A cushioning energy-absorbing system based on negative stiffness honeycomb

Abstract

The application discloses a buffering and energy-absorbing system based on an oil negative stiffness honeycomb. The buffering and energy-absorbing system comprises a negative stiffness honeycomb, an oil cavity cover, an oil cavity body and oil liquid. The negative stiffness honeycomb is in a dome shape, and the dome shape is formed by rotating a cosine curve for one circle. A cylindrical support column is arranged at the center of the dome, and the support column is connected with a load generating component. A plurality of damping holes are uniformly distributed on the circumference of 1 / 2 radius of the dome-shaped body. The oil cavity cover and the oil cavity body form an oil cavity, and the oil cavity is filled with the oil liquid. The dome-shaped body of the negative stiffness honeycomb is located in the oil cavity, and the oil liquid is higher than the damping holes. The outermost edge of the dome-shaped body is press-connected between the oil cavity cover and the oil cavity body. The bottom of the oil cavity body is connected with a component to be protected through a connecting column. The height-to-thickness ratio of the negative stiffness honeycomb is adjusted to realize single use and repeated use of the negative stiffness honeycomb. The area of the damping holes is adjusted to realize adjustment of the energy-absorbing capacity, and then the buffering and energy-absorbing effect under different loads is realized.

Description

Technical Field

[0001] This invention belongs to the field of buffer energy absorption, specifically relating to a buffer energy absorption system based on oil-based negative stiffness honeycomb. Background Technology

[0002] Negative stiffness honeycomb is a type of negative stiffness honeycomb structure that utilizes the jump transition of buckling modes in curved beams to achieve negative stiffness behavior. It is a mechanical superstructure with high stiffness and recoverability. Due to its special properties or functions, such as negative stiffness effect, multi-steady-state effect, and repeatability, negative stiffness honeycomb structure, as a novel lightweight multifunctional structure, has broad application prospects in fields such as impact energy absorption, vibration control, and noise isolation.

[0003] The essence of negative stiffness honeycomb is to amplify the elastic characteristics of materials, allowing the structural material to absorb energy during compression and release it after unloading, thus achieving reusability. However, since most existing negative stiffness honeycomb structures are curved beams, this form of negative stiffness honeycomb has low energy absorption efficiency and cannot withstand strong loads. Summary of the Invention

[0004] The purpose of this invention is to provide a buffer energy absorption system based on an oil-based negative stiffness honeycomb structure. This invention rotates a curved beam negative stiffness honeycomb to form a dome-shaped negative stiffness honeycomb, integrating fluid damping into the negative stiffness honeycomb. Volume changes during compression generate damping force, which improves load-bearing capacity while maintaining the original characteristics of the negative stiffness honeycomb. Furthermore, by adjusting the ratio of the height to the thickness of the negative stiffness honeycomb, single-use and repeated use of the negative stiffness honeycomb can be achieved. By adjusting the area of ​​the damping holes, the energy absorption capacity can be adjusted, thereby achieving buffer energy absorption effects under different load magnitudes.

[0005] The technical solution to achieve the purpose of this invention is: a buffer energy absorption system based on oil negative stiffness honeycomb, including negative stiffness honeycomb, oil chamber cover, oil chamber body and oil;

[0006] The main body of the negative stiffness honeycomb is dome-shaped. The dome shape is formed by rotating a cosine curve. A cylindrical support column is set at the center of the dome. The support column is connected to the load-generating component. Multiple damping holes are evenly distributed on the circumference of the dome-shaped main body with a radius of 1 / 2.

[0007] The oil chamber cover and the oil chamber body form an oil chamber, which contains oil. The negative stiffness honeycomb dome-shaped body is located inside the oil chamber, and the oil does not pass through the damping hole. The outermost edge of the dome-shaped body is pressed between the oil chamber cover and the oil chamber body.

[0008] The bottom of the oil chamber body is equipped with a connecting column, which is connected to the component to be protected.

[0009] Furthermore, the oil chamber cover and the oil chamber body are stepped at the joint, with a threaded connection in the middle of the step, and sealant is added during the connection.

[0010] Furthermore, the outermost periphery of the oil cavity cover is provided with an outer edge, and after assembly, the outer edge is located on the annular side wall of the oil cavity body for installation and positioning.

[0011] Furthermore, the oil chamber cover has a through hole in the center for the passage of the central support column of the negative stiffness honeycomb, and there is a groove on the inner wall of the through hole for installing the sealing ring.

[0012] Furthermore, the cosine curve is given by equation (1), where y represents the vertical distance from the horizontal chord to the contour shape at a distance x from the center line, and the axis of rotation is the y-axis:

[0013]

[0014] In the formula: h is the height of the vertex, t is the thickness, L is the span, and R is the radius of the small hole.

[0015] Furthermore, the damping force can be adjusted by changing the number and radius of the damping holes, i.e., the total area of ​​the damping holes. The damping force is inversely proportional to the square of the sum of the areas of the damping holes, as follows:

[0016]

[0017] In the formula: F is the damping force, For the oil cavity compression volume change rate, C d For flow coefficient, A x ρ is the sum of the total areas of the damping orifices, ρ is the oil density, and A1 is the working area.

[0018] A rope-net launch buffer system includes a launch cavity, the aforementioned oil-based negative stiffness honeycomb buffer energy absorption system, an adapter, and a fixing ring.

[0019] The adapter is first connected to the oil-hydraulic negative stiffness honeycomb buffer energy absorption system via threads. Then, the adapter passes through the through hole of the external platform of the launch cavity, and the adapter and the oil-hydraulic negative stiffness honeycomb buffer energy absorption system are threadedly connected to the launch cavity via a retaining ring.

[0020] Furthermore, it also includes a towing body, a launch tube, an igniter, and a launch pad;

[0021] The traction body is a mass block that moves with the traction rope net; the launch tube is used to fix the traction body; the launch cavity is used to fix the launch tube; the igniter is used to provide the kinetic energy for the traction body to launch; and the launch frame is used to fix the launch buffer system and the launch platform together.

[0022] When the igniter is activated, the gas expands inside the launch chamber. Part of the gas propels the traction body along the launch tube, while the other part acts inside the launch chamber, causing the launch chamber and the adapter to move downwards, thereby compressing the oil-hydraulic negative stiffness honeycomb buffer energy absorption system. The central support column of the negative stiffness honeycomb moves downwards under the compressive load, and its curved damping orifice also moves downwards, compressing the oil inside the oil chamber. This causes the oil to flow out through the curved damping orifice of the negative stiffness honeycomb, creating a pressure difference between the upper and lower curved surfaces of the negative stiffness honeycomb, which in turn generates oil damping force. After the compression process is completed, the negative stiffness honeycomb, according to the design parameters, namely the ratio of height to thickness, produces a monostable or multistable effect, achieving a repeated or single stable buffer energy absorption effect against impact loads.

[0023] Compared with the prior art, the significant advantages of this invention are:

[0024] (1) Compared with the negative stiffness honeycomb buffer energy absorption form, the system adds oil as a damping medium, which greatly improves the load-bearing capacity of the whole system.

[0025] (2) The buffer energy absorption system based on oil negative stiffness honeycomb can set the buffer stroke as needed and can achieve strong buffer energy absorption capacity under low stroke.

[0026] (3) The buffer energy absorption system based on oil negative stiffness honeycomb has a wide range of applications. It can be designed to match different parameters according to different size space, compression speed, compression stroke and buffer requirements. Attached Figure Description

[0027] Figure 1 This is a cross-sectional view of a buffer energy absorption system based on oil-hydraulic negative stiffness honeycomb.

[0028] Figure 2 This is a diagram showing the external shape of a negative stiffness honeycomb.

[0029] Figure 3 Displacement curves for different types of negative stiffness honeycomb loads;

[0030] Figure 4 Load-displacement curve of oil-based negative stiffness honeycomb buffer energy absorption system;

[0031] Figure 5 This is a structural diagram of a rope net launching buffer system.

[0032] Explanation of reference numerals in the attached figures:

[0033] 1-Traction body, 2-Launch tube, 3-Launch cavity, 4-Oil negative stiffness honeycomb buffer energy absorption system, 5-Adapter seat, 6-Fixing ring, 7-Igniter, 8-Launch frame, 401-Negative stiffness honeycomb, 402-Oil cavity cover, 403-Oil cavity body, 404-Sealing ring, 405-Oil. Detailed Implementation

[0034] The present invention will now be described in further detail with reference to the accompanying drawings.

[0035] A buffer energy absorption system based on an oil-based negative stiffness honeycomb structure is disclosed. The buffer energy absorption system 4 has an overall cylindrical shape, with threads on the upper and lower ends of the central disk for connection and fixation to external components. The system mainly includes a dome-shaped negative stiffness honeycomb 401, an oil chamber cover 402, an oil chamber 340, a sealing ring 404, and oil 405. When an impact load is transmitted to the buffer energy absorption system, the central support column of the dome-shaped negative stiffness honeycomb is in direct contact with the component generating the impact load. Therefore, the negative stiffness honeycomb is compressed under the load. As the compression displacement increases, the oil inside the negative stiffness honeycomb is squeezed out through small holes on the honeycomb surface, generating oil damping force. During this process, the oil repeatedly collides and rubs against the honeycomb, consuming a large amount of energy.

[0036] When the compression of the honeycomb ends, based on the design parameters of the negative stiffness honeycomb, the buffer energy absorption system can exist in two states. When the negative stiffness honeycomb is monostable, the deformation of the honeycomb throughout the process is elastic deformation. Therefore, without external load, the negative stiffness honeycomb will return to its initial state, achieving repeated buffer energy absorption. When the negative stiffness honeycomb is multistable, after being compressed by a certain displacement, the honeycomb will maintain its current state without external force, achieving single-time stable buffer energy absorption. At the same time, the compression displacement of the entire buffer energy absorption system can be determined based on the design parameters of the negative stiffness honeycomb.

[0037] The negative stiffness honeycomb 401 is dome-shaped, such as... Figure 2 As shown, it is formed by rotating a cosine curve one revolution. A cylinder at the center of the dome serves as a support column, connecting to the load-bearing components. The cosine curve is shown in Formula 1, where y represents the vertical distance from the horizontal chord to the contour shape at a distance x from the center line, and the axis of rotation is the y-axis.

[0038]

[0039] In the formula: h is the height of the vertex, t is the thickness, L is the span, and R is the radius of the small hole.

[0040] The curved surface of the negative stiffness honeycomb 401 can be achieved through 3D printing or machining. The honeycomb has small holes at its center radiating outwards from the central support pillar; these holes are damping holes. The damping force can be adjusted by changing the number and radius of these holes, i.e., the total area of ​​the damping holes. The damping force is inversely proportional to the square of the sum of the total areas of the damping holes, as detailed below:

[0041]

[0042] In the formula: F is the damping force, For the oil cavity compression volume change rate, C dFor flow coefficient, A x ρ is the sum of the total areas of the damping orifices, ρ is the oil density, and A1 is the working area.

[0043] The oil chamber cover 402 is disc-shaped with a platform at the center for easy thread tightening. A through hole is provided at the center of the disc for the passage of the central support column of the negative stiffness honeycomb 401. A groove is provided on the inner wall of the through hole for installing the sealing ring 404, ensuring that the oil 405 is always kept inside the cavity formed by the oil chamber 403 and the oil chamber cover 402 during the compression process. The oil chamber cover 402 is threaded to connect with the oil chamber 403. Sealant can be added during connection to ensure the sealing performance of the system. A boss is provided at the top of the thread to ensure proper installation during connection with the oil chamber 403.

[0044] The oil chamber 403 is cylindrical, with an external thread at the bottom center of the cylinder connecting to a fixed component, and an internal thread at the top of the cylinder connecting to the oil chamber cover 402 so that the oil 405 is stored in the chamber; the sealing ring 404 is a standard sealing ring; the oil 405 is commonly used hydraulic buffer oil.

[0045] The negative stiffness honeycomb 401 exists in three states: monostable, multistable, and critical. These three states mainly depend on the shape of the hybrid displacement curve of the negative stiffness honeycomb 401, such as... Figure 3 As shown. When the load-displacement curve has no negative force segment, it is defined as a monostable response. In this type of response, as long as the material is not damaged, it can recover to its original state after unloading without external restoring force. In the multistable case, without external restoring load, the negative stiffness honeycomb 401 cannot recover, so the curve has a negative force segment. In the critical state, there is zero force at non-zero displacement in the curve. This response marks the transition state between bistable and monostable responses, where the structure can recover to its initial state without external restoring force, but this process has a time delay due to the viscoelastic properties of the material. The negative stiffness honeycomb 401 in the three states is determined by the ratio of its vertex height h to its thickness t, when h / t < 2.879 / ν 0.052 When ν is the Poisson's ratio of the honeycomb substrate, the negative stiffness honeycomb 401 is a monostable honeycomb. In this state, as long as the material is not damaged, the honeycomb can return to its original state without external restoring force after unloading, thus enabling repeated buffering and energy absorption; when h / t > 2.879 / ν 0.052 At this time, the negative stiffness cell 401 is a multi-stable cell. When the cell in this state is compressed and ends, it will remain in the compressed state and requires an external restoring force to return to its original state. Therefore, it can achieve single-time stable buffer energy absorption.

[0046] The effective compressive displacement of the negative stiffness honeycomb 401 is 2h. When the compressive displacement exceeds this value, the material will undergo plastic deformation, destroying the system. Therefore, in the parameter design of the negative stiffness honeycomb 401, the parameters of the honeycomb and the substrate can be determined by the design requirements for buffer energy absorption, thus achieving controllable displacement buffer energy absorption. Figure 4 The load-displacement test curves with and without oil damping are shown. It can be found that compared with a single negative stiffness honeycomb 401 oil damping, the load-bearing capacity of the buffer energy absorption system is significantly increased.

[0047] like Figure 5 The diagram shows the structure of the rope net launch buffer system, which mainly includes a traction body 1, a launch tube 2, a launch cavity 3, an oil-hydraulic negative stiffness honeycomb buffer energy absorption system 4, an adapter 5, a fixing ring 6, an igniter 7, and a launch frame 8. The traction body 1 is the mass block that pulls the rope net forward; the launch tube 2 is used to fix the traction body 1; the launch cavity 3 is used to fix the launch tube 2; the adapter 5 is first connected to the oil-hydraulic negative stiffness honeycomb buffer energy absorption system 4 via threads, and then the adapter 5 passes through a through hole in the external platform of the launch cavity 3, and the adapter 5 and the oil-hydraulic negative stiffness honeycomb buffer energy absorption system 4 are threadedly connected to the launch cavity 3 via the fixing ring 6; the igniter 7 provides the launch kinetic energy for the traction body, and the launch frame 8 is used to fix the launch buffer system and the launch platform. When the igniter 7 is activated, the gas expands rapidly inside the launch cavity 3. Part of the gas pushes the traction body 1 along the launch tube 2, while the other part of the gas acts inside the launch cavity 3, causing the launch cavity 3 and the adapter 5 to move downwards, thereby compressing the oil-hydraulic negative stiffness honeycomb buffer energy absorption system 4. When the central support column of the negative stiffness honeycomb 401 is subjected to a compressive load, it moves downwards, and its curved damping orifice also moves downwards, compressing the oil 405 inside the oil chamber 403. This causes the oil 405 to flow out through the curved damping orifice of the negative stiffness honeycomb 401, creating a pressure difference between the upper and lower curved surfaces of the negative stiffness honeycomb 401, thus generating an oil damping force. After the compression process ends, the negative stiffness honeycomb 401, according to its design parameters (height to thickness ratio), produces a monostable or multistable effect, achieving a repeated or single-time stable buffering and energy absorption effect against impact loads.

[0048] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of this utility model. It should be understood that the above description is only a specific embodiment of this utility model and is not intended to limit this utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A buffer energy absorption system based on oil-hydraulic negative stiffness honeycomb, characterized in that, It includes a negative stiffness honeycomb structure (401), an oil chamber cover (402), an oil chamber body (403), and oil (405); The negative stiffness honeycomb (401) is a dome-shaped main body. The dome-shaped main body is formed by rotating a cosine curve. A cylindrical support column is provided at the center of the dome. The support column is connected to the load-generating component. Multiple damping holes are evenly distributed on the circumference of the dome-shaped main body with a radius of 1 / 2. The oil cavity cover (402) and the oil cavity body (403) form an oil cavity, and oil (405) is provided in the oil cavity. The negative stiffness honeycomb (401) dome-shaped body is located in the oil cavity, and the oil (405) does not pass through the damping hole. The outermost edge of the dome-shaped body is pressed between the oil cavity cover (402) and the oil cavity body (403). The bottom of the oil cavity body (403) is provided with a connecting column, and is connected to the component to be protected through the connecting column; The cosine curve is shown in equation (1), where y represents the vertical distance from the horizontal chord to the contour shape at a distance x from the center line, and the axis of rotation is the y-axis: In the formula: h is the height of the vertex, and L is the span; The working state of the negative stiffness honeycomb (401) is determined by the ratio of its vertex height h to its thickness t, when h / t < 2.879 / ν 0.052 When h / t > 2.879 / ν, the negative stiffness honeycomb (401) is a monostable honeycomb, achieving repeated buffering and energy absorption; 0.052 When the negative stiffness honeycomb (401) is a multi-stable honeycomb, it achieves single-time stable buffer energy absorption; where ν is the Poisson's ratio of the honeycomb substrate.

2. The buffer energy absorption system according to claim 1, characterized in that, The oil chamber cover (402) and the oil chamber body (403) are stepped at the joint, with a threaded connection in the middle of the step, and sealant is added during the connection.

3. The buffer energy absorption system according to claim 2, characterized in that, The outermost edge of the oil cavity cover (402) is provided, and after assembly, the outer edge is located on the annular side wall of the oil cavity body (403) for installation and positioning.

4. The buffer energy absorption system according to claim 3, characterized in that, The oil chamber cover (402) has a through hole in the center for the central support column of the negative stiffness honeycomb (401) to pass through. There is a groove on the inner wall of the through hole for installing the sealing ring (404).

5. The buffer energy absorption system according to claim 1, characterized in that, The damping force is adjusted by changing the number and radius of the damping orifices, i.e., the total area of ​​the damping orifices. The damping force is inversely proportional to the square of the sum of the areas of the damping orifices, as detailed below: In the formula: F is the damping force, For the oil cavity compression volume change rate, C d For flow coefficient, A x ρ is the sum of the total areas of the damping orifices, ρ is the oil density, and A1 is the working area.

6. A rope net launching buffer system, characterized in that, It includes a launching cavity (3), an oil-based negative stiffness honeycomb buffer energy absorption system (4) as described in any one of claims 1-5, an adapter (5), and a fixing ring (6); The adapter (5) is first connected to the oil negative stiffness honeycomb buffer energy absorption system (4) by threads. Then the adapter (5) passes through the through hole of the external platform of the launch cavity (3) and the adapter (5) and the oil negative stiffness honeycomb buffer energy absorption system (4) are connected to the launch cavity (3) by threads through the fixing ring (6).

7. The rope-net launching buffer system according to claim 6, characterized in that, It also includes a towing body (1), a launch tube (2), an igniter (7), and a launcher (8); The traction body (1) is a mass block that moves the traction rope net. The launch tube (2) is used to fix the traction body. The launch cavity (3) is used to fix the launch tube (2). The igniter (7) is used to provide the launch kinetic energy of the traction body. The launch frame (8) is used to fix the launch buffer system and the launch platform. When the igniter (7) is working, the gas expands inside the launching cavity (3). Part of the gas pushes the traction body (1) to move along the launching tube (2), while the other part of the gas acts inside the launching cavity (3), causing the launching cavity (3) and the adapter (5) to move downward, thereby compressing the oil negative stiffness honeycomb buffer energy absorption system (4). The central support column of the negative stiffness honeycomb (401) moves downward under the compression load, and its curved damping hole also moves downward, compressing the oil (405) inside the oil cavity (403), causing the oil (405) to flow out through the curved damping hole of the negative stiffness honeycomb (401). The upper and lower curved surfaces of the negative stiffness honeycomb (401) generate a pressure difference, thereby generating oil damping force. After the compression process is over, the negative stiffness honeycomb (401) produces a monostable or multistable effect according to the design parameters, namely the ratio of height to thickness, to achieve a repeated or single stable buffer energy absorption effect against the impact load.

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