Composite lattice curved sandwich shell and method of making same

Abstract

The application provides a composite material lattice curved surface sandwich shell and a preparation method thereof. The shell comprises 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 net structures. The intermediate lattice sandwich layer is composed of a vertical interpenetrating woven periodic lattice structure. The application has reasonable concept. On the basis of the curved surface structure, a composite material lattice is prepared by using a wet interpenetrating weaving technology, so that the lattice can meet the requirements of the curved surface configuration on the basis of meeting the mechanical properties, the surface core integrated forming is more easily realized, the process advantage for improving the shear resistance of the lattice is relatively greater, the overall structure design is relatively free, the cost is lower, a multilayer complex structure can be formed, the size parameter changes greatly, and the application is suitable for promotion and application.

Description

TECHNICAL FIELD

[0001] The application 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

[0002] The composite material lattice has the advantages of light weight, high efficiency and multifunctional integration, and the internally open space structure can be filled with various multifunctional materials, so it is widely used in the field of aerospace. At present, the preparation of the composite material lattice is mainly concentrated on the flat plate lattice structure, and there is still great difficulty in the preparation of the curved surface lattice. SUMMARY

[0003] In view of the technical problems in the above background art, the application proposes a composite material lattice curved surface sandwich shell and a preparation method thereof, which are prepared by using the wet interpenetrating weaving technology on the basis of the curved surface structure, can meet the requirements of the curved surface configuration on the basis of meeting the mechanical properties, are easier to realize the surface-core integrated forming, have relatively greater process advantages for improving the shear resistance of the lattice, have relatively free overall structure design, are lower in cost, can form a multi-layer complex structure, and have large size parameter changes.

[0004] To solve the above technical problems, the application provides a composite material lattice curved surface sandwich shell, which comprises an upper curved surface layer, a lower curved surface layer and an intermediate lattice interlayer.

[0005] 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 phenolic resin impregnated glass fibers.

[0006] The composite material lattice curved surface sandwich shell, wherein: the material of the intermediate lattice interlayer is a phenolic resin impregnated glass fiber.

[0007] The composite material lattice curved surface sandwich shell, wherein: the intermediate lattice interlayer is any one of a periodic pyramid lattice structure and a tetrahedral lattice structure, and is used for bearing the compression and shear load of the structure.

[0008] The composite material lattice curved surface sandwich shell, wherein: the intermediate lattice interlayer is any one of a periodic pyramid lattice structure and a tetrahedral lattice structure, and is used for bearing the compression and shear load of the structure.

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

[0010] 1) prepare a curved mold, and coat the compound material release agent on the curved mold forming surface;

[0011] 2) make the intermediate plate required for the upper and lower curved surface layers and the upper and lower bottom plates used to fix the point lattice fiber rods of the woven composite material;

[0012] 3) place the intermediate plate on the curved mold, cut the composite material fiber, weave the mesh structure on the intermediate plate and lay it on the corresponding groove of the curved mold to fix it;

[0013] 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;

[0014] 5) remove the excess resin after the composite material impregnation forming, adjust the excess fiber of the composite material fiber layer formed on the curved mold, and solidify to obtain a single upper curved surface layer or lower curved surface layer;

[0015] 6) vertically align the solidified and formed upper and lower curved surface layers and connect and fix them with each other by means of the screw rod with the nut, arrange the upper and lower bottom plates at both ends of the screw rod, cut the composite material fiber, and weave the intermediate point lattice interlayer;

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

[0017] 8) complete the resin infiltration of the fiber of the composite material point lattice curved surface interlayer shell structure by referring to the method of step 4) above, remove the excess resin, and complete the solidification of the composite material point lattice curved surface interlayer 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 point lattice curved surface interlayer shell structure to meet the design requirements.

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

[0020] The preparation method of the composite material point lattice curved surface interlayer shell structure, wherein: in step 3), the composite material fiber is cut into a circular profile with a diameter of 800 mm.

[0021] The preparation method of the composite material point lattice curved surface interlayer shell structure, wherein: in step 5), the single upper curved surface layer or lower curved surface layer is solidified at a temperature of 150°C to 180°C.

[0022] The preparation method of the composite lattice curved sandwich shell, wherein: in the step 6), the number of composite fibers is four times of the number of lattice cells, the length is 800mm, and the single fiber is used for interpenetrating weaving, one fiber represents one column of the lattice cell, four composite fibers interpenetrating around the node constitute a lattice cell, and the interpenetrating weaving of the single fiber is repeated to complete the weaving of the intermediate lattice sandwich (3).

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

[0024] By adopting the technical scheme, the present application has the following beneficial effects:

[0025] The composite lattice curved sandwich shell structure is simple and reasonable in design, the curved surface layer can improve the bending resistance of the composite lattice, the intermediate lattice sandwich is a periodic pyramid lattice structure or a tetrahedron lattice structure, and can be used to bear compression and shear load of the structure; the intermediate lattice sandwich is a periodic three-dimensional composite lattice structure, has good compression resistance and shear deformation resistance, and is filled with various multifunctional materials in an open space structure, can meet the design requirements of lightweight and multifunctional integration, is more suitable for complex service environments, and therefore has important application value in actual engineering.

[0026] The preparation method of the composite lattice curved sandwich shell is reasonable in concept, can realize the curved surface configuration without affecting the mechanical properties of the structure, and can realize the weaving and integration of the lattice core layer and the panel on the basis of the curved surface structure, has greater process advantages for improving the shear resistance of the composite lattice, and has relatively free overall structure design, lower cost, can form a multilayer complex structure, and has large size parameters. BRIEF DESCRIPTION OF DRAWINGS

[0027] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the drawings needed in the specific embodiments or the prior art description will be briefly introduced as follows. Obviously, the drawings in the following description are some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without creative labor.

[0028] Figure 1 It is a whole structure schematic view of the composite pyramid lattice curved sandwich shell.

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

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

[0031] Figure 4 This is a schematic diagram of the auxiliary tooling required for the preparation of the composite material pyramid lattice curved surface sandwich shell of the present invention;

[0032] Figure 5 This is a schematic diagram of the preparation process of the composite material pyramid lattice curved surface sandwich shell of the present invention. Detailed Implementation

[0033] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] The present invention will be further explained below with reference to specific embodiments.

[0035] like Figures 1-3 As shown in the figure, the 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 interlayer 3 is located between the upper curved layer 1 and the lower curved layer 2; wherein, the material of the intermediate lattice interlayer 3 is glass fiber impregnated with phenolic resin; the upper curved layer 1 and the lower curved layer 2 can improve the bending resistance of the composite lattice.

[0037] The upper curved layer 1 and the lower curved layer 2 are mesh structures woven according to a certain pattern; wherein, the material of the upper curved layer 1 and the lower curved layer 2 is glass fiber impregnated with phenolic resin.

[0038] The intermediate lattice interlayer 3 is composed of a periodic lattice structure that is vertically interwoven; wherein, the core layer of the intermediate lattice interlayer 3 has periodically dense composite material lattice fiber rods in the vertical direction.

[0039] The intermediate lattice interlayer 3 is a periodic pyramid lattice structure or a tetrahedral lattice structure, used to bear the compressive and shear loads on the structure; and the open spatial structure of the intermediate lattice interlayer 3 (the spatial structure between the lattice cells themselves) can be filled with multifunctional materials to achieve the design requirements of lightweight and multifunctional integration.

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

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

[0042] (1) According to the required curvature of the structure and the lattice cell size, a polytetrafluoroethylene curved surface mold of corresponding size is prepared, and a composite release agent is coated on the mold forming surface;

[0043] (2) According to the required lattice cell size (cell size 7mm×7mm×7mm), the intermediate plate 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 woven composite lattice fiber rods are designed and made;

[0044] (3) Place the intermediate plate on the polytetrafluoroethylene curved surface mold, cut the composite fiber of the corresponding size (diameter 800mm circular contour) according to the design requirements, and weave it into the required mesh structure on the intermediate plate according to the rules, and lay it on the corresponding groove of the curved surface mold and fix it;

[0045] (4) According to the required phenolic resin mass of the composite curved surface layer, the resin glue solution is prepared, the mixed resin glue solution is introduced into the packaged mold through the vacuum bag, and the resin infiltration of the composite curved surface layer is completed;

[0046] (5) Remove the excess resin after the composite impregnation forming, adjust the excess fiber of the composite fiber layer formed on the curved surface mold, and according to the properties of the phenolic resin, solidify at a temperature of 150℃-180℃ to obtain a single upper curved surface layer 1 or lower curved surface layer 2;

[0047] (6) The cured and formed upper curved surface layer 1 and lower curved surface layer 2 are arranged vertically in order and have a certain interval, and are connected and fixed by a screw rod and a nut, and the upper and lower bottom plates are arranged at both ends of the screw rod. Cut the composite fiber of four times the number of lattice cells, the length is 800mm, and the single fiber is woven, one fiber represents a column of lattice cells, and four composite fibers woven around the node constitute a lattice cell. Repeat the insertion of single fiber to complete the weaving of the intermediate lattice sandwich layer 3;

[0048] (7) According to the lattice cell height (lattice cell height is 7mm) specified by the design requirement, adjust the spacing of the upper curved surface layer 1 and the lower curved surface layer 2, and complete the overall weaving of the composite lattice curved surface sandwich shell structure;

[0049] ​(8) Refer to the method of step (4) above to complete the resin infiltration of the fibers of the composite lattice curved sandwich shell, and remove the excess resin, and after heating at 150-180 DEG C, complete the curing of the composite lattice curved sandwich shell structure;

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

[0051] Wherein, the curvature radius of the curved mold is 940 mm, and the lattice cell size corresponding to the curved mold is 7 mm x 7 mm x 7 mm.

[0052] The present application has reasonable concept, on the basis of the curved structure, the composite lattice is prepared by using the wet interpenetrating weaving technology, which can meet the requirements of the curved configuration on the basis of meeting the mechanical properties, and is easier to realize the surface core integrated forming, has relatively greater process advantage for improving the shear resistance of the lattice, and has relatively free overall structure design, lower cost, can form multi-layer complex structure, large size parameter change, and is suitable for promotion and application.

[0053] Finally, it should be noted that: the above examples are only used to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the above examples, those skilled in the art should understand that: it can still modify the technical solutions recorded in the above examples, or make equivalent replacement for part 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 application.

Claims

1. A method for preparing a composite material lattice curved sandwich shell, the shell comprising an upper curved layer (1), a lower curved layer (2), and an intermediate lattice sandwich layer (3); the intermediate lattice sandwich layer (3) is located between the upper curved layer (1) and the lower curved layer (2); the upper curved layer (1) and the lower curved layer (2) are woven mesh structures; the intermediate lattice sandwich layer (3) is composed of a vertically interlaced periodic lattice structure; characterized in that: The preparation method includes the following steps: 1) Prepare a curved mold and apply a composite material release agent to the forming surface of the curved mold; 2) The intermediate plates required for making the upper curved layer (1) and the lower curved layer (2), as well as the upper and lower base plates used to fix the interlaced woven composite matrix fiber rods; 3) Place the intermediate plate on the curved mold, cut the composite material fibers, weave a mesh structure on the intermediate plate and lay it on the corresponding groove of the curved mold to fix it. 4) Prepare the resin solution and pour it into the sealed mold to complete the resin impregnation of the composite material curved surface layer; 5) Remove excess resin after impregnation and molding of composite material, adjust excess fibers of composite material fiber layer formed on the mold on the curved surface, and cure to obtain a single upper curved surface layer (1) or lower curved surface layer (2). 6) The solidified upper curved layer (1) and lower curved layer (2) are arranged vertically and fixed together by screws and nuts. The upper and lower base plates are arranged at both ends of the screws. The composite material fibers are cut and the intermediate lattice sandwich layer (3) is woven. 7) Adjust the spacing between the upper curved layer (1) and the lower curved layer (2) to complete the overall weaving of the composite material lattice curved sandwich shell structure; 8) Following the method in step 4) above, resin impregnates the fibers of the composite lattice curved sandwich shell, removes excess resin, and then heats to complete the curing of the composite lattice curved sandwich shell structure. 9) Remove the middle plate and the upper and lower bottom plates, and modify the shape of the composite material lattice curved surface sandwich shell structure to meet the design requirements.

2. The method for preparing the composite material lattice curved surface sandwich shell as described in claim 1, characterized in that: The upper curved layer (1) and the lower curved layer (2) are both made of glass fiber impregnated with phenolic resin.

3. The method for preparing the composite material lattice curved surface sandwich shell as described in claim 1, characterized in that: The material of the intermediate lattice interlayer (3) is glass fiber impregnated with phenolic resin.

4. The method for preparing the composite material lattice curved surface sandwich shell as described in claim 1, characterized in that: The intermediate lattice interlayer (3) is any one of the periodic pyramid lattice structure and tetrahedral lattice structure, used to bear the compressive and shear loads on the structure.

5. The method for preparing the composite material lattice curved surface sandwich shell as described in claim 1, characterized in that: Multifunctional materials can be injected into the lattice structure cells of the intermediate lattice interlayer (3) and the spaces between the cells.

6. The method for preparing the composite material lattice curved surface sandwich shell as described in claim 1, characterized in that: The curved mold is made of polytetrafluoroethylene with a curvature radius of 940 mm; the lattice cell size corresponding to the curved mold is 7 mm × 7 mm × 7 mm.

7. The method for preparing the composite material lattice curved surface sandwich shell as described in claim 1, characterized in that: In step 3), the composite material fibers are cut into a circular outline with a diameter of 800 mm.

8. The method for preparing the composite material lattice curved surface sandwich shell as described in claim 1, characterized in that: In step 5), a single upper curved layer (1) or lower curved layer (2) is obtained by curing at a temperature of 150℃~180℃.

9. The method for preparing a composite material lattice curved surface sandwich shell as described in claim 1, characterized in that: In step 6), four times the number of lattice cells are cut into composite fiber with a length of 800 mm. Single fibers are interwoven and woven together. One fiber represents one column of the lattice cell. Four composite fibers interwoven around the node constitute a lattice cell. Repeating the interwoven weaving of single fibers can complete the weaving of the intermediate lattice interlayer (3).

10. The method for preparing the composite material lattice curved surface sandwich shell as described in claim 1, characterized in that: The heating temperature in step 8) is also 150℃~180℃.

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