CN217157290U - Multi-scale hierarchical triangular anti-impact structure - Google Patents

Abstract

The utility model belongs to the technical field of triangle impact resistance, and discloses a multi-scale hierarchical triangle impact resistance structure. Triangles with different geometrical shapes are inlaid inside the triangular hierarchical structure. Micro-scale triangles are embedded in meso-scale triangles. The mesoscopic-scale triangle divides the macro-scale triangle into four regions. The top of the four regions is the first region, the middle is the second region, the lower left end is the third region, and the lower right end is the fourth region. Micro-scale triangles are inlaid in the first area, the third area and the fourth area. Has higher compressive properties and energy absorption properties. Under static compression, the energy absorption characteristics of multi-scale hierarchical triangles are nearly doubled compared with that of single-scale triangular lattice structures, and their energy absorption characteristics are also partially improved under dynamic impact. Good engineering application value.

Description

A Multi-scale Hierarchical Triangular Impact-resistant Structure

technical field

The utility model belongs to the technical field of triangle impact resistance, in particular to a multi-scale hierarchical triangle impact resistance structure.

Background technique

At present, shock resistance is a key technical indicator of equipment such as large armored vehicles, ships and aircraft carriers, and it is related to their battlefield survivability. By laying a sacrificial layer on the outside of the equipment that is vulnerable to blows, it is a common technical means to realize the absorption of the explosion impact energy by the plastic deformation and destruction of the sacrificial layer. Considering the overall performance and actual working conditions of large-scale equipment, the design of light-weight and high-strength shock-resistant and energy-absorbing structures is of great significance for improving armor protection capabilities and ensuring armor safety.

Honeycomb materials have good mechanical properties and lightweight characteristics, and have been widely used in related engineering fields. For honeycomb structures, the topological form of the smallest periodic unit has a significant impact on the mechanical properties of macroscopic structures, for example, the mechanical properties of triangular, quadrilateral, and kagome honeycombs are quite different. The purpose of improving the performance of the honeycomb structure by designing the topology of a single cell is the focus of researchers. With the high requirements for quality, strength and stiffness in modern equipment, the ordinary form of honeycomb structure has been difficult to meet the needs of its engineering applications. The hierarchical structure design idea with multiple scales of macro and micro provides a technology for improving the static and dynamic mechanical properties of honeycomb structures. way.

Hierarchical structure is a structure with multiple scales of macro and micro, in which the micro structure has topological characteristics similar to the macro structure, and is combined into a new structure in the form of adding or replacing a certain side or corner of the macro structure. The introduction of microstructure can significantly enhance the mechanical properties of the structure on the premise of maintaining the structural quality and volume to meet the application requirements. It has been used in aerospace, engineering construction and other fields.

Based on the design idea of multi-scale hierarchical structure, the utility model designs a triangular-level impact-resistant and explosion-proof structure. Compared with the traditional triangular grid structure, the compressive characteristics and the resistance of the structure can be significantly improved under the condition of maintaining the same quality. Impact characteristics, with good engineering application prospects.

Through the above analysis, the existing problems and defects of the existing technology are: the common form of honeycomb structure has been difficult to meet its engineering application requirements, and the hierarchical structure design idea with macro and micro scales provides a technical way to improve the static and dynamic mechanical properties of the honeycomb structure .

Utility model content

In order to solve the problems existing in the prior art, the present invention provides a multi-scale hierarchical triangular impact-resistant structure.

The utility model is realized in this way, a multi-scale hierarchical triangular impact-resistant structure is provided with:

Triangular hierarchical structure; the triangular hierarchical structure is inlaid with triangles of different geometries, the triangular hierarchy is provided with macro-scale triangles, the macro-scale triangles are inlaid with meso-scale triangles, and the meso-scale triangles are inlaid with Microscale triangles.

Further, the mesoscopic scale triangle divides the macroscopic scale triangle into four regions, the uppermost of the four regions is the first region, the middle is the second region, the lower left end is the third region, and the lower right end is the fourth region.

Further, micro-scale triangles are inlaid in the first area, the third area and the fourth area.

Further, the size ratio of the macro-scale triangle, the meso-scale triangle and the micro-scale triangle structure is all 0.5, that is, the side length of the meso-scale triangle is half of the macro-scale size, and the micro-triangle size is half of the meso-scale triangle. There is no gap between the contacts, and the stress wave can propagate continuously in the structure.

Further, the macro-scale triangles in the multi-scale hierarchical triangular structure are periodically arranged, and a single periodic unit thereof can be obtained by translation and rotation of the hierarchical triangles.

Combined with all the above-mentioned technical solutions, the advantages and positive effects possessed by the present utility model are:

Compared with the triangular grid structure, the new triangular hierarchical structure has higher compressive properties and energy absorption properties. Under static compression, the energy absorption characteristics of multi-scale hierarchical triangles are nearly doubled compared with that of single-scale triangular lattice structures, and their energy absorption characteristics are also partially improved under dynamic impact, which can be used for compression and impact resistance sandwich panel structure design. Good engineering application value.

Description of drawings

In order to explain the technical solutions of the embodiments of the present application more clearly, the following will briefly introduce the drawings that need to be used in the embodiments of the present application. Obviously, the drawings described below are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can also be obtained from these drawings without creative effort.

FIG. 1 is a schematic diagram of a multi-scale hierarchical triangular impact resistance structure provided by an embodiment of the present invention.

2 is a schematic diagram of a single-scale triangular grid structure and a multi-scale triangular-level impact-resistant structure provided by an embodiment of the present invention.

FIG. 3 is the stress-strain curves of three structures provided by the embodiment of the present invention under quasi-static compression and different impact velocities.

4 is a stress-strain curve diagram of a multi-scale triangular hierarchical structure and a single-scale triangular grid structure provided by an embodiment of the present invention at low speed (5m/s) and high speed (100m/s)

In the figure: 1. Macro-scale triangle; 2. Mesoscopic-scale triangle; 3. Micro-scale triangle; 4. First region; 5. Second region; 6. Third region; 7. Fourth region.

Detailed ways

In order to make the purpose, technical solutions and advantages of the present utility model more clear, the present utility model will be further described in detail below with reference to the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, and are not intended to limit the present invention.

Aiming at the problems existing in the prior art, the present invention provides a multi-scale hierarchical triangular impact-resistant structure. The present invention is described in detail below with reference to the accompanying drawings.

The purpose of the present utility model is to design a novel triangular-level impact-resistant and explosion-proof structure in order to overcome the problems existing in the above-mentioned background, such as insufficient compressive properties and energy-absorbing properties of the triangular grid structure under certain mass and volume constraints. Compared with the triangular grid structure, the new triangular hierarchical structure has higher compressive properties and energy absorption properties. Under static compression, the energy absorption characteristics of multi-scale hierarchical triangles are nearly doubled compared with that of single-scale triangular lattice structures, and their energy absorption characteristics are also partially improved under dynamic impact, which can be used for compression and impact resistance sandwich panel structure design. Good engineering application value.

The purpose of the present utility model can be achieved through the following technical solutions:

The multi-scale triangular-level impact-resistant structure provided by the utility model is composed of m×n hierarchical periodic units, wherein m is the number of horizontal cells, n is the number of vertical layers, m is greater than or equal to 1, and n is greater than or equal to 1. In a single hierarchical periodic unit, there are four multi-scale hierarchical triangles symmetrically arranged; a single hierarchical triangle can be obtained by filling one mesoscale triangle and three microscale triangles in the macroscale triangle. The multi-scale triangular-level impact-resistant structure can be applied to the design of sandwich beams and sandwich panels. It has good compression resistance, impact resistance and energy absorption, and effectively reduces the damage to the insured structure.

The multi-scale triangular hierarchical structure, composition materials and geometric dimensions can be adjusted according to specific engineering application conditions.

According to the designed triangular hierarchical structure, a simulation model is established in LS-DYNA finite element software. The material is TPU, and the material parameters are: density 1168kg/cm3, Poisson's ratio 0.48, elastic modulus 72.25Mpa, tangent modulus It is 10.74Mpa, the yield modulus is 2.747Mpa, and the stress limit is 25.5417Mpa. The side length of the macro-scale triangle is 2 cm, and the side length of the meso-scale and micro-scale triangle is 1 cm and 0.5 cm, respectively. In order to prove the excellent performance of the multi-scale triangular hierarchical structure proposed by the present invention, a single-scale triangle and a multi-scale triangle are established as a comparison. In order to ensure that the three structures have the same equivalent density, the macroscopic, mesoscopic and multi-scale triangular structure walls The thicknesses were 0.3 cm, 0.15 cm and 0.088 cm, respectively.

The stress-strain curves of the three structures under quasi-static compression and different impact velocities are extracted, as shown in Fig. 3.

In order to evaluate the energy absorption characteristics of the structure, the energy absorption characteristics of the structure are calculated according to the stress-strain curves of the structure under compression and impact:

In the formula, δ _D is the densification stroke of the structure under compression conditions, and F(x) is the compression force.

According to the simulated stress-strain curve, the densification strain, initial peak stress, energy absorption characteristics and average stress of the platform area of the structure are extracted to evaluate the structural performance. The densification strain is the travel required for the structure to compress to the incompressible stage, the initial peak stress is the compressive force required for the structure to enter the yield stage, and the average stress in the plateau region is the average stress from the structure entering the yield stage to the time of densification. The energy characteristic is the energy required to compress the structure from its initial state to densification.

Figure 1 presents the relevant data for the three structures under quasi-static compression, and Figure 2 presents the relevant data for the structures at different impact velocities. It can be seen that under quasi-static compression, the multi-scale triangular hierarchical structure has better compressive properties and energy absorption properties. Under the same mass and volume, the compressive properties of the multi-scale triangular hierarchical structure are improved by 34.2% compared with the single-scale triangular grid structure, and the energy absorption properties are nearly doubled.

Chart 1

Chart 2

Figure 4 shows the stress-strain curves of the multi-scale triangular hierarchical structure and the single-scale triangular lattice structure at low speed (5m/s) and high speed (100m/s). It can be seen from the figure that under low-speed and high-speed impact, the multi-scale triangular hierarchical structure has better energy absorption characteristics, and during the impact process, the fluctuation of the stress value is relatively gentle, which is more conducive to the protection of the protected structure.

To sum up, the technical effects of the present utility model are:

1. Has good compressive properties and energy absorption properties. Compared with the traditional single-scale triangular grid structure, the multi-scale triangular hierarchical structure can significantly improve the energy absorption characteristics under the premise of the same quality. When , the energy absorption properties of the multi-scale triangular hierarchical structure are also slightly higher than that of the single-scale triangular lattice structure.

2. Under the dynamic impact condition, the stress-strain curve of the multi-scale triangular hierarchical structure is more gentle and the fluctuation is smaller, which also means that the deformation of the multi-scale triangular hierarchical structure is relatively uniform under the impact condition, which reduces the impact of the protective structure on the protected structure. The transient impact of the structure can more effectively protect the structure.

3. The multi-scale triangular hierarchical structure proposed in this paper has the characteristics of highly adjustable material and geometric size, which can be adjusted according to the actual application conditions, and has good engineering application value.

As shown in FIG. 1 and FIG. 2 , the multi-scale hierarchical triangular impact-resistant structure provided by the embodiment of the present invention is inlaid with triangles of different geometries inside the triangular hierarchical structure, and the triangular level is provided with a macro-scale triangle 1. A mesoscopic scale triangle 2 is inlaid, and a microscopic scale triangle 3 is inlaid in the mesoscopic scale triangle 2 .

The meso-scale triangle 2 divides the macro-scale triangle 1 into four regions. The uppermost of the four regions is the first region 4 , the middle is the second region 5 , the lower left end is the third region 6 , and the lower right end is the fourth region 7 .

Micro-scale triangles 3 are embedded in the first area 4 , the third area 6 and the fourth area 7 .

The macro-scale triangle 1, the meso-scale triangle 2 and the micro-scale triangle 3 all have a structure size ratio of 0.5, that is, the side length of the meso-scale triangle 2 is half the size of the macro-scale triangle 1, and the size of the micro-scale triangle 3 is the size of the meso-scale triangle 2. In half of the triangles, there is no gap in contact between the three triangles, and the stress wave can propagate continuously in the structure.

The macro-scale triangles are periodically arranged in the multi-scale hierarchical triangular structure, and its single periodic unit can be obtained by the translation and rotation of the hierarchical triangles.

The working principle of the multi-scale hierarchical triangular impact-resistant structure of the present invention: a macro-scale triangle 1 is inlaid with a meso-scale triangle 2, and a meso-scale triangle 2 is inlaid with a micro-scale triangle 3. Compared with the triangular grid structure, the new triangular hierarchical structure has higher compressive properties and energy absorption properties. Under static compression, the energy absorption characteristics of multi-scale hierarchical triangles are nearly doubled compared with that of single-scale triangular lattice structures, and their energy absorption characteristics are also partially improved under dynamic impact, which can be used for compression and impact resistance sandwich panel structure design. Good engineering application value.

In the description of the present utility model, unless otherwise specified, "multiple" means two or more; the terms "upper", "lower", "left", "right", "inner", "outer" ", "front end", "rear end", "head", "tail" and other indications of orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, only for the convenience of describing the present utility model and simplifying the description, Rather than indicating or implying that the indicated device or element must have a particular orientation, be constructed and operate in a particular orientation, it should not be construed as a limitation of the present invention. Furthermore, the terms "first," "second," "third," etc. are used for descriptive purposes only and should not be construed to indicate or imply relative importance.

The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any modifications, equivalent replacements and improvements made within the spirit and principle of the present invention shall be covered within the protection scope of the present invention.

Claims (5)

1. A multi-scale hierarchical triangular impact-resistant structure, characterized in that it is provided with:

a triangular hierarchy;

the triangular structure is characterized in that triangular shapes with different geometries are embedded in the triangular hierarchical structure, a macro-scale triangle is arranged on the triangular hierarchy, an mesoscale triangle is embedded in the macro-scale triangle, and a micro-scale triangle is embedded in the mesoscale triangle.

2. The multi-scale, hierarchical, triangular impact-resistant structure according to claim 1, wherein the mesoscale triangles divide the macroscale triangle into four regions, the four regions being a first region at the top, a second region in the middle, a third region at the bottom left, and a fourth region at the bottom right.

3. The multi-scale, hierarchical triangular impact-resistant structure of claim 2, wherein micro-scale triangles are embedded within the first, third, and fourth regions.

4. The multi-scale hierarchical triangular impact-resistant structure according to claim 1, wherein the dimensional proportions of the macro-scale triangle, the meso-scale triangle and the micro-scale triangle are all 0.5, that is, the side length of the meso-scale triangle is half of the macro size, the size of the micro-scale triangle is half of the meso-scale triangle, the three triangles are contacted without a gap, and the stress wave can be continuously propagated in the structure.

5. The multi-scale, hierarchical, triangular impact-resistant structure according to claim 1, wherein the macro-scale triangles of the multi-scale, hierarchical, triangular structure are periodically arranged, and the single periodic unit of the macro-scale triangles of the multi-scale, hierarchical, triangular structure can be obtained by translation and rotation of the hierarchical triangles.

Images