CN104818567A - Synchronous heterodromous three-dimensional fabric of 2.5D braided structure and preparation method thereof - Google Patents

Abstract

The invention discloses a synchronous heterodromous three-dimensional fabric of a 2.5D braided structure and a preparation method thereof. The synchronous heterodromous three-dimensional fabric comprises a columnar fabric, the top part of the columnar fabric is sealed or not sealed, and the bottom part of the columnar fabric is provided with an outer flanging; the outer flanging comprises a vertical flanging and an inclined flanging, the vertical flanging means a flanging which is vertical to a certain side of the columnar fabric, and the inclined flanging means a flanging which is not vertical to the certain side of the columnar fabric; the preparation method comprises the steps of knitting by taking a mandrel as an inner core, and adopting a 2.5D curved shallow-crossing linking knitting unit structure. According to the preparation method of the synchronous heterodromous three-dimensional fabric of the 2.5D braided structure provided by the invention, the integral forming of the fabrics with more complicate shapes can be realized; furthermore, a prepared fabric unit is complete in structure and good in fiber continuity; meanwhile, a complete unit structure has a strong designability in the fabric forming process; in addition, fibers of 2.5D braided structures have more weaving points, and the unit structure is low in degree of freedom, controllable in process parameters and good in structural uniformity; finally, the obtained fabric is compact in structure, good in integrality and excellent in mechanical property.

Description

A kind of 2.5D braided structure synchronous different is to stereo fabric and preparation method thereof

Technical field

The present invention relates to a kind of 2.5D braided structure synchronous different to stereo fabric and preparation method thereof, belong to stereo fabric field.

Background technology

2.5D fabric is on the basis of woven three-dimensional woven equipment, many monofilaments are utilized to make warp fiber form multilayer opening, the class layer stereo fabric formed after introducing weft fiber in certain sequence, but intertwined point is less each other for the 3-d braided fiber of current 2.5D fabric, the free degree of cellular construction change greatly, structural manufacturing process parameter designing is many by cellular construction variable effect factor, technological parameter is uncontrollable, structural homogeneity is poor, in order to better meet the demand of aerospace field, be badly in need of a kind of 2.5D new product of exploitation.There is no at present about the relevant report of 2.5D braided structure synchronous different to stereo fabric.

Summary of the invention

In order to overcome the 3-d braided fiber of 2.5D fabric in prior art intertwined point be less each other, technological parameter is uncontrollable and the defect such as structural homogeneity is poor, the invention provides a kind of 2.5D braided structure synchronous different to stereo fabric and preparation method thereof.

For solving the problems of the technologies described above, the technical solution adopted in the present invention is as follows:

A kind of 2.5D braided structure synchronous different is to stereo fabric, comprise the column fabric of the bottom belt flanging bound or do not bind, wherein, flanging comprises: straight flange and oblique flange, straight flange refers to the flange vertical with column fabric side, and oblique flange refers to and column fabric side off plumb flange.

Above-mentioned 2.5D braided structure synchronous different comprises flanging and side and/or top to stereo fabric, specifically have good integrity, even structure closely, the advantage such as excellent in mechanical performance, the demand of aerospace field can be met better.

2.5D braided structure synchronous different comprises warp fiber system and weft fiber system to stereo fabric, and warp fiber system is interweaved into Angular interlocking structure with weft fiber system.Which increase the 3-d braided fiber controlled and even structure of intertwined point, technological parameter each other.

Above-mentioned 2.5D braided structure synchronous different is to the preparation method of stereo fabric, and 2.5D braided structure synchronous different is that inner core weaves to the braiding of stereo fabric with core, and adopts the curved binding of the shallow friendship of 2.5D to knit cellular construction.

The application's said method can realize the global formation of complex-shaped fabric; Prepared fabric unit structural integrity, fiber continuity are good; In fabric forming process, to have design strong for full unit structure; Fiber each other intertwined point is many, and the free degree of cellular construction change is little, and structural manufacturing process parameter designing is little by cellular construction variable effect factor, and technological parameter is controlled, and structural homogeneity is good; The composite obtained by the application's stereo fabric is utilized to have the features such as close structure, good integrity, good mechanical performance.

In order to improve the close structure of fabric, good integrity and mechanical property further, if bind, the paving top braiding that top adopts paving yarn, inlaid thread method completes top, side and flanging adopt synchronous different to weave to forming method; If do not bind, adopt and directly hang the side that warp fiber introduces weft fiber braiding column fabric again, then adopt synchronous different to weave flanging to forming method.

If bind, after paving top braiding is completed, carry out following steps successively: a, turning over through weft fiber of end face to be turn 90 degrees downwards, draw the warp fiber of the side fabric perpendicular with end face, carry out synchronous forming, weaving direction changes, interweave warp fiber and weft fiber formation side fabric; B, the warp fiber of side fabric is outwards overturn 0-90 degree, as the warp fiber of flanging, carry out synchronous forming, weaving direction changes, interweave warp fiber and weft fiber formation flanging; If do not bind, directly extension warp fiber is adopted to introduce the side that weft fiber has woven column fabric again, again the warp fiber of side fabric is outwards overturn 0-90 degree, as the warp fiber of flanging, carry out synchronous forming, weaving direction changes, interweave warp fiber and weft fiber formation flanging.

Above-mentioned can according to the change of flanging size, design multiple spot adds warp fiber technology, realizes the braiding of flanging.

In order to improve the adaptability of gained fabric, 2.5D braided structure synchronous different is cylindric to the side of stereo fabric, flanging is straight flange, the shape of straight flange is round, straight flange adds warp fiber quantity and calculates according to outer perimeter difference and warp fiber density in circumference, often weave two latitudes to need to add a warp fiber, straight flange adds warp fiber quantity formula and is:

m＝(C ₁-C ₂)×P _j(1)

In formula: m is for adding warp fiber quantity; C1 is excircle girth, C2 is inner periphery girth; P _jfor warp fiber density.

As the another kind of technical scheme of the application, 2.5D braided structure synchronous different is cylindric to the side of stereo fabric, flanging is oblique flange, the shape of oblique flange is ellipse, oblique flange adds warp fiber quantity and calculates according to oval interior outer perimeter difference and warp fiber density, often weave two latitudes to need to add a warp fiber, oval perimeters formula is:

$P=2\mathrm{\πa}(1-\frac{1}{2^2}{e}^2-\frac{1^2\·3}{2^2\·4^2}{e}^4-b_{n-1}\×\frac{2n-1}{{\left(2n\right)}^2}\×e^{2n}...)$

If $b_1=\frac{1}{2^2},$ General term formula is: $b_n=b_{n-1}\×\frac{2n-1}{{\left(2n\right)}^2}---\left(2\right)$

In formula: p is oval perimeters, a and b is respectively oval major semiaxis and semi-minor axis, and e is eccentricity, and n is the natural number of>=2;

Oblique flange adds warp fiber quantity formula:

m＝(P ₁-P ₂)×P _j(3)

In formula: m is for adding warp fiber quantity; P ₁for outer oval perimeters, P ₂for interior oval perimeters; P _jfor warp fiber density.

For the ease of preparation, improve compactness and the uniformity of gained flanging, being divided equally by flanging is the fan-shaped of 12 deciles, carries out adding warp fiber simultaneously.

The NM technology of the present invention is all with reference to prior art.

Compared with prior art, 2.5D braided structure synchronous different of the present invention is to the advantage of the preparation method of stereo fabric: can realize the global formation of shape compared with complex textile, meet the mechanical property of complicated abnormal shape component; Prepared fabric unit structural integrity, fiber continuity is good, parameter is controlled, steady quality, add yarn point without hole, fabric corner fiber keeps continuity, and corner is without broken yarn, fabric face breaks end without fiber, achieves complex component fabric single cell structure complete yams continuous; In fabric forming process, to have design strong for full unit structure; Intertwined point is many each other for 2.5D braided structure fiber of the present invention, and the free degree of cellular construction change is little, and structural manufacturing process parameter designing is little by cellular construction variable effect factor, and technological parameter is controlled, and structural homogeneity is good; 2.5D braided structure synchronous different is to stereo fabric good integrity, and fiber is evenly distributed, and the composite materials property made of it and excellent electrical property, can be widely used in aerospace field; Gained composite has the features such as close structure, good integrity, good mechanical performance.

Accompanying drawing explanation

Fig. 1 is the structural representation of embodiment 1 gained fabric.

Fig. 2 is the structural representation of embodiment 2 gained fabric.

Fig. 3 is the structural representation of embodiment 3 gained fabric.

Fig. 4 is that embodiment 3 adds warp fiber schematic diagram, and in figure, 1-12 represents 12 zoness of different.

In figure, the direction of arrow is weaving direction, and 13 is top, and 14 is side, and 15 is flanging.

Detailed description of the invention

In order to understand the present invention better, illustrate content of the present invention further below in conjunction with embodiment, but content of the present invention is not only confined to the following examples.

Embodiment 1:

2.5D braided structure synchronous different, to stereo fabric, comprises and binding and the column fabric of bottom belt flanging, and wherein, flanging is straight flange.

Warp fiber is T3003K fiber × 1 strand, weft yarn is T3003K fiber × 1 strand, fabric through close be 10 pieces/centimetre, filling density is 3.5 pieces/centimetre, the warp thread number of plies be designed to 10 layers (fabric from top to side to flange through close, filling density is all the same with the warp thread number of plies, other embodiment too), the end face of fabric is square face, and side is cubic cylinder, flanging be each side of cubic cylinder extend square, as shown in Figure 1, concrete preparation method is as follows for fabric form:

(1) described braided structure synchronous different adopts the curved binding of the shallow friendship of 2.5D to knit cellular construction to stereo fabric, and its structure comprises warp fiber system and weft fiber system, and warp fiber system is interweaved into Angular interlocking structure with weft fiber system;

(2) braiding of fabric is that inner core weaves with core;

(3) the paving top braiding that employing spreads yarn, inlaid thread technology completes center top, as shown in direction a in Fig. 1;

(4), after completing the paving top braiding of center top, synchronous different is adopted to carry out the braiding of stereo fabric side and flange to forming technique;

(5) according to the feature of component, turning over downwards through weft fiber of paving top plane easily extensible fabric is turn 90 degrees, as shown in direction b in Fig. 1, draw the warp fiber of the side fabric perpendicular with end face, carry out synchronous forming, weaving direction changes, interweave warp fiber and weft fiber formation side fabric;

(6) after side has woven, continue the warp fiber of side fabric outwards to turn over to turn 90 degrees, as shown in direction c in Fig. 1, as the warp fiber of flanging, carry out synchronous forming, weaving direction changes, realize side to weave to the conversion of perpendicular corners flanging, interweave warp fiber and weft fiber formation flanging;

(7), after the braiding of completing steps (6), the braiding of 2.5D braided structure synchronous different of the present invention to stereo fabric is namely completed.

Embodiment 2:

2.5D braided structure synchronous different, to stereo fabric, comprises and not binding and the cylindric fabric of bottom belt flanging, and wherein, flanging is straight flange (annular).

Warp fiber is T3003K fiber × 1 strand, weft yarn is T3003K fiber × 1 strand, straight flange internal diameter is 40mm, straight flange external diameter is 80mm, and the warp thread number of plies is designed to 10 layers, fabric through close be 10 pieces/centimetre, filling density is 3.5 pieces/centimetre, fabric flange is straight flange (circle), and as shown in Figure 2, concrete preparation method is as follows for fabric form:

(1) described braided structure synchronous different adopts the curved binding of the shallow friendship of 2.5D to knit cellular construction to stereo fabric, and its structure comprises warp fiber system and weft fiber system, and warp fiber system is interweaved into Angular interlocking structure with weft fiber system;

(2) braiding of fabric is that inner core weaves with core;

(3) adopt directly extension warp fiber to introduce broadwise (hoop) fiber again and complete cylindric braiding, as shown in direction d in Fig. 2;

(4) after completing cylindric braiding, synchronous different is adopted to carry out the braiding of the straight flange of fabric to forming technique, according to the feature of component, the warp fiber of column fabric is outwards turned over and turn 90 degrees, as shown in direction e in Fig. 2, as the warp fiber of flanging, carry out synchronous forming, weaving direction changes, interweave warp fiber and weft fiber formation flanging; Being divided equally by straight flange is the fan-shaped of 12 deciles, carry out adding warp fiber, straight flange adds warp fiber quantity and calculates according to outer perimeter difference and warp fiber density in circumference, and often weaving two latitudes needs to add a warp fiber, and straight flange adds warp fiber quantity formula and is:

m＝(C ₁-C ₂)×P _j(1)

In formula: m is for adding warp fiber quantity; C1 is excircle girth, C2 is inner periphery girth; P _jfor warp fiber density;

(5), after the braiding of completing steps (4), the braiding of 2.5D braided structure synchronous different of the present invention to stereo fabric is namely completed.

Embodiment 3:

2.5D braided structure synchronous different, to stereo fabric, comprises the column fabric of the bottom belt flanging do not bound, and wherein, flanging is oblique flange (oval ring).

Warp fiber is T3003K fiber × 1 strand, weft yarn is T3003K fiber × 1 strand, oblique flange internal diameter is 40mm, oblique flange external diameter is 80mm, and the warp thread number of plies is designed to 10 layers, fabric through close be 10 pieces/centimetre, filling density is 3.5 pieces/centimetre, fabric flange is oblique flange (ellipse), and as shown in Figure 3, concrete preparation method is as follows for fabric form:

(1) described braided structure synchronous different adopts the curved binding of the shallow friendship of 2.5D to knit cellular construction to stereo fabric, and its structure comprises warp fiber system and weft fiber system, and warp fiber system is interweaved into Angular interlocking structure with weft fiber system;

(2) braiding of fabric is that inner core weaves with core;

(3) adopt directly extension warp fiber to introduce broadwise (hoop) fiber again and complete cylindric braiding, as shown in direction f in Fig. 3;

(4) after completing cylindric braiding, synchronous different is adopted to carry out the braiding of the oblique flange of fabric to forming technique, according to the feature of component, by the warp fiber of column fabric upset θ degree, as shown in direction g in Fig. 3, as the warp fiber of flanging, carry out synchronous forming, weaving direction changes, interweave warp fiber and weft fiber formation flanging; Being divided equally by oblique flange is the fan-shaped of 12 deciles, carries out adding warp fiber, and oblique flange adds warp fiber quantity and calculates according to oval interior outer perimeter difference and warp fiber density, and often weaving two latitudes needs to add a warp fiber, and oval perimeters formula is:

$P=2\mathrm{\πa}(1-\frac{1}{2^2}{e}^2-\frac{1^2\·3}{2^2\·4^2}{e}^4-b_{n-1}\×\frac{2n-1}{{\left(2n\right)}^2}\×e^{2n}...)$

If $b_1=\frac{1}{2^2},$ General term formula is: $b_n=b_{n-1}\×\frac{2n-1}{{\left(2n\right)}^2}---\left(2\right)$

In formula: p is oval perimeters, a and b is respectively oval major semiaxis and semi-minor axis, and e is eccentricity, and n is the natural number of>=2;

Oblique flange adds warp fiber quantity formula:

m＝(P ₁-P ₂)×P _j(3)

In formula: m is for adding warp fiber quantity; P ₁for outer oval perimeters, P ₂for interior oval perimeters; P _jfor warp fiber density;

(5), after the braiding of completing steps (4), the braiding of 2.5D braided structure synchronous different of the present invention to stereo fabric is namely completed.

Fabric unit structural integrity prepared by the various embodiments described above, fiber continuity is good, parameter is controlled, steady quality, add yarn point without hole, fabric corner fiber keeps continuity, corner is without broken yarn, fabric face breaks end without fiber, achieves complex component fabric single cell structure complete yams continuous; In fabric forming process, to have design strong for full unit structure; Intertwined point is many each other for 2.5D braided structure fiber, and the free degree of cellular construction change is little, and structural manufacturing process parameter designing is little by cellular construction variable effect factor, and technological parameter is controlled, and structural homogeneity is good; 2.5D braided structure synchronous different is to stereo fabric good integrity, and fiber is evenly distributed, the composite materials property made of it and excellent electrical property.

The test of the fabric mechanics in the various embodiments described above is with the plate of same process parameter and the test data adopting resin transfer molding (RTM) process method (RTM) to carry out the mechanical property of composite molding embodies.The structural parameters of plate are as follows:

Fabric size specification: 430mm × 120mm × 3mm

Warp count: 10/cm; Weft count: 3.5/cm; The warp thread number of plies: 10 layers; Weft layers: 10 layers

Warp thread specification: T-300 3K sub-thread; Weft yarn specification: T-300 3K sub-thread

The mechanical property of plate is as shown in Table 1-2:

Table 1 bending property

Table 2 tensile property

Claims (8)

1. a 2.5D braided structure synchronous different is to stereo fabric, it is characterized in that: the column fabric comprising the bottom belt flanging bound or do not bind, wherein, flanging comprises: straight flange and oblique flange, straight flange refers to the flange with the lateral vertical of column fabric, and oblique flange refers to the side off plumb flange with column fabric.

2. 2.5D braided structure synchronous different as claimed in claim 1 is to stereo fabric, it is characterized in that: 2.5D braided structure synchronous different comprises warp fiber system and weft fiber system to stereo fabric, and warp fiber system is interweaved into Angular interlocking structure with weft fiber system.

3. the 2.5D braided structure synchronous different described in claim 1 or 2, to the preparation method of stereo fabric, is characterized in that: 2.5D braided structure synchronous different is that inner core weaves to the braiding of stereo fabric with core, and adopts the curved binding of the shallow friendship of 2.5D to knit cellular construction.

4. preparation method as claimed in claim 3, is characterized in that: if bind, the paving top braiding that top adopts paving yarn, inlaid thread method completes top, and side and flanging adopt synchronous different to weave to forming method; If do not bind, adopt and directly hang the side that warp fiber introduces weft fiber braiding column fabric again, then adopt synchronous different to weave flanging to forming method.

5. preparation method as claimed in claim 4, it is characterized in that: if bind, after paving top braiding is completed, carry out following steps successively: a, turning over through weft fiber of end face to be turn 90 degrees downwards, draw the warp fiber of the side fabric perpendicular with end face, carry out synchronous forming, weaving direction changes, interweave warp fiber and weft fiber formation side fabric; B, the warp fiber of side fabric is outwards overturn 0-90 degree, as the warp fiber of flanging, carry out synchronous forming, weaving direction changes, interweave warp fiber and weft fiber formation flanging; If do not bind, directly extension warp fiber is adopted to introduce the side that weft fiber has woven column fabric again, again the warp fiber of side fabric is outwards overturn 0-90 degree, as the warp fiber of flanging, carry out synchronous forming, weaving direction changes, interweave warp fiber and weft fiber formation flanging.

6. the preparation method as described in claim 3-5 any one, it is characterized in that: 2.5D braided structure synchronous different is cylindric to the side of stereo fabric, flanging is straight flange, the shape of straight flange is round, straight flange adds warp fiber quantity and calculates according to outer perimeter difference and warp fiber density in circumference, often weave two latitudes to need to add a warp fiber, straight flange adds warp fiber quantity formula and is:

m＝(C ₁-C ₂)×P _j(1)

In formula: m is for adding warp fiber quantity; C1 is excircle girth, C2 is inner periphery girth; P _jfor warp fiber density.

7. the preparation method as described in claim 3-5 any one, it is characterized in that: 2.5D braided structure synchronous different is cylindric to the side of stereo fabric, flanging is oblique flange, the shape of oblique flange is ellipse, oblique flange adds warp fiber quantity and calculates according to oval interior outer perimeter difference and warp fiber density, often weave two latitudes to need to add a warp fiber, oval perimeters formula is:

$P=2\mathrm{\πa}(1-\frac{1}{2^2}{e}^2-\frac{1^2\·3}{2^2\·4^2}{e}^4-b_{n-1}\×\frac{2n-1}{{\left(2n\right)}^2}\×e^{2n}...)$

If $b_1=\frac{1}{2^2},$ General term formula is: $b_n=b_{n-1}\×\frac{2n-1}{{\left(2n\right)}^2}---\left(2\right)$

In formula: p is oval perimeters, a and b is respectively oval major semiaxis and semi-minor axis, and e is eccentricity, and n is the natural number of>=2;

Oblique flange adds warp fiber quantity formula:

m＝(P ₁-P ₂)×P _j(3)

In formula: m is for adding warp fiber quantity; P ₁for outer oval perimeters, P ₂for interior oval perimeters; P _jfor warp fiber density.

8. the preparation method as described in claim 3-5 any one, is characterized in that: being divided equally by flanging is the fan-shaped of 12 deciles, carries out adding warp fiber.