Energetic wave impedance gradient material for space debris hypervelocity impact protection

Abstract

The application discloses an energetic wave impedance gradient material for space debris super-high-speed impact protection, which is based on inert metal component materials and adds an energetic active material layer as a component material. In the application, the inert metal material and the energetic active material are combined according to a certain rule through wave impedance gradient matching design and impact initiation threshold adjustment, so that the new composite material has both wave impedance gradient and impact initiation reaction under super-high-speed impact, and the two effects jointly promote the fragmentation and dispersion of the projectile, thereby further improving the protection capability. The new high-performance space debris protection material combines the two protection mechanisms of wave impedance gradient and impact initiation reaction, has higher protection capability under the same mass, and can be directly applied to the space debris protection design of manned spacecraft and high-value satellites, so as to ensure the long-life and high-reliability operation of on-orbit spacecraft of China.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of space debris protection, and particularly relates to an energetic wave impedance gradient material for space debris super-high-speed impact protection. BACKGROUND

[0002] In order to improve the survival ability of a spacecraft in a severe space debris environment, a large number of advanced protection materials, including Kevla, Nextel, Beta cloth, honeycomb aluminum, and foam metal, are developed by NASA, the European Space Agency, Japan, and the like based on super-high-speed impact protection mechanisms, and a plurality of high-performance protection structures, including a single-protection-screen enhanced protection structure, a multi-layer impact protection structure, and a filled Whipple protection structure, are developed based on various advanced materials. Through the application of the above high-performance protection structures, space stations and high-value satellites are effectively protected. The protection performance of the protection structure is largely dependent on the mechanical properties of the protection material, and the advanced protection material is complex in process and difficult to prepare. In view of the current situation that the engineering demand for spacecraft space debris protection is becoming increasingly strong, a plurality of high-performance protection materials are developed in China. A wave impedance gradient material with high kinetic energy dissipation characteristics is proposed in a patent with the application number 201710316128.2, and an energetic active material protection structure based on an explosion reaction protection mechanism is invented in patents with the application numbers 201418004111.0 and 201418004115.9. Although good protection effects are achieved, there is still a large gap between the protection capacity and the engineering demand for spacecraft space debris protection in China.

[0003] In engineering application practice, advanced protection materials with light weight and high impact resistance are the eternal theme of spacecraft space debris protection research. By combining the impact initiation and wave impedance gradient energy dissipation protection concepts, and through optimized matching design, the advantages of the two protection concepts are fully utilized to form a new type of energetic wave impedance gradient material, which has important engineering significance for realizing the localization of high-performance protection materials in China and greatly improving the space debris protection capacity in China. SUMMARY

[0004] The present application relates to the technical field of space debris protection, and particularly relates to an energetic wave impedance gradient material for space debris super-high-speed impact protection.

[0005] In order to achieve the above-mentioned purpose, the present application adopts the following technical scheme:

[0006] An energetic wave impedance gradient material for space debris super-high-speed impact protection, which is based on an inert metal component material and adds an energetic active material layer as a component material. The energetic active material is mixed by two or more non-explosive materials.

[0007] Preferably, the energetically active material is inert under quasi-static or static loads, but can undergo an impact detonation reaction to release a large amount of energy when the projectile impacts at high speed.

[0008] Preferably, the products released by the energetic active material are mostly gaseous and have no ability to penetrate the back plate. The optimal ratio is the mass fraction ratio of the components when the energy released during the impact reaction of the energetic active material per unit mass reaches the maximum.

[0009] Preferably, on the basis of the clear overall surface density of the energetic wave impedance gradient material, appropriate inert metals and energetic active materials are selected as component materials based on the wave impedance distribution law, and the distribution order of the component materials is determined.

[0010] Preferably, a hypervelocity impact simulation calculation model is established for the component materials, the surface material is given an initial thickness, and the thicknesses of other components are varied from small to large, and exhaustive combinations are performed.

[0011] Preferably, the areal density of the component materials of each layer is defined according to the impact detonation characteristics of the energetically active material.

[0012] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0013] 1. This application combines inert metal materials and energetic active materials according to certain rules through wave impedance gradient matching design and shock detonation threshold adjustment, so that the new composite material has both wave impedance gradient and shock detonation reaction under hypervelocity impact. The two effects jointly promote the fragmentation and dispersion of the projectile, thereby further improving the protection capability. The new high-performance space debris protection material that combines the two protection mechanisms of wave impedance gradient and shock detonation reaction has higher protection capability at the same mass and can be directly applied to the space debris protection design of manned spacecraft and high-value satellites, ensuring the long life and high reliability operation of my country's in-orbit spacecraft. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 A schematic diagram of the wave impedance gradient distribution principle of an energetic wave impedance gradient material for protection against hypervelocity impact of space debris provided by an embodiment of the present invention is shown;

[0015] Figure 2 A flowchart of a simulation design process of an energetic wave impedance gradient material according to an embodiment of the present invention is shown;

[0016] Figure 3 A schematic diagram of a material optimization design scheme for an energetic wave impedance gradient material provided according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0017] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0018] See also Figures 1-3 , the present invention provides a technical solution:

[0019] An energetic wave impedance gradient material for protecting space debris from hypervelocity impacts. The energetic wave impedance gradient material comprises an inert metal component material and an energetic active material layer added thereto as a component material. The energetic active material is a mixture of two or more non-explosive materials, such as thermite, metal polymers or mixtures, intermetallic compounds, and composite materials.

[0020] Energetic active materials are inert under quasi-static or static loads, but can undergo impact detonation reactions when the projectile hits at high speed, releasing a large amount of energy. This promotes the fragmentation of the projectile and disperses the kinetic energy. At the same time, the high-temperature, high-pressure, high-speed detonation products will also generate a reverse impulse on the projectile.

[0021] The products released by energetic active materials are mostly gaseous and have no ability to penetrate the rear plate, thereby further reducing the axial kinetic energy of the projectile fragments and reducing the damage potential to the rear wall. Considering the application background of space debris protection, it is hoped that the optimal ratio of the component mass fractions is achieved when the energy released during the impact reaction of the unit mass of energetic active materials reaches the maximum.

[0022] On the basis of the clear overall surface density of the energetic wave impedance gradient material, appropriate inert metals and energetic active materials are selected as component materials based on the wave impedance distribution law, and the distribution order of the component materials is determined;

[0023] A hypervelocity impact simulation calculation model is established for the component materials. The surface material is given an initial thickness, and the thicknesses of other components vary from small to large, and exhaustive combinations are performed. The condition for the exhaustive combination is to keep the surface density of the energetic wave impedance gradient material unchanged. Since the energetic wave impedance gradient material is composed of multiple layers of component materials with different wave impedance characteristics, the surface density of each layer of component materials is limited and cannot be too large. The impact initiation characteristics of energetic active materials are the basis for their protective effectiveness. This determines that if the material is too thin, under the action of the rarefaction wave on the back surface, its impact energy release effect cannot be fully exerted. Therefore, in the design of energetic wave impedance gradient materials, it is necessary to ensure the thickness of the energetic active material as much as possible; the size of the surface density of each layer of component materials is limited according to the impact initiation characteristics of the energetic active material;

[0024] The biggest advantage of wave impedance gradient materials over ordinary homogeneous materials is that they can achieve targeted regulation of the impact process of the hypervelocity impact between the projectile and the protective screen, optimizing the shock wave action process between the projectile and the protective screen. Under the same surface density conditions, the wave impedance value of the incident surface material of the projectile hypervelocity impact protective screen should be increased as much as possible to increase the initial impact pressure of the projectile and the protective screen, and improve the impact pressure's ability to crush the projectile and protective screen materials; at the same time, lower wave impedance value materials should be arranged in sequence behind the high wave impedance value materials, so as to achieve the purpose of extending the impact pressure action time and delaying the shock pressure unloading process, thereby maximizing the shock wave action process on the projectile material and the protective screen material, achieving the purpose of improving the protective performance of the protective screen material while maintaining the same surface density. Traditional wave impedance gradient materials are mainly composed of inert metal materials, and the selected materials include titanium alloys, aluminum alloys, magnesium alloys, etc. suitable for spacecraft space debris protection structures.

[0025] Specifically, an energetic wave impedance gradient material with an area density equivalent to that of 1.5 mm aluminum alloy is designed, with an area density of 0.417 g / cm 2 .in accordance with Figure 1 According to the principle of wave impedance gradient distribution shown in the figure, high wave impedance materials should be selected as much as possible to increase the initial pressure at the moment of projectile-projectile collision and improve the degree of projectile fragmentation. Taking into account the adaptability to the space environment, titanium alloy is selected as the front surface material. The wave impedance of the rear surface material needs to be smaller than that of titanium alloy. Fluoropolymer-based energetic active material PTFE / Al is selected with a density of 2.2g / cm 3 The energy released by the impact reaction of the material reaches its maximum under the zero oxygen ratio, at which time the mass fractions of PTFE and Al are 73.5% and 26.5% respectively. Considering the continuous change of wave impedance as much as possible, aluminum alloy is selected as the middle layer.

[0026] Simulation design process such as Figure 2 As shown in the figure, the titanium alloy is first given a certain thickness, and the aluminum alloy thickness is varied from small to large. In each variation, PTFE / Al is exhaustively combined to include every material thickness combination within the computational capacity. The exhaustive combination condition is to maintain the surface density of the energetic wave impedance gradient material constant, always equivalent to a 1.0 mm thick aluminum alloy, and the minimum thickness of each material layer is 0.1 mm.

[0027] Table 1 Design method of energetic wave impedance gradient material

[0028]

[0029] According to the above design method, the thickness of each component material in the energetic wave impedance gradient material equivalent to 1.5mm thick aluminum alloy was simulated and calculated. The numerical simulation results show that the protective structure with the energetic wave impedance gradient material configuration of 0.3Ti-0.2Al-1.1PTFE / Al can withstand the normal impact of an aluminum alloy projectile with an impact speed of 7km / s and a projectile diameter of 5.0mm. Therefore, it can be known that the energetic active wave impedance gradient material with an equivalent surface density of 1.5mm aluminum alloy is composed of 0.3mm thick titanium alloy, 0.2mm thick aluminum alloy and 1.1mm thick PTFE / Al, such as Figure 3 shown.

[0030] This application combines inert metal materials and energetic active materials according to certain rules through wave impedance gradient matching design and shock initiation threshold adjustment, so that the new composite material has both wave impedance gradient and shock initiation reaction under hypervelocity impact. The two effects jointly promote the fragmentation and dispersion of the projectile, thereby further improving the protection capability. The new high-performance space debris protection material that combines the two protection mechanisms of wave impedance gradient and shock initiation reaction has higher protection capability at the same mass and can be directly applied to the space debris protection design of manned spacecraft and high-value satellites, ensuring the long life and high-reliability operation of my country's in-orbit spacecraft.

[0031] The above description of the embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An energetic wave impedance gradient material for protection against hypervelocity impact of space debris, characterized in that: The energetic wave impedance gradient material is based on an inert metal component material and has an energetic active material layer added as a component material. The energetic active material is a mixture of two or more non-explosive materials. The energetic active material is inert under quasi-static or static loads, but can undergo an impact detonation reaction to release a large amount of energy when a projectile hits it at high speed.

2. The energetic wave impedance gradient material for space debris hypervelocity impact protection according to claim 1, characterized in that: The products released by the energetic active material are mostly gaseous and have no ability to penetrate the back plate. The optimal ratio is the mass fraction ratio of the components corresponding to the maximum energy released during the impact reaction of the energetic active material per unit mass.

3. The energetic wave impedance gradient material for protection against hypervelocity impact of space debris according to claim 1, characterized in that: On the basis of the clear overall surface density of the energetic wave impedance gradient material, appropriate inert metals and energetic active materials are selected as component materials based on the wave impedance distribution law, and the distribution order of the component materials is determined.

4. The energetic wave impedance gradient material for protection against hypervelocity impact of space debris according to claim 3, characterized in that: A hypervelocity impact simulation calculation model is established for the component materials. The surface material is given an initial thickness, and the thicknesses of other components vary from small to large, and exhaustive combinations are performed.

5. The energetic wave impedance gradient material for space debris hypervelocity impact protection according to claim 4, characterized in that: The surface density of each layer of component materials is limited according to the impact detonation characteristics of the energetic active material.

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