阅读说明：本技术 一种带法兰的超大尺寸高厚度异型预制体的制备方法 (Preparation method of oversized high-thickness special-shaped preform with flange ) 是由 缪云良 于 2021-08-19 设计创作，主要内容包括：本发明涉及预制体制备技术领域,尤其是一种带法兰的超大尺寸高厚度异型预制体的制备方法,包括以下步骤：步骤S1：将整个预制体模具以几何轴线为中心,按照厚度和密度分为多个区域,每个区域仿形裁剪纤维布；步骤S2：以轴线为基准,按区域铺放第一层单元结构层,在区域边界和层内形成搭接,随后固定；步骤S3：以轴线为中心,以起始基准旋转一定角度设置为第二层搭接位置,按区域铺放第二层单元结构层；步骤S4：重复步骤S3,完成N个单元结构层的铺放；步骤S5：制备获得超大尺寸高厚度异形预制体,本发明解决了超大尺寸和高厚度预制体的连接问题,并克服了现有设备由于织造尺寸的限制,无法制备超大尺寸预制体的问题。(The invention relates to the technical field of preparation of preforms, in particular to a method for preparing an oversized high-thickness special-shaped preform with a flange, which comprises the following steps: step S1: dividing the whole prefabricated body mould into a plurality of areas according to the thickness and the density by taking a geometric axis as a center, and cutting fiber cloth in each area in a profiling mode; step S2: laying a first layer of unit structural layer according to regions by taking the axis as a reference, forming lap joints in the region boundary and the layer, and then fixing; step S3: setting the axis as a center, rotating a certain angle by using an initial reference to be a second layer of lap joint position, and laying a second layer of unit structure layer according to the region; step S4: repeating the step S3 to finish the laying of the N unit structural layers; step S5: the invention solves the problem of connection of the oversized and high-thickness prefabricated bodies and solves the problem that the oversized prefabricated bodies cannot be prepared due to the limitation of weaving size of the existing equipment.)

1. A preparation method of an oversized high-thickness special-shaped preform with a flange comprises the following steps:

step S1: taking a prefabricated body mould (10) with a flange (11), dividing the whole prefabricated body mould (10) into a plurality of areas by taking a geometric axis as a center according to the thickness and the density, and cutting fiber cloth in a copying manner in each area, wherein the missing position of the copying cloth in the flange area is enhanced by adopting equal-division fan-shaped copying cloth;

step S2: laying a first layer of unit structural layer according to regions by taking the axis as a reference, forming lap joints in the region boundary and the layer, and then fixing; taking the lapping position of the first layer as an initial reference, wherein the lapping positions of different areas are different, namely the initial references of different areas are also different;

step S3: setting the axis as a center, rotating a certain angle by using an initial reference to be a second layer of lap joint position, and laying a second layer of unit structure layer according to the region;

step S4: repeating the step S3, setting an Nth layer initial position by rotating (N-1) 360 DEG/N according to the initial reference, finishing the laying of the N unit structure layers until the layer lapping position returns to the initial reference position; taking N unit structure layers as circulating layers;

step S5: and laying the repeated circulating layer until the thickness requirement is met, and preparing the super-large-size high-thickness special-shaped prefabricated body.

2. The method for preparing a flanged oversized high-thickness profiled preform as claimed in claim 1, wherein: in step S1, the boundaries of two adjacent regions overlap, and the distance of the overlapping portions is the overlap distance of the region boundaries.

3. The method for preparing a flanged oversized high-thickness profiled preform as claimed in claim 1, wherein: the shape and size of the profile-cut fiber cloth in the step S1 are determined according to the shape of each layer after the area is spread.

4. The method for preparing a flanged oversized high-thickness profiled preform as claimed in claim 1, wherein: after the fiber cloth is cut in the shape of the trapezoid structure expanded in the fan-shaped ring shape at the inner ring of the flange area in the step S1, the missing part of the outer ring is cut into the fan-shaped shape cloth in equal parts according to the size difference of the inner diameter and the outer diameter.

5. The method for preparing a flanged oversized high-thickness profiled preform as claimed in claim 1, wherein: the unit structure layer in the step S2 is one or more of n net tires or non-woven fabrics.

6. The method for preparing a flanged oversized high-thickness profiled preform as claimed in claim 1, wherein: the lap joint distance between the unit structure layers in the step S2 is 20-60 mm; in order to ensure that the density is consistent with other parts after lapping, fiber cloth at lapping parts is thinned 1/2, or the fiber cloth is subjected to a staggered layer treatment of a unit structure.

7. The method for preparing a flanged oversized high-thickness profiled preform as claimed in claim 1, wherein: the fixing method in the step S2 adopts a needle punching process or adopts glue spraying for fixing.

8. The method for preparing a flanged oversized high-thickness profiled preform as claimed in claim 1, wherein: the start references of the different regions in step S2 differ by an angle of less than (N-1) × 360 °/N.

9. The method for preparing a flanged oversized high-thickness profiled preform as claimed in claim 1, wherein: the diameter range of the prefabricated body prepared in the step S5 is 2-5 m, the thickness range is 50-100mm, and the volume density range of the carbon fiber is 0.16-0.45g/cm³。

Technical Field

The invention relates to the technical field of preparation of preforms, in particular to a preparation method of an oversized high-thickness special-shaped preform with a flange.

Background

The high-performance fiber reinforced composite material has light weight and high strength, and is more and more emphasized in the fields of aerospace and national defense. With the large-scale, light-weight and integration of composite materials for spacecrafts, the requirements of large size and high thickness are also put forward for fiber preforms. The preparation method of the large-size prefabricated body mainly comprises prepreg lamination, three-dimensional integral weaving and needling of the prefabricated body at present. The prepreg laminate has poor interlayer adhesiveness, and the three-dimensional integrally woven preform and the needled preform have good integral adhesiveness but are limited by the size of the weaving equipment. In addition, three-dimensional weaving requires a large number of yarns to be arranged, and the number of workers is large. Patent CN201711304876.5 discloses a large-size variable thickness revolving body preform, the wall thickness of which continuously changes along the axial direction, and which is formed by winding multiple layers of variable thickness preforms, namely three-dimensional layer-connected structure fabrics, and the weft direction of the variable thickness preforms and the central axis of the variable thickness revolving body preforms are located in the same plane. The method adopts a winding mode for forming, has the advantages of continuous manufacturing, high efficiency and the like, but is mainly suitable for the revolving body with small inner diameter change and is not suitable for the revolving body with abrupt inner diameter change and a flange and a special body. The maximum size of the foreign body preform reported at present is phi 2600 mm. Due to the limitation of equipment and the limitation of the length of a mechanical arm, the irregular body with overlarge size and high thickness is still a difficult problem in the preparation of a prefabricated body.

Disclosure of Invention

The applicant provides a preparation method of an oversized high-thickness special-shaped preform with a flange aiming at the defects in the prior art, solves the connection problem of the oversized and high-thickness preforms, and overcomes the problem that the oversized preform cannot be prepared due to the limitation of weaving size of the prior equipment.

The technical scheme adopted by the invention is as follows: a preparation method of an oversized high-thickness special-shaped preform with a flange comprises the following steps:

step S1: taking a prefabricated body mould with a flange, dividing the whole prefabricated body mould into a plurality of areas by taking a geometric axis as a center according to the thickness and the density, and cutting fiber cloth in a copying manner in each area, wherein the missing position of the copying cloth in the flange area is enhanced by adopting an equally-divided fan-shaped copying cloth;

step S2: laying a first layer of unit structural layer according to regions by taking the axis as a reference, forming lap joints in the region boundary and the layer, and then fixing; taking the lapping position of the first layer as an initial reference, wherein the lapping positions of different areas are different, namely the initial references of different areas are also different;

step S3: setting the axis as a center, rotating a certain angle by using an initial reference to be a second layer of lap joint position, and laying a second layer of unit structure layer according to the region;

step S4: repeating the step S3, setting an Nth layer initial position by rotating (N-1) 360 DEG/N according to the initial reference, finishing the laying of the N unit structure layers until the layer lapping position returns to the initial reference position; taking N unit structure layers as circulating layers;

step S5: and laying the repeated circulating layer until the thickness requirement is met, and preparing the super-large-size high-thickness special-shaped prefabricated body.

In step S1, the boundaries of two adjacent regions overlap, and the distance of the overlapping portions is the overlap distance of the region boundaries.

The shape and size of the profile-cut fiber cloth in the step S1 are determined according to the shape of each layer after the area is spread.

After the fiber cloth is cut in the shape of the trapezoid structure expanded in the fan-shaped ring shape at the inner ring of the flange area in the step S1, the missing part of the outer ring is cut into the fan-shaped shape cloth in equal parts according to the size difference of the inner diameter and the outer diameter.

The unit structure layer in the step S2 is one or more of n net tires or non-woven fabrics.

The lap joint distance between the unit structure layers in the step S2 is 20-60 mm; in order to ensure that the density is consistent with other parts after lapping, fiber cloth at lapping parts is thinned 1/2, or the fiber cloth is subjected to a staggered layer treatment of a unit structure.

The fixing method in the step S2 adopts a needle punching process or adopts glue spraying for fixing.

The start references of the different regions in step S2 differ by an angle of less than (N-1) × 360 °/N.

The diameter range of the prefabricated body prepared in the step S5 is 2-5 m, the thickness range is 50-100mm, and the carbon fiberThe bulk density is in the range of 0.16-0.45g/cm³。

The invention has the following beneficial effects: the preparation method of the oversized high-thickness special-shaped preform with the flange, which is provided by the application, is characterized in that the geometric axis of the preform is used as the center, a partition laying and layered laying mode is adopted, and the oversized high-thickness special-shaped preform is obtained through lap joint design between different areas and between unit structure layers in the same layer, so that the connection problem of the oversized high-thickness preform and the oversized high-thickness preform is solved, and the problem that the oversized preform cannot be prepared due to the limitation of weaving size of the existing equipment is solved.

Drawings

FIG. 1 is a schematic representation of a circumferential ply zone of a sample of the present invention.

FIG. 2 is a schematic view of the axial ply section of example 1 of the present invention.

FIG. 3 is a schematic view of the circumferential ply zones of embodiment 1 of the present invention.

FIG. 4 is a schematic view of a (0 °/90 °) cross-ply of a first layer of carbon fiber laid fabric of example 1 of the present invention.

FIG. 5 is a schematic view of a second layer of carbon fiber laid fabric (rotated 45 °) orthogonally laid in accordance with example 1 of the present invention.

Figure 6 is a schematic view of the straight section area hoop winding of example 1 of the present invention.

FIG. 7 is a schematic view of a ply in which two layers of carbon fiber laid fabric (0 °/90 °) are orthogonally laid as a unit structure layer in example 1 of the present invention.

FIG. 8 is a schematic view of a ply of example 1 after hoop reinforcement with carbon fibers in a second straightaway section.

FIG. 9 is a schematic view of the axially layered sections of a mat according to example 2 of the present invention.

FIG. 10 is a schematic view of a section of a mat hoop ply of example 2 of the present invention.

Wherein: 10. a preform mold; 11. and (4) a flange.

Detailed Description

The following description of the present invention will be made with reference to the accompanying drawings 1 to 10.

A preparation method of an oversized high-thickness special-shaped preform with a flange comprises the following steps:

step S1: taking a prefabricated body mould 10 with a flange 11, dividing the whole prefabricated body mould 10 into a plurality of areas by taking a geometric axis as a center according to the thickness and the density, and cutting fiber cloth in a copying manner in each area, wherein the missing position of the copying cloth in the flange area is reinforced by adopting an equally-divided fan-shaped copying cloth; the fiber cloth can be a net tire, a non-woven cloth or other fabrics made of one or more of carbon fiber, quartz fiber and the like.

Step S2: laying a first layer of unit structural layer according to regions by taking the axis as a reference, forming lap joints in the region boundary and the layer, and then fixing; taking the lapping position of the first layer as an initial reference, wherein the lapping positions of different areas are different, namely the initial references of different areas are also different;

step S3: setting the axis as a center, rotating a certain angle by using an initial reference to be a second layer of lap joint position, and laying a second layer of unit structure layer according to the region;

step S4: repeating the step S3, setting an Nth layer initial position by rotating (N-1) 360 DEG/N according to the initial reference, finishing the laying of the N unit structure layers until the layer lapping position returns to the initial reference position; taking N unit structure layers as circulating layers;

step S5: and laying the repeated circulating layer until the thickness requirement is met, and preparing the super-large-size high-thickness special-shaped prefabricated body.

In step S1, the boundaries of two adjacent regions overlap, and the distance of the overlapping portions is the overlap distance of the region boundaries.

The shape and size of the profile-cut fiber cloth in the step S1 are determined according to the shape of each layer after the area is spread.

After the fiber cloth is cut in the shape of the trapezoid structure expanded in the fan-shaped ring shape at the inner ring of the flange area in the step S1, the missing part of the outer ring is cut into the fan-shaped shape cloth in equal parts according to the size difference of the inner diameter and the outer diameter.

The unit structure layer in the step S2 is one or more of n net tires or non-woven fabrics.

The lap joint distance between the unit structure layers in the step S2 is 20-60 mm; in order to ensure that the density is consistent with other parts after lapping, fiber cloth at lapping parts is thinned 1/2, or the fiber cloth is subjected to a staggered layer treatment of a unit structure.

The fixing method in the step S2 adopts a needle punching process or adopts glue spraying for fixing.

The start references of the different regions in step S2 differ by an angle of less than (N-1) × 360 °/N.

The diameter range of the prefabricated body prepared in the step S5 is 2-5 m, the thickness range is 50-100mm, and the volume density range of the carbon fiber is 0.16-0.45g/cm³。

Example 1:

an oversized high-thickness special-shaped prefabricated body with a flange, the diameter of the prefabricated body is 5 meters, the thickness of the prefabricated body is 50mm, and the volume density of the prefabricated body is 0.45g/cm³. The prefabricated body adopts two layers of (0 degree/90 degree) orthogonal layering of carbon fiber laid fabric as a unit structure layer, and the adjacent unit structure layers are staggered by 45 degrees in a counterclockwise way. The 10 unit structure layers are a circulating unit layer. The middle area of the cambered surface adopts integral circular unit structure layer layering; the straight section area is reinforced by adopting an axial fan-shaped unit structure layer and carbon fiber circumferential winding; the flange area adopts an axial fan-shaped unit structure layer, and the missing area is reinforced by dividing the fan-shaped unit structure layer by 10 parts in the circumferential direction along the circumferential direction. The overlapping distance of the three areas is 60 mm. The unit structure layers are overlapped by staggered glue spraying, and the overlapping seam of each unit structure layer is staggered by 36 degrees. The unit structure layers of the flange region and the straight section region are overlapped and sewed by 15 degrees, and the distance between the region overlapping and the interlayer overlapping is 60 mm.

The preparation method of the oversized high-thickness special-shaped preform with the flange comprises the following steps:

step S1: the preform was divided into 3 regions centered on the axis. The flange area (area one) is axially layered from the surface of the flange 11 to a height H2, the straight section area (area two) is axially layered from a height H1 to H4, and the cambered surface middle area (area three) is highly layered from H3 to the top. The height difference between H1 and H2 is 60mm, and the height difference between H3 and H4 is 60 mm. The third area is in the shape of an integral disc, and the second area and the first area are in the shape of a sector ring. And cutting the weftless fabric by using a whole disc structure in the area III, cutting the weftless fabric by using a trapezoid structure after the sector ring is unfolded in the area II, cutting the weftless fabric by using a trapezoid structure after the inner ring structure is unfolded in the area I, cutting the outer ring sector according to 10 equal parts to form 5 sectors, and cutting the 5 missing sectors.

Step S2: the two layers of carbon fiber non-woven cloth (0 degree/90 degree) orthogonal layers are used as unit structure layers, and the disc-shaped unit structure layers are firstly laid in three positions of the central area of the prefabricated body mould 10. Then, laying a second annular unit structure layer, carrying out adhesive spraying and bonding lap joint on the overlapped position of the annular unit structure layer after dislocation of 60mm in the unit structure layer, and marking the central position of the lap joint as an initial position on a mould as an initial reference; and laying unit structure layers at the initial position of a first region, namely the fan-shaped splicing seam position of the inner ring, which is obtained by rotating 15 degrees anticlockwise according to the initial reference, supplementing 5 fan-shaped unit structure layers at the missing part, and bonding the fan-shaped weftless fabric of the inner ring and 10 fan-shaped unit structure layers of the outer ring by adopting a glue spraying mode. The edges of the three areas are overlapped by adopting staggered unit structure layers and then spraying glue, and the overlapping distance is 60 mm. And after three areas are layered, spraying glue for fixing.

Step S3: and laying a second unit structure layer on the basis of the first unit structure layer by rotating the cloth cover anticlockwise for 45 degrees. When the first area and the second area are laid, the first layer unit structure layer is rotated anticlockwise by 1 x 36 degrees by the starting reference to be the starting position of the second layer unit structure layer; and after the second layer of unit structure layer is laid, spraying glue for fixing.

Step S4: and (4) repeating the step (3), and laying the next unit structural layer by rotating counterclockwise by 45 degrees in the cloth cover direction in sequence. Forming an Nth layer starting position by counterclockwise rotating (N-1) 36 degrees on the starting basis when the first area and the second area are laid; and returning the initial position of the structural layer of the second unit of the region to the initial reference until the laying of the 10 unit layers is finished. The 10 unit layers are a circulation unit layer.

Step S5: and after the circulating unit layers are repeated until the thickness requirement is met, reinforcing by annularly winding carbon fibers in a second straight-line section area to obtain the oversized high-thickness special-shaped prefabricated body with the flange and the diameter of 5 m.

To further illustrate the advantages of the method of the present invention, the results of the composite molding with phenolic resin are shown in table 1, compared with the conventional full-area large-area ply preform.

Structural form of prefabricated body	Density of preform	Tensile strength of composite material
			Ordinary layering process	0.41g/cm3	25MPa
Partitioned layering process	0.45g/cm3	32MPa

TABLE 1

Example 2:

an oversized high-thickness special-shaped preform with a flange, which has the diameter of 2 meters, the thickness of 100mm and the volume density of 0.16g/cm 3. The prefabricated body adopts a layer of quartz fiber net felt and two layers of carbon fiber net felts as unit structure layers. The 8 unit structure layers are a circulating unit layer. The middle area of the cambered surface adopts integral circular unit structure layer layering; the straight section area adopts an axial fan-shaped unit structure layer; the flange area adopts an axial fan-shaped unit structure layer, and the missing area is reinforced by the fan-shaped unit structure layer which is equally divided in the circumferential direction by 8. The three areas overlap by a distance of 20 mm. And the unit structure layers are overlapped by thinning 1/2 mesh felts, and the overlapping seams of each unit structure layer are staggered by 45 degrees. The unit structure layers of the flange region and the straight section region are overlapped and sewed by 20 degrees, and the distance between the region overlapping and the interlayer overlapping is 20 mm.

The preparation method of the oversized high-thickness special-shaped preform with the flange comprises the following steps:

step S1: the preform was divided into 3 regions centered on the axis. Zone one is layered axially from the face of flange 11 to height H2, zone two is layered axially from height H1 to H4, and zone three is layered highly from H3 to the top. The height difference between H1 and H2 is 20mm, and the height difference between H3 and H4 is 20 mm. The third area is in the shape of an integral disc, and the second area and the first area are in the shape of a sector ring. And a third area cuts the weftless fabric by using a whole disc structure, a second area cuts the weftless fabric by using a trapezoid structure after the sector ring is unfolded, a third area cuts the weftless fabric by using a trapezoid structure after the inner ring structure is unfolded, and an outer ring sector is cut into 4 sectors according to 8 equal parts and the 4 missing sectors are cut. The web mat was thinned 1/2 at 20mm from the edge.

Step S2: a layer of quartz fiber net felt and two layers of carbon fiber net felts are used as unit structure layers, and a disc-shaped unit structure layer is firstly laid in three positions of a central area of a mould. Secondly, laying a structural layer of the circular ring unit in a second area, carrying out needling lap joint on the circular ring splicing position by adopting a net tire with the thickness reduced by half, and marking the central position of the lap joint as an initial position on a mould as an initial reference; and (3) laying unit structure layers at the initial position of the first region, namely the fan-shaped splicing seam position of the inner ring, which is obtained by rotating the initial reference by 20 degrees anticlockwise, supplementing 4 fan-shaped unit structure layers at the missing part, and fixing the fan-shaped weft-free cloth of the inner ring and 8 fan-shaped unit structure layers of the outer ring by adopting a needling mode. The edges of the three areas are fixedly lapped by adopting needle punching of a net tire with the thickness reduced by half, and the lapping distance is 20 mm. After three areas are layered, needling is carried out for fixation.

Step S3: and laying a second unit structural layer on the basis of the first unit structural layer. When the first area and the second area are laid, the first layer is rotated by 1 x 45 degrees in a counterclockwise direction according to the starting reference to form a second layer starting position; and after the second layer of unit structure layer is laid, needling fixation is carried out.

Step S4: and 3, repeating the step 3, and laying the subsequent unit structural layer. When the first area and the second area are laid, the initial position of the Nth layer is formed by rotating (N-1) 45 degrees counterclockwise according to the initial reference; and returning the lapping initial position of the two regional unit structure layers to the initial reference until the 8 unit structure layers are laid. The 8 unit structure layers are a circulation unit.

Step S5: and repeating the circulating unit until the thickness requirement is met, thus obtaining the oversized high-thickness special-shaped preform with the flange and the diameter of 2 meters.

To further illustrate the advantages of the method of the present invention, the results of the composite molding with phenolic resin are shown in table 2, compared with the conventional full-area large-area ply preform.

Structural form of prefabricated body	Density of preform	Tensile strength of composite material
			Ordinary layering process	0.16g/cm3	0.15MPa
Partitioned layering process	0.16g/cm3	0.20MPa

TABLE 2

The oversized high-thickness special-shaped preform with the flange is essentially of a layered structure design, the oversized preform is divided into a plurality of regions by partitioning and splicing, the size of each region is simplified, and the preparation of the high-thickness preform is realized by the layered structure design. The preparation method of the oversized high-thickness special-shaped preform with the flange, which is provided by the application, is characterized in that the geometric axis of the preform is used as the center, a partition laying and layered laying mode is adopted, and the oversized high-thickness special-shaped preform is obtained through lap joint design between different areas and between unit structure layers in the same layer, so that the connection problem of the oversized high-thickness preform and the oversized high-thickness preform is solved, and the problem that the oversized preform cannot be prepared due to the limitation of weaving size of the existing equipment is solved.

The above description is intended to be illustrative and not restrictive, and the scope of the invention is defined by the appended claims, which may be modified in any manner within the scope of the invention.