A structural node with negative poisson's ratio effect and a flexible protection system

Abstract

The application provides a structural node with a negative Poisson's ratio effect and a flexible protection system, and relates to the technical field of flexible protection. The structural node comprises two end face structures arranged upward and downward. Each end face structure is composed of two first arc-shaped plates with coinciding geometric centers and orthogonal arrangement. The projections of the two end face structures on a bottom surface coincide. The distance between the geometric center of the first arc-shaped plate in the upper end face structure and the corresponding geometric center below is m, the distance between the corresponding end portions is M, and m < M is satisfied. Four connecting plates are circumferentially arranged between the two end face structures. The two ends of the connecting plate are fixedly connected with the end portions of the corresponding first arc-shaped plates in the upper and lower end face structures, respectively. The passive and centralized energy consumption of the traditional protection net is converted into active and dispersed energy consumption through the negative Poisson's ratio structure design. The anti-puncture capacity, energy absorption efficiency and overall safety are significantly improved.

Description

Technical Field

[0001] This invention relates to flexible protection technology, and in particular to a structural node with a negative Poisson's ratio effect and a flexible protection system. Background Technology

[0002] Flexible protective netting is widely used in the prevention and control of natural disasters such as slope rockfalls and debris flows, as well as in areas such as structural blast resistance and counter-terrorism protection, due to its excellent energy absorption capacity and terrain adaptability. Currently, mainstream passive protection systems mainly consist of wire rope netting, pressure-reducing rings, steel columns, anchor bolts, and bases. Among these, the wire rope netting, as the main load-bearing structure, is woven into a diamond or square grid and secured with rope clips at the intersections.

[0003] The protective mechanism of traditional flexible protective nets relies on two points: first, the net undergoes large deformation under impact, converting the impact kinetic energy into the elastic potential energy and plastic deformation energy of the net; second, energy-dissipating elements such as pressure-reducing rings set at the boundaries further absorb energy through plastic deformation.

[0004] However, this structure has significant shortcomings when faced with high-energy, high-speed impacts:

[0005] Low energy absorption efficiency and prone to central breakdown: Traditional mesh is a "passive response" structure, where impact energy needs to be transferred gradually through the mesh, resulting in a large energy dissipation range but low density. When faced with high-energy, small-area impacts, energy tends to concentrate in the central mesh, causing local steel wire ropes to break or be sheared, leading to "central breakdown" and overall failure.

[0006] The impact force is transmitted violently, and the anchoring system is under great burden: relying on the energy dissipation of the overall deformation, a large amount of impact energy is rapidly transmitted to the boundary anchoring system, causing a huge peak load on the anchor rod and the base, which can easily lead to the anchor rod being pulled out or the base being damaged, thereby increasing the engineering difficulty and cost.

[0007] Rigid connections at nodes limit the advantages of flexibility: Rope clamp nodes are rigid connections and do not participate in energy dissipation. When the mesh at the impact point is stretched to its limit, the stiffness increases sharply, creating a "hard-on-hard" situation, weakening the "softness overcomes hardness" effect, and exacerbating stress concentration, increasing the risk of failure at the nodes.

[0008] It is evident that traditional protective nets, relying on "passive overall deformation" to dissipate energy, are ill-suited for efficiently responding to high-energy impacts, particularly in terms of timely energy dissipation and reducing boundary loads in localized impact areas. Therefore, there is an urgent need to develop new protective structures capable of proactive and efficient energy dissipation in impact zones, thereby comprehensively improving interception reliability and system safety. Summary of the Invention

[0009] This invention provides a structural node with a negative Poisson's ratio effect and a flexible protection system, which aims to solve the problems of weak center penetration capability, large boundary load, and node rigidity constraints in the resistive protection net.

[0010] To achieve the above objectives, embodiments of the present invention provide a structural node with a negative Poisson's ratio effect, comprising:

[0011] The end face structure includes two first arc-shaped plates, which are arranged orthogonally and whose geometric centers coincide.

[0012] The two end-face structures are arranged vertically and their projections on the bottom surface coincide. The distance between the geometric center of the first arc-shaped plate in the upper end-face structure and the geometric center of the first arc-shaped plate in the lower end-face structure is m; the distance between the end of the first arc-shaped plate in the upper end-face structure and the corresponding end of the first arc-shaped plate in the lower end-face structure is M, where m < M;

[0013] Four connecting plates are arranged around the two end face structures, and the two ends of each connecting plate are fixedly connected to the ends of the corresponding first arc-shaped plates in the two end face structures.

[0014] Preferably, a pair of arc-shaped bends are provided between adjacent connecting plates, with the pair of arc-shaped bends respectively located at the upper and lower ends of the connecting plates, and the bending directions of the pair of arc-shaped bends being opposite.

[0015] Preferably, the structural node further includes an impact-receiving structure, which includes an impact-receiving panel and a second arc-shaped plate. The two second arc-shaped plates are arranged orthogonally, and the geometric centers of the two second arc-shaped plates coincide. The impact-receiving panel is disposed at the ends of the two second arc-shaped plates.

[0016] The two intercepting structures are respectively fixed on the two end face structures, and the second arc-shaped plate in each corresponding connected intercepting structure and end face structure has the same bending direction as the first arc-shaped plate;

[0017] The curvature of the second arc-shaped plate is greater than that of the first arc-shaped plate.

[0018] Preferably, the widths of the first arc-shaped plate, the connecting plate, and the second arc-shaped plate are: Thickness is , and satisfy ;

[0019] The horizontal span of the adjacent connecting plates is , and satisfy .

[0020] Preferably, the radius of the first arc-shaped plate is , and satisfy ;

[0021] The radius of the second arc-shaped plate is , and satisfy .

[0022] Preferably, the thickness of the first arc-shaped plate, the connecting plate, and the second arc-shaped plate is [missing information]. It has the same diameter as the curved rod.

[0023] Preferably, an anchoring channel is also formed on the connecting plate, the anchoring channel having a central through hole formed along the axial direction, the radius of the central through hole being... , and satisfy ;

[0024] The length of the anchoring channel protruding from the connecting plate is , and satisfy .

[0025] This application also provides a flexible protection system, which, in addition to the aforementioned structural nodes, also includes:

[0026] The warp has at least one structural node passing through it, and the warp passes through a pair of opposite connecting plates of the structural node and is fixedly connected to the connecting plates.

[0027] The weft thread is threaded through another pair of opposite connecting plates at the structural node and fixedly connected to the connecting plates;

[0028] The meridians and the parallels form a grid-like structure.

[0029] Preferably, both the warp and the weft are steel strands.

[0030] The above-described solution of the present invention has the following beneficial effects:

[0031] This application fundamentally changes the energy absorption and transfer mechanism of the protective net by designing structural nodes with a negative Poisson's ratio effect, upgrading the traditional passive and centralized energy consumption mode of the protective net to an active and decentralized energy consumption mode, thereby improving the puncture resistance, energy absorption efficiency and overall safety.

[0032] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the structural nodes;

[0034] Figure 2 This is a schematic diagram of the end face structure;

[0035] Figure 3 This is a schematic diagram of the interceptor structure;

[0036] Figure 4 This is the front view of a structural node;

[0037] Figure 5 This is a top view of the structural nodes;

[0038] Figure 6 yes Figure 5 AA section view;

[0039] Figure 7 This is a schematic diagram of a flexible protection system;

[0040] Figure 8 yes Figure 7 Enlarged view of section B.

[0041] [Explanation of Labels in the Attached Image]

[0042] 10-End face structure, 11-First arc-shaped plate, 12-First plane, 13-Side wing

[0043] 20-Connecting plate, 21-Anchoring channel, 22-Central through hole

[0044] 30-Arc-shaped bend bar,

[0045] 40 - Impact-receiving structure, 41 - Impact-receiving panel, 42 - Second curved plate, 43 - Second plane

[0046] 50-longitude,

[0047] 60-latitude line,

[0048] 70 - Structural node. Detailed Implementation

[0049] To make the technical problems, technical solutions and advantages of the present invention clearer, a detailed description will be given below in conjunction with the accompanying drawings and specific embodiments.

[0050] like Figures 1-6As shown, an embodiment of the present invention provides a structural node with a negative Poisson's ratio effect, including an end face structure 10 and a connecting plate 20 connecting the end face structure 10. The end face structure 10 includes two first arc-shaped plates 11, which are curved rectangular plates arranged orthogonally, with their geometric centers coinciding. The two end face structures 10 are arranged vertically at intervals, and their projections on the bottom surface coincide, i.e., the projection of each end face structure 10 on the bottom surface is a cross shape, and the two cross shapes coincide on the bottom surface, thus satisfying a one-to-one correspondence between the first arc-shaped plates 11 in the vertical direction of the two end face structures 10.

[0051] In the two vertically arranged end face structures 10, the distance between the geometric center of the first arc plate 11 in the upper end face structure 10 and the geometric center of the first arc plate 11 in the lower end face structure 10 is m, and the distance between the end of the first arc plate 11 in the upper end face structure 10 and the corresponding end of the first arc plate 11 in the lower end face structure 10 is M, where m < M, so that the bending directions of the end face structures 10 are opposite.

[0052] The aforementioned connecting plates 20 are provided in four parts. The two ends of each connecting plate 20 are fixedly connected to the ends of the corresponding connecting plates 20 in the upper and lower end face structures 10, respectively. The connecting plates 20 are arranged in the circumferential direction of the end face structure 10. From the connection position and spatial relationship between the connecting plates 20 and the end face structure 10, it can be seen that the upper end of the connecting plate 20 is connected to one end of the first arc plate 11 in one end face structure 10, and the lower end of the connecting plate 20 is connected to the end of the first arc plate 11 in another end face structure 10. The projections of the ends of the first arc plates 11 connected to both ends of the same connecting plate 20 on the bottom surface coincide.

[0053] Furthermore, a pair of arc-shaped bending rods 30 are provided on adjacent connecting plates 20. The pair of arc-shaped bending rods 30 are respectively provided at the upper and lower ends of the connecting plates 20, and the bending directions of the pair of arc-shaped bending rods 30 are opposite.

[0054] Specifically, the aforementioned arc-shaped bending rods 30 are provided on a set of adjacent connecting plates 20, with one arc-shaped bending rod 30 positioned above the adjacent connecting plate 20 and the other arc-shaped bending rod 30 positioned below the adjacent connecting plate 20. One arc-shaped bending rod 30 is fixedly connected between the upper ends of the two adjacent connecting plates 20, and the other arc-shaped bending rod 30 is fixedly connected between their lower ends. In this application, the arc-shaped bending rod 30 located at the lower end of the connecting plate 20 bends upward, and the arc-shaped bending rod 30 located at the upper end of the connecting plate 20 bends downward.

[0055] Furthermore, to optimize the effect of receiving and transmitting impact force in the end face structure 10, the structural node 70 also includes an impact-receiving structure 40. This impact-receiving structure 40 includes an impact-receiving panel 41 and a second arc-shaped plate 42. The two arc-shaped plates are arranged orthogonally, and their geometric centers coincide. The impact-receiving panel 41 is located at the ends of the two arc-shaped plates 42 and is supported by the ends of each arc-shaped plate 42. The two impact-receiving structures 40 are respectively fixed to the two end face structures 10. Each end face structure 10 has a corresponding impact-receiving structure 40. The second arc-shaped plate 42 in one of the impact-receiving structures 40 has the same bending direction as the first arc-shaped plate 11 in the end face structure 10 it is connected to. The curvature of the second arc-shaped plate 42 is greater than the curvature of the first arc-shaped plate 11. The bottom of the impact-receiving structure 40 is fixedly connected to the bottom of the end face structure 10, thereby partially enclosing the impact-receiving structure 40 in the end face structure 10.

[0056] Preferably, the impact-receiving panel 41 is a regular octagon.

[0057] Preferably, in order to better achieve the connection between the impact structure 40 and the end face structure 10, the connection point of the two first arc-shaped plates 11 is planarized to form a first plane 12, and the connection point of the two second arc-shaped plates 42 is planarized to form a second plane 43. The first plane 12 and the second plane 43 are fixed together, thereby fixing the impact structure 40 and the end face structure 10.

[0058] In this application, the planarization process is as follows: the first plane 12 extends along the orthogonal direction to form four side wings 13 of the same length. The first plane 12 and a pair of side wings 13 form a first arc plate 11. The first plane 12 and another pair of side wings 13 form another first arc plate 11.

[0059] In this application, the widths of the first arc-shaped plate 11, the connecting plate 20, and the second arc-shaped plate 42 are: Thickness is , and satisfy ;

[0060] The horizontal span of adjacent connecting plates 20 is , and satisfy .

[0061] The radius of the circle of the first arc plate 11 is , and satisfy ;

[0062] The radius of the circle of the second arc plate 42 is , and satisfy ;

[0063] The thicknesses of the first arc-shaped plate 11, the connecting plate 20, and the second arc-shaped plate 42 are: It has the same diameter as the curved bending rod 30.

[0064] Preferably, an anchoring channel 21 is also formed on the connecting plate 20, the anchoring channel 21 having a central through hole 22 formed along the axial direction, the radius of the central through hole 22 being... , and satisfy ;

[0065] The length of the anchoring channel 21 protruding from the connecting plate 20 is , and satisfy .

[0066] Preferably, the structural node 70 is manufactured using an integrated molding process such as precision casting or metal 3D printing to ensure its structural accuracy and overall strength.

[0067] like Figure 7 and Figure 8 As shown, this application also provides a flexible protection system, including the aforementioned structural node 70, as well as a warp 50 and a weft 60. At least one structural node 70 is provided on a warp 50. The warp 50 passes through a pair of opposing connecting plates 20 of the structural node 70 and is fixedly connected to the connecting plates 20. A weft 60 is also provided on the same structural node 70. The weft 60 passes through another pair of opposing connecting plates 20 of the structural node 70 and is fixedly connected to the connecting plates 20.

[0068] Understandably, when multiple structural nodes 70 are set on the same meridian 50, multiple parallels 60 are connected on the same meridian 50 through the structural nodes 70. When there are multiple meridians 50, the multiple meridians 50 and the multiple parallels 60 form a grid-like structure.

[0069] Preferably, when the connecting plate 20 is provided with an anchoring channel 21, the warp 50 or weft 60 passes through the anchoring channel 21 and is injected with a high-strength, fast-curing anchoring agent in the central through hole 22, thereby achieving a high-strength connection between the connecting plate 20 and the warp 50 or weft 60, ensuring the effective transmission of force, and improving the integrity and durability.

[0070] In this application, when the application is impacted by falling rocks, the anti-rock structure 40, due to its protruding end face structure 10, is the first to receive the impact force. The anti-rock structure 40 transmits this impact force (mainly compressive force) to the core structure composed of the end face structure 10 and the connecting plate 20. This compressive force causes the geometric centers of the first arc-shaped plates 11 in the upper and lower end face structures 10 to tend to move closer to each other, thereby causing the two ends of the first arc-shaped plates 11 to contract respectively, which in turn causes the connecting plate 20 to displace inward. That is, when the structural node 70 is impacted, a negative Poisson's ratio effect is generated, which in turn causes the connecting plate 20 to move towards the center of the structural node 70, and actively causes the cable fixedly connected to the connecting plate 20 to tighten.

[0071] During the impact, the curved rod 30 acts as an elastic reinforcing rib, which not only enhances the overall stability of the structural node 70, but also stores and dissipates energy during deformation.

[0072] This application transforms the force along the impact direction into a lateral contraction force perpendicular to the impact direction through the structure of structural node 70, thereby achieving a macroscopic negative Poisson's ratio effect and obtaining the effect of active mesh tightening and energy concentration.

[0073] Compared to traditional protective nets, this application transforms passive response into active energy focusing, improving impact resistance and puncture resistance. In traditional protective nets, the rope clips only serve a fixing function, passively dissipating energy upon impact. After being passively stretched to its limit, the central mesh is easily broken, resulting in central puncture.

[0074] When subjected to impact compression, the structural node 70 undergoes lateral contraction, actively and forcibly pulling the four ropes connected to it towards the center, achieving an active energy-concentrating effect. This active energy-concentrating effect effectively disperses the impact force from a point to a surface, greatly improving the protective system's ability to resist central penetration, and its effectiveness is even more pronounced when dealing with sharp, high-speed impacts.

[0075] Compared to traditional protective nets, this application achieves highly efficient energy dissipation in the impact zone, significantly reducing the impact load on the boundary anchoring system. Traditional protective nets absorb impact energy through the overall deformation of the entire net body and the energy-absorbing rings at the boundaries. A large amount of unreduced impact energy is directly transferred to the anchor bolts and bases, resulting in huge peak loads on the anchor bolts and bases, posing a serious threat to them. This decentralized energy dissipation mode of traditional protective nets relies on the large-area deformation of the entire net body and the decompression of the boundary pressure-reducing rings during energy dissipation. It lacks an energy absorption core. Although the entire net surface participates in deformation, the energy absorption rate of each local area is low. When the impact energy is too concentrated, it is easy to cause untimely energy dissipation, resulting in central breakdown.

[0076] In this application, during the active tightening process of structural node 70, components such as the arc-shaped plate and arc-shaped bending rod 30 undergo severe elastoplastic deformation, absorbing and dissipating a large amount of impact energy in the impact zone, greatly attenuating the impact energy, significantly reducing the residual energy transmitted to the anchor rod and base, and significantly reducing the peak impact load. This improves the safety redundancy of the flexible protection system, optimizes the anchoring design of the anchor rod and base while ensuring safety, and reduces project costs. This application concentrates energy dissipation at the structural node through centralized energy consumption. When an impact occurs, the severe deformation of the structural node itself and the active tightening of the surrounding mesh dissipate most of the energy, preventing the impact energy from spreading to the flexible protection system, thereby improving the efficiency and density of energy absorption.

[0077] Compared to traditional protective netting, this application improves the overall integrity and collaborative working ability of the flexible protective system, eliminating weak points. In traditional protective netting, the rope clips and wire ropes are fixed by friction, which is prone to slippage under high-intensity impact, leading to loosening of the mesh, uneven deformation, and the formation of stress concentration points, which become weak points in the protective netting.

[0078] In this application, structural node 70 adopts a one-piece molded structure with extremely high overall strength. It is rigidly connected to the rope through grouting anchoring, avoiding the risk of slippage. Furthermore, the negative Poisson's ratio effect enables structural node 70 and the surrounding mesh to work collaboratively and respond synchronously under stress, forming an integrated flexible protective net. This makes the overall stress distribution more uniform, avoids local stress concentration, and improves the reliability and durability of the system.

[0079] In summary, this application fundamentally changes the energy absorption and transfer mechanism of the protective net by designing structural nodes with a negative Poisson's ratio effect, upgrading the traditional passive and decentralized energy consumption mode of the protective net to an active and centralized energy consumption mode, thereby improving the puncture resistance, energy absorption efficiency and overall safety.

[0080] This embodiment also provides a replacement protective net with a mesh width of 220mm. Specifically, the structural node 70 is made of Q345D high-strength low-alloy structural steel and is integrally formed using selective laser melting (SLM) metal 3D printing technology. Each component meets the following requirements: the widths of the first arc plate 11, the connecting plate 20, and the second arc plate 42 are... Horizontal span of adjacent connecting plates 20 Height of connecting plate 20 The radius of the circle corresponding to the first arc plate 11 The radius of the circle of the second arc plate 42 is .

[0081] radius of the center through hole 22 The length of the anchoring channel 21 protruding from the connecting plate 20 is .

[0082] 8mm steel strands are threaded through the connecting plate 20 of the fabricated structural node 70, and multiple structural nodes 70 and steel strands are combined to form a diamond grid. Anchoring agent is injected into the anchoring channel 21 to fix the steel strands to the anchoring channel 21, thus forming the entire flexible protection system.

[0083] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A structural node with a negative Poisson's ratio effect, characterized in that, include: The end face structure (10) includes two first arc-shaped plates (11), which are arranged orthogonally and whose geometric centers coincide. Two end face structures (10) are arranged vertically and their projections on the bottom surface coincide. The distance between the geometric center of the first arc plate (11) in the upper end face structure (10) and the geometric center of the first arc plate (11) in the lower end face structure (10) is m; the distance between the end of the first arc plate (11) in the upper end face structure (10) and the corresponding end of the first arc plate (11) in the lower end face structure (10) is M, where m < M; Connecting plates (20), four connecting plates (20) are set in the circumference of the two end face structures (10), and the two ends of each connecting plate (20) are fixedly connected to the ends of the corresponding first arc plate (11) in the two end face structures (10); The structural node also includes an impact structure (40), which includes an impact-receiving panel (41) and a second arc-shaped plate (42). The two second arc-shaped plates (42) are arranged orthogonally, and the geometric centers of the two second arc-shaped plates (42) coincide. The impact-receiving panel (41) is located at the ends of the two second arc-shaped plates (42). The two intercepting structures (40) are respectively fixed on the two end face structures (10), and the second arc plate (42) in each corresponding connected intercepting structure (40) and end face structure (10) has the same bending direction as the first arc plate (11); The curvature of the second arc plate (42) is greater than that of the first arc plate (11).

2. The structural node with negative Poisson's ratio effect according to claim 1, characterized in that: A pair of curved rods (30) are also provided between adjacent connecting plates (20). The pair of curved rods (30) are respectively provided at the upper and lower ends of the connecting plates (20), and the bending directions of the pair of curved rods (30) are opposite.

3. The structural node with negative Poisson's ratio effect according to claim 2, characterized in that: The widths of the first arc-shaped plate (11), the connecting plate (20), and the second arc-shaped plate (42) are: Thickness is , and satisfy ; The horizontal span of the adjacent connecting plates (20) is , and satisfy .

4. The structural node with negative Poisson's ratio effect according to claim 3, characterized in that: The radius of the circle of the first arc plate (11) is , and satisfy ; The radius of the circle of the second arc plate (42) is , and satisfy .

5. The structural node with negative Poisson's ratio effect according to claim 4, characterized in that: The thicknesses of the first arc plate (11), the connecting plate (20), and the second arc plate (42) are: It has the same diameter as the curved rod (30).

6. The structural node with negative Poisson's ratio effect according to claim 3, characterized in that: An anchoring channel (21) is also formed on the connecting plate (20), the anchoring channel (21) having a central through hole (22) formed along the axial direction, the radius of the central through hole (22) being... , and satisfy ; The length of the anchoring channel (21) protruding from the connecting plate (20) is , and satisfy .

7. A flexible protection system comprising a plurality of structural nodes (70) as described in any one of claims 1-6, characterized in that: The warp (50) has at least one structural node (70) passing through it. The warp (50) passes through a pair of opposite connecting plates (20) of the structural node (70) and is fixedly connected to the connecting plates (20). The weft thread (60) passes through another pair of opposite connecting plates (20) at the structural node (70) and is fixedly connected to the connecting plate (20); The meridians (50) and the parallels (60) form a grid-like structure.

8. The flexible protection system according to claim 7, characterized in that: Both the warp (50) and the weft (60) are steel strands.

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