Three-layer structured ultrasonic design composite material and preparation method thereof

Abstract

The invention discloses a three-layer structured ultrasonic design composite material and a preparation method thereof, the three-layer structured ultrasonic design composite material comprises an upper layer fiber layer unit, a middle layer fiber layer unit and a lower layer fiber layer unit, the middle layer fiber layer unit is a cross microstructure, the upper layer fiber layer unit and the lower layer fiber layer unit are respectively a spiral microstructure, and the spiral microstructure is a cross microstructure. The upper-layer fiber laying unit, the middle-layer fiber laying unit and the lower-layer fiber laying unit are respectively provided with different fiber laying directions and laying angles, and the laying angles of the upper-layer fiber laying unit and the laying angles of the lower-layer fiber laying unit are symmetrically arranged. According to the ultrasonic design composite material, the structures and the arrangement modes of the upper, middle and lower fiber laying units are improved, so that the laying modes and laying angles of the three-layer structure are obviously different, the stress form of the three-layer structure is improved, the layering damage position of the composite material can be effectively predicted, a weak interface is improved, and the service life of the composite material is prolonged. The characteristics of high strength and high toughness of the composite material can be considered.

Description

Technical Field

[0001] The present invention relates to the technical field of composite materials, and particularly relates to a three-layer ultrasonically designed composite material and a preparation method thereof. Background Art

[0002] Fiber-reinforced resin matrix composites have been widely used in the fields of national defense, aviation, etc. due to their many advantages such as high specific strength, high specific modulus, strong designability of material properties, good corrosion resistance and durability. Many advantages of carbon fiber-reinforced resin matrix composites also include light weight, high strength, fatigue resistance, corrosion resistance, flexible design possibilities and excellent impact resistance. These advantages make composite materials an indispensable material in the field of modern science and technology, significantly improving performance, durability and economy, and at the same time meeting the requirements of the development of various fields and promoting technological innovation and development.

[0003] Due to the difference in mechanical properties of the two-phase materials, traditional fiber-reinforced composites are prone to damage and cause structural failure. The main failure types include fiber fracture and interlayer delamination. Although composite materials have high strength, they are usually more brittle than metals, especially when subjected to impact or sudden loads, and are prone to fracture or breakage. Although the reinforcing fibers can provide high strength, the overall fracture toughness of composite materials is relatively poor, and crack propagation is likely to occur when subjected to uneven stress or impact. Therefore, the structure of composite materials needs to be further improved. Summary of the Invention

[0004] The purpose of the present invention is to provide a three-layer ultrasonically designed composite material and a preparation method thereof for the problems existing in the prior art.

[0005] To achieve the above purpose, the technical solution adopted by the present invention is: A three-layer ultrasonically designed composite material includes an upper layer fiber laying unit, an intermediate layer fiber laying unit and a lower layer fiber laying unit. The intermediate layer fiber laying unit is a cross microstructure, and the upper layer fiber laying unit and the lower layer fiber laying unit are respectively spiral microstructures. The upper layer fiber laying unit, the intermediate layer fiber laying unit and the lower layer fiber laying unit are respectively provided with different fiber laying directions and laying angles, and the laying angles of the upper layer fiber laying unit and the lower layer fiber laying unit are symmetrically arranged.

[0006] This three-layer ultrasonically designed composite material improves the structure and arrangement mode of the upper, middle and lower three-layer fiber laying units, making the laying mode and laying angle of the three-layer structure have obvious differences, improving the stress form of the three-layer structure, being able to effectively predict the position of delamination failure of the composite material, and at the same time being able to take into account the characteristics of high strength and high toughness of the composite material.

[0007] When the composite material is subjected to external loads, the continuous fiber plies in the upper and lower layers enable the structure to undergo large deformations. The fiber stretching, fiber pull-out, and delamination within the same fiber ply absorb part of the energy. At the same time, numerous small tunnel cracks appear in the cross structure of the middle layer, and fiber bridging, fiber slip, and resin matrix stretching consume a large amount of energy, effectively preventing crack propagation in the thickness direction. The main failure mode of the composite material specimen is delamination failure at the large interface of the macroscopic three layers, effectively solving the drawback of traditional composite materials being difficult to predict the delamination failure location. At the same time, the periodic variation of the fiber ply laying method in the three layers effectively solves the problem of mutual exclusion between strength and toughness and insufficient fracture toughness of traditional composite materials.

[0008] Further, the middle layer fiber ply unit includes several first fiber sheets, and the several first fiber sheets are sequentially cross-laid along the overall width direction.

[0009] Further, adjacent first fiber sheets are orthogonally arranged along the overall width direction, or adjacent first fiber sheets are cross-laid at ±45° along the overall width direction, with 180 degrees as one spiral period.

[0010] Further, the upper layer fiber ply unit and the lower layer fiber ply unit respectively include multiple second fiber sheets, and the several second fiber sheets are sequentially spiral-laid along the overall thickness direction. The multiple second fiber sheets in the upper layer fiber ply unit and the multiple second fiber sheets in the lower layer fiber ply unit are symmetrically arranged up and down.

[0011] Further, the second fiber sheets with the same layer sequence in the upper layer fiber ply unit and the lower layer fiber ply unit are periodically spiral-laid along the ply direction.

[0012] Further, adjacent second fiber sheets within each spiral period have a consistent spiral rotation angle. The spiral period is an integer multiple of 180°, and the corresponding number of spiral periods of the upper layer fiber ply unit and the lower layer fiber ply unit is greater than or equal to 1.

[0013] Further, the spiral rotation angle is 0° to 90°.

[0014] Further, resin adhesive films are respectively added at the interfaces of the upper layer fiber ply unit, the middle layer fiber ply unit, and the lower layer fiber ply unit, and toughening agents are evenly sprinkled.

[0015] A preparation method of a three-layer structure ultra-sonic design composite material, the preparation method includes the following steps: Cut out several unidirectional fiber cloth prepregs infiltrated with resin; Lay up several single - layer unidirectional fiber cloth prepregs in sequence according to a preset angle in a periodic sequence to obtain several spiral - periodic fiber lay - up units, and place the laid - up fiber lay - up units into the mold cavity; Hot - press the several fiber lay - up units arranged in a spiral - periodic manner in the mold cavity at a preset temperature, a preset pressure, and for a preset time to obtain an upper - layer fiber lay - up unit and a lower - layer fiber lay - up unit of a single - layer macroscopic layer; Cut the preset unidirectional fiber cloth prepreg used as the intermediate layer into the required size to obtain an intermediate - layer specimen. Rotate the cut intermediate - layer specimen 90° along the long - axis direction, and then stack the rotated intermediate - layer specimens in an orderly manner so that the laying method of the intermediate - layer specimens is along the width direction. After sequential laying, an intermediate - layer fiber lay - up unit is obtained; Bond the upper - layer fiber lay - up unit and the lower - layer fiber lay - up unit with the intermediate - layer fiber lay - up unit through a resin film and evenly sprinkle toughening agents, and place the laid - up three - layer fiber lay - up unit into the mold cavity; Perform secondary curing hot - press molding on the three - layer fiber lay - up units arranged in a periodic manner in different directions in the mold cavity at a preset temperature, a preset pressure, and for a preset time to obtain a three - layer - structured ultra - sound - designed composite material.

[0016] Furthermore, the fibers used in the unidirectional fiber cloth prepreg are one or more of carbon fiber, glass fiber, basalt fiber, and aramid fiber, and the resin is a thermosetting resin or a thermoplastic resin; the preset temperature, the preset pressure, the preset time, and the type of curing agent used during hot - press molding are determined according to the type of fiber and the type of resin.

[0017] For the ultra - sound - designed composite material prepared by this preparation method, due to the differences in the laying method and laying angle of the three - layer structure, when the composite material is subjected to an external load, the continuous fiber lay - ups in the upper and lower layers enable the structure to undergo large deformations. The fiber stretching, fiber pull - out, and delamination within the same fiber lay - up absorb part of the energy. At the same time, numerous small tunnel cracks appear in the cross - structure of the intermediate layer, and fiber bridging, fiber slip, and the stretching of the resin matrix consume a large amount of energy, effectively preventing the crack from expanding in the thickness direction, and greatly improving the material properties.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. Through the improvement of the structure and arrangement of the upper, middle, and lower fiber ply units of the present three-layer ultra-sonic design composite material, there are obvious differences in the laying method and laying angle of the three-layer structure, improving the stress form of the three-layer structure, being able to effectively predict the position of delamination failure of the composite material, and at the same time being able to take into account the characteristics of high strength and high toughness of the composite material; 2. The present three-layer ultra-sonic design composite material not only improves the laying arrangement of the upper, middle, and lower three-layer structures, but also improves the laying method of the laminae in each ply unit, improving the layered structure of the entire composite material from micro to macro, and effectively improving the various properties of the composite material; 3. When the composite material is subjected to external loads, the continuous fiber plies in the upper and lower layers enable the structure to undergo large deformations. The fiber stretching, fiber pull-out, and delamination within the same fiber ply absorb part of the energy. At the same time, numerous small tunnel cracks appear in the cross structure of the middle layer, and fiber bridging, fiber slip, and resin matrix stretching consume a large amount of energy, effectively preventing the crack from expanding in the thickness direction. The main failure mode of the composite material specimen is delamination failure at the large interface of the macroscopic three layers, effectively solving the drawback that it is difficult to predict the position of delamination failure of traditional composite materials. At the same time, the periodically changing laying method of the three-layer fiber plies effectively solves the problem of mutual exclusion between strength and toughness and insufficient fracture toughness of traditional composite materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the overall structure of a three-layer ultra-sonic design composite material of the present invention; Figure 2 is Figure 1 the front view of the three-layer ultra-sonic design composite material in Figure 3 is Figure 1 the side view of the three-layer ultra-sonic design composite material in Figure 4 is Figure 1 the top view of the three-layer ultra-sonic design composite material in Figure 5 is Figure 1 the front view of the upper or lower layer structure of the three-layer ultra-sonic design composite material in Figure 6 is Figure 1 the side view of the upper or lower layer structure of the three-layer ultra-sonic design composite material in Figure 7 is Figure 1 the front view of the middle layer structure of the three-layer ultra-sonic design composite material in Figure 8 is Figure 1 the side view of the middle layer structure of the three-layer ultra-sonic design composite material in Figure 9 Yes Figure 1 Top view of the middle layer structure of the ultrasonic design composite material with a three-layer structure; In the figure: 1. Upper layer fiber ply unit; 2. Middle layer fiber ply unit; 3. Lower layer fiber ply unit; 4. First fiber sheet layer; 5. Second fiber sheet layer. Specific implementation manner

[0020] Next, the technical solutions of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work conditions belong to the scope of protection of the present invention.

[0021] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "middle", "upper", "lower", "left", "right", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. Embodiment 1

[0022] As Figures 1 to 9 shown, a three-layer structure ultrasonic design composite material includes an upper layer fiber ply unit 1, a middle layer fiber ply unit 2, and a lower layer fiber ply unit 3. The middle layer fiber ply unit 2 is a cross microstructure, and the upper layer fiber ply unit 1 and the lower layer fiber ply unit 3 are respectively spiral microstructures. The upper layer fiber ply unit 1, the middle layer fiber ply unit 2, and the lower layer fiber ply unit 3 are respectively provided with different fiber laying directions and laying angles, and the laying angles of the upper layer fiber ply unit 1 and the lower layer fiber ply unit 3 are symmetrically arranged.

[0023] The ultrasonic design composite material with this three-layer structure improves the structure and arrangement of the upper, middle, and lower layer fiber ply units, making the laying methods and laying angles of the three-layer structure significantly different, improving the stress form of the three-layer structure, being able to effectively predict the position of delamination failure of the composite material, and improving the weak interface targeted, so that it can simultaneously take into account the characteristics of high strength and high toughness of the composite material.

[0024] In addition, the concept of a targeted interface is introduced. Due to the discontinuity of the material properties of the three-layer structure, analyzing the interlayer stress according to the solution of elasticity mechanics, even in the ideal state where the bonding of the three-layer interface is good, without defects, and can effectively transfer the load, the interlayer shear stress at the three-layer interface is still the largest and most prone to delamination failure. Therefore, to fully utilize the mechanical properties of the material, it is crucial to design the targeted interface of the structure and improve the mechanical properties between layers. Adding toughening agents to increase the fracture toughness of the three-layer interface is an effective method.

[0025] The ultrasonic-designed composite material with a three-layer structure not only improves the laying method of the upper, middle, and lower three-layer structures but also improves the laying method of the laminae in each laying unit of each layer, improving the layered structure of the entire composite material from the micro to the macro scale and effectively enhancing the various properties of the composite material. Specifically, the laying directions of the three macro fiber laying units (fiber laying groups) are not the same. The laying directions of the upper and lower layers are along the thickness direction, and the laying direction of the middle layer is along the width direction; the fiber layers with the same layer sequence in each fiber laying group are spirally laid periodically along the laying direction.

[0026] When the composite material is subjected to an external load, the continuous fiber laying of the upper and lower layers enables the structure to undergo large deformations. The stretching of the fibers, the pulling out of the fibers, and delamination within the same fiber laying absorb part of the energy. At the same time, numerous small tunnel cracks appear in the cross structure of the middle layer, and fiber bridging, fiber slip, and the stretching of the resin matrix consume a large amount of energy, effectively preventing the crack from expanding in the thickness direction. The main failure mode of the composite material specimen is delamination failure at the large interface of the macroscopic three layers, effectively solving the drawback of traditional composite materials being difficult to predict the delamination failure position. At the same time, the periodically varying laying method of the three-layer fiber laying effectively solves the problem of mutual exclusivity between strength and toughness and insufficient fracture toughness of traditional composite materials.

[0027] Furthermore, the middle layer fiber laying unit 2 includes several first fiber laminae 4, and several of the first fiber laminae 4 are cross-laid in sequence along the overall width direction.

[0028] The upper layer fiber laying unit 1 and the lower layer fiber laying unit 3 each contain multiple second fiber laminae 5, and several of the second fiber laminae 5 are spirally laid in sequence along the overall thickness direction. The multiple second fiber laminae in the upper layer fiber laying unit 1 and the multiple second fiber laminae in the lower layer fiber laying unit 3 are symmetrically arranged up and down.

[0029] As Figure 1As shown in the figure, for a macroscopic three-dimensional composite material, assuming its length direction is the X-axis direction, its width direction is the Y-axis direction, and its thickness direction (height direction) is the Z-axis direction, each first fiber ply of the intermediate layer fiber ply unit is arranged in a cross-laminated manner in sequence along the Y-axis direction, and each second fiber ply in the upper layer fiber ply unit and the lower layer fiber ply unit is stacked in the Z-axis direction; in this three-layer structure ultrasonic design composite material, each fiber ply of the three macroscopic fiber ply units is arranged in a periodic spiral along its respective ply direction. Since the arrangement method of the upper and lower layers is changed, a relatively obvious large interface is formed among the upper, middle, and lower layers. When the overall composite material is abnormally stressed and damage occurs, the position of delamination failure can be effectively predicted to come from the large interface.

[0030] The upper layer fiber ply unit 1 and the lower layer fiber ply unit 3 are not only arranged in the same ply direction, but also the upper and lower layers are symmetrically arranged with the intermediate layer as the symmetry axis, which is also beneficial to improving its strength and toughness.

[0031] Furthermore, adjacent first fiber plies 4 are orthogonally arranged along the overall width direction, that is, adjacent first fiber plies are deflected by 90 degrees, and the fibers of adjacent layers are perpendicular in space; alternatively, adjacent first fiber plies are arranged in a ±45° cross along the overall width direction, that is, adjacent first fiber plies are deflected by 45 degrees, and 180 degrees is a spiral period, and four first fiber plies form a spiral unit.

[0032] Furthermore, the second fiber plies 5 with the same layer sequence in the upper layer fiber ply unit 1 and the lower layer fiber ply unit 3 are arranged in a periodic spiral along the ply direction.

[0033] Furthermore, adjacent second fiber plies 5 within each spiral period have a consistent spiral rotation angle, that is, adjacent second fiber plies 5 are deflected by a certain angle, and this angle is the spiral rotation angle. Completing one spiral period forms a spiral unit. The spiral period is an integer multiple of 180°, and the number of spiral periods corresponding to the upper layer fiber ply unit 1 and the lower layer fiber ply unit 3 is greater than or equal to 1.

[0034] Furthermore, the spiral rotation angle is between 0° and 90°.

[0035] Furthermore, resin adhesive films are respectively added at the interfaces of the upper layer fiber ply unit 1, the intermediate layer fiber ply unit 2, and the lower layer fiber ply unit 3, and toughening agents are evenly sprinkled. This is the treatment method for the interfaces between the three macroscopic plies. After such treatment, the bonding strength between the large layers of the composite material can be improved, the anti-shear strength between the large layers can be increased, and the risk of interlayer delamination can be reduced.

[0036] The improvement of the properties of fiber-reinforced composites by traditional means has entered a bottleneck period. The present invention proposes a new laying structure scheme to improve the problems of poor fracture toughness and low damage energy dissipation of fiber-reinforced composites. This composite material is not only a bionic design, but more prominently a supersonic design, which proposes a new structure based on the research of species. The queen conch is a mollusk of the family Strombidae in the order Neogastropoda. The shell of its adult consists of aragonite lamellar calcium carbonate accounting for about 99% of the volume fraction and 1% of the protein matrix. Its fracture toughness can even reach thousands of times that of its constituent materials. This characteristic far exceeding the mechanical properties of its component materials is attributed to the three-layer orthogonal microstructure of the conch shell. The main toughening mechanisms of the cross-layered structure of the conch shell are crack bridging and crack deflection. The increase in fracture toughness is achieved through the energy dissipation brought by the interfacial delamination between the first-order lamellae and the second-order lamellae. Crustaceans such as mantis shrimps and lobsters have evolved spiral microstructures as their main offensive mechanisms to prey on their victims. Their forelimbs resemble the forearms of mantises and can exert force quickly like springs. Mantis shrimps use these pincers to attack at a speed of dozens of meters per second, generating a strong impact force sufficient to break the shells of their prey without obvious damage to their own structures. Current research has elaborated on the excellent mechanical properties of the spiral structure. When there is a small rotation angle between consecutive layers, this structure exhibits isotropy to external loads at the macroscopic scale. The spiral structure exhibits high and direction-independent fracture toughness on the spiral plane of nanofibers. This significant advantage enables the material to have superior load-bearing capacity in all directions.

[0037] Based on the three-layer cross-layered microstructure of the conch shell and the spiral microstructure of the lobster claw in nature, in order to solve the problems that traditional fiber-reinforced resin-based composites are difficult to simultaneously meet the requirements of high strength and high toughness, are prone to fracture or breakage, have relatively poor overall fracture toughness, and are prone to crack propagation when subjected to uneven stress or impact, the present invention provides a supersonic design high-performance composite material combining the characteristics of the cross-layered microstructure of the conch shell and the spiral microstructure of the lobster claw. The supersonic design composite material includes: retaining the three-layer macroscopic microstructure imitating the conch shell and the orthogonal microstructure in which the middle-layer fiber plies are laid out along the width direction, and replacing the upper and lower layers with spiral structures in which the fiber plies are laid out along the thickness direction, and there is a periodically changing spiral rotation angle between adjacent fiber plies; the three-layer structure has different fiber laying directions and laying angles. The middle-layer fiber plies are laid out along the width direction, and the laying directions of the fiber plies in the upper and lower layers are along the thickness direction, and the laying angles are symmetrically arranged. Example 2

[0038] A preparation method of a supersonic design composite material with a three-layer structure, the preparation method comprising the following steps: Step 1: Cut out a number of unidirectional fiber cloth prepregs impregnated with resin; Step 2: Arrange a number of single-layer unidirectional fiber cloth prepregs in a periodic sequence at a preset angle in a machine or manual laying manner to obtain a number of spiral periodic fiber laying units, and place the laid fiber laying units into the mold cavity; Step 3: Thermally press and form the number of fiber laying units arranged in a spiral periodic manner in the mold cavity at a preset temperature, preset pressure, and preset time to obtain an upper fiber laying unit and a lower fiber laying unit of a single-layer macroscopic layer; Step 4: Use a wire cutting machine to cut the preset unidirectional fiber cloth prepreg used as the intermediate layer into the required size to obtain an intermediate layer specimen. Rotate the cut intermediate layer specimen 90° along the long axis direction, and then stack the rotated intermediate layer specimens in an orderly manner so that the laying method of the intermediate layer specimens is along the width direction. After sequential laying, an intermediate layer fiber laying unit is obtained; Step 5: Bond the upper fiber laying unit and the lower fiber laying unit with the intermediate layer fiber laying unit together with a resin film, add a toughening agent, and place the laid three-layer fiber laying unit into the mold cavity; Step 6: Thermally press and form the three-layer fiber laying unit arranged in a periodic manner in different directions in the mold cavity at a preset temperature, preset pressure, and preset time to obtain a three-layer structure ultra-sonic design composite material.

[0039] For the ultra-sonic design composite material prepared by this preparation method, due to the differences in the laying method and laying angle of the three-layer structure, when the composite material is subjected to an external load, the continuous fiber laying in the upper and lower layers enables the structure to undergo large deformations. The fiber stretching, fiber pull-out, and delamination within the same fiber laying absorb part of the energy. At the same time, numerous fine tunnel cracks appear in the cross structure of the intermediate layer, and fiber bridging, fiber slip, and the stretching of the resin matrix consume a large amount of energy, effectively preventing the crack from expanding in the thickness direction, and greatly improving the material properties.

[0040] Furthermore, the fiber used in the unidirectional fiber cloth prepreg is one or more of carbon fiber, glass fiber, basalt fiber, and aramid fiber, and the resin is a thermosetting resin or a thermoplastic resin; the preset temperature, the preset pressure, the preset time, and the type of curing agent used during the thermocompression molding are determined according to the type of the fiber and the type of the resin. Through the fiber prepreg infiltrated with resin, the fiber cloths are well combined with each other through physical and chemical actions, thereby improving the mechanical properties of the composite material.

[0041] When preparing the composite material of the ultrasonic design, a marking method for different laminated fiber materials is also provided, so that the fiber laminations can correspond to different lamination directions and lamination angles without error.

[0042] In a specific embodiment, the three-layer lamination corresponds to different lamination directions and lamination angles. The period corresponding to a number of the fiber lamination groups (upper layer fiber lamination unit, middle layer fiber lamination unit, and lower layer fiber lamination unit) is 180°, and one cycle is 180° of helix; the number of periods corresponding to a number of the fiber lamination groups is greater than or equal to 1. For example, when the helix angle of a number of the fiber lamination groups is 10°, the composite material is marked as B-10 helix structure; when the helix angle of the fiber lamination group is 45°, the composite material is marked as B-45 helix structure; when the laying angle of the fiber lamination group is ±45° cross arrangement, the composite material is marked as A-45 cross structure. By analogy, when the helix angle of a number of the fiber lamination groups is n°, the composite material is marked as B-n helix structure.

[0043] According to the different fiber content per unit volume, the thickness of the prepreg is different. In a specific embodiment, the ultra-thin prepreg is marked as T, and the conventional prepreg is not marked. The use of the ultra-thin prepreg can provide more possibilities for the refined design of the composite material. For example, when the helix angle of a number of the fiber lamination groups is 10° and the ultra-thin laminated prepreg is used, the composite material is marked as BT-10 helix structure; when the helix angle of the fiber lamination group is 45° and the ultra-thin laminated prepreg is used, the composite material is marked as BT-45 helix structure.

[0044] Specifically, the helix rotation angle corresponding to a number of the fiber lamination groups refers to the helix rotation angle between adjacent fiber sheets. For example, taking Figure 5 the shown helical lamination structure as an example, the laying directions of the upper and lower layers of the three-layer structure are along the z direction, the helix period is 180°, Figure 5 and the corresponding helix angle is 45°; taking Figure 7 the shown helical lamination structure as an example, the laying direction of the middle layer of the three-layer structure is along the y direction, the helix period is 180°, Figure 7 and the corresponding is ±45° cross structure. In a specific implementation scheme, the helix rotation angle corresponding to the fiber sheet is 0° to 90°.

[0045] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A three-layer super-engineered composite material, characterized in that: The invention comprises an upper fiber layer unit, a middle fiber layer unit and a lower fiber layer unit, wherein the middle fiber layer unit is a cross microstructure, the upper fiber layer unit and the lower fiber layer unit are spiral microstructures respectively, the upper fiber layer unit, the middle fiber layer unit and the lower fiber layer unit are respectively provided with different fiber laying directions and laying angles, and the laying angles of the upper fiber layer unit and the lower fiber layer unit are symmetrically arranged.

2. The three-layer super-engineered composite material according to claim 1, characterized in that: The middle layer fiber ply unit includes a plurality of first fiber plies, and the plurality of first fiber plies are cross-laid in sequence along the overall width direction.

3. The three-layer super-engineered composite material according to claim 2, characterized in that: Adjacent first fiber sheets are arranged orthogonally along the overall width direction, or adjacent first fiber sheets are arranged crosswise at ±45° along the overall width direction, with 180 degrees being one spiral period.

4. The three-layer super-engineered composite material according to claim 1, characterized in that: The upper fiber layer unit and the lower fiber layer unit respectively include multiple layers of second fiber sheets, and a plurality of the second fiber sheets are spirally laid in sequence along the overall thickness direction. The multiple layers of second fiber sheets in the upper fiber layer unit and the multiple layers of second fiber sheets in the lower fiber layer unit are symmetrically arranged up and down.

5. The three-layered super-engineered composite material according to claim 4, characterized in that: The second fiber sheets with the same layer sequence in the upper fiber layer unit and the lower fiber layer unit are periodically spirally laid along the laying direction.

6. The three-layered super-engineered composite material according to claim 4, characterized in that: Adjacent second fiber layers within each spiral period have consistent spiral angles, the spiral period is an integer multiple of 180°, and the number of spiral periods corresponding to the upper fiber ply unit and the lower fiber ply unit is greater than or equal to 1.

7. The three-layered super-engineered composite material according to claim 6, characterized in that: The spiral angle is 0° to 90°.

8. The three-layered super-engineered composite material according to claim 1, characterized in that: Resin films are added to interfaces of the upper fiber layer unit, the middle fiber layer unit and the lower fiber layer unit respectively, and toughening agents are evenly sprinkled therein.

9. A method for preparing a three-layered super-engineered composite material according to any one of claims 1 to 8, characterized in that: The preparation method comprises the following steps: Cut out a number of unidirectional fiber cloth prepregs impregnated with resin; Laying out a plurality of single layers of the unidirectional fiber cloth prepreg in a periodic sequence according to a preset angle to obtain a plurality of spiral periodic fiber layer units, and placing the laid fiber layer units into a mold cavity; Hot pressing the plurality of fiber ply units spirally and periodically arranged in the mold cavity at a preset temperature, a preset pressure, and a preset time to obtain an upper fiber ply unit and a lower fiber ply unit of a single macroscopic layer; The unidirectional fiber cloth prepreg preset as the middle layer is cut into required sizes to obtain a middle layer specimen, the cut middle layer specimen is rotated 90° along the long axis direction, and the rotated middle layer specimens are stacked together in order so that the layout of the middle layer specimens is along the width direction, and the middle layer fiber ply units are obtained after being laid out in sequence; The upper fiber layer unit, the lower fiber layer unit and the middle fiber layer unit are bonded together by a resin film and a toughening agent is evenly sprinkled therein, and the laid three-layer fiber layer unit is placed in a mold cavity; The three-layer fiber laying unit periodically arranged in different directions in the mold cavity is subjected to secondary curing hot pressing molding at a preset temperature, preset pressure and preset time to obtain a three-layer structured super-designed composite material.

10. The method for preparing the three-layer super-engineered composite material according to claim 9, characterized in that: The fibers used in the unidirectional fiber cloth prepreg are one or more of carbon fiber, glass fiber, basalt fiber, and aramid fiber, and the resin is a thermosetting resin or a thermoplastic resin; the preset temperature, the preset pressure, the preset time, and the type of curing agent used during the hot pressing molding are determined according to the type of the fiber and the type of the resin.

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