Bionic laminated lap joint composite material structure and design method and preparation method thereof

Abstract

The invention discloses a bionic laminated lap joint composite material structure and a design method and a preparation method thereof. The bionic laminated lap joint composite material structure comprises a plurality of fiber lap joint units which are coaxially overlapped and stacked in the thickness direction. The fiber lap joint units are stacked layer by layer through fiber prepregs, and the fiber prepregs laid on each layer and the fiber prepregs on the upper layer form a lap joint area in the span direction; all the fiber lap joint units are stacked in the thickness direction, so that the fiber lap joint units have the same lap joint length at the coaxial position, and a laminated lap joint structure in the span direction is formed. Through the synergistic effect of the lap joint areas with different lengths in the fiber lap joint units, the bending damage resistance characteristic and damage distribution of the composite material structure are regulated and controlled, on one hand, the process difficulty can be reduced, and meanwhile various combinations such as various lamination lengths, various fiber lap joint units and overall changes can be achieved; and on the other hand, the strength, the toughness and the damage resistance of the composite material laminated plate can be improved, and good balance between the mechanical properties of joints is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of composite materials, and in particular to a bionic laminated overlap composite material structure and a design method and a preparation method thereof. Background Art

[0002] Composite materials play a key role in modern science and technology, especially in high-demand fields, with their excellent specific strength, specific stiffness, fatigue resistance and corrosion resistance. They have gradually moved from laboratories to actual engineering, becoming the first choice for the new generation of structural materials and are widely used in aerospace, sports equipment, medical equipment and other industries. Composite structures are usually composed of large-sized components that need to be connected and assembled through joint methods. In order to meet the needs of complex structural shapes, as well as considerations of repair, maintenance, weight reduction and strength enhancement, effective joint design is essential.

[0003] Among them, fiber-reinforced composites are widely used, but how to strike a balance between strength and toughness to achieve the characteristics of "hardness and flexibility" is still a huge challenge. For fiber-reinforced composites, the joint design directly affects the stress distribution and damage characteristics inside the composite material, and the different mechanical properties presented in turn provide a broad space for the design of composite laminates. However, the laminated microstructures currently studied are mostly limited to uniform laminate designs, which often cannot adapt to the complex requirements of different application scenarios. Especially when faced with complex mechanical environments, this single design may not provide the best performance. Therefore, we urgently need to introduce more diversified design strategies, such as gradient design, to improve the mechanical properties of composite laminates. Summary of the invention

[0004] The purpose of the present invention is to provide a bionic laminated composite material structure and a design method and a preparation method thereof in view of the problems existing in the prior art.

[0005] To achieve the above object, the technical solution adopted by the present invention is: In the first aspect, a bionic laminated lap composite material structure is provided, comprising a plurality of fiber lap units coaxially overlapped and stacked in the thickness direction; the fiber lap units are stacked layer by layer through fiber prepreg, and each layer of laid fiber prepreg forms an overlap area with the fiber prepreg of the previous layer in the span direction; all the fiber lap units are stacked in the thickness direction so that they have the same overlap length in the coaxial position, forming a laminated lap structure along the span direction.

[0006] The present invention regulates the bending damage characteristics and damage distribution of the composite material structure through the synergistic effect of overlapping areas of different lengths in the fiber overlapping unit. On the one hand, it can realize various combinations of stacking lengths, various fiber overlapping units and overall changes while reducing the process difficulty. On the other hand, it can improve the strength, toughness and damage resistance of the composite material laminate, achieve a good balance between the mechanical properties of the joint, and make it better meet the actual application.

[0007] Furthermore, the fiber prepreg is a carbon fiber prepreg or a glass fiber prepreg.

[0008] Furthermore, the fiber prepreg includes continuous fibers, short fibers and long fibers, which are respectively used to form a continuous fiber laminated overlapping structure, a short fiber uniformly laminated overlapping structure and a long fiber uniformly laminated overlapping structure.

[0009] Furthermore, the fiber splicing unit is composed of at least one 90° direction layer and two 0° direction overlapping layers.

[0010] In a second aspect, a design method for a bionic laminated composite material structure is provided, the design method comprising the following steps: Determine the total thickness T of the composite material structure, the thickness t of a single layer of fiber prepreg, and calculate the number of layers N of the fiber overlap unit and the total number of layers N′; Determine the length L of the composite material structure and set the laminate length formed in the selected fiber overlap unit , calculate the combination of laminate lengths in different fiber overlap units; According to the determined fiber overlap unit stacking length According to the different combinations of the length of the laminated layers in the fiber lamination units, the length of the fiber prepreg required to form each laminated layer in the corresponding fiber lamination unit is calculated. ; Construct a single fiber overlap unit; the fiber sheets begin to be stacked layer by layer, and each laid fiber sheet forms an overlap area with the previous fiber sheet, which is the stacking length , a single fiber splicing unit is constructed according to the combination of different stacking lengths in the span direction; Finally, laminated composite materials with different topological structures are formed according to the number of fiber overlap unit layers N; A plurality of fiber-bonded unit stacking groups with different stacking lengths are formed.

[0011] This method, through thinking about the structure of biological scales, benefits from the "rigid and flexible" scale structure characteristics of fish, pangolins and other organisms. By combining multiple fiber lap units with different stacking lengths in the span direction, it can respond to the different mechanical responses of the tensile and compressive sides of the composite laminate under the bending load, and delay the formation of initial damage in each local area. As a multi-layer joint structure inspired by the structure of biological scales, this laminated lap composite structure can avoid the limitations of complex manufacturing process operations and limited design space on the one hand, and on the other hand, it can break through and improve the performance of the composite laminate by regulating the overlapping lap area of ​​the joints of the composite laminate.

[0012] Furthermore, when the stack length If the lamination lengths are the same along the span direction, a uniformly laminated lap composite material structure is formed; when there are two lamination lengths, a two-gradient laminated lap composite material structure is formed; when there are three lamination lengths, a three-gradient laminated lap composite material structure is formed; when there are four lamination lengths, a four-gradient laminated lap composite material structure is formed.

[0013] Furthermore, the total number of laying layers N′ satisfies the following relationship: N′=3*N.

[0014] Furthermore, the stack length Satisfies the following relationship: , where n is a positive integer.

[0015] Furthermore, the length of the fiber prepreg required to form each laminate in the fiber splicing unit is Should satisfy the relationship ; The length L of the composite material structure satisfies the relationship ,in .

[0016] In a third aspect, a method for preparing a bionic laminated composite material structure is provided, the method comprising the following steps: Cutting the fiber prepreg according to the design requirements of each overlap length in the fiber overlap unit to obtain a plurality of fiber sheets of appropriate size and number; According to the designed lamination sequence, the fiber sheets are laid layer by layer on a flat mold to form a fiber lap unit, and then the laid fiber lap unit is laid layer by layer along the thickness direction to form a preliminary lamination composite material structure; The stacked preliminary laminated lap composite material structure is formed at high temperature and high pressure according to the autoclave forming process, and finally the finished product is taken out from the mold to obtain a bionic laminated lap composite material structure.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. The present invention regulates the bending damage characteristics and damage distribution of the composite material structure through the synergistic effect of the overlapping areas of different lengths in the fiber overlapping unit. On the one hand, it can reduce the process difficulty while realizing various combinations such as various stacking lengths, various fiber overlapping units and overall changes. On the other hand, it can achieve the improvement of the strength, toughness and damage resistance of the composite laminate, and achieve a good balance between the mechanical properties of the joint, so that it can better meet the actual application; 2. The bionic laminated overlap composite material structure is based on the characteristics of the biological scale structure, draws on the design strategy of the biological laminated gradient structure, integrates it with the ply design of the fiber composite laminate, and manufactures a multi-lap gradient structure in the span direction by using the ply staggered method; 3. The laminated overlap composite material structure of the present invention is a multi-layer joint structure inspired by the biological scale structure. On the one hand, it can avoid the limitations of complex preparation process operations and the limited design space. On the other hand, by regulating the overlapping overlap area of ​​the joint of the composite laminate, the performance of the composite laminate is broken through and improved, which is of great significance to the development of carbon fiber composite materials in engineering fields such as aerospace. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A schematic diagram of a laminated structure of a composite material with continuous overlap and uniform overlap provided by an embodiment of the present invention; Among them, (a) UC-120, i.e., a continuous composite laminate without joint design; (b) XU-1, i.e., a composite laminate with a laminate length of 10 mm in each fiber overlap unit; (c) XU-3, i.e., a composite laminate with a laminate length of 20 mm in each fiber overlap unit; Figure 2 The load displacement curves of the continuous overlap and uniform overlap composite laminates obtainable by the present invention; Figure 3 A schematic diagram of a composite material laminate structure with gradient overlap provided by an embodiment of the present invention; Among them, (a) XDG-1441, that is, each fiber overlap unit has two laminate lengths (10 mm, 30 mm) of the composite laminate; (b) XTG-134431, that is, each fiber overlap unit has three laminate lengths (10 mm, 20 mm, 30 mm) of the composite laminate; (c) XQG-1234321, that is, each fiber overlap unit has four laminate lengths (10 mm, 15 mm, 20 mm, 30 mm) of the composite laminate; Figure 4 It is a schematic diagram of the enlarged structure of the composite laminate (XQG-1234321) of four stacking lengths of the present invention; Figure 5is a load displacement curve of a gradient lap composite laminate obtainable by the present invention; Figure 6 The radar diagrams of various properties of the composite laminates with uniform and gradient overlap structures that can be obtained by the present invention include strength, dissipated energy, stiffness, failure strain, failure strain and residual strength ratio. DETAILED DESCRIPTION

[0019] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] In the description of the present invention, it should be noted that the directions or positional relationships indicated by the terms "middle", "upper", "lower", "left", "right", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings, and are 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 direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting 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. Example 1

[0021] A bionic laminated lap composite material structure comprises a plurality of fiber lap units coaxially overlapped and stacked in the thickness direction; the fiber lap units are stacked layer by layer through fiber prepreg, and each layer of laid fiber prepreg forms an overlap area with the fiber prepreg of the previous layer in the span direction; all the fiber lap units are stacked in the thickness direction so that they have the same overlap length at the coaxial position, forming a laminated lap structure along the span direction.

[0022] The present invention regulates the bending damage characteristics and damage distribution of composite material structures (such as composite material laminates) through the synergistic effect of overlapping areas of different lengths in the fiber overlapping unit. On the one hand, it can achieve various combinations of stacking lengths, various fiber overlapping units and overall changes while reducing the process difficulty. On the other hand, it can improve the strength, toughness and damage resistance of the composite material laminate, achieve a good balance between the mechanical properties of the joint, and make it better meet the actual application.

[0023] This bionic laminated lap composite material structure is based on the structural characteristics of biological scales. It draws on the design strategy of biological laminated gradient structure, integrates it with the ply design of fiber composite laminates, and uses the ply staggered method to manufacture a multi-lap gradient structure in the span direction.

[0024] Biologically inspired material design has proven to be a fruitful strategy for designing composite materials with higher efficiency, higher damage tolerance and better mechanical properties. By observing and studying the microstructure in organisms, the most effective structural elements are extracted from the multi-scale and complex microstructures of natural materials, rather than simply copying these principles, and further designing, reconstructing and studying the impact of microstructures on material properties, relying on design innovation to solve the problem of strength and toughness trade-off faced by traditional composite materials, providing a broader perspective for the research of this invention and providing solid support for the design of new high-performance bionic composite materials. As an ultra-lightweight biomaterial, fish scales are characterized by a flexible and complex layered structure, which significantly improves their penetration resistance while providing fish with excellent flexibility. In addition, the unique ordered arrangement of scales connected by fish skin reduces local stress by redistributing the penetration load, enhancing the protective ability of fish scales while ensuring the flexibility of fish.

[0025] The present invention benefits from the "rigid and flexible" scale structure characteristics of fish, pangolins and other organisms through thinking about the biological scale structure. By combining multiple fiber overlap units with different stacking lengths in the span direction, it responds to the different mechanical responses of the tensile side and the compression side of the composite laminate under the bending load, and delays the formation of initial damage in each local area. As a multi-layer joint structure inspired by the biological scale structure, the laminated overlap composite structure can avoid the limitations of complex preparation process operations and the limited design space on the one hand, and on the other hand, by regulating the overlapping overlap area of ​​the joints of the composite laminate, break through and improve the performance of the composite laminate. This is of great significance to the development of carbon fiber composites in engineering fields such as aerospace.

[0026] Furthermore, the fiber prepreg is a carbon fiber prepreg or a glass fiber prepreg.

[0027] Furthermore, the fiber prepreg includes continuous fibers, short fibers and long fibers, which are respectively used to form a continuous fiber laminated overlapping structure, a short fiber uniformly laminated overlapping structure and a long fiber uniformly laminated overlapping structure.

[0028] Furthermore, the fiber overlap unit is composed of at least one 90° layer and two 0° overlapping layers. Since the composite material structure has 90° plies with continuous fibers in the structural design, symmetry should be considered when stacking the fiber overlap units along the thickness direction. Example 2

[0029] In actual use, facing the three-point bending load condition, the composite structure is in different stress distribution states along the thickness direction. The maximum normal stress is located on the upper and lower surfaces, resulting in premature fiber fracture. The highest shear stress exists near the neutral layer, making the composite laminate prone to delamination. The evolution of these initial damages significantly affects the mechanical response of the structure.

[0030] Based on the above loading conditions, this embodiment provides a design method for a bionic laminated composite material structure, the design method comprising the following steps: Step 1: Determine the total thickness T of the composite material structure, the thickness t of a single layer of fiber prepreg, and calculate the number of layers N of the fiber overlap unit and the total number of layers N′; In actual use, the total number of laid layers N′ satisfies the following relationship: N′=3*N, and each constructed fiber overlap unit consists of a 90° direction layer and two 0° direction overlapping layers.

[0031] Step 2: Determine the length L of the composite material structure and set the laminate length formed in the selected fiber overlap unit , calculate the combination of laminate lengths in different fiber overlap units; In actual use, the stack length Satisfies the following relationship: , where n is a positive integer.

[0032] Step 3: According to the determined lamination length of the fiber overlap unit According to the different combinations of the length of the laminated layers in the fiber lamination units, the length of the fiber prepreg required to form each laminated layer in the corresponding fiber lamination unit is calculated. ; In actual use, the length of the fiber prepreg required to form each laminated layer in the fiber splicing unit is set Should satisfy the relationship ; The length L of the composite material structure satisfies the relationship ,in .

[0033] Step 4: First, construct a single fiber overlap unit; the fiber sheets begin to be stacked layer by layer, and each laid fiber sheet forms an overlap area with the previous fiber sheet, which is the stacking length , a single fiber overlap unit is constructed according to the combination of different stacking lengths in the span direction; finally, a stacked overlap composite material structure with different topological structures is stacked according to the number of fiber overlap unit layers N; In actual use, since there are 90° plies with continuous fibers in the structural design, symmetry should be considered when stacking the fiber overlap units along the thickness direction.

[0034] Step 5: According to step 4, a plurality of fiber splicing unit stacking groups with different stacking lengths are formed.

[0035] When the stack length If the lamination lengths are the same along the span direction, a uniform (XU) laminated lap composite structure is formed; when there are two laminated lengths, a two-gradient (XDG) laminated lap composite structure is formed; when there are three laminated lengths, a three-gradient (XTG) laminated lap composite structure is formed; when there are four laminated lengths, a four-gradient (XQG) laminated lap composite structure is formed.

[0036] According to the present invention, the bionic laminated composite material structure design method is not limited to the design of the total number of plies, uniform thickness and laminate length, and the appropriate total number of plies, thickness and laminate length can be selected according to actual needs.

[0037] The embodiment of the present invention proposes a gradient stacking design strategy based on the uniform stacking design, and the present invention can effectively improve the comprehensive performance of composite laminates, breaking through the problem of mutual exclusion of strength and toughness of traditional continuous lap composite laminates; from the perspective of bionics, a bionic stacked lap composite material structure and design and manufacturing method are proposed, which provides new design ideas and technical support for the research and application of new bending-resistant composite laminates.

[0038] Furthermore, a method for preparing the bionic laminated composite material structure in Example 1 comprises the following steps: S1: cutting the fiber prepreg according to the design requirements of each overlap length in the fiber overlap unit to obtain a plurality of fiber sheets of appropriate size and number; S2: Laying the fiber sheets layer by layer on a flat mold according to the designed lamination sequence to form a fiber lapping unit, and then laying the laid fiber lapping unit layer by layer along the thickness direction to form a preliminary lamination composite material structure; S3: The stacked preliminary laminated lap composite material structure is formed at high temperature and high pressure according to the autoclave molding process, and finally the finished product is taken out from the mold to obtain a bionic laminated lap composite material structure.

[0039] The present invention will be further described in detail below with reference to specific examples, taking the design of unidirectional carbon fiber prepreg and the preparation of a bionic laminated lap composite material structure as an example to illustrate the present invention.

[0040] (1) It is preliminarily determined that the number of fiber overlap unit layers N is 6 and the total number of layers N′ is 18. The ultra-thin carbon fiber prepreg model is USN 12500 and the thickness of the cured layer is 0.12 mm.

[0041] (2) According to ASTM D7264, the overall size of the bending sample is designed to be 120 mm × 13 mm, so the longest laminate length that can be set is 120 mm and it belongs to continuous laminate fibers, which is a jointless design; in addition, the optional laminate lengths are set to be 10 mm, 15 mm, 20 mm and 30 mm; three composite laminate structures (UC-120, XU-1, XU-3) are prepared, including continuous overlap and uniform overlap structures. Figure 1 The embodiment of the present invention provides a method based on the stacking length Schematic diagram of the stacked composite laminate structure.

[0042] (3) Figure 2 In the displayed structure, although the continuous overlap has higher strength and dissipated energy, it will experience fatal brittle fracture during the bending process; in the uniform overlap structure, although XU-1 and XU-3 have lower strength and dissipated energy, their flexibility is significantly higher than that of the continuous overlap, and they are proven to be an effective structure for delaying catastrophic damage. This structure allows layer sliding in the overlap area, so it has a progressive failure process and significant ductility; among them, XU-1 with a shorter stacking length shows better flexibility and dissipated energy than XU-3 with a longer stacking length, and exhibits the characteristics of progressive failure.

[0043] (4) The optional lamination length in each fiber lamination unit The composite materials were combined and arranged from left to right in the span direction. Three gradient lap composite laminate structures (XDG-1441, XTG-134431, and XQG-1234321) were designed and prepared. Figure 3 and Figure 4As shown, XDG-1441 is a two-gradient laminated structure, specifically, each fiber overlap unit is composed of a laminated structure of 10 mm and 30 mm, which are 10 mm, 10 mm, 10 mm, 30 mm, 30 mm, 10 mm, 10 mm, and 10 mm from left to right; 6 identical fiber overlap units are laid along the thickness direction, and symmetry is taken into account; XTG-134431 is a three-gradient laminated structure, specifically, each fiber overlap unit is composed of a laminated structure of 10 mm, 20 mm and 30 mm, which are 10 mm, 20 mm, 30 mm, 30 mm, 20 mm, and 10 mm from left to right; 6 identical fiber overlap units are laid along the thickness direction, and symmetry is taken into account; XQG-1234321 is a four-gradient laminated structure, specifically, each fiber overlap unit is composed of a laminated structure of 10 mm, 15 mm, 20 mm and 30 mm, which are 10 mm, 15 mm, 20 mm and 30 mm from left to right mm, 20 mm, 30 mm, 20 mm, 15 mm, 10 mm, and 6 identical fiber overlapping units are laid along the thickness direction, taking symmetry into consideration.

[0044] (5) From Figure 5 By comparing the gradient overlaps, it can be seen that the bionic gradient stacking design has higher structural performance and achieves a balance of mechanical properties, including peak load, final failure displacement, energy dissipation and damage tolerance, especially the four-gradient stacking structure. Although the peak load and dissipated energy are still slightly lower than the continuous overlap, the brittle fracture problem of the continuous overlap structure is effectively improved.

[0045] (6) Conduct three-point bending tests on all the above composite laminate structures. Figure 6 It is shown that under bending load, the designed biomimetic laminate lap composite joints exhibit higher structural performance, including flexibility, residual strength ratio and maximum failure displacement, although there are still problems with lower strength and dissipated energy. In particular, the four-gradient lap laminate design can achieve structural strength and dissipated energy close to those of laminates with continuous fibers, while significantly improving flexibility and delaying catastrophic failure. The gradient change of the laminate overlap length matches well with the stress distribution in the joint subjected to three-point bending, presenting better results.

[0046] In this embodiment, the number of units of the gradient stacking and the length and number of the stacking layers in the fiber overlap unit can be reasonably adjusted according to the length of the stacking layer and the single-layer thickness of the fiber sheet layer.

[0047] The present invention regulates the three-point bending damage characteristics and damage distribution of the composite laminate through the synergistic effect of different stacking lengths in the fiber overlap unit, thereby improving the strength, toughness and delayed failure capacity of the composite laminate.

[0048] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A bionic laminated composite material structure, characterized in that: It comprises a plurality of fiber overlap units coaxially overlapped and stacked in the thickness direction; the fiber overlap units are stacked layer by layer through fiber prepreg, and each layer of laid fiber prepreg forms an overlap area with the fiber prepreg of the previous layer in the span direction; All the fiber overlapping units are stacked along the thickness direction so that they have the same overlapping length at coaxial positions, forming a laminated overlapping structure along the span direction.

2. The bionic laminated composite material structure according to claim 1, characterized in that: The fiber prepreg is a carbon fiber prepreg or a glass fiber prepreg.

3. The bionic laminated composite material structure according to claim 1, characterized in that: The fiber prepreg comprises continuous fibers, short fibers and long fibers, which are respectively used to form a continuous fiber laminated overlapping structure, a short fiber uniform laminated overlapping structure and a long fiber uniform laminated overlapping structure.

4. The bionic laminated composite material structure according to claim 1, characterized in that: The fiber splicing unit is composed of at least one 90° direction layer and two 0° direction overlapping layers.

5. A method for designing a bionic laminated composite material structure according to any one of claims 1 to 4, characterized in that: The design method comprises the following steps: Determine the total thickness T of the composite material structure, the thickness t of a single layer of fiber prepreg, and calculate the number of layers N of the fiber overlap unit and the total number of layers N′; Determine the length L of the composite material structure and set the laminate length formed in the selected fiber overlap unit , calculate the combination of laminate lengths in different fiber overlap units; According to the determined fiber overlap unit stacking length According to the different combinations of the length of the laminated layers in the fiber overlap units, the length of the fiber prepreg required to form each laminated layer in the corresponding fiber overlap unit is calculated. ; Construct a single fiber overlap unit; the fiber sheets begin to be stacked layer by layer, and each laid fiber sheet forms an overlap area with the previous fiber sheet, which is the stacking length , a single fiber splicing unit is constructed according to the combination of different stacking lengths in the span direction; Finally, laminated composite materials with different topological structures are formed according to the number of fiber overlap unit layers N; A plurality of fiber-bonded unit stacking groups with different stacking lengths are formed.

6. The design method of the bionic laminated composite material structure according to claim 5, characterized in that: When the stack length If the lamination lengths are the same along the span direction, a uniformly laminated lap composite material structure is formed; when there are two lamination lengths, a two-gradient laminated lap composite material structure is formed; when there are three lamination lengths, a three-gradient laminated lap composite material structure is formed; when there are four lamination lengths, a four-gradient laminated lap composite material structure is formed.

7. The design method of the bionic laminated composite material structure according to claim 5, characterized in that: The total number of laying layers N′ satisfies the following relationship: N′=3*N.

8. The design method of the bionic laminated composite material structure according to claim 5, characterized in that: The stack length Satisfies the following relationship: , where n is a positive integer.

9. The design method of the bionic laminated composite material structure according to claim 5, characterized in that: The length of the fiber prepreg required to form each laminate in the fiber splicing unit is set Should satisfy the relationship ; The length L of the composite material structure satisfies the relationship ,in .

10. A method for preparing a bionic laminated composite material structure according to any one of claims 1 to 4, characterized in that: The preparation method comprises the following steps: Cutting the fiber prepreg according to the design requirements of each overlap length in the fiber overlap unit to obtain a plurality of fiber sheets of appropriate size and number; According to the designed lamination sequence, the fiber sheets are laid layer by layer on a flat mold to form a fiber lap unit, and then the laid fiber lap unit is laid layer by layer along the thickness direction to form a preliminary lamination composite material structure; The stacked preliminary laminated lap composite material structure is formed at high temperature and high pressure according to the autoclave forming process, and finally the finished product is taken out from the mold to obtain a bionic laminated lap composite material structure.

Images