Buffer energy absorption system based on oil negative stiffness honeycombs

Abstract

The invention relates to a buffer energy absorption system based on an oil negative stiffness honeycomb. Comprising a negative stiffness honeycomb, an oil cavity cover, an oil cavity main body and oil, the main body of the negative stiffness honeycomb is in a dome-like shape, the dome-like shape is formed by rotating a cosine curve by a circle, a cylindrical supporting column is arranged at the center of the dome and is connected with a component for generating a load, and a plurality of damping holes are uniformly distributed in the 1 / 2 radius circumference of the dome-like shape of the main body; the oil cavity cover and the oil cavity main body form an oil cavity, oil liquid is arranged in the oil cavity, the negative stiffness honeycomb dome-like main body is located in the oil cavity, the oil liquid submerges the damping hole, and the outermost edge of the dome-like main body is connected between the oil cavity cover and the oil cavity main body in a pressed mode; the bottom of the oil cavity body is connected with a to-be-protected component through a connecting column. Single use and repeated use of the negative stiffness honeycomb are achieved by adjusting the ratio of the height to the thickness of the negative stiffness honeycomb, adjustment of the energy absorption capacity is achieved by adjusting the area of the damping holes, and then the buffering energy absorption effect under different loads is achieved.

Description

Technical Field

[0001] The invention belongs to the field of buffering energy absorption, and in particular relates to a buffering energy absorption system based on oil negative stiffness honeycomb. Background Art

[0002] Negative stiffness honeycomb is a negative stiffness honeycomb structure that uses the jump conversion of the bending beam buckling mode 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-stable effect, repeatable characteristics, etc., negative stiffness honeycomb structure as a new type of lightweight multifunctional structure has broad application prospects in the fields of impact energy absorption, vibration control, noise isolation, etc.

[0003] The essence of negative stiffness honeycomb is to amplify the elastic characteristics of the material, so that the structural material can absorb energy by using the elasticity of the material during compression and release it after unloading, thus achieving reusability. Since the existing negative stiffness honeycomb is mostly a curved beam structure, this form of negative stiffness honeycomb has low energy absorption efficiency and cannot withstand strong loads. Summary of the invention

[0004] The purpose of the present invention is to provide a buffer energy absorption system based on oil negative stiffness honeycomb. The present invention rotates the curved beam negative stiffness honeycomb for one circle to form a dome-shaped negative stiffness honeycomb, integrates fluid damping into the negative stiffness honeycomb, and generates damping force during the compression process. This maintains the characteristics of the original negative stiffness honeycomb while improving the load-bearing performance. By adjusting the ratio of the height to the thickness of the negative stiffness honeycomb, the single use and repeated use of the negative stiffness honeycomb are achieved, and by adjusting the area of ​​the damping hole, the energy absorption capacity is adjusted, thereby achieving a buffer energy absorption effect under different load sizes.

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

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

[0007] The oil chamber cover and the oil chamber body form an oil chamber, in which oil is arranged, the negative stiffness honeycomb dome-shaped body is located in the oil chamber, and the oil submerges the damping hole, and the outermost edge of the dome-shaped body is pressed between the oil chamber cover and the oil chamber body;

[0008] A connecting column is provided at the bottom of the oil chamber body, and is connected to the component to be protected through the connecting column.

[0009] Furthermore, the matching portion between the oil chamber cover and the oil chamber body is in a step shape, the middle portion of the step is threadedly connected, and sealant is added during the connection.

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

[0011] Furthermore, a through hole is provided in the center of the oil chamber cover for passing the central support column of the negative stiffness honeycomb, and a circle of grooves is provided on the inner wall of the through hole for installing a sealing ring.

[0012] Furthermore, the cosine curve is as shown in formula (1), where y represents the vertical distance from the horizontal chord line to the contour shape at the distance x from the center line, and the rotation axis is the y axis:

[0013]

[0014] Where: h is the vertex height, 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 adjusting the number and radius of the damping holes, that is, the total area of ​​the damping holes. The damping force is inversely proportional to the square of the sum of the total area of ​​the damping holes, as follows:

[0016]

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

[0018] A rope net launch buffer system comprises a launch cavity, the above-mentioned oil liquid negative stiffness honeycomb buffer energy absorption system, an adapter and a fixing ring;

[0019] The adapter is firstly connected to the oil negative stiffness honeycomb buffer energy absorption system through threads, and then the adapter passes through the through hole of the external platform of the launch cavity, and the adapter and the oil negative stiffness honeycomb buffer energy absorption system are threadedly connected to the launch cavity through a fixing ring.

[0020] Furthermore, it also includes a traction body, a launching tube, an igniter and a launching frame;

[0021] The traction body is a mass block for the traction rope net to move, 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 launch kinetic energy of the traction body, and the launch frame is used to connect the launch buffer system and the launch platform;

[0022] When the igniter works, the gas expands inside the launching cavity. Part of the gas pushes the traction body to move along the launching tube, and the other part of the gas acts on the inside of the launching cavity, causing the launching cavity and the adapter to move downward, thereby compressing the oil negative stiffness honeycomb buffer energy absorption system; the negative stiffness honeycomb central support column moves downward under the compression load, and its curved surface damping hole also moves downward, compressing the oil inside the oil cavity, causing the oil to flow out through the negative stiffness honeycomb curved surface damping hole, and a pressure difference is generated between the upper and lower curved surfaces of the negative stiffness honeycomb, thereby generating an oil damping force; when the compression process is completed, the negative stiffness honeycomb produces a monostable or multi-stable effect according to the design parameters, that is, the ratio of height to thickness, thereby achieving repeated or single stable buffer energy absorption effect for impact loads.

[0023] Compared with the prior art, the present invention has the following significant advantages:

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

[0025] (2) The buffer energy absorption system based on the oil negative stiffness honeycomb can set the buffer stroke according to needs, and can achieve strong buffer energy absorption capacity at a low stroke.

[0026] (3) The buffer energy absorption system based on oil negative stiffness honeycomb has a wide range of application scenarios, and the buffer energy absorption system with different parameters can be designed according to different size spaces, compression speeds, compression strokes and buffer requirements. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0028] Figure 2 It is the appearance diagram of the negative stiffness honeycomb;

[0029] Figure 3 It is the load displacement curve diagram of different types of negative stiffness honeycomb;

[0030] Figure 4 It is the load displacement curve diagram of the oil negative stiffness honeycomb buffer energy absorption system;

[0031] Figure 5 This is the structural diagram of the rope net launch buffer system.

[0032] Description of reference numerals:

[0033] 1- traction body, 2- launching tube, 3- launching cavity, 4- oil negative stiffness honeycomb buffer energy absorption system, 5- adapter, 6- fixing ring, 7- igniter, 8- launching frame, 401- negative stiffness honeycomb, 402- oil cavity cover, 403- oil cavity body, 404- sealing ring, 405- oil. DETAILED DESCRIPTION

[0034] The present invention is further described in detail below in conjunction with the accompanying drawings.

[0035] A buffer energy absorption system based on oil negative stiffness honeycomb. The overall appearance of the buffer energy absorption system 4 is cylindrical, and the upper and lower end faces of the center of the disk are respectively connected and fixed with external components by threads. The system mainly includes a dome-shaped negative stiffness honeycomb 401, an oil cavity cover 402, an oil cavity 340, a sealing ring 404 and oil 405. When the impact load is transmitted to the buffer energy absorption system, since the central support column of the dome-shaped negative stiffness honeycomb is in direct contact with the component generating the impact load source, the negative stiffness honeycomb is compressed by the load. As the compression displacement increases, the oil inside the negative stiffness honeycomb is squeezed out through the small holes on the surface of the honeycomb, generating oil damping force. In this process, the oil and the honeycomb repeatedly collide and rub, consuming a lot of energy.

[0036] When the honeycomb compression ends, according to the parameter design 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 in the whole process is elastic deformation. Therefore, when there is no external load, the negative stiffness honeycomb will return to its initial state to achieve repeated buffer energy absorption; when the negative stiffness honeycomb is multistable, after being compressed to a certain displacement, the honeycomb will maintain the current state in the absence of external force to achieve single stable buffer energy absorption; at the same time, the compression displacement of the entire buffer energy absorption system can be determined according to 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 the cosine curve once. There is a cylinder in the center of the dome as a support column connected to the load-generating component; the cosine curve is shown in Formula 1, where y represents the vertical distance from the horizontal chord line to the contour shape at a distance from the center line x, and the rotation axis is the y axis:

[0038]

[0039] Where: h is the vertex height, 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 realized by 3D printing technology or mechanical processing technology. The honeycomb has small holes in the center from the central support column to the surrounding directions as damping holes. The damping force can be adjusted by adjusting the number and radius of the damping holes, that is, the total area of ​​the damping holes. The damping force is inversely proportional to the square of the sum of the total area of ​​the damping holes, as follows:

[0041]

[0042] Where: F is the damping force, is the oil chamber compression volume change rate, C dis the flow coefficient, A x is the sum of the total areas of the damping holes, ρ is the oil density, and A1 is the working area.

[0043] The oil chamber cover 402 is disc-shaped with a platform in the center of the disc for tightening the thread. A through hole is provided in the center of the disc for passing the central support column of the negative stiffness honeycomb 401. The inner wall of the through hole has a circle of grooves for installing a sealing ring 404 to ensure that the oil 405 of the system always remains in the cavity composed of the oil chamber 403 and the oil chamber cover 402 during the compression process; the outside of the oil chamber cover 402 is provided with a thread connected to the oil chamber 403, and sealant can be added during the connection to ensure the sealing performance of the system; a boss is provided at the outer end of the top of the thread to ensure that it is installed in place during the connection with the oil chamber 403.

[0044] The oil chamber 403 is cylindrical, with an external thread at the center of the bottom of the cylinder connected to the fixed component, and an internal thread at the top of the cylinder connected 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; and the oil 405 is a commonly used hydraulic buffer oil.

[0045] The negative stiffness honeycomb 401 has 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 case of multistable, without an 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 a transition state between bistable and monostable responses, in which the structure can recover to its initial state without an external restoring force, but this process will have a time delay due to the viscoelastic properties of the material. The three states of the negative stiffness honeycomb 401 are determined by the ratio of its vertex height h to thickness t, when h / t<2.879 / ν 0.052 When h / t>2.879 / ν, 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 be restored to its original state without external restoring force after unloading, so repeated buffering and energy absorption can be achieved. 0.052 When the negative stiffness honeycomb 401 is a multi-stable honeycomb, when the honeycomb in this state is compressed to the end, it will maintain the compressed state and require an external restoring force to return to its original state, so a single stable buffering energy absorption can be achieved.

[0046] The effective compression displacement of the negative stiffness honeycomb 401 is 2h. When the compression displacement exceeds this value, the material will undergo plastic deformation and destroy the system. Therefore, when designing the parameters of the negative stiffness honeycomb 401, the parameters and base material of the honeycomb can be determined according to the design requirements of buffering energy absorption, and controllable displacement buffering energy absorption can be achieved. Figure 4 The load displacement test curves with and without oil damping are shown. It can be found that compared with the single negative stiffness honeycomb 401, the oil damping significantly increases the load-bearing capacity of the buffer energy absorption system.

[0047] like Figure 5 The structure diagram of the rope net launch buffer system shown in the figure mainly includes a traction body 1, a launch tube 2, a launch cavity 3, an oil-liquid negative stiffness honeycomb buffer energy absorption system 4, an adapter 5, a fixing ring 6, an igniter 7 and a launch stand 8. The traction body 1 is a mass block for the traction rope net movement, 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 firstly connected with the oil-liquid negative stiffness honeycomb buffer energy absorption system 4 by threading, and 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-liquid negative stiffness honeycomb buffer energy absorption system 4 are threadedly connected with the launch cavity 3 through the fixing ring 6; the igniter 7 is used to provide the launch kinetic energy of the traction body, and the launch stand 8 is used to fix the launch buffer system and the launch platform. When the igniter 7 is working, the gas expands rapidly inside the launch cavity 3, part of the gas pushes the traction body 1 to move along the launch tube 2, and the other part of the gas acts on the inside of the launch cavity 3, so that the launch cavity 3 and the adapter 5 move downward, thereby compressing the oil-liquid 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 surface damping hole also moves downward, compressing the oil 405 inside the oil chamber 403, so that the oil 405 flows out through the negative stiffness honeycomb 401 curved surface damping hole, and a pressure difference is generated between the upper and lower curved surfaces of the negative stiffness honeycomb 401, thereby generating an oil damping force. When the compression process is completed, the negative stiffness honeycomb 401 produces a monostable or multistable effect according to the design parameters, that is, the ratio of height to thickness, to achieve a repeated or single stable buffering and energy absorption effect for the impact load.

[0048] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A buffer energy absorption system based on oil negative stiffness honeycomb, characterized in that: It comprises a negative rigidity honeycomb (401), an oil chamber cover (402), an oil chamber body (403) and oil (405); The negative stiffness honeycomb (401) is a main body in a dome-like shape, which is formed by rotating a cosine curve for one circle. A cylindrical support column is provided at the center of the dome, and the support column is connected to a component that generates a load. A plurality of damping holes are evenly distributed on a 1 / 2 radius circumference of the main body of the dome-like shape. The oil chamber cover (402) and the oil chamber body (403) form an oil chamber, in which oil (405) is arranged, the negative stiffness honeycomb (401) dome-shaped body is located in the oil chamber, and the oil (405) covers the damping hole, and the outermost edge of the dome-shaped body is pressed between the oil chamber cover (402) and the oil chamber body (403); A connecting column is provided at the bottom of the oil chamber body (403), and is connected to the component to be protected via the connecting column.

2. The buffer energy absorption system according to claim 1, characterized in that: The matching part between the oil chamber cover (402) and the oil chamber body (403) is in a step shape, the middle part of the step is threaded and connected, and sealant is added during the connection.

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

4. The buffer energy absorption system according to claim 3, characterized in that: A through hole is provided at the center of the oil chamber cover (402) for passing the center support column of the negative stiffness honeycomb (401), and a circle of grooves is provided on the inner wall of the through hole for installing a sealing ring (404).

5. The buffer energy absorption system according to claim 1, characterized in that: The cosine curve is as shown in formula (1), where y represents the vertical distance from the horizontal chord line to the contour shape at the distance x from the center line, and the rotation axis is the y axis: Where: h is the vertex height, t is the thickness, L is the span, and R is the radius of the small hole.

6. The buffer energy absorption system according to claim 1, characterized in that: The damping force can be adjusted by adjusting the number and radius of the damping holes, that is, the total area of ​​the damping holes. The damping force is inversely proportional to the square of the sum of the total area of ​​the damping holes, as follows: Where: F is the damping force, is the oil chamber compression volume change rate, C d is the flow coefficient, A x is the sum of the total areas of the damping holes, ρ is the oil density, and A1 is the working area.

7. A rope net launching buffer system, characterized in that: It comprises a launching cavity (3), an oil liquid negative stiffness honeycomb buffer energy absorption system (4) as claimed in any one of claims 1 to 6, an adapter (5) and a fixing ring (6); The adapter (5) is firstly connected to the oil liquid negative stiffness honeycomb buffer energy absorption system (4) by means of threads, and 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 liquid negative stiffness honeycomb buffer energy absorption system (4) are threadedly connected to the launch cavity (3) by means of a fixing ring (6).

8. The rope net launching buffer system according to claim 7, characterized in that: It also includes a traction body (1), a launching tube (2), an igniter (7) and a launching frame (8); The traction body (1) is a mass block for the traction rope net to move; 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 connect the launch buffer system and the launch platform; When the igniter (7) is working, the gas expands inside the launch cavity (3), part of the gas pushes the traction body (1) to move along the launch tube (2), and the other part of the gas acts inside the launch cavity (3), causing the launch 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 surface damping hole also moves downward, compressing the oil (405) inside the oil cavity (403), causing the oil (405) to flow out through the curved surface damping hole of the negative stiffness honeycomb (401), and a pressure difference is generated between the upper and lower curved surfaces of the negative stiffness honeycomb (401), thereby generating an oil damping force; when the compression process is completed, the negative stiffness honeycomb (401) produces a monostable or multi-stable effect according to the design parameter, that is, the ratio of height to thickness, thereby achieving a repeated or single stable buffer energy absorption effect for the impact load.

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