A flexible sandwich core

Abstract

The present application provides a kind of flexible sandwich core, comprising: symmetrical corrugated level honeycomb and level support column;The symmetrical corrugated level honeycomb is formed by periodic array by level corrugated edge, the level corrugated edge includes top topology formed using the symmetry of f (x) = ± Asin (wx) about x axis based on sinusoidal function f (x) = Asin (wx), and bottom topology formed using the symmetry of f (x) = ± Acos (wx) based on sinusoidal function f (x) = Asin (wx);In the cell space of symmetrical corrugated level honeycomb, the level support column is provided;The cross section of the level support column adopts gradient level topology from inside to outside, wherein the relationship between the outermost layer subcell edge length l i And the innermost layer cell edge length l0 satisfies l i =(1 / 2) i l0,i indicates the number of layers of level support column.

Description

Technical Field

[0001] This invention patent relates to the field of passive safety of vehicles, and more specifically, to a flexible sandwich core. Background Technology

[0002] Sandwich structures typically consist of upper and lower panels and a core. Due to their ability to fully utilize the mechanical properties of multiple materials and structures, they are widely used in critical load-bearing components of transportation vehicles, such as automobile door sills, aircraft wings, helmets, and ship floors. The core is crucial for the stable load-bearing capacity and efficient energy absorption of sandwich structures, thus its mechanical properties have attracted active research. Currently, typical core materials such as traditional honeycomb and foam materials, due to their high peak impact force and low material utilization, are no longer sufficient to meet the protection requirements of advanced vehicles for sandwich structures. Therefore, developing a highly safe flexible sandwich core has significant engineering value and scientific research significance for promoting the progress and development of traffic safety protection structure design in my country.

[0003] In recent years, the highly impact-resistant biological hierarchical structures have provided new inspiration for improving the load-bearing capacity of core materials. Researchers have developed various forms of hierarchical honeycombs by simulating the microstructure of biological tissues. During impact, hierarchical honeycombs significantly improve material utilization and enhance the energy absorption effect of sandwich structures through short-wave folding. However, existing hierarchical honeycomb materials are all two-dimensional stretched lattice structures, which are prone to overall bending deformation under high-speed impact. This leads to violent fluctuations in the sandwich structure during load-bearing, significantly reducing the material's energy absorption effect and posing a significant threat to occupant safety. Therefore, this invention addresses this issue by proposing a sandwich core capable of stable deformation and efficient energy absorption, which has significant engineering value for promoting the application of sandwich structures in high-end equipment. Summary of the Invention

[0004] This invention utilizes a hierarchical design to develop a highly secure flexible sandwich core, aiming to solve the unstable mechanical behavior of hierarchical honeycomb under extreme working conditions and realize its efficient energy absorption load-bearing characteristics, thereby promoting the application of sandwich structures in high-end equipment protection structures.

[0005] To address the aforementioned technical problems, the present invention provides a flexible sandwich core, comprising: a symmetrical corrugated hierarchical honeycomb and hierarchical support columns;

[0006] The symmetrical corrugated hierarchical honeycomb is formed by a periodic array of hierarchical corrugated edges. The hierarchical corrugated edges include a top topology formed based on the sine function f(x)=Asin(wx) and utilizing the symmetry of f(x)=±Asin(wx) about the x-axis, and a bottom topology formed based on the sine function f(x)=Asin(wx) and utilizing the symmetry of f(x)=±Acos(wx).

[0007] Within the cell space of a symmetrical corrugated hierarchical honeycomb, there are hierarchical support pillars; the cross-section of the hierarchical support pillars adopts a gradient hierarchical topology from the inside to the outside, wherein the outermost sub-cell has a side length l. i The relationship between the innermost cell side length l0 and the innermost cell side length l0 satisfies l i =(1 / 2) i l0, i represents the number of layers of the hierarchical support column.

[0008] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0009] 1. Stable deformation and small load fluctuation.

[0010] This invention provides a flexible sandwich core. Compared to straight-walled hierarchical honeycombs, the symmetrical corrugated hierarchical honeycomb has staggered conical subcells, which makes it less prone to overall bending deformation under load, thus improving the deformation and load-bearing stability of the honeycomb. Furthermore, the hierarchical support columns adopt a gradient hierarchical topology design from the inside out. Compared to regular cells, the gradient design of the hierarchical support columns enhances the multi-angle impact adaptability of the sandwich core. The hierarchical support columns arranged in the cell space of the symmetrical corrugated hierarchical honeycomb provide effective support during impact, reducing the possibility of instability and deformation.

[0011] 2. High energy absorption efficiency and high material utilization rate.

[0012] This invention provides a flexible sandwich core in which the symmetrical corrugated hierarchical honeycomb and hierarchical support columns retain the characteristics of hierarchical topology. Compared to non-hierarchical structures, hierarchical structures can achieve short-wave folding energy dissipation under the same mass conditions, allowing more material to participate in deformation, thereby improving the specific energy absorption of the sandwich core. Furthermore, each hierarchical support column has an arched induction device on its side. During impact, this device causes the outer sub-cells of the hierarchical support columns to be squeezed into the symmetrical corrugated hierarchical honeycomb, enhancing the interaction between structures and thus improving the energy absorption effect of the sandwich core.

[0013] 3. Flexible collision, low peak collision force.

[0014] This invention provides a flexible sandwich core. The staggered conical daughter cells ensure that the folding deformation of the symmetrical corrugated hierarchical honeycomb is always triggered from the tip, which significantly reduces the peak impact force of the sandwich core and facilitates the energy absorption process of the protective structure in flexible impacts. On the other hand, the sides of the hierarchical support columns are equipped with arched induction devices, which provide effective buffering for the sandwich core during impact, thereby enabling the flexible impact bearing process. Attached Figure Description

[0015] Figure 1 A schematic diagram of a highly secure flexible sandwich core;

[0016] Figure 2 This is a schematic diagram illustrating the formation process of the layered corrugated edge.

[0017] Figure 3 A schematic diagram illustrating the formation of a symmetrical corrugated hierarchical honeycomb.

[0018] Figure 4 Comparison of straight-walled hierarchical honeycomb and symmetrical corrugated hierarchical honeycomb;

[0019] Figure 5 This is a schematic diagram of the distribution and structure of the hierarchical support columns. Detailed Implementation

[0020] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0021] In the description of this invention, it should be noted that the terms "upper," "lower," "inner," "outer," "top / bottom," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and 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. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0022] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed", "equipped", "sleeved / connected", "connected", etc., should be interpreted broadly. For example, "connection" can be a wall-mounted connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. For those skilled in the art, the specific meaning of the above terms in this invention can be understood according to the specific circumstances.

[0023] The high-safety flexible sandwich core provided in this embodiment is as follows: Figure 1 As shown, specifically, it is divided into two parts: symmetrical corrugated hierarchical honeycomb 101 and hierarchical support columns 102.

[0024] The symmetrical corrugated hierarchical honeycomb 101 is formed by a periodic array 301 through a hierarchical corrugated edge 204, with its top topology as shown in 302 and its bottom topology as shown in 303.

[0025] The hierarchical corrugated edge 204 is based on the sine function f(x) = Asin(wx) shown in 201, and utilizes the symmetry of f(x) = ±Asin(wx) about the x-axis to form the top topology 202 of the hierarchical corrugated edge 204. Furthermore, the bottom topology 203 of the hierarchical corrugated edge 204 is formed using the symmetry of f(x) = ±Acos(wx). A top view of the hierarchical corrugated edge 204 is shown in 204, where the thick solid line represents the top topology 202 of the hierarchical corrugated edge 204, and the dashed line represents the bottom topology 203 of the hierarchical corrugated edge 204.

[0026] Compared to the daughter cells 402 of the straight-walled hierarchical honeycomb 401, the daughter cells 403 of the symmetrical corrugated hierarchical honeycomb 101 have an interlaced conical structure, which not only preserves the efficient energy absorption characteristics of the hierarchical honeycomb but also enhances the load-bearing stability of the honeycomb. In addition, the interlaced conical daughter cells 403 ensure that the folding deformation of the symmetrical corrugated hierarchical honeycomb 101 is always triggered from the tip, which significantly reduces the peak impact force of the sandwich core and is beneficial for the protective structure to achieve a flexible impact energy absorption process.

[0027] Additionally, in the cell space of the symmetrical corrugated hierarchical honeycomb 101 shown in Figure 501, hierarchical support pillars 102 are provided. The top view of the hierarchical support pillars 102 is shown in Figure 502, and their cross-section adopts a gradient hierarchical topology from the inside out. The outermost sub-cell has a side length l. i The relationship between the innermost cell side length l0 and the innermost cell side length l0 satisfies l i =(1 / 2) il0, i represents the number of layers in the hierarchical support column. Compared to regular cells, the gradient design of the hierarchical support column 102 enhances the multi-angle impact adaptability of the sandwich core. Furthermore, as shown in the front view of 503, the hierarchical support column 102 utilizes a concave arched design with an arc to induce deformation. During impact, the outer sub-cells of the hierarchical support column 102 are compressed towards the symmetrical bidirectional hierarchical honeycomb 101, enhancing the interaction between structures and thus improving the energy absorption effect of the sandwich core.

[0028] The aforementioned flexible sandwich core, firstly, compared to the straight-walled hierarchical honeycomb 401, has staggered conical structures 403 for the sub-cells of its hierarchical corrugated edges. This makes the symmetrical corrugated hierarchical honeycomb 101 less prone to overall bending deformation under load, thereby improving the deformation stability and load-bearing stability of the honeycomb. Secondly, the hierarchical support columns 102 adopt a gradient hierarchical topology design from the inside out. Compared to regular cells, the gradient design of the hierarchical support columns 102 can enhance the multi-angle impact adaptability of the sandwich core. Finally, the hierarchical support columns 102 arranged in the cell space of the symmetrical corrugated hierarchical honeycomb 101 provide effective support for the symmetrical corrugated hierarchical honeycomb 101 during impact, reducing the possibility of instability and deformation of the symmetrical corrugated hierarchical honeycomb 101.

[0029] The symmetrical corrugated hierarchical honeycomb 101 and hierarchical support columns 102 retain the characteristics of hierarchical topology. Compared with non-hierarchical structures, hierarchical structures can achieve short-wave folding energy dissipation processes under the same mass conditions, allowing more material to participate in deformation, thereby improving the specific energy absorption of the sandwich core. In addition, the side of the hierarchical support columns 102 is provided with an arched induction device 503. During the impact process, the outer daughter cells of the hierarchical support columns 102 are squeezed into the symmetrical bidirectional hierarchical honeycomb 101, enhancing the interaction between structures and thus improving the energy absorption effect of the sandwich core.

[0030] On the one hand, the staggered conical daughter cells 403 ensure that the folding deformation of the symmetrical corrugated hierarchical honeycomb 101 is always triggered from the tip, which significantly reduces the peak impact force of the sandwich core and facilitates the energy absorption process of the protective structure in flexible impact. On the other hand, the sides of the hierarchical support columns 102 are provided with arched induction devices 503, which can provide effective buffering for the sandwich core during impact, thereby realizing the bearing process of flexible impact.

[0031] The above description is merely a preferred embodiment of the present invention, but the design concept of the present invention is not limited thereto. Any non-substantial modifications made to the present invention by those skilled in the art within the scope of the technology disclosed in the present invention using this concept shall be deemed as an infringement of the protection scope of the present invention.

Claims

1. A flexible sandwich core, characterized in that... include: Symmetrical corrugated hierarchical honeycomb structure and hierarchical support columns; The symmetrical corrugated hierarchical honeycomb is formed by a periodic array of hierarchical corrugated edges, and the sub-cells of the hierarchical corrugated edges are staggered conical structures; the hierarchical corrugated edges include a top topology formed based on the sine function f(x)=Asin(wx) and utilizing the symmetry of f(x)=±Asin(wx) about the x-axis, and a bottom topology formed based on the sine function f(x)=Asin(wx) and utilizing the symmetry of f(x)=±Acos(wx); Within the cell space of a symmetrical corrugated hierarchical honeycomb, there are hierarchical support pillars; the cross-section of the hierarchical support pillars adopts a gradient hierarchical topology from the inside to the outside, wherein the outermost sub-cell has a side length l. i The relationship between the innermost subcell side length l0 and the innermost subcell side length l0 satisfies l i =(1 / 2) i l0, i represents the number of layers of the hierarchical support column; The cells of the symmetrical corrugated hierarchical honeycomb are square, and the sub-cells of the hierarchical support columns are also square.

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