阅读说明：本技术 基于数字化导向模板的三维织造中空结构预制体及其成形方法 (Three-dimensional weaving hollow structure prefabricated body based on digital guide template and forming method thereof ) 是由 单忠德 吴思远 战丽 刘丰 张群 于 2020-04-09 设计创作，主要内容包括：本发明涉及到一种三维中空结构预制体及其成形方法。可以实现中空结构预制体一体化柔性织造,中空预制体包含上面板、中间连接芯、下面板,预制体可以进而复合基体,基体包含树脂基、金属基、碳陶基等,复合基体后,在中空部分加入填充芯,可以得到一体化中空复合材料,其上面板、连接芯、下面板由三维结构纤维增强,相对于传统中空结构,其减少了机械或胶性连接,结构整体力学性能更优异。其次,其可设计性更灵活,成形预制体纤维可以是单种或多种,预制体的纤维空间结构可以是一种或几种的组合,成形中空结构可以是点阵式,筋肋式,环状式,也可以是几种结构的混合组成。采用本方法织造一体化中空结构预制体,具有成形原理简易,设计灵活的优点。(The invention relates to a three-dimensional hollow structure preform and a forming method thereof. The integrated flexible weaving of the hollow structure preform can be realized, the hollow structure preform comprises an upper panel, an intermediate connecting core and a lower panel, the preform can further be compounded with a base body, the base body comprises a resin base, a metal base, a carbon ceramic base and the like, after the base body is compounded, a filling core is added into a hollow part, the integrated hollow composite material can be obtained, the upper panel, the connecting core and the lower panel of the integrated hollow composite material are reinforced by three-dimensional structural fibers, and compared with the traditional hollow structure, the integrated flexible weaving of the hollow structure preform has the advantages that mechanical or adhesive connection is reduced, and the overall mechanical property of. Secondly, the designability is more flexible, the fiber of the formed preform can be single or multiple, the fiber space structure of the preform can be one or the combination of several, and the formed hollow structure can be in a dot matrix type, a rib type, an annular type or the mixed composition of several structures. The method for weaving the integrated hollow structure preform has the advantages of simple forming principle and flexible design.)

1. A method for forming a three-dimensional weaving hollow structure preform is characterized by comprising the following steps:

step 1: according to design requirements, a guide array is used for weaving an upper panel in a layered mode, and guide needles are reserved in a core weaving area;

step 2: according to design requirements, a lower panel is woven in a layered mode by using a guide array, and guide needles are reserved in a core weaving area;

and step 3: according to design requirements, weaving a core in a reserved guide needle area by taking an upper panel or a lower panel as a base surface;

and 4, step 4: superposing the reserved guide needles of the upper panel and the lower panel, and moving the upper panel or the lower panel to enable the upper panel, the lower panel and the connecting core to be in close contact;

and 5: the reserved guide needle array is replaced by yarns, and the yarns are connected with the upper panel, the lower panel and the connecting core to finish the integral weaving of the hollow structure prefabricated body.

2. The method as claimed in claim 1, wherein the upper panel is layered-woven using a guide array, and guide pins are reserved in the joining core region.

3. The method as claimed in claim 1, wherein the lower panel is layered-woven using a guide array, and guide pins are reserved in the joining core region.

4. The method for forming a three-dimensional woven hollow structure preform according to claim 1, wherein the connecting core is woven in the region of the reserved guide pins by using the upper panel or the lower panel as a base surface.

5. The method as claimed in claim 1, wherein the pre-prepared guide pins of the upper and lower panels are overlapped, and the upper or lower panel is moved to make the upper, lower and connecting cores contact closely.

6. The method for forming a three-dimensional woven hollow structure preform as claimed in claim 1, wherein the hollow preform is integrally woven by replacing the reserved guide needles with yarns.

7. A three-dimensionally woven hollow structure preform, comprising: the structure of the composite fabric is designed and manufactured in a layered mode, the upper panel, the middle connecting core and the lower panel can be made of different fibers, the fibers comprise one or more of various fibers such as carbon fibers, silicon carbide fibers, quartz fibers, aramid fibers, glass fibers, basalt fibers and the like, and the specification of the fibers can be selected according to weaving requirements, such as 3K and 6K.

8. The preform of claim 7, wherein the upper panel, the middle connecting core, and the lower panel are constructed by different weaving structures and different weaving thicknesses, and the weaving structures include orthogonal structures, angle-interlocking structures, and staggered structures.

9. The three-dimensional weaving hollow structure preform as claimed in claim 7, wherein the hollow structure can be formed in various structures, including lattice, rib, ring, etc., or a combination of several structures. The lattice structure has a core main body composed of discrete units, the unit shapes can be rectangular, polygonal, cross-shaped and the like, a plurality of units are arranged, can be arrayed and annularly arranged, and form a lattice support hollow structure, and rights protection covers a lattice sandwich panel and a related forming lattice structure formed by a hexagonal core 19, an I-shaped core 21 and a cross-shaped core 22 in figure 6.

The rib type structure, the main body shape of the core is composed of ribs, the final area is in the rib type layout, the right protection covers the rib hollow fabric and the related forming rib structure which are composed of a rib-shaped core 23, a fishbone-shaped core 24 and a corrugated core 25 in the figure 7.

The core body of the ring-shaped hollow structure is composed of annular structures, the annular structures can be tangent rings, intersecting rings and separating rings, and the right protection covers hollow structure prefabricated bodies and related formed annular structures respectively formed by an inner polygonal ring-shaped core 26, an outer polygonal ring-shaped core 27, a polygonal hollow core array 28 and a honeycomb core 29 shown in figure 8.

Technical Field

The invention belongs to the technical field of three-dimensional weaving of composite materials, and particularly relates to a three-dimensional weaving hollow structure preform and a forming method thereof.

Background

The sandwich composite material has the characteristics of high specific strength and specific modulus, good fatigue resistance and shock resistance and the like, can effectively absorb impact load, is light and efficient, and can realize multifunctional integration, such as integration of heat prevention and insulation, integration of shock insulation and noise reduction and the like. The conventional sandwich structure is generally manufactured by bonding a panel and a core material, so that the bonding capability of a bonding part is poor, and the overall mechanical property is limited.

The three-dimensional fabric forming technology adopts methods of weaving, braiding, knitting and the like to weave fibers into a spatial three-dimensional shape to obtain a prefabricated body, and then the prefabricated body is compounded with a matrix, so that the obtained composite material is excellent in mechanical property, delamination-resistant and high in designability. With the development of the three-dimensional fabric forming technology, a new way is provided for the manufacture of the three-dimensional integral sandwich composite material, namely, an integrated hollow structure prefabricated body is manufactured by adopting the three-dimensional fabric forming technology, then resin and a metal matrix or a carbon ceramic matrix is immersed in the prefabricated body, and finally a core material is filled in the hollow part to form the sandwich composite material.

The patent provides a flexible weaving method, which can realize the integrated flexible weaving of a hollow structure prefabricated body, flexibly control the structural parameters according to the actual requirements and improve the comprehensive bearing performance.

Disclosure of Invention

The formed hollow structure prefabricated body has high design flexibility, can be used for forming a hollow plate with larger thickness, the whole thickness can reach 150mm, and can be used for forming a hollow plate with thinner thickness, and the thickness can reach 3 mm.

The basic forming principle is as follows: the method comprises the steps of utilizing a guide post template, laying fibers between the guide post template and the guide post template, weaving an upper panel and a lower panel of the hollow prefabricated body in a layering mode, weaving a middle supporting core, replacing a connecting guide post with yarns, connecting the upper panel, the lower panel and the middle core, and integrally weaving the hollow prefabricated body.

In order to achieve the above purpose, the three-dimensional weaving hollow structure preform based on the digitalized guide template and the forming method thereof of the invention are carried out according to the following steps:

step 1: according to design requirements, a guide array is used for weaving an upper panel in a layered mode, and guide needles are reserved in a core weaving area;

step 2: according to design requirements, a lower panel is woven in a layered mode by using a guide array, and guide needles are reserved in a core weaving area;

and step 3: according to design requirements, weaving a core in a reserved guide needle area by taking an upper panel or a lower panel as a base surface;

and 4, step 4: superposing the reserved guide needles of the upper panel and the lower panel, and moving the upper panel or the lower panel to enable the upper panel, the lower panel and the connecting core to be in close contact;

and 5: the reserved guide needle array is replaced by yarns, and the yarns are connected with the upper panel, the lower panel and the connecting core to finish the integral weaving of the hollow prefabricated body.

By adopting the technical scheme, the method has the following advantages:

1. the integrated forming of the prefabricated body with the fiber hollow structure is realized, and the forming method is simple;

2. the flexible weaving of the hollow fabric can be realized, and parameters such as the thicknesses of the upper panel and the lower panel, the fiber types, the fabric structure and the like can be designed and formed according to requirements;

3. the structure of the core can be flexibly designed, can be in a dot matrix shape, a rib shape and an annular shape, can also be in a mixed shape of the dot matrix shape, the rib shape and the annular shape, and can realize the forming of a multilayer hollow structure.

Drawings

The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the invention and not to limit the invention. In the drawings:

FIG. 1 is a schematic structural diagram of a dot matrix type hollow structure preform;

FIG. 2 is a fabric forming method based on a digital guide template;

FIG. 3 is a flow chart of the forming process with the pre-formed array panel and core;

FIG. 4 is a schematic view of a hollow preform integrally formed by an upper panel, a core and a lower panel;

FIG. 5 is a schematic illustration of a core containing a guide array rod;

FIG. 6 is a schematic view, partly by way of example, of a hollow-structured preform in a dot matrix;

FIG. 7 is a schematic view, partly by way of example, of a ribbed hollow-structured preform;

FIG. 8 is a schematic view of a ring-shaped hollow structure preform, partly by way of example;

in the figure: 1. a hollow preform upper panel; 2. a hollow preform core; 3. a hollow preform lower panel; 4. longitudinal fibers; 5. transverse fibers; 6. a guide bar; 7. laying fibers longitudinally and transversely; 8. a guide rod fixing plate; 9 a woven upper or lower panel; 10 weaving and forming a panel reserved with a guide array; 11. weaving a core; 12. an upper panel with a guide bar; 13. a lower panel with a guide bar and a core; 14. a replacement guide bar array; 15. a shaped hollow preform; 16. the core forms an array of guide rods; 17. laying down fibers of a forming core; 18. an example upper panel; 19. a hexagonal core; 20. an example lower panel; 21. an I-shaped core; 22. a cross-shaped core; 23. a rib-shaped core; 24. a "fishbone" core; 25. a "corrugated" core; 26. an inner polygonal annular core; 27. an outer polygonal annular core; 28. a polygonal hollow core array; 29. a honeycomb core.

Detailed Description

The three-dimensional weaving hollow preform based on the digital guide template and the forming method thereof are shown in figures 1-8, and as shown in figure 1, the three-dimensional hollow preform comprises three area parts, namely an upper panel 1, a middle support core 2 and a lower panel 3.

Firstly, according to the design requirement of a hollow prefabricated body, an upper panel and a lower panel are woven in a layered mode by utilizing a guide rod array, as shown in fig. 2, transverse fibers 4 and longitudinal fibers 5 are laid and formed along the array formed by guide rods 6, the guide rods 6 are positioned by guide rod fixing plates 8, laid fibers 7 are stacked and formed layer by layer, the upper panel and the lower panel are obtained, the weaving structures of the upper panel, the lower panel and a middle supporting core can be a single weaving structure or a mixed structure, and can also be a gradient structure, and the thicknesses of the upper panel and the lower panel can be the same or different.

Subsequently, as shown in fig. 3, an intermediate support core guide bar area 10 is reserved on the upper panel or the lower panel 9, and an intermediate support core 11 is layered and woven by the lower panel reserved guide bar, and the forming process of the lattice core is shown in fig. 3 by taking a lattice sandwich structure as an example.

As shown in fig. 4, the upper panel 12 with the reserved guide array, the core 13 with the reserved guide array and the lower panel 14 which are woven and formed in the previous step are moved and tightly combined in the direction of the guide array through the guide array, finally, the guide rods of the guide array are replaced by fibers, and the replacement fibers connect the parts in the thickness direction, and finally, the hollow structure preform 15 is obtained. FIG. 5 shows a structure of a core in a rectangular lattice, 16 being a pre-oriented array and 17 being a laid fiber forming the core. The fibers 4, 6 and 17 used for weaving comprise one or more of carbon fibers, silicon carbide fibers, quartz fibers, aramid fibers, glass fibers, basalt fibers and the like, and the specification of the fibers can be selected according to the use requirement, such as 3K and 6K.

The shape and the number of the middle supporting cores can be designed in various ways, so that different hollow structures including dot matrixes, ribs, annular structures and the like can be obtained, and the forming process is similar to the forming method of the rectangular core dot matrix type hollow prefabricated body structure in the figures 3, 4 and 5.

The lattice structure, its core main part comprises discrete unit, and the unit shape can be rectangle, polygon, cross etc. and a plurality of unit are arranged, can be rectangle arrangement or annular arrangement, constitutes lattice support hollow structure promptly, as shown in fig. 6, has enumerated hexagon core 19, "worker" font core 21, "the lattice structure that ten" font core 22 formed, 18 is the top panel, 20 is the lower panel.

The rib type structure, the main body shape of the core is composed of ribs, the final area is rib type layout, as shown in figure 7, a rib type hollow fabric composed of a rib type core 23, a fishbone type core 24 and a ripple type core 25 is listed.

The core body of the ring-shaped hollow structure can be a closed-loop structure, or can be a tangent ring, an intersecting ring, or an isolated ring, as shown in fig. 8, hollow structure preforms respectively composed of an inner polygonal ring-shaped core 26, an outer polygonal ring-shaped core 27, a polygonal hollow core array 28, and a honeycomb core 29 are enumerated.