1. The lightweight composite reinforcing plate for the automobile body is characterized by comprising a composite main body shell plate (1) capable of being mounted on an automobile frame, an embedded reinforcing structure (2) arranged inside the composite main body shell plate (1), and an external reinforcing structure (3) arranged outside the composite main body shell plate (1) and connected with the embedded reinforcing structure (2);

the composite main body shell plate (1) comprises a first main body (4) in a cambered surface shell shape, and a second main body (5) which is arranged around the first main body (4) and is used as a flanging structure;

the first main body (4) and the second main body (5) respectively comprise a base layer (10) formed by a plurality of layers of carbon fiber cloth and a plurality of layers of glass fiber cloth in a mixed and paved manner, a first reinforcing layer (11) arranged on the upper surface of the base layer (10) and paved by a plurality of layers of mixed and woven cloth made of carbon fibers and glass fibers, and a second reinforcing layer (12) arranged on the lower surface of the base layer (10) and paved by a plurality of layers of mixed and woven cloth made of carbon fibers and glass fibers;

the embedded reinforcing structure (2) comprises a first embedded metal ring (20) arranged in a basic layer (10) of the second main body (5), a second embedded metal ring (21) arranged in the basic layer (10) of the first main body (4), an arc-shaped metal strip (22) with one end connected with the first embedded metal ring (20) and the other end connected with the second embedded metal ring (21) and positioned in the basic layer (10), and a connecting piece (23) arranged in the basic layer (10) of the second main body (5);

the arc-shaped metal strips (22) are a plurality of metal strips made of spring steel and are uniformly distributed in the center of the first embedded metal ring (20);

the external reinforcing structure (3) comprises a peripheral flanging reinforcing ring (30) which is arranged on the upper end face of the first reinforcing layer (11) and is bolted with the connecting piece (23), and a plurality of internal supporting rods (31) which are arranged on the lower end face of the second reinforcing layer (12) in a crossed mode and are bolted with the connecting piece (23).

2. The composite reinforcing plate for the lightweight automobile body according to claim 1, wherein the connecting piece (23) comprises a plurality of pre-embedded fixing pieces (230) which are uniformly distributed in the center of the first pre-embedded metal ring (20) and fixed with the first pre-embedded metal ring (20), first connecting holes (231) which are formed in the pre-embedded fixing pieces (230) and connected with the peripheral flanging reinforcing ring (30) and the inner supporting rod (31), and second connecting holes (232) which are formed in the pre-embedded fixing pieces (230) and connected with the automobile frame.

3. The composite reinforcing plate for the lightweight automobile body as recited in claim 1, wherein the first embedded metal ring (20) is a steel ring.

4. The composite reinforcing plate for the lightweight automobile body according to claim 1, wherein the peripheral flanging reinforcing ring (30) and the inner supporting rod (31) are made of aluminum alloy; and the peripheral flanging reinforcing ring (30) is attached to the outer edge of the first reinforcing layer (11).

5. The method for preparing the light-weight automobile body composite reinforcing plate according to any one of claims 1 to 4, characterized by comprising the following steps:

the method comprises the following steps: manufacture of pre-buried reinforcing structure

Firstly, machining and manufacturing a first embedded metal ring (20), an embedded fixing sheet (230), a second embedded metal ring (21) and an arc-shaped metal strip (22); then, two ends of the arc-shaped metal strip (22) are respectively welded and fixed with the first embedded metal ring (20) and the second embedded metal ring (21); the embedded fixing sheet (230) and the first embedded metal ring (20) are obtained by cutting a whole steel plate with the thickness of 0.6-1.4 mm through slow wire walking;

the size and the shape of the first embedded metal ring (20) are determined according to the whole area of the composite reinforcing plate;

step two: manufacturing mixed woven fabric and preparation mold

Preparing carbon fiber tows and glass fiber tows; arranging the prepared carbon fiber tows and glass fiber tows according to the ratio of 3-5: 1 to be used as weaving wefts; and the glass fiber tows in the weaving weft are uniformly spaced; arranging the prepared carbon fiber tows in a warp direction to serve as weaving warps; weaving the weaving weft and the weaving warp in a vertically staggered manner to obtain mixed woven cloth;

preparing an RTM process mould;

step three: laying composite reinforced plate

Firstly, cutting a mixed woven cloth, a carbon fiber cloth and a glass fiber cloth, and soaking the cut materials in composite epoxy resin at 130 ℃ for 20-30 min;

then, uniformly smearing a release agent on the prepared RTM process mould, and taking out the soaked mixed woven cloth and paving a second enhancement layer (12) on the RTM process mould; placing the pre-buried reinforcing structure (2) on the second reinforcing layer (12), taking out the soaked carbon fiber cloth and glass fiber cloth, and continuously laying to form a base layer (10); then, taking out the soaked mixed woven cloth and laying the mixed woven cloth on the upper surface of the base layer (10) to form a first enhancement layer (11);

and finally, closing the RTM process mold, heating to 130-160 ℃, simultaneously pumping negative pressure to 5-20 kPa, keeping for 5-8 h, and cooling to obtain the composite reinforcing plate.

6. The preparation method of the light-weight automobile body composite reinforcing plate is characterized in that the basic layer (10) laid in the third step comprises 8 layers of carbon fiber cloth and 2 layers of glass fiber cloth which are sequentially laid from bottom to top;

wherein, the laying angles of the 8 layers of carbon fiber cloth are 120 degrees, +60 degrees, 90 degrees, 0 degree, 90 degrees, -60 degrees and 120 degrees in sequence according to the arrangement direction of the carbon fiber yarns; the first layer of glass fiber cloth is clamped between +60 degrees and 90 degrees, and the second layer of glass fiber cloth is clamped between 90 degrees and-60 degrees.

7. The preparation method of the light-weight automobile body composite reinforcing plate is characterized in that the warp yarns in the second step are 12K carbon fiber tows; the weaving weft is 1200TEX glass fiber tows and 12K carbon fiber tows in a ratio of 3:1 to 1200TEX glass fiber tows.

8. The preparation method of the light-weight automobile body composite reinforcing plate is characterized in that the first reinforcing layer (11) in the third step comprises 8 layers of mixed woven cloth consisting of carbon fibers and glass fibers; wherein, the laying angles of the 8 layers of mixed woven cloth are +45 degrees, -90 degrees, -0 degrees, -45 degrees and +45 degrees from bottom to top according to the arrangement direction of the carbon fiber yarns;

the second reinforcing layer (12) has the same number of layers as the first reinforcing layer (11) and is laid symmetrically with respect to the center of the base layer (10).

9. The composite reinforcing plate for the lightweight automobile body as claimed in claim 7, wherein the edges of the mixed woven cloth of the first reinforcing layer (11) and the second reinforcing layer (12) are shrunk inwards layer by layer during the third laying step, so that the edges are triangular; wherein the ratio of the thickness of the first reinforcement layer (11) to the height of the triangle is not more than 1: 10.

10. The preparation method of the light-weight automobile body composite reinforcing plate is characterized in that the composite epoxy resin is prepared by mixing and stirring 28 parts of bisphenol A epoxy resin, 15 parts of high-temperature-toughness epoxy resin and 8 parts of aminotetrafunctional group epoxy resin at 90 ℃ for 20-30 min.

Background

Compared with other novel materials, the carbon fiber composite material vehicle body has the most obvious weight reduction effect; compared with the traditional steel vehicle body, the vehicle body made of the carbon fiber composite material can reduce more than half of the weight. The carbon fiber composite material not only has the advantages of light weight and high strength, but also has good designability. Moreover, the composite material can be integrally molded, so that the number of parts and fasteners is greatly reduced; in addition, the carbon fiber composite material is applied to an automobile body, and can improve the collision energy absorption property, the vibration reduction property and the fatigue resistance. When losing weight, guarantee vehicle collision security and promote the riding comfort.

At present, the carbon fiber composite material is applied to vehicle bodies and parts and has mass production cases abroad. BMW i8 and 7 have been applied to carbon fiber vehicle bodies. In the passenger compartment area of the BMW 7 system, the vehicle body is formed by combining a steel part, an aluminum alloy part and a carbon fiber part, and the synergistic complementation in performance among different materials is realized. The carbon fiber composite material is used as a vehicle body structure reinforcing part, so that the vehicle body weight is reduced, and the collision safety of the whole vehicle is improved.

The carbon fiber composite plate provided by the prior art is usually made of a single carbon fiber material, and the carbon fiber belongs to an anisotropic material, so that the mechanical property is unbalanced, and certain technical defects exist in the mechanical structure with complex working conditions, such as a vehicle.

Disclosure of Invention

The technical problem solved by the invention is as follows: the problems of unbalanced mechanical property and weak front impact resistance of the carbon fiber composite board in the prior art are solved.

The technical scheme of the invention is as follows: a lightweight composite reinforcing plate for an automobile body comprises a composite main body shell plate capable of being mounted on an automobile frame, an embedded reinforcing structure arranged inside the composite main body shell plate, and an external reinforcing structure arranged outside the composite main body shell plate and connected with the embedded reinforcing structure;

the composite main body shell plate comprises a first main body and a second main body, wherein the first main body is in a cambered surface shell shape, and the second main body is arranged around the periphery of the first main body and used as a flanging structure;

the first main body and the second main body respectively comprise a base layer formed by a plurality of layers of carbon fiber cloth and a plurality of layers of glass fiber cloth in a mixed manner, a first reinforcing layer arranged on the upper surface of the base layer and formed by a plurality of layers of mixed woven cloth made of carbon fiber and glass fiber, and a second reinforcing layer arranged on the lower surface of the base layer and formed by a plurality of layers of mixed woven cloth made of carbon fiber and glass fiber;

the embedded reinforcing structure comprises a first embedded metal ring arranged in the basic layer of the second main body, a second embedded metal ring arranged in the basic layer of the first main body, an arc-shaped metal strip, and a connecting piece, wherein one end of the arc-shaped metal strip is connected with the first embedded metal ring, the other end of the arc-shaped metal strip is connected with the second embedded metal ring and is positioned in the basic layer, and the connecting piece is arranged in the basic layer of the second main body;

the arc-shaped metal strips are made of spring steel and are uniformly distributed in the center of the first embedded metal ring;

the external reinforcing structure comprises a peripheral flanging reinforcing ring which is arranged on the upper end face of the first reinforcing layer and is bolted with the connecting piece, and a plurality of internal supporting rods which are arranged on the lower end face of the second reinforcing layer in a crossed mode and are bolted with the connecting piece.

Furthermore, the connecting piece includes a plurality of pre-buried stationary blades that are fixed with first pre-buried metal ring center evenly distributed and set up on the pre-buried stationary blade with peripheral turn-ups reinforcement ring, the first connecting hole of inside support rod to and set up on the pre-buried stationary blade with the second connecting hole of car frame connection. The most of load that can bear the composite reinforcement plate through the setting of pre-buried stationary blade, first connecting hole and second connecting hole is transmitted the frame from first pre-buried becket, pre-buried stationary blade on, can reduce greatly and cause the load that the composite reinforcement plate of automobile body bore in the vehicle striking, is favorable to the promotion of vehicle security performance.

Further, the first embedded metal ring is a steel ring. Most of impact load is directly transmitted to the first embedded metal ring through the arc-shaped metal strip, the uniformity of absorbed load can be ensured through the design of the steel ring, and the internal stress of the first embedded metal ring is prevented from generating and causing distortion; therefore, the front impact resistance of the composite reinforcing plate can be greatly improved.

Furthermore, the peripheral flanging reinforcing ring and the inner supporting rod are made of aluminum alloy materials; and the peripheral flanging reinforcing ring is attached to the outer edge of the first enhancement layer. Through the setting of the peripheral turn-ups reinforcing ring of aluminium system, inside bracing piece can the secondary promote the mechanical properties of compound reinforcing plate, can combine inside pre-buried additional strengthening to realize secondary protection to compound reinforcing plate, improve the life of compound reinforcing plate to a certain extent.

A preparation method of a lightweight automobile body composite reinforcing plate comprises the following steps:

the method comprises the following steps: manufacture of pre-buried reinforcing structure

Firstly, machining and manufacturing a first embedded metal ring, an embedded fixing sheet, a second embedded metal ring and an arc-shaped metal strip; then, welding and fixing two ends of the arc-shaped metal strip with the first embedded metal ring and the second embedded metal ring respectively; the embedded fixing piece and the first embedded metal ring are obtained by cutting a whole steel plate with the thickness of 0.6-1.4 mm through slow wire moving;

the size and the shape of the first embedded metal ring are determined according to the whole area of the composite reinforcing plate;

step two: manufacturing mixed woven fabric and preparation mold

Preparing carbon fiber tows and glass fiber tows; arranging the prepared carbon fiber tows and glass fiber tows according to the ratio of 3-5: 1 to be used as weaving wefts; and the glass fiber tows in the weaving weft are uniformly spaced; arranging the prepared carbon fiber tows in a warp direction to serve as weaving warps; weaving the weaving weft and the weaving warp in a vertically staggered manner to obtain mixed woven cloth;

preparing an RTM process mould;

step three: laying composite reinforced plate

Firstly, cutting a mixed woven cloth, a carbon fiber cloth and a glass fiber cloth, and soaking the cut materials in composite epoxy resin at 130 ℃ for 20-30 min;

then, uniformly coating a release agent on the prepared RTM process mould, and taking out the soaked mixed woven cloth and laying a second enhancement layer on the RTM process mould; placing a pre-buried reinforcing structure on the second reinforcing layer, taking out the soaked carbon fiber cloth and glass fiber cloth, and continuously laying to form a base layer; then, taking out the soaked mixed woven cloth and laying the mixed woven cloth on the upper surface of the base layer to form a first enhancement layer;

and finally, closing the RTM process mold, heating to 130-160 ℃, simultaneously pumping negative pressure to 5-20 kPa, keeping for 5-8 h, and cooling to obtain the composite reinforcing plate.

Further, the base layer laid in the third step comprises 8 layers of carbon fiber cloth laid in sequence from bottom to top, and 2 layers of glass fiber cloth clamped in the carbon fiber cloth;

wherein, the laying angles of the 8 layers of carbon fiber cloth are 120 degrees, +60 degrees, 90 degrees, 0 degree, 90 degrees, -60 degrees and 120 degrees in sequence according to the arrangement direction of the carbon fiber yarns; the first layer of glass fiber cloth is clamped between +60 degrees and 90 degrees, and the second layer of glass fiber cloth is clamped between 90 degrees and-60 degrees.

On the basis of 90 degrees and 0 degrees of vertical design, the shear resistance of the basic layer can be greatly improved through the arrangement of 120 degrees, 60 degrees and 120 degrees; because the carbon fiber material belongs to anisotropic material, the mechanical property of the composite reinforcing plate in the lateral direction can be compensated through the large-angle cross design, so that the capability of bearing load in all directions after the composite reinforcing plate piece is molded is relatively balanced.

Further, the weaving warp in the step two is 12K carbon fiber tows; the weaving weft is 1200TEX glass fiber tows and 12K carbon fiber tows in a ratio of 3:1 to 1200TEX glass fiber tows. Compared with small-tow carbon fiber precursors, when the large-tow carbon fiber precursors of more than 24K are used for manufacturing structures such as plates, tows are not easy to spread, the thickness of a single layer is increased, and the structural design is not facilitated; and the carbon fiber of the small tows is not easy to adhere, has less broken filaments and has small influence on the strength of the manufactured composite plate.

Further, the first reinforcing layer in the third step comprises 8 layers of mixed woven cloth consisting of carbon fibers and glass fibers; wherein, the laying angles of the 8 layers of mixed woven cloth are +45 degrees, -90 degrees, -0 degrees, -45 degrees and +45 degrees from bottom to top according to the arrangement direction of the carbon fiber yarns;

the second enhancement layer and the first enhancement layer have the same layer number and are symmetrically laid around the center of the base layer.

Because the carbon fibers have the thermal expansion phenomenon, the balanced and symmetrical layering design can effectively avoid coupling, thereby preventing the laminated plate from warping and deforming; the plus or minus 45-degree paving layer is paved close to the surface of the composite board, so that the yield strength of the composite board can be improved; the plus or minus 45-degree layering direction of the outermost layer also has the capability of bearing shear load, and simultaneously improves the shock resistance of the material.

Further, when the cloth is laid in the third step, the edges of the mixed woven cloth of the first reinforcing layer and the second reinforcing layer contract inwards layer by layer, so that the edges are triangular; wherein the ratio of the thickness of the first reinforcing layer to the height of the triangle is not more than 1: 10. The triangular transition design for realizing the edge of the composite reinforced plate can prevent the edge from generating cracks, so that potential safety hazards exist in the composite reinforced plate, the forming quality of the edge of the composite reinforced plate is effectively improved, and the service life is prolonged.

Further, the composite epoxy resin is prepared by mixing and stirring 28 parts of bisphenol A epoxy resin, 15 parts of high-temperature toughness epoxy resin and 8 parts of amino tetrafunctional group epoxy resin at 90 ℃ for 20-30 min. The viscosity of the epoxy resin after composite modification is greatly increased, and the high-temperature viscosity interval of a resin system can be expanded and prolonged, so that the mechanical property of the cured resin can be effectively improved, and the tensile strength and the impact strength of the composite reinforcing plate can be enhanced.

The invention has the beneficial effects that: according to the lightweight composite reinforcing plate for the automobile body, provided by the invention, composite materials such as carbon fibers and glass fibers are combined with metal materials, and the metal framework which is made of the metal materials and is directly connected with a frame is pre-embedded in the center of the composite materials, so that the mechanical property of the composite reinforcing plate can be greatly improved; compared with the traditional composite carbon fiber plate, the front impact resistance of the composite reinforcing plate can be greatly improved, and the impact load bearing capacity of the vehicle body can be greatly improved; when the front side impact breaks through the load bearing capacity of the composite reinforcing plate, the composite reinforcing plate is collapsed due to the design of the metal embedded structure, most of impact is absorbed, and the composite material is few in fragments after being broken and weak in penetrating capacity; the safety performance of the vehicle can be greatly improved.

According to the preparation method of the lightweight automobile body composite reinforcing plate, the carbon fiber cloth and the glass fiber cloth are layered and the carbon fiber tows and the glass fiber tow mixed woven cloth are designed, so that the mechanical strength of the pure carbon fiber cloth can be improved to a certain degree, the impact resistance of the composite reinforcing plate is improved, and the heat resistance and the corrosion resistance of the formed composite reinforcing plate are improved.

Drawings

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

FIG. 2 is a schematic cross-sectional view of a composite body skin in accordance with example 1 of the present invention;

fig. 3 is a schematic structural view of an embedded reinforcement structure in embodiment 1 of the present invention;

the composite structure comprises a 1-composite main body shell plate, a 10-base layer, a 11-first enhancement layer, a 12-second enhancement layer, a 2-embedded reinforcement structure, a 20-first embedded metal ring, a 21-second embedded metal ring, a 22-arc metal strip, a 23-connecting piece, a 230-embedded fixing piece, a 231-first connecting hole, a 232-second connecting hole, a 3-external reinforcement structure, a 30-peripheral flanging reinforcing ring, a 31-internal supporting rod, a 4-first main body and a 5-second main body.

Detailed Description

Example 1:

as shown in fig. 1, the composite reinforcing plate for the lightweight automobile body comprises a composite main body shell plate 1 capable of being mounted on an automobile frame, an embedded reinforcing structure 2 arranged inside the composite main body shell plate 1, and an external reinforcing structure 3 arranged outside the composite main body shell plate 1 and connected with the embedded reinforcing structure 2;

the composite main body shell plate 1 comprises a first main body 4 in a cambered surface shell shape, and a second main body 5 which is arranged around the periphery of the first main body 4 and is used as a flanging structure;

the first main body 4 and the second main body 5 respectively comprise a basic layer 10 formed by laying 8 layers of carbon fiber cloth and 2 layers of glass fiber cloth in a mixed manner, a first enhancement layer 11 arranged on the upper surface of the basic layer 10 and formed by laying a plurality of layers of mixed woven cloth made of carbon fiber and glass fiber, and a second enhancement layer 12 arranged on the lower surface of the basic layer 10 and formed by laying a plurality of layers of mixed woven cloth made of carbon fiber and glass fiber;

the embedded reinforcing structure 2 comprises a first embedded metal ring 20 arranged in the basic layer 10 of the second main body 5, a second embedded metal ring 21 arranged in the basic layer 10 of the first main body 4, an arc-shaped metal strip 22 with one end connected with the first embedded metal ring 20 and the other end connected with the second embedded metal ring 21 and positioned in the basic layer 10, and a connecting piece 23 arranged in the basic layer 10 of the second main body 5;

the arc-shaped metal strips 22 are 36 metal strips made of spring steel and are uniformly distributed in the center of the first embedded metal ring 20;

the outer reinforcing structure 3 comprises a peripheral flanged reinforcing ring 30 disposed on the upper end surface of the first reinforcing layer 11 and bolted to the connecting member 23, and 3 inner support rods 31 crosswise disposed on the lower end surface of the second reinforcing layer 12 and bolted to the connecting member 23.

The connecting piece 23 includes 6 pre-buried stationary sheets 230 that are fixed with first pre-buried becket 20 center evenly distributed, set up on pre-buried stationary sheet 230 with peripheral turn-ups reinforcement ring 30, the first connecting hole 231 of inside bracing piece 31 to and set up on pre-buried stationary sheet 230 with the second connecting hole 232 of vehicle frame connection.

The first embedded metal ring 20 is a steel ring with a thickness of 0.6 mm.

The peripheral flanging reinforcing ring 30 and the inner supporting rod 31 are made of aluminum alloy materials; and the peripheral flange reinforcing ring 30 is attached to the outer edge of the first reinforcing layer 11.

Wherein, the composite reinforcing plate is connected with the external automobile frame through the second connecting hole 232 by bolts.

Example 2:

the present example illustrates a method for manufacturing a lightweight composite automotive body gusset of example 1, including the steps of:

the method comprises the following steps: manufacture of pre-buried reinforcing structure

Firstly, machining and manufacturing a first embedded metal ring 20, an embedded fixing sheet 230, a second embedded metal ring 21 and an arc-shaped metal strip 22; then, welding and fixing two ends of the arc-shaped metal strip 22 with the first embedded metal ring 20 and the second embedded metal ring 21 respectively; the embedded fixing sheet 230 and the first embedded metal ring 20 are obtained by cutting a whole steel plate with the thickness of 0.6mm through slow wire walking;

the first embedded metal ring 20 is a steel ring with the diameter of 63 cm;

step two: manufacturing mixed woven fabric and preparation mold

Preparing 12K carbon fiber tows and 1200TEX glass fiber tows; arranging the prepared carbon fiber tows and glass fiber tows according to the ratio of 3:1 to be used as weaving wefts; and the glass fiber tows in the weaving weft are uniformly spaced; arranging the prepared carbon fiber tows in a warp direction to serve as weaving warps; weaving the weaving weft and the weaving warp in a vertically staggered manner to obtain mixed woven cloth;

preparing an RTM process mould;

step three: laying composite reinforced plate

Firstly, cutting a mixed woven cloth, a carbon fiber cloth and a glass fiber cloth, and soaking the cut materials in composite epoxy resin at 130 ℃ for 20 min; the composite epoxy resin is prepared by mixing and stirring 28 parts of bisphenol A epoxy resin, 15 parts of high-temperature tough epoxy resin and 8 parts of amino tetrafunctional group epoxy resin at 90 ℃ for 20 min;

then, uniformly coating a release agent on the prepared RTM process mould, and taking out the soaked mixed woven cloth and laying a second enhancement layer 12 on the RTM process mould; placing the pre-buried reinforcing structure 2 on the second reinforcing layer 12, taking out the soaked carbon fiber cloth and glass fiber cloth, and continuously laying to form a base layer 10; then, taking out the soaked mixed woven cloth and laying the mixed woven cloth on the upper surface of the base layer 10 to form a first enhancement layer 11;

and finally, closing the RTM process mold, heating to 130 ℃, simultaneously pumping negative pressure to 20kPa, keeping for 5h, and cooling to obtain the composite reinforcing plate.

The base layer 10 laid in the third step comprises 8 layers of carbon fiber cloth laid in sequence from bottom to top, and 2 layers of glass fiber cloth clamped in the carbon fiber cloth; the laying angles of the 8 layers of carbon fiber cloth are 120 degrees, +60 degrees, 90 degrees, 0 degree, 90 degrees, -60 degrees and 120 degrees in sequence according to the arrangement direction of the carbon fiber yarns; the first layer of glass fiber cloth is clamped between +60 degrees and 90 degrees, and the second layer of glass fiber cloth is clamped between 90 degrees and-60 degrees.

The first enhancement layer 11 laid in the third step comprises 8 layers of mixed woven cloth consisting of carbon fibers and glass fibers; wherein, the laying angles of the 8 layers of mixed woven cloth are +45 degrees, -90 degrees, -0 degrees, -45 degrees and +45 degrees from bottom to top according to the arrangement direction of the carbon fiber yarns;

the second reinforced layer 12 and the first reinforced layer 11 have the same layer number and are symmetrically laid around the center of the base layer 10; the edges of the first reinforcing layer 11 and the second reinforcing layer 12 are shrunk inwards layer by layer to form a triangle; wherein the ratio of the thickness of the first reinforcing layer 11 to the height of the triangle is 0.08.

Example 3:

the difference from example 2 is: in the first step, the pre-buried fixing sheet 230 and the first pre-buried metal ring 20 are obtained by cutting a whole steel plate with the thickness of 1.2mm through slow wire-moving;

wherein, the first pre-buried metal ring 20 is a rectangular steel ring with the side length of 55 cm;

preparing 8K carbon fiber tows and 800TEX glass fiber tows in the second step; arranging the prepared carbon fiber tows and glass fiber tows according to the proportion of 5:1 to be used as weaving wefts; weaving the weaving weft and the weaving warp in a vertically staggered manner to obtain mixed woven cloth;

in the third step, the cut material is put into the composite epoxy resin to be soaked for 30min at the temperature of 130 ℃; the composite epoxy resin is prepared by mixing and stirring 28 parts of bisphenol A epoxy resin, 15 parts of high-temperature tough epoxy resin and 8 parts of amino tetrafunctional group epoxy resin at 90 ℃ for 30 min;

and (3) heating to 160 ℃ in the mold closing process of the RTM process, simultaneously pumping negative pressure to 12kPa, keeping for 6.5h, and cooling to obtain the composite reinforcing plate.

The base layer 10 laid in the third step comprises 7 layers of carbon fiber cloth laid in sequence from bottom to top and 2 layers of glass fiber cloth clamped in the carbon fiber cloth; the laying angles of the 7 layers of carbon fiber cloth are 120 degrees, +60 degrees, 90 degrees, 0 degree, 90 degrees, -60 degrees and 120 degrees in sequence according to the arrangement direction of the carbon fiber yarns; the first layer of glass fiber cloth is clamped between +60 degrees and 90 degrees, and the second layer of glass fiber cloth is clamped between 90 degrees and-60 degrees.

The first enhancement layer 11 laid in the third step comprises 7 layers of mixed woven cloth consisting of carbon fibers and glass fibers; wherein, the laying angles of the 7 layers of mixed woven cloth are +45 degrees, -90 degrees, -0 degrees, -90 degrees, -45 degrees and +45 degrees from bottom to top according to the arrangement direction of the carbon fiber yarns;

example 4: the difference from example 2 is: in the first step, the pre-buried fixing sheet 230 and the first pre-buried metal ring 20 are obtained by cutting a whole steel plate with the thickness of 0.8mm through slow wire-moving;

the first embedded metal ring 20 is a steel ring with the diameter of 55 cm;

preparing 10K carbon fiber tows and 800TEX glass fiber tows in the second step; arranging the prepared carbon fiber tows and glass fiber tows according to the ratio of 4:1 to be used as weaving wefts; weaving the weaving weft and the weaving warp in a vertically staggered manner to obtain mixed woven cloth;

in the third step, the cut material is put into the composite epoxy resin to be soaked for 25min at the temperature of 130 ℃; the composite epoxy resin is prepared by mixing and stirring 28 parts of bisphenol A epoxy resin, 15 parts of high-temperature tough epoxy resin and 8 parts of amino tetrafunctional group epoxy resin at 90 ℃ for 25 min;

and (3) heating to 145 ℃ in the mold closing process of the RTM process, simultaneously pumping negative pressure to 5kPa, keeping for 8h, and cooling to obtain the composite reinforcing plate.

The basic layer 10 laid in the third step comprises 9 layers of carbon fiber cloth laid in sequence from bottom to top, and 2 layers of glass fiber cloth clamped in the carbon fiber cloth; the laying angles of the 9 layers of carbon fiber cloth are 120 degrees, +60 degrees, +45 degrees, 0 degree, 90 degrees, 0 degree, -45 degrees, -60 degrees and 120 degrees in sequence according to the arrangement direction of the carbon fiber yarns; the first layer of glass fiber cloth is clamped between +60 degrees and +45 degrees, and the second layer of glass fiber cloth is clamped between-45 degrees and-60 degrees.

The first enhancement layer 11 laid in the third step comprises 9 layers of mixed woven cloth consisting of carbon fibers and glass fibers; wherein, the laying angles of the 8 layers of mixed woven cloth from bottom to top are +45 degrees, -0 degrees, -90 degrees, -0 degrees, -45 degrees and +45 degrees in sequence according to the arrangement direction of the carbon fiber yarns.

Test example: composite reinforcing plates capable of being connected with an automobile frame are prepared according to the methods of the above examples 2, 3 and 4, and the obtained composite reinforcing plates are subjected to experimental detection, so that the following data are obtained:

table 1: comparison of mechanical parameters of composite reinforcing plate and steel body plate

Steel plates with the thickness of more than 1.8mm are generally adopted at the positions needing to be reinforced by steel body plates connected with a frame; the thickness of the composite reinforcing plate obtained by the method is 5-6 mm; the data in Table 1 show that example 3 is the best embodiment of the method, and the tensile strength can reach 2895 MPa.

By combining the density, tensile strength and elastic modulus data in the table 1, the strength of the vehicle application plate can be improved to a great extent, the safety performance of the vehicle is improved, the weight reduction of the vehicle can be realized, and the composite plate has the advantages of light weight and high strength and has obvious progress in the technical field of automobile body composite plates.