A lightweight biomimetic discontinuous fiber helical composite armor structure

Abstract

The present application relates to a kind of lightweight biomimetic discontinuous fiber spiral composite protective structure, belong to lightweight protective structure design technical field.The lightweight high-strength high-toughness biomimetic discontinuous fiber spiral composite protective structure of the present application is stacked by unit intermittent fiber fabric according to different arrangement angles and arrangement ways, under the condition of local stress concentration in relaxation layer, shear stress is distributed to the intermittent connecting part in each layer, the concentration of interlaminar shear stress is relieved, using the interlaminar shear stress distribution mechanism of the composite material makes crack frequently deflect when it bears load, can delay material failure and destruction, greatly improve the bearing and energy absorption capacity of the composite protective structure.

Description

Technical Field

[0001] This invention relates to a lightweight biomimetic discontinuous fiber spiral composite protective structure, belonging to the field of lightweight protective structure design technology. Background Technology

[0002] In modern science and engineering applications, the demand for high-performance protective structures is increasingly urgent in the fields of military protection, aerospace, rail transportation, and special equipment manufacturing. Equipment and personnel in these fields frequently face extreme hazards such as high-speed impacts, collisions, and explosions, thus requiring protective structures to be lightweight, high-strength, high-toughness, and possess excellent energy absorption characteristics. Traditional protective structures mainly use metallic materials (such as steel and aluminum alloys) and single polymer materials. While metallic materials have high strength, their high density results in excessively heavy protective systems, and they are prone to stress concentration and localized damage when subjected to high-speed impacts, failing to effectively absorb and dissipate impact energy. Although polymer materials have relatively low density, single polymer materials cannot simultaneously meet the requirements for high-strength protection in terms of both strength and toughness, and their structural stability and durability are poor. Summary of the Invention

[0003] The technical problem solved by this invention is to overcome the shortcomings of the prior art and propose a lightweight biomimetic discontinuous fiber spiral composite protective structure.

[0004] The technical solution of this invention is:

[0005] A lightweight biomimetic discontinuous fiber spiral composite protective structure is composed of several layers of intermittent fiber fabric stacked together, with adjacent layers rotating at a set angle in a set direction.

[0006] The unit discontinuous fiber fabric is composed of one or more single-layer discontinuous fiber fabrics.

[0007] The shear positions of adjacent single-layer discontinuous fiber fabrics are offset by the same distance; the offset distance is any distance that the single-layer discontinuous fiber fabric can withstand within its surface.

[0008] If a unit discontinuous fiber fabric is composed of two or more layers of single-layer discontinuous fiber fabric combined in a manner in which the shear lines do not overlap, then the shear positions must not all overlap.

[0009] The single-layer discontinuous fiber fabric is composed of unidirectional continuous fibers and polymers. The continuous fibers are discontinuous by shearing, and the shearing direction is not parallel to the unidirectional fiber direction.

[0010] Beneficial effects

[0011] (1) The single-layer discontinuous fiber fabric of the present invention is different from the previous single-layer continuous fiber fabric. The fibers are discontinuous, which can effectively alleviate local stress concentration within the layer.

[0012] (2) The unit interrupted fiber fabric of the present invention is composed of one or more single-layer interrupted fiber fabrics, which can effectively alleviate local stress concentration within the layer on the basis of single-layer interrupted fiber fabrics, while improving the toughness and energy absorption characteristics of the protective structure.

[0013] (3) The lightweight, high-strength and high-toughness biomimetic discontinuous fiber spiral composite protective structure of the present invention is made of unit discontinuous fiber fabric stacked according to different arrangement angles and arrangements. Under the condition of effectively relieving local stress concentration in the layer, the shear stress is distributed to the discontinuous connection part in each layer, which alleviates the concentration of interlayer shear stress. By utilizing the tensile stress distribution mechanism of the composite material in the layer and the shear stress distribution mechanism between the layers, the cracks deflect frequently when subjected to load, which can delay the failure of the material and greatly improve the load-bearing and energy absorption capacity of the composite material. Attached Figure Description

[0014] Figure 1 A schematic diagram of a unit discontinuous fiber fabric composed of a single layer of discontinuous fiber fabric.

[0015] Figure 2 A schematic diagram of a unit discontinuous fiber fabric composed of three layers of single-layer discontinuous fiber fabric;

[0016] Figure 3 A schematic diagram of a unit discontinuous fiber fabric composed of 5 layers of single-layer discontinuous fiber fabric;

[0017] Figure 4 A schematic diagram of stacking unit discontinuous fiber fabrics according to different interlayer rotation angles and arrangement methods;

[0018] Figure 5 for Figure 4 A schematic diagram when θ1=θ2=θ3=……=45°;

[0019] Figure 6 for Figure 4 A schematic diagram when θ1=θ2=θ3=……=90°;

[0020] Figure 7 This is a schematic diagram of a unit discontinuous fiber fabric being laid layer by layer by rotating at an interlayer rotation angle θ = 15°. Detailed Implementation

[0021] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0022] Example

[0023] A lightweight biomimetic discontinuous fiber spiral composite protective structure, by laying discontinuous fibers at a set spiral angle, can not only make full use of their lightweight advantages, but also optimize the mechanical properties within and between layers through the biomimetic structure. This effectively improves the energy absorption and dissipation efficiency of the protective structure when facing high-speed impacts, significantly enhances the overall protective performance, and provides an innovative solution for the protection needs of key fields such as military and aerospace.

[0024] This invention provides a lightweight, high-strength, and high-toughness protective structure that reduces the weight of the protective system while improving impact resistance and energy absorption performance. By optimizing the arrangement of discontinuous fibers, it achieves a synergistic improvement in intralayer and interlayer mechanical properties. It overcomes the shortcomings of existing continuous fiber helical laminate structures under impact loads, such as stress concentration, interfacial bonding, and stress transfer, significantly improving the overall protective performance and durability of the material. This meets the special needs of military protection, aerospace, and other fields under extreme conditions such as high-speed impacts and collisions, promoting the development and application of protective structure technology.

[0025] This invention provides a lightweight, biomimetic, discontinuous fiber spiral composite protective structure. It consists of multiple layers of discontinuous fiber fabric stacked at different methods and angles. In this composite material, the discontinuous tensile stress within a single layer is distributed discontinuously under load, effectively alleviating localized stress concentration within the layer. The different angles between layers distribute interlaminar shear stress to the discontinuous connections within each layer, further mitigating interlaminar shear stress concentration. Utilizing the intralaminar tensile stress and interlaminar shear stress distribution mechanism of this composite material causes frequent crack deflection under load, delaying material failure and significantly improving the load-bearing and energy absorption capacity of the composite material.

[0026] Single-layer discontinuous fiber fabrics are composed of unidirectional fibers and polymers, with continuous fibers being discontinuous through shearing. For example... Figure 1 The diagram shown is a specific example of a single-layer discontinuous fiber fabric, where the unidirectional fiber direction is along the X direction and the shearing direction is along the Y direction. In actual implementation, the shearing direction should not be parallel to the unidirectional fiber direction.

[0027] Unit discontinuous fiber fabric is composed of one or more single-layer discontinuous fiber fabrics.

[0028] Figure 1 An example diagram of a unit discontinuous fiber fabric consisting of a single layer of discontinuous fiber fabric is given;

[0029] Figure 2 An example diagram of a unit discontinuous fiber fabric consisting of three layers of single-layer discontinuous fiber fabric is given;

[0030] Figure 3An example diagram of a unit discontinuous fiber fabric consisting of 5 layers of single-layer discontinuous fiber fabric is given;

[0031] exist Figure 2 and Figure 3 In this process, the shear positions of adjacent single-layer discontinuous fiber fabrics are staggered by the same distance.

[0032] The shear positions between adjacent and non-adjacent layers can be the same or different, and the offset distance can be any distance that a single-layer discontinuous fiber fabric can withstand.

[0033] If a unit discontinuous fiber fabric is composed of two or more single-layer discontinuous fiber fabrics combined in such a way that the shear lines do not overlap, then the shear positions must not all overlap.

[0034] The lightweight, high-strength, and high-toughness biomimetic discontinuous fiber spiral composite protective structure material is made of unit discontinuous fiber fabrics stacked according to different interlayer rotation angles and arrangement methods. Figure 4 The image shows an example of a lightweight, high-strength, and high-toughness biomimetic discontinuous fiber spiral composite protective structure material. θ1, θ2, θ3, ... are the angles between the discontinuous fiber fabrics of adjacent units, and these angles can be any values.

[0035] Figure 5 and Figure 6 These are two more examples of lightweight, high-strength, and high-toughness biomimetic discontinuous fiber spiral composite protective structural materials. Figure 5 in, θ1=θ2=θ3=……=45°; in Figure 6 In, θ1=θ2=θ3=……=90°.

[0036] Unlike traditional single-layer continuous fiber fabrics, single-layer discontinuous fiber fabrics are characterized by intermittent fibers, effectively alleviating localized stress concentration within the layer. Unit-type discontinuous fiber fabrics, composed of one or more single-layer discontinuous fiber fabrics, maintain and alleviate localized stress concentration within the layer while retaining the properties of a single-layer discontinuous fiber fabric. Lightweight, high-strength, and high-toughness biomimetic discontinuous fiber spiral composite protective structural material is composed of unit-type discontinuous fiber fabrics stacked at different angles and arrangements. While alleviating localized stress concentration within the layer, it distributes shear stress to the discontinuous connections within each layer, mitigating interlaminar shear stress concentration. Utilizing the intralaminar tensile stress and interlaminar shear stress distribution mechanism of this composite material causes frequent crack deflection under load, delaying material failure and significantly improving the composite material's load-bearing and energy absorption capabilities. Single-layer discontinuous fiber fabrics and unit discontinuous fiber fabrics, due to the presence of broken fibers, can effectively alleviate localized stress concentration within layers. Lightweight, high-strength, and high-toughness biomimetic discontinuous fiber spiral composite protective structures, formed by stacking unit discontinuous fiber fabrics at different angles and arrangements, distribute shear stress to the discontinuous connections within each layer, mitigating interlaminar shear stress concentration. This composite material's intralaminar tensile stress and interlaminar shear stress distribution mechanism causes frequent crack deflection under load, delaying material failure and significantly improving its load-bearing and energy absorption capabilities.

[0037] Example

[0038] This embodiment provides a lightweight, biomimetic discontinuous fiber spiral composite protective structure. It reduces the mass of the protective structure while maintaining high strength, high toughness, and excellent energy absorption characteristics. For example... Figure 4 As shown.

[0039] In this embodiment, the lightweight biomimetic discontinuous fiber spiral composite protective structure is made of T700 unidirectional carbon fiber prepreg with a single layer thickness of 0.1 mm.

[0040] In this embodiment, the T700 unidirectional carbon fiber prepreg is cut into a square with a side length of L, where L = 140 mm;

[0041] In this embodiment, a square unidirectional carbon fiber prepreg with a side length of L is arranged as follows: Figure 7 The two sizes shown are cut into discontinuous fiber thin films (a) and (b);

[0042] In this embodiment, discontinuous fiber sheets (a) and (b) are arranged according to... Figure 7 The structure shown is interlaced to obtain a unit discontinuous fiber fabric, each unit discontinuous fiber fabric consisting of 2 layers (a) and 1 layer (b);

[0043] In this embodiment, the lightweight biomimetic discontinuous fiber spiral composite protective structure has 75 layers and a total thickness of 7.5 mm;

[0044] In this embodiment, the unit discontinuous fiber fabric is laid out layer by layer in a rotating manner with an interlayer angle θ = 15° between adjacent layers, such as... Figure 7 As shown, the sample was prepared by high-temperature hot pressing and curing.

[0045] The prepared biomimetic discontinuous fiber spiral composite protective structure specimen was subjected to static compression-bending mechanical property testing on an Instron 5544 material tensile-compression testing machine, with experimental procedures and settings similar to ASTM D6264. The results show that the layered composite material, combining a "brick-and-mortar" staggered laminate structure and a spiral laminate structure, exhibits improved load-bearing capacity and energy absorption, which is closely related to its discontinuous fiber structure within the layers. The discontinuous distribution of tensile stress within the layers effectively alleviates local stress concentration and delays material failure. Simultaneously, this "intralayer discontinuity-interlayer spiral" structure distributes interlayer shear stress to the discontinuous connections within each layer, mitigating interlayer shear stress concentration. These mechanisms will significantly impact the load-bearing capacity and energy absorption of the structure. Combining these two biological structures has positive implications for the design and performance optimization of lightweight structural materials and holds promise for applications in aerospace, new energy, and other fields.

[0046] In summary, the above are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A lightweight, biomimetic discontinuous fiber spiral composite protective structure, characterized in that: This composite protective structure is composed of several layers of intermittent fiber fabric stacked together, with adjacent layers rotating at a set angle in a set direction. Unit discontinuous fiber fabric is composed of two or more layers of single-layer discontinuous fiber fabric combined in a manner in which the shear lines do not overlap, which requires that the shear positions do not all overlap. The single-layer discontinuous fiber fabric is composed of unidirectional continuous fibers and polymers. The continuous fibers are discontinuous by shearing, and the shearing direction is not parallel to the unidirectional fiber direction. The shear positions of adjacent single-layer discontinuous fiber fabrics are staggered by the same distance; The offset distance is any distance that a single-layer discontinuous fiber fabric can withstand within its surface.

2. The lightweight biomimetic discontinuous fiber spiral composite protective structure according to claim 1, characterized in that: In this composite protective structure, adjacent layers are rotated 45° in the same direction.

3. The lightweight biomimetic discontinuous fiber spiral composite protective structure according to claim 1, characterized in that: In this composite protective structure, adjacent layers are rotated 90° in the same direction.

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