Fiber hybrid woven composite material based on bionic multistage gradient design

Abstract

The invention relates to the field of woven materials, in particular to a fiber hybrid woven composite material based on bionic multistage gradient design. The material is obtained through material gradient design, structure gradient design and interface gradient design. The material comprises a surface layer high-rigidity area, a transition area and a core high-toughness area, wherein the surface layer high-rigidity area adopts carbon fibers I as warp and weft yarns; in the transition area, basalt fibers I are adopted as weft yarns, carbon fibers II are adopted as warp yarns, and Z-direction yarns are aramid fibers I; warp yarns of the core high-toughness area are basalt fibers II, and weft yarns and Z-direction yarns of the core high-toughness area are aramid fibers II. The defects of stress concentration, insufficient interlayer toughness, interface slippage and the like existing in traditional plain / twill weaving are effectively overcome. According to the design, on the premise that the cost is kept controllable, the interlayer performance, the impact resistance and the energy absorption characteristic of the composite material are remarkably improved by optimizing the three-dimensional combination mode of the warp yarns, the weft yarns and the Z-direction yarns at each stage, and the synergistic enhancement of mechanical properties is achieved.

Description

Technical Field

[0001] This invention relates to the field of braided materials, and more particularly to a fiber hybrid braided composite material based on a biomimetic multi-level gradient design. Background Technology

[0002] With the development of modern industry, the demand for lightweight, high-strength, and highly durable materials is increasing. Traditional metallic materials, due to their high density and susceptibility to corrosion, are gradually being replaced by high-performance composite materials. Among them, basalt fiber, due to its wide availability of raw materials, low cost, high temperature resistance, and acid and alkali resistance, has been widely used in aerospace, construction, and automotive industries. In the construction industry, basalt fiber is widely used for concrete reinforcement and external wall insulation due to its high strength, corrosion resistance, and high-temperature stability. In the aerospace field, its high specific strength and high modulus make it an important component of lightweight composite materials. In the automotive industry, the application of basalt fiber has not only significantly reduced vehicle weight and improved fuel economy but also enhanced impact resistance. However, traditional basalt fiber composites suffer from problems such as low interlaminar shear strength and sensitivity to crack propagation, and a single fiber system cannot simultaneously achieve both strength and toughness. Therefore, blending different types of fibers can achieve complementary performance.

[0003] Furthermore, most current fiber hybrid weaving methods are plain weave or twill weave. Plain weave results in dense interlacing points, leading to stress concentration and making the yarns prone to brittle fracture upon impact. While it exhibits in-plane isotropy, it suffers from poor interlayer toughness and low energy absorption. Twill weave, although improving flexibility, reduces impact resistance, and insufficient interlayer bonding strength can cause interfacial slip failure. Therefore, existing fiber composite hybrid weaving designs for strengthening and toughening have certain shortcomings. Summary of the Invention

[0004] To address the problems existing in the background technology, a fiber hybrid braided composite material based on biomimetic multi-level gradient design is proposed. This material is obtained through material gradient design, structural gradient design, and interface gradient design. The material includes a surface high-stiffness region, a transition region, and a core high-toughness region. Specifically, the surface high-stiffness region uses carbon fiber 1 as warp and weft yarns; the transition region uses basalt fiber 1 as weft yarn, carbon fiber 2 as warp yarn, and aramid fiber 1 as Z-axis yarn; the core high-toughness region uses basalt fiber 2 as warp yarn, and aramid fiber 2 as weft and Z-axis yarn.

[0005] Preferably, the surface high-stiffness area adopts two-dimensional plain weave, with an in-plane fiber volume fraction ≥65%.

[0006] Preferably, the intermediate transition zone uses three-dimensional angular interlocking weaving, with Z-direction binding yarns connecting adjacent layers.

[0007] Preferably, the core high-toughness zone is woven using three-dimensional orthogonal weaving.

[0008] Preferably, a resin-coated base layer is formed on a mixed woven fabric.

[0009] Preferably, a nano-SiO2 / POSS hybrid coating is introduced at the fiber-resin interface.

[0010] Compared with existing technologies, this invention has the following beneficial technical effects: the biomimetic multi-gradient fiber hybrid weaving composite material exhibits better reinforcement and toughening effects. Compared with plain / twill single-fiber weaving methods, it improves the tensile strength, interlaminar shear strength, and fracture toughness of the composite material structure. Applying the high toughness and high strength of this invention to low / high-speed impact scenarios can demonstrate excellent impact energy absorption characteristics and toughness. The multi-gradient fiber hybrid weaving method significantly improves the reinforcement and toughening effect of the composite material. This biomimetic gradient weaving process enables the three high-performance fibers to form an interlocking structure in space, which not only fully utilizes the synergistic effect of the high toughness and impact resistance of basalt fiber / aramid fiber and the high strength and high modulus of carbon fiber, but also effectively suppresses failure modes such as interlaminar delamination and fiber pull-out through the angular interlocking mechanism, and the regional delamination further improves the performance. Compared with the traditional plain / twill two-dimensional weaving method, this composite material has improved mechanical properties such as tensile strength, bending stiffness, interlaminar shear strength, and fracture toughness. This excellent impact resistance and energy absorption property makes it a promising candidate for application in extreme working conditions such as aerospace cushioning components, military armor protection, and collision protection for new energy vehicles. Attached Figure Description

[0011] Figure 1 This is a conceptual block diagram for designing fiber hybrid braided composite materials based on biomimetic multi-level gradients.

[0012] Figure 2 An overall diagram of a fiber-mixed woven composite material;

[0013] Figure 3 A schematic diagram showing the combination of the surface high-stiffness zone, the transition zone, and the core high-toughness zone;

[0014] Figure 4 This is a schematic diagram of the high-stiffness surface region;

[0015] Figure 5 This is a schematic diagram of the transition zone;

[0016] Figure 6 This is a schematic diagram of the core high-toughness region.

[0017] Figure reference numerals: 1. Surface high stiffness zone; 101. Carbon fiber one; 2. Transition zone; 201. Carbon fiber two; 202. Basalt fiber one; 203. Aramid fiber one; 3. Core high toughness zone; 302. Basalt fiber two; 303. Aramid fiber two; 4. Resin base layer. Detailed Implementation

[0018] Example 1: This example proposes a method for designing fiber hybrid braided composite materials based on biomimetic multi-level gradient design.

[0019] Considering that a single fiber often struggles to simultaneously achieve both high strength and high toughness, multi-fiber hybrid weaving technology has become an effective way to achieve complementary performance. Taking a carbon fiber / basalt fiber hybrid system as an example: while carbon fiber possesses excellent modulus and tensile strength, its cost is high; whereas basalt fiber / aramid fiber excels in toughness and economy. Through reasonable hybrid weaving design, composite materials with superior overall performance can be obtained while keeping costs under control. Furthermore, traditional plain weave structures, due to their dense interlacing points, are prone to stress concentration, leading to brittle fracture under impact loads. Moreover, their in-plane isotropic properties often come at the cost of interlaminar toughness, resulting in poor energy absorption performance. While twill weave structures improve material flexibility to some extent, they weaken impact resistance, and insufficient interlaminar bonding strength can easily lead to interfacial slip failure. Therefore, a three-dimensional weaving method is designed and compared with plain / twill weaving methods to verify the feasibility of the design approach.

[0020] Example 2 proposes a hybrid woven composite material based on the biomimetic multi-level gradient design concept of Example 1. This material includes a surface high-stiffness region 1, a transition region 2, and a core high-toughness region 3. The surface high-stiffness region 1 uses carbon fiber-101 as warp and weft yarns; the transition region 2 uses basalt fiber-202 as weft yarn, carbon fiber-201 as warp yarn, and aramid fiber-203 as Z-axis yarn; the core high-toughness region 3 uses basalt fiber-302 as warp yarn, and aramid fiber-303 as both weft and Z-axis yarns.

[0021] The surface high-stiffness zone 1 employs a two-dimensional plain weave with an in-plane fiber volume fraction ≥65%, using carbon fiber-101 interlaced layers to give the composite material high stiffness. The intermediate transition zone 2, located between the surface high-stiffness zone 1 and the core high-toughness zone 3, uses a three-dimensional interlocking weave and plays a crucial role in stress transfer and performance gradient transition. Its weave structure uses basalt fiber-202 as the weft yarn, facilitating a smooth performance transition; carbon fiber-201 as the warp yarn, providing the main in-plane stiffness; and aramid fiber-203 as the Z-axis yarn. Binding yarns connect adjacent layers, providing a direct physical channel for effective stress transfer from the high-stiffness zone to the core high-toughness zone and mitigating interfacial stress concentration caused by abrupt modulus changes. The core high-toughness zone fully utilizes the high toughness, high fracture energy, and excellent energy absorption characteristics of aramid fiber. The core high-toughness zone 3 employs three-dimensional orthogonal weaving, with warp yarns made of basalt fiber 2.302 and weft and Z-axis yarns made of aramid fiber 2.303. This region creates a toughness-dominant structure. The high elongation, high toughness, high fracture energy, and excellent energy absorption capacity of the two fibers give this region good deformation capacity, effectively dissipating impact energy and preventing crack initiation and propagation, significantly improving the composite material's damage resistance and safety. A resin-coated base layer 4 is applied to the hybrid woven fabric. The resin material can be polyurethane resin, epoxy resin, phenolic resin, etc. A nano-SiO2 / POSS hybrid coating is introduced at the fiber-resin interface, with the coating concentration gradient along the thickness direction: high concentration at the surface (enhancing stiffness) to low concentration in the core region (improving toughness).

[0022] Compared to traditional plain or twill weave structures, the novel gradient fiber hybrid weave structure divides the composite material into distinct stiffness, transition, and toughness zones. It also incorporates different Z-axis yarns, combining warp and weft yarns in three-dimensional space. In the thickness direction, fiber type, fiber modulus, and fiber toughness all exhibit continuous or stepped gradient changes. The primary purpose of this structural design is to significantly improve the interlaminar properties and overall mechanical properties of the composite material. Further, by precisely controlling the density, interlacing method, and Z-axis yarn insertion density, path, and angle in each region, the interfacial failure of the composite material can be effectively mitigated, and structural performance characteristics can be enhanced, achieving an integrated load-bearing and energy-absorbing design.

[0023] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited thereto. Various changes can be made within the scope of knowledge possessed by those skilled in the art without departing from the spirit of the present invention.

Claims

1. A fiber hybrid braided composite material based on a biomimetic multi-level gradient design, characterized in that, This material was obtained through material gradient design, structural gradient design, and interface gradient design. The material includes a surface high-stiffness zone (1), a transition zone (2), and a core high-toughness zone (3); the surface high-stiffness zone (1) uses carbon fiber I (101) as warp and weft yarns; the transition zone (2) uses basalt fiber I (202) as weft yarn, carbon fiber II (201) as warp yarn, and aramid fiber I (203) as Z-direction yarn; the core high-toughness zone (3) uses basalt fiber II (302) as warp yarn, and aramid fiber II (303) as weft yarn and Z-direction yarn.

2. The fiber hybrid braided composite material based on biomimetic multi-level gradient design according to claim 1, characterized in that, The surface high-stiffness zone (1) is woven with two-dimensional plain weave, and the fiber volume fraction in the surface is ≥65%.

3. The fiber hybrid braided composite material based on biomimetic multi-level gradient design according to claim 1, characterized in that, The intermediate transition zone (2) adopts three-dimensional angular interlocking weaving, and the Z-direction binding yarn connects the adjacent layers.

4. The fiber hybrid braided composite material based on biomimetic multi-level gradient design according to claim 1, characterized in that, The core high-toughness zone (3) is woven in three-dimensional orthogonal weave.

5. The fiber hybrid braided composite material based on biomimetic multi-level gradient design according to claim 1, characterized in that, A resin base layer is applied to a mixed woven fabric (4).

6. The fiber hybrid braided composite material based on biomimetic multi-level gradient design according to claim 5, characterized in that, A nano-SiO2 / POSS hybrid coating is introduced at the fiber-resin interface.

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