阅读说明：本技术 一种t型结构纤维针刺预制体 (T-shaped structure fiber needling preform ) 是由 缪云良 于 2019-11-04 设计创作，主要内容包括：本发明涉及复合材料技术领域,尤其涉及一种T型结构纤维针刺预制体,所述预制体的结构包括蒙皮薄层(1)、位于蒙皮薄层(1)上呈对称L形排布的左加强筋(2)和右加强筋(3)；所述预制体采用整体针刺工艺成型。本发明采用模块化的制备方式,将T型结构纤维针刺预制体分成4个模块分别制备,再采用整体针刺将4个模块结合；该方法具有操作简单,模具用量少的特点,同时制备的T型结构纤维针刺预制体尺寸稳定、承载能力强,方便运输。(The invention relates to the technical field of composite materials, in particular to a T-shaped structural fiber needling preform, which structurally comprises a skin thin layer (1), and a left reinforcing rib (2) and a right reinforcing rib (3) which are symmetrically arranged in an L shape and are positioned on the skin thin layer (1); the prefabricated body is formed by adopting an integral needling process. The invention adopts a modularized preparation mode, divides a T-shaped structural fiber needling prefabricated body into 4 modules to be prepared respectively, and then adopts integral needling to combine the 4 modules; the method has the characteristics of simple operation and less mold consumption, and the prepared T-shaped structure fiber needling preform has stable size, strong bearing capacity and convenient transportation.)

1. The T-shaped structural fiber needling preform is characterized by comprising a skin thin layer (1), and a left reinforcing rib (2) and a right reinforcing rib (3) which are symmetrically arranged in an L shape on the skin thin layer (1); the prefabricated body is formed by adopting an integral needling process.

2. The preform according to claim 1, characterised in that the skin laminate (1) is produced by laying a web and a fibre cloth in a sequence and needling.

3. The preform according to claim 2, characterised in that the skin laminate (1) is made of high-performance fibres by a textile process and has an areal density of 50-600g/cm²The fabric of (a); the high-performance fiber is one or more of carbon fiber, glass fiber, quartz fiber and aramid fiber; the fabric is plain weave, satin weave, twill weave,A unidirectional fabric or mesh; the thin skin layer (1) is formed by 10-100 layers of fabric lamination and has the thickness of 5-25 mm.

4. The preform according to claim 1, wherein the left reinforcement rib (2) and the right reinforcement rib (3) are formed by corner fold lay-up needling of a mesh and a fiber cloth in a certain order.

5. The preform according to claim 4, wherein the left and right reinforcing bars (2, 3) are made of high performance fibers by textile process and have an areal density of 50-600g/cm²The fabric of (a); the high-performance fiber is one or more of carbon fiber, glass fiber, quartz fiber and aramid fiber; the fabric is plain weave, satin weave, twill weave, unidirectional fabric or net tire; the left reinforcing rib (2) and the right reinforcing rib (3) are formed by 10-100 layers of fabric lamination, and the thickness is 5-25 mm.

6. The preform according to claim 1, characterised in that the L-shaped corners of the left (2) and right (3) reinforcement bars are 60-120 °.

7. The preform according to claim 1, wherein a gap is left between the L-shaped corners of the left reinforcing bar (2) and the right reinforcing bar (3), the gap is of a triangle-like structure, and one side of the triangle-like structure, which is close to the reinforcing bars, is provided with a certain radian; the gap is filled with carbon fiber, glass fiber, quartz fiber or aramid fiber which is prepared by textile technology and has the surface density of 50-600g/cm²The fiber fabric of (1); the fiber fabric is plain, satin or twill two-dimensional fabric, and can also be unidirectional fabric or net tire.

8. The preform according to claim 1, characterised in that the left reinforcement bar (2) and the right reinforcement bar (3) can also be arranged symmetrically.

9. A method for preparing a T-shaped structural fiber needled preform according to claim 1, said method comprising the steps of:

(1) the fiber fabric is flatly laid according to a certain sequence and is needled to form a 'one' skin thin layer;

(2) folding and layering fiber fabrics on a cornea according to a certain sequence, and preparing the left side of a '+' -shaped reinforcing rib and the right side of the '+' -shaped reinforcing rib by adopting a needling process;

(3) sequentially cutting the fiber fabric into strips and strips, sequentially laying the strips according to the size from large to small to form an ▲ shape, and performing pre-needling from top to bottom to form a ▲ folded angle filling layer, or sequentially cutting the fiber fabric into strips and strips, and forming a' shaped folded angle filling layer in a curling mode;

(4) the method comprises the steps of placing a skin thin layer on a lower layer, sequentially placing a left side of a ' + ' reinforcing rib, an ▲ ' or a ' dog-ear filling layer and a right side of the ' + ' reinforcing rib on the skin thin layer, carrying out needling from the upper side while carrying out needling from the left side and the right side, and then carrying out needling from three directions of a ' ▲ ' gap at a corner position to obtain a T-shaped structural member fiber needling prefabricated body, wherein the ' ▲ ' or ' dog-ear filling layer deforms in the needling process to fill the gap between the L-shaped corners of the left reinforcing rib (2) and the right reinforcing rib (3).

Technical Field

The invention relates to the technical field of composite materials, in particular to a T-shaped structural fiber needling preform and a preparation method thereof.

Background

The space remote sensing earth observation technology has become one of the important marks of the national strategic ability at present, and with the progress of the space remote sensing technology and the gradual improvement of the resolution ratio, the space camera is increasingly developed to a large caliber, a long focal length and a light weight, which puts a rigorous requirement on the performance of a camera supporting structure, and the space camera not only has light weight and high rigidity, but also has extremely low thermal expansion coefficient. The traditional metal materials have difficulty in meeting performance requirements, and the support structure of carbon fiber composite materials (particularly carbon fiber reinforced carbon-based and silicon carbide-based composite materials) becomes a hot spot and a main development trend of international research in recent years.

The carbon fiber composite material is composed of a carbon fiber preform and a matrix. The carbon fiber preform structure determines the properties of the composite article. In order to further create a clear and light space camera and make the overhead satellite take a good picture, the optical support structure of the camera needs to be large and light, and high strength and stability are needed. As a result, there are many complex structures for the support structure, such as a stiffened panel structure, and the like. The ribbed wall panels are further classified into "T" -shaped ribbed wall panels, "i" -shaped ribbed wall panels, hybrid ribbed wall panels, and the like, according to the difference in ribbed section.

At present, most of T-shaped structural members are composed of composite material ribs and composite material skins, and the forming technology generally comprises the steps of preparing the skins and the reinforced ribs respectively, and then mechanically connecting the skins and the reinforced ribs by fasteners or forming a reinforced wall plate structure by means of secondary bonding. Because the wall plate and the reinforcement are manufactured separately, all parts need to be connected by a mechanical connection or glue joint method, so that the whole process is complicated, the production cost is increased, the continuity of fibers is easy to damage in the machining process, and the whole performance and the stability are reduced. 201710129412.9 discloses a forming tool and a forming method for a composite material T-shaped stiffened wall plate, the method adopts a skin forming flat plate, a skin forming cover plate, a positioning pin and a T-shaped rib forming unit for paving and forming T-shaped ribs as the tool, the ribs are accurately positioned by reserving rib positioning grooves on the skin forming cover plate, the skin area is uniformly pressed by adopting the skin cover plate, and the overall dimension tolerance of a reinforcing rib web plate of a wall plate structure is effectively controlled by adopting the rib forming cover plate. The method improves the rigidity and the strength of the integral large-scale wall plate structure, more effectively improves the integral process quality of the structure, and simultaneously saves the process preparation period and the cost, but the used tools and dies are more and complicated, and need accurate positioning grooves for positioning, and the demoulding can be carried out after curing, so the method is not suitable for preparing the carbon/carbon and carbon/ceramic composite material T-shaped structural member by a chemical vapor infiltration method.

Disclosure of Invention

In view of the above problems in the prior art, the present applicant provides a T-shaped structural fiber needled preform. The invention adopts a modularized preparation mode, divides a T-shaped structural fiber needling preform into 4 modules to be prepared respectively, and then adopts integral needling to combine the 4 modules. The method has the characteristics of simple operation and less mold consumption, and the prepared T-shaped structure fiber needling preform has stable size, strong bearing capacity and convenient transportation.

The technical scheme of the invention is as follows:

a T-shaped structural fiber needling preform structurally comprises a skin thin layer (1), and a left reinforcing rib (2) and a right reinforcing rib (3) which are symmetrically arranged in an L shape on the skin thin layer (1); the prefabricated body is formed by adopting an integral needling process.

The skin thin layer (1) is formed by flatly laying net tires and fiber cloth according to a certain sequence and then needling.

The skin thin layer (1) is made of high-performance fibers through a textile process and has the areal density of 50-600g/cm²The fabric of (a); the high-performance fiber is one or more of carbon fiber, glass fiber, quartz fiber and aramid fiber; the fabric is plain weave, satin weave, twill weave, unidirectional fabric or net tire; the thin skin layer (1) is formed by 10-100 layers of fabric lamination and has the thickness of 5-25 mm.

The left reinforcing rib (2) and the right reinforcing rib (3) are formed by carrying out corner folding and layering needling on the net tire and the fiber cloth according to a certain sequence.

The left reinforcing rib (2) and the right reinforcing rib (3) are made of high-performance fibers through a textile process, and the areal density of the reinforcing ribs is 50-600g/cm²The fabric of (a); the high-performance fiber is one or more of carbon fiber, glass fiber, quartz fiber and aramid fiber; the fabric is plain weave, satin weave, twill weave, unidirectional fabric or net tire; the left reinforcing rib (2) and the right reinforcing rib (3) are formed by 10-100 layers of fabric lamination, and the thickness is 5-25 mm.

The L-shaped corner of the left reinforcing rib (2) and the right reinforcing rib (3) is 60-120 degrees.

A gap is reserved between the L-shaped corner of the left reinforcing rib (2) and the L-shaped corner of the right reinforcing rib (3), the gap is of a similar triangular structure, and one side, close to the reinforcing ribs, of the similar triangular structure is provided with a certain radian; the gap is filled with carbon fiber, glass fiber, quartz fiber or aramid fiber which is prepared by textile technology and has the surface density of 50-600g/cm²The fiber fabric of (1); the fiber fabric is plain, satin or twill two-dimensional fabric, and can also be unidirectional fabric or net tire.

The left reinforcing rib (2) and the right reinforcing rib (3) can also be symmetrically arranged in a shape of a Chinese character 'ji'.

A method for preparing a T-shaped structural fiber needling preform, which comprises the following steps:

(1) the fiber fabric is flatly laid according to a certain sequence and is needled to form a 'one' skin thin layer;

(2) folding and layering fiber fabrics on a cornea according to a certain sequence, and preparing the left side of a '+' -shaped reinforcing rib and the right side of the '+' -shaped reinforcing rib by adopting a needling process;

(3) sequentially cutting the fiber fabric into strips and strips, sequentially laying the strips according to the size from large to small to form an ▲ shape, and performing pre-needling from top to bottom to form a ▲ folded angle filling layer, or sequentially cutting the fiber fabric into strips and strips, and forming a' shaped folded angle filling layer in a curling mode;

(4) the method comprises the steps of placing a skin thin layer on a lower layer, sequentially placing a left side of a ' + ' reinforcing rib, an ▲ ' or a ' dog-ear filling layer and a right side of the ' + ' reinforcing rib on the skin thin layer, carrying out needling from the upper side while carrying out needling from the left side and the right side, and then carrying out needling from three directions of a ' ▲ ' gap at a corner position to obtain a T-shaped structural member fiber needling prefabricated body, wherein the ' ▲ ' or ' dog-ear filling layer deforms in the needling process to fill the gap between the L-shaped corners of the left reinforcing rib (2) and the right reinforcing rib (3).

The beneficial technical effects of the invention are as follows:

the invention adopts a modularized preparation method, the method is simple and easy to operate, the preparation of the fiber acupuncture preform with the T-shaped structure is completed by two simple corneas, and the using amount of a die is small. Meanwhile, the bevel filling layer is used for filling the bevel position, so that the stress concentration of the bevel position is reduced, and the bearing capacity of the T-shaped structure fiber needling preform is improved. The fiber is fixed by adopting an integral needling process, so that a fiber needling preform with a T-shaped structure and stable size is obtained, the preform can be separated from a cornea for transportation, and a subsequent resin impregnation curing or chemical vapor deposition process is carried out.

Drawings

FIG. 1 is a schematic view of the present invention;

FIG. 2 is a schematic view of the present invention;

in the figure: 1. a thin skin layer; 2. a left stiffener; 3. and a right reinforcing rib.

Detailed Description

The present invention will be described in detail with reference to the accompanying drawings and examples.