A kind of spring-like superstructure with repeatable high-efficiency buffering energy absorption

Abstract

The application belongs to the technical field of aerospace, weapon equipment buffering and energy absorption protection, and particularly relates to a spring-like superstructure capable of repeated and efficient buffering and energy absorption, which is formed by spirally winding hollow tubes or filling tubes with circular, square, hexagonal, concave negative Poisson's ratio, self-locking or other special cross-sectional shapes; by adjusting the distribution forms of geometric parameters such as the spiral angle, polar angle, number of turns, pitch, winding diameter, tube diameter and wall thickness of the structure, the mechanical properties of the structure can be regulated and controlled. Compared with conventional foam, honeycomb and other traditional energy absorption materials, the application can achieve the purpose of efficient buffering and energy absorption, and can achieve the effect of being reusable.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of aerospace, weapon equipment cushioning and energy absorption protection, and particularly relates to a spring-like superstructure capable of repeated efficient cushioning and energy absorption. BACKGROUND

[0002] During normal service, aerospace and weapon equipment and other devices are long subjected to harsh space or battlefield environments, and are extremely vulnerable to the adverse effects of various impact loads. For example, a spacecraft will suffer an overload impact several times its own weight during landing; various weapons and protective facilities will also suffer severe blast wave overload impact damage when attacked by missiles, explosives and the like. Therefore, it is necessary to take necessary protective measures for aerospace vehicles and weapon equipment and other facilities to ensure their safe operation. At present, common cushioning and energy absorption protection structures include honeycomb, foam, negative Poisson's ratio structure and other porous materials and various composite sandwich structures made of these porous materials. When subjected to impact loads, such cushioning and energy absorption protection structures have a relatively obvious stress-strain curve platform area, thereby absorbing more external impact energy and protecting key instruments and equipment from damage caused by impact.

[0003] However, in the application process, it is found that the above-mentioned cushioning and energy absorption protection structures still have some deficiencies: the elastic deformation stage of the conventional cushioning and energy absorption protection structure is too short, resulting in a rapid rise in the initial stage of impact, which can form a high instantaneous overload, thereby transferring to the rear protected equipment in a "hard" manner, causing impact damage risk; the conventional cushioning and energy absorption protection structure mainly absorbs impact energy through local progressive buckling and damage of its own microstructure, but this process is not reversible, and the permanently damaged part cannot be restored to its original state, so it cannot be reused.

[0004] In summary, the conventional cushioning and energy absorption protection structure has the deficiencies of too short elastic deformation stage, easy to cause instantaneous overload and cannot be reused. SUMMARY

[0005] (I) Technical problem to be solved

[0006] The technical problem to be solved by the present application is: in view of the deficiencies of the existing cushioning and energy absorption protection structure, how to provide a spring-like superstructure capable of repeated efficient cushioning and energy absorption.

[0007] (II) Technical solution

[0008] To solve the above technical problems, the present application provides a spring-like superstructure capable of repeated efficient cushioning and energy absorption, which is spirally coiled by hollow tubes or filled tubes with circular, square, hexagonal, concave negative Poisson's ratio type and self-locking type cross-sectional shapes.

[0009] The self-locking section refers to any special-shaped section with upper and lower inlaid complementary features.

[0010] The tube wall of the hollow tube or the filled tube is made of aluminum alloy, titanium alloy, composite material or shape memory alloy.

[0011] The internal filling material of the filled tube includes various foams, honeycombs or other porous filling materials.

[0012] The tube wall of the hollow tube or the filled tube is designed as a circular, square or other shaped hole array to realize the heat flow exchange characteristics of the structure.

[0013] The spiral winding mode of the structure includes cylindrical spiral winding, conical spiral winding or other special-shaped spiral winding to regulate the elastic-plastic mechanical properties of the structure.

[0014] By adjusting the distribution form of the geometric parameters of the spiral angle, polar angle, number of turns, pitch, winding diameter, tube diameter and wall thickness of the structure, the mechanical properties of the structure are regulated.

[0015] (Three) beneficial effects

[0016] The present application takes the common cylindrical spiral spring as the design inspiration and provides a new type of spring-like superstructure. The structure has sufficient elastic buffer energy absorption stage in the initial compression stage. The structure mainly absorbs impact energy through elastic deformation in this stage and has recoverability. When the elastic stage is exceeded, the structure can utilize the progressive crushing damage of local microelements to absorb a large amount of external impact energy. Therefore, the structure has the effects of being reusable under small energy impact and having high efficient buffer energy absorption under large energy impact.

[0017] Compared with the prior art, the spring-like superstructure with repeatable and efficient buffer energy absorption (hereinafter referred to as the structure) has the following technical effects:

[0018] 1) The hollow tube or the filled tube is wound into a spiral structure, which can first exhibit mechanical properties similar to conventional springs under external impact load, i.e. a very flat characteristic line, thereby buffering the impact load and avoiding high overload damage to the equipment before the structure yields and fails.

[0019] 2) Since the elastic deformation stage of the structure is obvious, the stress curve is smooth and the growth slope is flat, which will not cause instantaneous overload when the structure yields and fails.

[0020] 3) When the structure is compressed to close fit under the continuous action of impact load, an energy absorption tube structure is formed by stacking multiple layers of hollow circular rings. Each layer of hollow circular ring is crushed and fails layer by layer under the action of impact load, so that the stress-strain curve of the structure is no longer monotonously rising, but forms a clear platform stage, thereby achieving the effect of effectively absorbing impact energy.

[0021] 4) By changing the tube wall material, filling material, coiling method, and key geometric parameters such as spiral angle, pitch, tube diameter, and wall thickness of the structure, the characteristics of the stress-strain curve, such as the slope of the elastic stage and the stress level of the platform stage, can be adjusted to achieve the effect of regulating the mechanical properties of the structure.

[0022] 5) When subjected to small impact loads, the structure is in the elastic deformation stage, so it can achieve the effect of repeated use of cushioning protection under small loads. If the hollow tube is made of shape memory alloy, the elastic deformation-plastic crushing stage of the structure can achieve the effect of repeated use.

[0023] 6) Adding a hollow array of holes to the tube wall of the hollow tube or the filling tube can further regulate the mechanical properties of the structure, and also can make it have additional functions such as heat flow exchange.

[0024] 7) Using different hollow tube cross-sectional shapes can achieve different layer-by-layer crushing effects to meet different engineering needs. For example, using a hollow tube with a quadrilateral or hexagonal cross-section can make the structure form an energy absorption tube structure composed of multiple layers of quadrangular honeycomb or hexagonal honeycomb hollow circular rings when compressed to close fit; using a hollow tube with a special self-locking cross-sectional shape can make the structure form a multi-layer energy absorption tube structure with stronger stability through the interlocking of the upper and lower circular rings; using a hollow tube with a negative Poisson's ratio concave cross-sectional shape can make the structure achieve the extraordinary mechanical property of negative Poisson's ratio when deformed under pressure. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figures 1(a) to 1(f) Typical configurations of the spring-like superstructure with repeatable and efficient cushioning and energy absorption of the present application; wherein Figure 1(a) is made of a circular hollow tube coiled in a spiral, Figure 1(b) is made of a hexagonal hollow tube coiled in a spiral, Figure 1(c) is made of a foam-filled negative Poisson's ratio concave hollow tube coiled in a spiral, Figure 1(d) is made of a special self-locking filling tube coiled in a spiral, and Figure 1(e) is made of a square hollow tube with a conical spiral coiled in a conical spiral with a gradient tube diameter; Figure 1(f) is made of a circular hollow tube with a circular hole array coiled in a spiral.

[0026] Wherein: 01 is the tube wall of the hollow tube or the filling tube; 02 is the filling material.

[0027] Figure 2 is a numerical simulation result of the reusable hollow circular tube spiral buffer energy absorption metamaterial under the action of dynamic compression load; wherein figure 2(a) is a compression model schematic diagram, figure 2(b) is the deformation and stress-strain curve in the elastic compression stage, and figure 2(c) is the structural deformation and corresponding stress-strain curve in the energy absorption tube deformation and energy absorption stage.

[0028] Wherein: 1 is the linear elastic stage; 2 is the gradual crushing energy absorption platform stage, and 3 is the dense failure stage.

[0029] Figure 3 It is a compression stress-strain curve schematic diagram of conventional foam, honeycomb material and corresponding sandwich structure.

[0030] Wherein, 1 is the linear elastic stage, 2 is the gradual crushing energy absorption platform stage, and 3 is the dense failure stage.

[0031] Figure 4 It is the self-locking process of the repeatable buffer energy absorption spring-like superstructure made of a special-shaped self-locking hollow tube.

[0032] Figure 5 It is a deformation and recovery process schematic diagram of the repeatable buffer energy absorption spring-like superstructure made of a shape memory alloy. DETAILED DESCRIPTION

[0033] In order to make the purpose, content and advantages of the present application more clear, the specific embodiments of the present application are further described in detail below in combination with the drawings and examples.

[0034] To solve the above technical problems, the present application provides a repeatable high-efficiency buffer energy absorption spring-like superstructure, which is spirally coiled by hollow tubes or filled tubes with circular, square, hexagonal, concave negative Poisson's ratio type, self-locking type cross-sectional shape.

[0035] Wherein, the self-locking type cross-section refers to any special-shaped cross-sectional shape with upper and lower inlaid complementary features.

[0036] Wherein, the tube wall of the hollow tube or the filled tube is made of aluminum alloy, titanium alloy, composite material or shape memory alloy.

[0037] Wherein, the internal filling material of the filled tube includes various foams, honeycombs or other porous filling materials.

[0038] Wherein, the tube wall of the hollow tube or the filled tube is designed as a circular, square or other shape hole array to realize the heat flow exchange characteristics of the structure.

[0039] Wherein, the spiral coiling mode of the structure includes cylindrical spiral coiling, conical spiral coiling or other special-shaped spiral coiling mode to regulate the elastic-plastic mechanical properties of the structure.

[0040] The mechanical properties of the structure can be controlled by adjusting the distribution of geometric parameters such as helix angle, polar angle, number of turns, pitch, coil diameter, pipe diameter, and wall thickness.

[0041] Example 1

[0042] The repeatable, high-efficiency buffering and energy-absorbing spring-like superstructure of this embodiment is formed by winding hollow tubes or filled tubes of different configurations in different spiral patterns. Figures 1(a) to 1(f) The diagram shows several typical structures designed according to the present invention, the basic configuration of which is a hollow circular tube spirally wound into a cylinder. Based on this, the stability and energy absorption characteristics of this structure under compression can be improved by selecting different cross-sectional shapes for the hollow tube, such as square, hexagonal, concave negative Poisson's ratio, and irregular self-locking shapes. Furthermore, the energy absorption capacity of this structure can be enhanced by adding filling materials such as foam or honeycomb to the hollow tube. The thermal and mechanical properties of the structure can also be controlled by using different winding methods and adding an array of holes in the tube wall.

[0043] by Figures 2(a) to 2(c) Taking the hollow circular tube-like spiral superstructure shown as an example, the working principle of the repeatable buffer energy absorption spring-like superstructure is introduced.

[0044] Figure 2(a) shows a schematic diagram of this structure under uniformly distributed compressive load, where the upper end face is subjected to pressure, and the lower end face is fixed to a plane. The hollow circular tube wall is made of aluminum alloy with a density of 2700 kg / m³. 3 The elastic modulus is 70 GPa, Poisson's ratio is 0.3, and yield strength is 274 MPa. The entire model is discretized using the Lagrange discretization method. The compressed spring-like superstructure is composed of three-dimensional shell elements with a thickness of 0.5 mm. To simplify the calculation process, the material failure effect is not considered; only its plastic yield deformation effect is taken into account.

[0045] When this structure is subjected to compressive load, it first undergoes initial compressive deformation, as shown in Figure 2(b). The stress-strain curve corresponding to this stage shows a roughly linear growth trend, indicating that the structure is in the stage of recoverable elastic compressive deformation.

[0046] If compressive loads are continued to be applied, compressing the structure until it is tightly packed, it will enter the plastic crushing energy absorption stage. As shown in Figure 2(c), the second stage is the plateau segment corresponding to the plastic crushing process. This structure absorbs external impact energy through its own localized, gradual crushing deformation process. If compressive loads are continued to be applied, the structure will be compressed to complete compaction, the stress curve will rise rapidly, and it will lose its protective capability.

[0047] like Figure 3The figures show the compressive stress-strain curves of conventional foam, honeycomb materials, and corresponding sandwich structures. Throughout the compression process, the initial elastic deformation stage of this type of traditional energy-absorbing buffer structure is not significant, and the compressive stress rises rapidly, indicating that it lacks a recoverable elastic deformation stage. Simultaneously, the initial yield load is large, suggesting that this type of structure experiences significant overload before entering the crushing energy-absorbing stage, potentially damaging the protected target behind it.

[0048] In contrast, the compressive stress-strain curve of the hollow circular tube-like spiral superstructure, as shown in Figure 2(c), has a clear recoverable elastic deformation stage and does not exhibit an excessively large initial yield load, thus preventing damage to the protected target behind it.

[0049] like Figure 4 The diagram shows a spiral-like superstructure made of a non-circular self-locking hollow tube. When the structure is compressed, the upper and lower tube walls contact each other and lock in a complementary interlocking manner, forming a multi-layered circular tube structure, which can improve the stability and load-bearing capacity of the structure.

[0050] If this structure is prepared using shape memory alloy materials, such as Figure 5 As shown, it can also be restored to its original shape by heating after plastic compression deformation, realizing the reversibility of the entire compression deformation process, thereby improving the reuse efficiency.

[0051] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical 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 repeatable high-efficiency energy-absorbing spring-like superstructure, characterized in that, The spring-like superstructure is formed by spirally winding hollow tubes with self-locking cross-section shapes; The self-locking cross-section refers to any special cross-section shape with upper and lower inlaid complementary features; The hollow tube wall is designed with circular or square hole array hollowing to realize the heat flow exchange characteristics of the spring-like superstructure; The spring-like superstructure spirally winds the hollow tubes into a spiral structure, so that the stress-strain curve is smooth and the growth slope is gentle under the action of external impact load, and the instantaneous overload will not be caused when the structure yields and breaks down; When the spring-like superstructure is compressed to closely fit under the continuous action of impact load, an energy-absorbing tube structure formed by the stacking of hollow tubes with self-locking cross-section shapes is formed; under the action of impact load, each layer of hollow tubes appears layer-by-layer crushing failure, so that the stress-strain curve of the spring-like superstructure no longer rises, but forms a clear platform stage, thereby achieving the effect of effectively absorbing impact energy; The hollow tubes are made of shape memory alloy, and the elastic deformation-plastic crushing full stage of the spring-like superstructure can realize the repeated use effect.

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