single upper curved surface layer (1) or lower curved surface layer (2); 6) Arrange the cured upper curved surface layer (1) and the lower curved surface layer (2) vertically in a neat manner and connect and fix them to each other with screws and nuts. Arrange the upper and lower bottom plates at both ends of the screws, cut the composite material fibers, and complete the weaving of the intermediate lattice sandwich layer (3); 7) Adjust the spacing between the upper curved surface layer (1) and the lower curved surface layer (2) to complete the overall weaving of the composite material lattice curved surface sandwich housing structure; 8) Refer to the method in step 4) above to complete the resin infiltration of the fibers of the composite material lattice curved surface sandwich housing, remove the excess resin, and complete the curing of the composite material lattice curved surface sandwich housing structure after heating; 9) Remove the intermediate plate and the upper and lower bottom plates, and trim the shape of the composite material lattice curved surface sandwich housing structure to meet the design requirements.

7. The preparation method of the composite material lattice curved surface sandwich shell according to claim 6, characterized in that: The curved surface mold is made of polytetrafluoroethylene and has a curvature radius of 940 mm; the lattice cell size corresponding to the curved surface mold is 7 mm × 7 mm × 7 mm.

8. The preparation method of the composite material lattice curved surface sandwich shell according to claim 6, characterized in that: In step 3), the composite material fibers are cut into a circular profile with a diameter of 800 mm.

9. The manufacturing method of the composite material lattice curved surface sandwich shell according to claim 6, characterized in that: In step 5), it is cured at a temperature of 150 °C to 180 °C to obtain a single upper curved surface layer (1) or lower curved surface layer (2).

10. The preparation method of the composite material lattice curved surface sandwich shell according to claim 6, characterized in that: In step 6), composite material fibers with a number of four times the number of lattice unit cells are cut, with a length of 800 mm, and single fibers are used for interlaced weaving. One fiber represents one column of the lattice unit cell. Four composite material fibers interlaced around the nodes form a lattice unit cell. Repeating the interlaced weaving of single fibers can complete the weaving of the middle lattice sandwich layer (3).

11. The preparation method of the composite material lattice curved surface sandwich shell according to claim 6, characterized in that: The heating temperature in step 8) is also 150°C to 180°C.

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