Lightweight arc edge concave honeycomb high-explosion-resistant energy-absorbing composite structure

Abstract

The present application relates to a kind of light-weighted arc edge recessed honeycomb high blast absorption energy composite structure, which is sandwich structure, wherein the core structure is arc edge recessed honeycomb, and the core structure is formed by adopting arc edge recessed honeycomb in the form of unit cell array in xy plane and xz plane.The present application is light in weight, high in energy absorption efficiency and specific strength, and compared with traditional single-direction core structure, the energy absorption performance of different-direction core structure is obviously improved.

Description

Technical Field

[0001] This invention relates to a lightweight, arc-edge concave honeycomb high explosion-resistant energy-absorbing composite structure, providing a new method for honeycomb structure design, and belongs to the field of novel material structures. Background Technology

[0002] Lightweight design is a major development trend in blast-resistant structures. Sandwich structures possess high specific strength and specific stiffness, as well as high specific energy absorption efficiency, exhibiting excellent performance in blast protection, energy absorption, and vibration reduction. Therefore, this invention designs a sandwich structure that meets the requirements of lightweighting while maintaining blast-resistant performance. Domestic and international scholars have conducted extensive research on the energy absorption mechanism of sandwich structures under impact and the influence of core layer parameters on energy absorption. Results show that sandwich structures possess characteristics of light weight, excellent energy absorption performance, and superior impact resistance, making them ideal structures for blast-resistant armor. Patents CN116512708A and CN109318542A respectively invented a biomimetic functional composite sandwich blast-resistant structure and a concave hybrid chiral superstructure. The complex structural forms give the structures unique energy absorption characteristics under external loads, providing ample inspiration for innovative core layer design in sandwich structures.

[0003] Unlike traditional honeycomb structures, negative Poisson's ratio (CHH) structures contract under compression and expand under tension. Currently, concave honeycomb CNHH (CHH) structures based on honeycomb are a special type of porous structure. They are widely used in many fields due to their advantages over traditional structures in shear strength, fracture resistance, energy absorption, and indentation resistance. However, they suffer from high peak stress and insufficient consistency in impact loads. Conversely, concave honeycomb with curved edges exhibits lower peak stress and better consistency in impact loads. Therefore, the core structure designed in this invention is primarily based on concave honeycomb with curved edges. Patents CN113459604A and CN116552079A respectively designed a composite structure of concave honeycomb and regular hexagonal honeycomb and an impact-resistant multilayer structure plate, improving the energy absorption performance of the sandwich structure. However, the energy absorption mode of the structure is relatively simple, resulting in insufficient energy absorption efficiency. Summary of the Invention

[0004] The purpose of this invention is to provide a lightweight, arc-edged concave honeycomb high-explosion-resistant energy-absorbing composite structure. By utilizing arc-edged honeycombs and arranging them in different ways, lightweight, energy-absorbing, and explosion-resistant properties are achieved.

[0005] This invention provides a lightweight, arc-edge concave honeycomb high explosion-proof energy-absorbing composite structure, comprising a panel, a base plate, and a core structure. The core structure is crucial in the overall structure. The core structure is designed by arranging identical unit cells in different layers. The N layer consists of unit cells arrayed along the x and z directions in the xz plane, and the W layer consists of unit cells arrayed along the x and y directions in the xy plane. In the three-layer structure, the N and W layers are randomly arranged, resulting in eight different combinations: WWW, NWW, NNW, NNN, NWN, WNW, WNN, and WWN.

[0006] The present invention provides a lightweight arc-edge concave honeycomb high explosion-resistant energy-absorbing composite structure. The cell structure is an arc-edge concave honeycomb, which is composed of straight upper and lower sides and arc edges that are concave inward on the left and right sides.

[0007] This invention provides a lightweight, concave honeycomb composite structure with high explosion resistance and energy absorption. To ensure good bonding between the W and N layers, the y-direction length L1 is determined by compression simulation, and the y-direction length L2 is determined by explosion impact simulation; that is, let the length in the y-direction be L. The W layer is an array of unit cells on the xy plane. To ensure the integrity of the unit cells in the y-direction, the following relationship should be satisfied: L = hx i +t(x i +1), x i This represents the number of unit cells in the array along the y-direction. Furthermore, to ensure the integrity of the unit cells in the W layer along both the x and y directions, the unit cell structures of the N layer and the W layer should have the same dimensions.

[0008] The present invention provides a lightweight arc-edge concave honeycomb high explosion-proof energy-absorbing composite structure, wherein the total height H of the arc-edge concave honeycomb structure core is between 50-80mm.

[0009] The present invention provides a lightweight arc-edge concave honeycomb high explosion-resistant energy-absorbing composite structure. The honeycomb unit cell structure is mainly controlled by the length l, height h, thickness t and angle θ.

[0010] The present invention provides a lightweight arc-edge concave honeycomb high explosion-resistant energy-absorbing composite structure, wherein the arc-edge concave honeycomb unit cell length l is 14-22mm, the unit cell height h is 14-22mm, the thickness t is 0.5-2.5mm, and the angle θ is 40-80°.

[0011] This invention provides a lightweight, arc-edge concave honeycomb high explosion-resistant energy-absorbing composite structure, wherein the above four parameters must satisfy the following relationship:

[0012] The present invention provides a lightweight arc-edge concave honeycomb high explosion-proof energy-absorbing composite structure. The rounded corners are designed within the unit cell to prevent sharp corners and the radius of the arc transition is between 0.5-2.5mm.

[0013] The present invention provides a lightweight arc-edge concave honeycomb high explosion-resistant energy-absorbing composite structure, wherein the honeycomb structure is prepared by metal additive or subtractive manufacturing methods.

[0014] The present invention provides a lightweight arc-edge concave honeycomb high explosion-resistant energy-absorbing composite structure, wherein the honeycomb core has at least three layers, and different combinations of different number of layers produce different structures; and different parameters can also produce different structures.

[0015] The present invention provides a lightweight arc-edge concave honeycomb high explosion-resistant energy-absorbing composite structure. The core structure is composed of cells, which are connected to each other by reinforcing ribs. The connection length is the same as the cell length l.

[0016] This invention provides a lightweight, arc-edge concave honeycomb high explosion-resistant energy-absorbing composite structure. The sandwich core structure has an upper plate thickness between 2-10mm and a lower plate thickness between 5-15mm. Different combinations of upper and lower plate thicknesses form different composite structures.

[0017] The present invention provides a lightweight arc-edge concave honeycomb high explosion-proof energy-absorbing composite structure, wherein the upper plate, core structure and lower plate are all made of armor steel.

[0018] Compared with the prior art, the present invention has the following advantages:

[0019] The arc-edge concave honeycomb composite structure of the present invention has high stiffness and high load-bearing capacity. At the same time, the maximum peak stress of the arc-edge concave honeycomb is smaller and the impact load consistency is better, making it safer. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of a concave honeycomb cell with an arc edge according to the present invention.

[0021] Figure 2 This is a schematic diagram of the WWW core structure of the present invention.

[0022] Figure 3 The diagram shows the NWW core structure of this invention.

[0023] Figure 4 The core structure is shown in the physical image of the sample prepared by WWW.

[0024] Figure 5 This is a 1 / 4 front view of the NWW composite structure of the core layer of the present invention.

[0025] Figure 6 This is a 1 / 4 schematic diagram of the NWW composite structure of the core layer of the present invention.

[0026] Figure 7 This is a simulation cloud diagram of the present invention when the strain is 0.5.

[0027] Figure 8 This is an experimental diagram of the present invention with a strain of 0.5.

[0028] Figure 9 This is a graph showing the comparison between nominal stress and strain. Detailed Implementation

[0029] The present invention will now be further described in conjunction with its embodiments and accompanying drawings:

[0030] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. The described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0032] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this invention. The directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0033] For ease of description, spatial relative terms such as "above," "over," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation besides the orientation of the device as described in the figures. For example, if the device in the figures is inverted, a device described as "above" or "above" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0034] Furthermore, it should be noted that the x, y, z directions and xy, xz, yz planes mentioned in this invention are based on Figure 2 The coordinate axes shown, i.e., the x-direction, are... Figure 2 The coordinate axes shown in the diagram represent the positive and negative x-axis; the y-axis is... Figure 2 The coordinate axes shown are the positive and negative directions of the y-axis; the z-axis is... Figure 2 The coordinate axes shown are the positive and negative directions of the z-axis. The xy plane is... Figure 2 The plane formed by the x-axis and y-axis; the xz plane is... Figure 2 The plane formed by the x-axis and z-axis; the yz plane is Figure 2 The plane formed by the y-axis and z-axis.

[0035] This invention provides a lightweight, arc-edge concave honeycomb high explosion-proof energy-absorbing composite structure, comprising a panel, a base plate, and a core structure. The core structure is crucial in the overall structure. The core structure is designed by arranging identical unit cells in different layers. The N layer consists of unit cells arrayed along the x and z directions in the xz plane, and the W layer consists of unit cells arrayed along the x and y directions in the xy plane. In the three-layer structure, the N and W layers are randomly arranged, resulting in eight different combinations: WWW, NWW, NNW, NNN, NWN, WNW, WNN, and WWN.

[0036] Concave arc-edge honeycomb unit cell structure, such as Figure 1Common honeycomb structures include regular hexagonal and concave hexagonal honeycombs. Compared to regular hexagonal honeycomb structures, concave hexagonal honeycomb structures with equal height and weight are more effective at reducing blast shock waves. Concave honeycomb structures with equal height and weight and curved edges have similar effects on absorbing blast energy and reducing blast shock waves compared to regular hexagonal honeycomb structures; however, the central deflection value of curved-edge concave honeycomb is smaller, resulting in better protective performance.

[0037] The following is combined with Figure 4 This invention describes a lightweight, arc-edge concave honeycomb high explosion-resistant energy-absorbing composite structure, comprising a panel 1 and a base plate 4. The core structure 5 is a three-layer structure consisting of an N-layer core structure 2 and a W-layer core structure 3.

[0038] Figure 1 It has a single-cell structure, consisting of straight upper and lower sides and concave curved sides on the left and right sides. Its structure is mainly controlled by length l, height h, thickness t, and angle θ, and these four parameters must satisfy the following relationship:

[0039] Core structure 5 is composed of, for example Figure 1 The cells shown are composed of concave honeycomb structures with identical unit cell parameters. The unit cell length *l* is 14-22 mm, the unit cell height *h* is 14-22 mm, the thickness *t* is 0.5-2.5 mm, and the angle *θ* is 40-80°. The total core height *H* of the concave honeycomb structure is between 50-80 mm.

[0040] The unit cell is designed with rounded corners to prevent sharp or pointed angles, with the radius of the rounded transition between 0.5 and 2.5 mm.

[0041] The honeycomb core has at least three layers, and different combinations of the number of layers create different structures; moreover, different parameters can also create different structures.

[0042] The core structure is composed of cells, which are connected by reinforcing ribs. The length of the connection is the same as the length l of the cell.

[0043] To ensure a good bond between layers W and N, the y-direction length is determined as L1 in the compression simulation and L2 in the explosion impact simulation; that is, let the length in the y-direction be L. Layer W is an array of unit cells on the xy plane. To ensure the integrity of the unit cell in the y-direction, the following relationship should be satisfied: L = hx i +t(x i +1), x i This represents the number of unit cells in the array along the y-direction. Furthermore, to ensure the integrity of the unit cells in the W layer along both the x and y directions, the unit cell structures of the N layer and the W layer should have the same dimensions.

[0044] The thickness of the upper panel in a sandwich structure is between 2-10mm, and the thickness of the lower panel is between 5-15mm. Combining different thicknesses of the upper and lower panels creates different composite structures.

[0045] The upper structural plate, core structure, and lower plate are all made of armor steel.

[0046] This article provides specific examples of WWW and NWW core layer structures, where the WWW core layer is as follows: Figure 2 As shown, it consists of three W layers, which is the core structure of WWW; the NWW core layer is as follows. Figure 3 As shown, the upper layer is layer N, and the middle and lower layers are layers W.

[0047] Figure 4 The WWW core structure sample shown was prepared by wire cutting using a subtractive manufacturing method, and the material was 603 armor steel.

[0048] The irregular arrangement of the core structure reduces the excessive gaps in the z-direction of the overall structure. At the same time, its irregular design improves the overall energy absorption effect of the structure. The appearance of the arc edge in the z-axis direction can effectively reduce the energy of the shock wave.

[0049] Example 1

[0050] Under the above conditions and within the parameter range, the specific parameters of the concave honeycomb cell with arc edge are selected as follows: l = 16mm, h = 16mm, t = 2mm, θ = 60°, the radius of the arc transition is 1mm, the length of the reinforcing rib between two cells is 16mm, the total height of the core layer is H = 56mm, the length in the y direction is L1 = 30mm, and the material is 603 armor steel. The obtained WWW core structure is simulated using LsDyna software: the concave honeycomb with arc edge of the WWW core layer is compressed to a strain of 0.6 under a compression rate of 5000mm / s on a rigid wall. The specific energy absorption and nominal stress results are shown in the table below.

[0051] type Specific energy absorption (kJ / kg) Nominal stress (MPa) Example 1 39.36 281.75

[0052] Under the above conditions, a WWW sample with the same simulated dimensions was prepared by wire cutting. The specific parameters of the concave honeycomb cell with curved edges are: l = 16 mm, h = 16 mm, t = 2 mm, θ = 60°, arc transition radius of 1 mm, reinforcing rib length between two cells of 16 mm, total core layer height H = 56 mm, and y-direction length L1 = 30 mm. A physical image is shown below. Figure 4 As shown. The material is 603 armor steel. The obtained sample was subjected to quasi-static compression at a rate of 3 mm / min. The comparison diagrams of the results at a strain of 0.5 and the stress-strain curves at a strain of 0.6 are shown below.

[0053] Under the above conditions, the specific parameters of the concave honeycomb cell with curved edges are: l = 16mm, h = 16mm, t = 2mm, θ = 60°, the radius of the circular arc transition is 1mm, the length of the reinforcing rib between two cells is 16mm, the total height of the core layer is H = 56mm, and the length in the y-direction is L2 = 200mm. Within the parameter range, the thickness of the upper plate of the overall structure is selected as 2mm, the thickness of the lower plate is 10mm, and the overall height of the structure is 68mm. The material is 603 armor steel. Simulation was performed using LsDyna software: the WWW core layer structure was subjected to an explosive impact of 1kg TNT at a distance of 100mm from the upper panel of the structure. The results are shown in the table below.

[0054] type Energy absorbed (kJ) Maximum displacement at the bottom (mm) Example 3 8.39 15.36

[0055] Example 2

[0056] Under the above conditions and within the parameter range, the specific parameters of the concave honeycomb cell with arc edge are selected as follows: l = 16mm, h = 16mm, t = 2mm, θ = 60°, the radius of the arc transition is 1mm, the length of the reinforcing rib between two cells is 16mm, the total height of the core layer is H = 56mm, the length in the y direction is L1 = 30mm, and the material is 603 armor steel. Simulation is performed using LsDyna software: the NWW core structure under the same height and weight conditions is compressed to a strain of 0.6 under a rigid wall at a compression rate of 5000mm / s. The specific energy absorption and nominal stress results are shown in the table below.

[0057] type Specific energy absorption (kJ / kg) Nominal stress (MPa) Example 2 54.14 298.46

[0058] Under the above conditions, the specific parameters of the concave honeycomb cell with curved edges are: l = 16mm, h = 16mm, t = 2mm, θ = 60°, the radius of the circular arc transition is 1mm, the length of the reinforcing rib between two cells is 16mm, the total height of the core layer is H = 56mm, and the length in the y-direction is L2 = 200mm. Within the parameter range, the thickness of the upper plate of the overall structure is selected as 2mm, the thickness of the lower plate is 10mm, and the overall height of the structure is 68mm. The material is 603 armor steel. Simulation was performed using LsDyna software: the NWW core layer structure was subjected to an explosive impact of 1kg TNT at a distance of 100mm from the center of the upper panel of the structure. The results are shown in the table below.

[0059] type Energy absorbed (kJ) Maximum displacement at the bottom (mm) Example 4 6.4 7.35

[0060] As can be seen from the above embodiments, when the two different core structures of Embodiment 1 and Embodiment 2 are compressed to a strain of 0.6 under a compression rate of 5000 mm / s in a rigid wall, the energy absorption performance of Embodiment 2 is significantly stronger than that of Embodiment 1. The nominal strain is not much different, indicating that the energy absorption performance of the NWW core structure is better.

[0061] As can be seen from the above embodiments, comparing the simulation and experimental results in Embodiment 1, i.e. Figures 7-9 The results show that the simulation results are in good agreement with the experimental results, proving the reliability of the simulation results.

[0062] As can be seen from the above embodiments, comparing Embodiment 1 and Embodiment 2, the energy absorption and bottom displacement characteristics of the two different overall structures under 1kg TNT are similar. However, compared with Embodiment 1, the maximum displacement of the bottom plate in Embodiment 2 is reduced by 52.1%, indicating that the overall protective performance of the NWW composite structure is better.

[0063] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

[0064] This invention creates a novel structure by altering different layers of an arc-edged concave honeycomb structure. Finite element simulations have shown that this invention possesses good load-bearing capacity and energy absorption capability.

Claims

1.A lightweight arc edge recessed honeycomb high blast-resistant energy-absorbing composite structure, characterized in that: The structure is a sandwich structure, which is composed of a panel, a core structure, and a bottom plate in sequence; the core structure is a three-layer structure of the same unit cell array, each layer is N or W, and the combination of the three layers is NWW, NNW, NWN, WNW, WNN, or WWN; the N layer is formed by arraying the unit cells in the x and z directions in the xz plane; and the W layer is formed by arraying the unit cells in the x and y directions in the xy plane. The unit cell structure is an arc edge recessed honeycomb, which is composed of two upper and lower straight edges and two inwardly recessed arc edges. The honeycomb unit cell structure is controlled by length l, height h, thickness t, and angle θ. The four parameters of the honeycomb cell structure satisfy the relationship: Let the length of the honeycomb cell structure in the y direction be L, L satisfies the relationship: L = hx i + t(x i + 1), x i is the number of cells in the y direction array; at the same time, the size of the N layer and the W layer cell structure is consistent; The total height H of the core is between 50 and 80 mm. 2.The lightweight arc edge recessed honeycomb high blast-resistant energy-absorbing composite structure according to claim 1, characterized in that: The length l of the unit cell is between 14 and 22 mm, the height h of the unit cell is between 14 and 22 mm, the thickness t is between 0.5 and 2.5 mm, the angle θ is between 40 and 80°, and the circular arc transition radius is between 0.5 and 2.5 mm. 3.The lightweight arc edge recessed honeycomb high blast-resistant energy-absorbing composite structure according to claim 1, characterized in that: The circular arc transition radius is between 0.5 and 2.5 mm. 4.The lightweight arc edge recessed honeycomb high blast-resistant energy-absorbing composite structure according to claim 1, characterized in that: The honeycomb unit cells are connected by reinforcing ribs, and the connection length is the same as the length l of the honeycomb unit cell. 5.The lightweight arc edge recessed honeycomb high blast-resistant energy-absorbing composite structure according to claim 1, characterized in that: The thickness of the panel of the sandwich structure is between 2 and 10 mm, and the thickness of the bottom plate is between 5 and 15 mm. 6.The lightweight arc edge recessed honeycomb high blast-resistant energy-absorbing composite structure according to claim 1, characterized in that: The materials used for the panel, core structure, and bottom plate of the sandwich structure are all armor steel.

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