A lightweight impact-reducing material for spacecraft pyrotechnic separation

Abstract

The present invention provides a lightweight impact reduction material for spacecraft pyrotechnic separation, which belongs to the field of spacecraft technology, including a non-self-similar hybrid hierarchical honeycomb, the non-self-similar hybrid hierarchical honeycomb includes a first-order cell and a second-order cell, the first-order cell is a regular hexagonal cell, and the second-order cell is formed at the six vertices of the regular hexagonal cell, and the second-order cell is composed of a regular triangle and a circle located inside the regular triangle. The second-order cell of this patent replaces the first-order regular hexagonal cell node, and based on the non-self-similarity of each order of cells and the hybrid combination of different geometric structures, a non-self-similar hybrid hierarchical honeycomb with early buffering and late energy absorption characteristics is established to achieve a gradient response, smooth transition and strengthening effect of crushing stress. The present invention proposes an aerospace pyrotechnic separation impact reduction element that meets the principles of light weight, strong impact attenuation ability, good energy absorption effect, and long deformation stroke, so as to ensure that the separation device works reliably and achieve effective impact reduction.

Description

Technical Field

[0001] The invention belongs to the technical field of spacecraft, and in particular relates to a light-weight impact-reducing material for pyrotechnic separation of spacecraft. Background Art

[0002] The pyrotechnic separation device is a key component for achieving separation of all levels of the rocket launch system, and is also a very typical source of high-amplitude shocks during the entire launch process. The strong impact generated by the separation device during the explosive separation process may cause functional failure of the structure or device, and in severe cases may even affect the launch safety of the launch vehicle and the smooth completion of the mission. According to statistics from the National Aeronautics and Space Administration (NASA), there were as many as 88 impact failures caused by pyrotechnic separation in U.S. space flight failures between 1963 and 1985 alone. With the diversification of launch missions, launch vehicles need to carry more high-precision equipment, which puts higher requirements on the low-impact environment during space launches.

[0003] In aerospace pyrotechnic separation devices, explosive bolts are a typical and commonly used device. Its main working process is that when the pyrotechnic receives the unlocking and separation command, the igniter works, and the high-pressure gas generated by the explosion pushes the support ring to move. When its movement reaches a certain extent (called the unlocking stroke), the split nut loses its constraint and separates. At this time, the docking bolt falls off, and the preload force of the bolts connecting the upper and lower parts is released. The moving support ring will finally hit the packaging shell. There are three parts of impact in this process. One is caused by the explosion of the pyrotechnic in the igniter, the second is caused by the release of the preload force of the bolt connection, and the third is caused by the impact of the support ring on the shell. Studies have shown that among these three parts, the impacts caused by the explosion of the pyrotechnic, the release of the preload force, and the impact of the support ring account for 15%, 25%, and 60% of the total impact energy, respectively. Therefore, the impact of the support ring is the main source of high-amplitude impact.

[0004] Existing technical solutions: Generally speaking, the main method of reducing the impact of the support ring is to fill the buffer energy-absorbing material between the support ring and the packaging shell. The existing impact-reducing materials mainly include metal honeycomb, metal rubber and foam aluminum. However, these impact-reducing methods are mutually restrictive with the separation reliability: if a higher-strength buffer energy-absorbing material is used, the impact attenuation may not be obvious, while increasing the unlocking damping and reducing the unlocking stroke of the split nut, affecting the reliability of the separation; if a lower-strength material is used, the initial buffering effect is good, but due to the limited overall energy absorption, the support ring hits the shell with a large residual speed, which still produces a relatively large impact. Therefore, how to comprehensively design the impact-reducing material so that it can steadily attenuate the impact overload in the initial stage, and have a relatively large energy-absorbing capacity after compression deformation to a certain extent, so as to effectively reduce the impact on the basis of ensuring the reliable separation of the separation device, is a key technical problem that needs to be solved urgently. Summary of the invention

[0005] In order to solve the above technical problems, this patent uses a second-order cell composed of regular triangles and circles to replace the first-order regular hexagonal cell nodes. Based on the non-self-similarity of each order of cells and the hybrid combination of different geometric structures, a non-self-similar hybrid hierarchical honeycomb with early buffering and late energy absorption characteristics is established to achieve the gradient response, smooth transition and strengthening effect of crushing stress. The present invention proposes an aerospace pyrotechnic separation and impact reduction element that meets the principles of light weight, strong impact attenuation ability, good energy absorption effect, and long deformation stroke, so as to ensure the reliable operation of the separation device and achieve effective impact reduction.

[0006] The present invention is achieved through the following technical solutions: a lightweight impact reduction material for spacecraft pyrotechnic separation, including a non-self-similar hybrid hierarchical honeycomb, the non-self-similar hybrid hierarchical honeycomb includes a first-order cell and a second-order cell, the first-order cell is a regular hexagonal cell, and a second-order cell is formed at the six vertices of the regular hexagonal cell, and the second-order cell is composed of an equilateral triangle and a circle located inside the equilateral triangle.

[0007] Preferably, the circle is located inside the equilateral triangle, and the inner surface of the equilateral triangle is tangent to the outer surface of the circular hole.

[0008] Preferably, the centroid of the regular triangle and the center of the circular hole of the second-order cell are both located at the vertices of the first-order regular hexagonal cell.

[0009] As a preference, the geometric constraints of the first-order cell and the second-order cell are set to 0<γ=l1 / Among them, l0 and l1 are the initial side lengths of the first-order cell and the second-order cell respectively, and γ is the hierarchical design factor. By selecting different γ values, hierarchical honeycomb cells with different buffering and energy absorption strokes can be obtained, that is, the larger the γ, the smaller the buffering stroke of the hierarchical honeycomb, and the larger the energy absorption stroke.

[0010] Preferably, the wall thicknesses of the first-order cell and the second-order cell are respectively expressed as t0 and t1, and the buffering energy absorption level of the impact reduction element is controlled by changing the first-order cell wall thickness t0 and the second-order cell wall thickness t1, that is, the smaller the t0 value is, the higher the buffering level of the impact reduction element is, and the larger the t1 value is, the higher the energy absorption level of the impact reduction element is.

[0011] Preferably, the number of the first-order cell main structures is not less than 15, the side length of the first-order cell is 5mm≤l0≤150mm, and the side length of the second-order cell is 0≤l1≤130mm.

[0012] Preferably, the first-order cell wall thickness is 0.2 mm ≤ t0 ≤ 5 mm, and the first-order cell wall thickness is 0.2 mm ≤ t1 ≤ 5 mm.

[0013] Preferably, the non-self-similar hybrid hierarchical honeycomb material is selected from one or a combination of 316L steel, AlSi10Mg alloy, and titanium alloy.

[0014] Preferably, the non-self-similar hybrid hierarchical honeycomb is manufactured using selective laser melting additive technology.

[0015] Compared with the traditional solution, the solution provided by this application is based on:

[0016] 1. Aiming at the urgent need to reduce the impact of pyrotechnic separation devices during space launch, the present invention proposes a non-self-similar hybrid hierarchical honeycomb ordered porous topology configuration with both early buffering and late energy absorption characteristics, which provides a reference for the effective unlocking of spacecraft pyrotechnic separation devices and the design of lightweight buffering and energy-absorbing components in high-amplitude impact environments.

[0017] 2. The present invention adopts second-order cells composed of regular triangles and circles to replace the first-order regular hexagonal cell nodes, and based on the non-self-similarity of cells of each order and the hybrid combination of different geometric structures, establishes a non-self-similar hybrid hierarchical honeycomb with early buffering and late energy absorption characteristics, thereby realizing the gradient response, smooth transition and strengthening effect of crushing stress.

[0018] 3. The present invention proposes an aerospace pyrotechnic separation and impact reduction element that meets the principles of light weight, strong impact attenuation capability, good energy absorption effect, and long deformation stroke, so as to ensure that the separation device works reliably and achieves effective impact reduction. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0020] Figure 1 Schematic diagram of the in-plane geometric structure of a non-self-similar hybrid hierarchical honeycomb.

[0021] In the figure, 1 is the first-order cell, 2 is the second-order cell. DETAILED DESCRIPTION

[0022] The following detailed description of the present application will make the features and advantages of the present application clearer and more explicit.

[0023] In the description of the present application, it should be noted that the terms "upper", "lower", "inner", "outer", "front", "back", "left" and "right" indicate positions or positional relationships based on the working state of the present application, which are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", "third" and "fourth" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0024] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of this application.

[0025] First, a brief introduction to the usage scenarios of this solution is given.

[0026] As described in the background technology, existing separation and impact reduction materials mainly include metal honeycombs, metal rubbers, and foamed aluminum. However, the mechanical properties of these materials are relatively simple, and it is difficult to meet the comprehensive needs of reliable separation and effective impact reduction. For example, materials with higher strength have strong overall energy absorption capabilities, but the impact attenuation effect is not ideal. At the same time, reliable separation may be affected due to increased unlocking damping and shortened unlocking stroke; materials with lower strength have better initial buffering performance, but due to the lower overall energy absorption efficiency, the residual speed of the separation device is large, which is easy to cause high-energy impact on surrounding components.

[0027] See also Figure 1, which is a basic structural diagram of a spacecraft pyrotechnic separation lightweight impact reduction material provided by an embodiment of the present invention. The in-plane configuration of the non-self-similar hybrid hierarchical honeycomb is as follows Figure 1 As shown. A spacecraft pyrotechnic separation lightweight impact reduction material in the present application includes a non-self-similar hybrid hierarchical honeycomb, the non-self-similar hybrid hierarchical honeycomb includes a first-order cell and a second-order cell, the first-order cell is a regular hexagonal cell, and a second-order cell is formed at the six vertices of the regular hexagonal cell, and the second-order cell is composed of an equilateral triangle and a circle located inside the equilateral triangle. The non-self-similar hierarchical honeycomb is: in a multi-level honeycomb, a honeycomb with different shapes of first-order cells and second-order cells is a non-self-similar hierarchical honeycomb.

[0028] The regular hexagonal main structure and the circular hole circumscribed triangular substructure of the in-plane skeleton are regarded as the first-order cell and the second-order cell respectively. Based on the functional gradient design concept, the non-self-similar hybrid hierarchical honeycomb in-plane configuration is designed as follows: in the single-cell structure, the regular triangle centroid and the circular hole center of the second-order cell are both located at the node of the first-order regular hexagonal cell, and the inner surface of the regular triangle is tangent to the outer surface of the circular hole to ensure the mutual constraint of the micro-element and the smooth transition of the crushing stress.

[0029] In some embodiments, the circle is located inside the equilateral triangle, and the inner surface of the equilateral triangle is tangent to the outer surface of the circular hole.

[0030] In some embodiments, the centroid of the regular triangle of the second-order cell and the center of the circular hole are both located at the vertices of the first-order regular hexagonal cell.

[0031] In some embodiments, to avoid the intersection and overlap between the second-order cells, the geometric constraints of the first-order cells and the second-order cells are set to 0 < γ = l1 / Among them, l0 and l1 are the initial side lengths of the first-order cell and the second-order cell respectively, and γ is the hierarchical design factor. By selecting different γ values, hierarchical honeycomb cells with different buffering and energy absorption strokes can be obtained, that is, the larger the γ, the smaller the buffering stroke of the hierarchical honeycomb, and the larger the energy absorption stroke.

[0032] In some embodiments, the wall thicknesses of the first-order cell and the second-order cell are represented as t0 and t1, respectively. The buffering energy absorption level of the impact reduction element is controlled by changing the first-order cell wall thickness t0 and the second-order cell wall thickness t1. That is, the smaller the t0 value is, the higher the buffering level of the impact reduction element is, and the larger the t1 value is, the higher the energy absorption level of the impact reduction element is.

[0033] In some embodiments, in the multi-cell material, the number of the first-order cell main structure is not less than 15, and the side length of the first-order cell is 5mm≤10≤150mm, so as to expand the relative density design range of the sample, and the number of cell design arrangement layers in the in-plane loading direction is not less than 5.

[0034] In some embodiments, the non-self-similar hybrid hierarchical honeycomb material is selected from one or more of 316L steel, AlSi10Mg alloy, and titanium alloy. The hybrid hierarchical honeycomb matrix material is selected from metal materials with good ductility (such as 316L steel, AlSi10Mg alloy, titanium alloy, etc.).

[0035] In some embodiments, the non-self-similar hybrid hierarchical honeycomb is prepared by selective laser melting additive technology. The sample is prepared by selective laser melting (SLM) additive technology. According to the molding quality of the thin-walled honeycomb sample, the printing parameters such as laser beam power, powder particle size, single layer powder thickness, scanning speed and scanning spacing are comprehensively evaluated and determined.

[0036] The following is a specific implementation case of the present invention

[0037] Embodiment 1: A lightweight impact reduction material for spacecraft pyrotechnic separation includes a non-self-similar hybrid hierarchical honeycomb, wherein the non-self-similar hybrid hierarchical honeycomb includes a first-order cell and a second-order cell, wherein the first-order cell is a regular hexagonal cell, and second-order cells are formed at the six vertices of the regular hexagonal cell, and the second-order cell is composed of an equilateral triangle and a circle located inside the equilateral triangle.

[0038] In this embodiment, the circle is located inside the equilateral triangle, and the inner surface of the equilateral triangle is tangent to the outer surface of the circular hole.

[0039] In this embodiment, the centroid of the regular triangle of the second-order cell and the center of the circular hole are both located at the vertices of the first-order regular hexagonal cell.

[0040] In this embodiment, the geometric constraints of the first-order cell and the second-order cell are set to 0 < γ = l1 / Among them, l0 and l1 are the initial side lengths of the first-order cell and the second-order cell, respectively, and γ is the hierarchical design factor; different γ values ​​can be selected to obtain hierarchical honeycomb cells with different buffering and energy absorption strokes. The side length parameters are designed as follows: l0 is 5mm, l1 is 0mm, and γ is 0. Under this parameter condition, the buffering stroke of the impact reduction element is larger, while the energy absorption stroke is smaller.

[0041] In this embodiment, the wall thicknesses of the first-order cell and the second-order cell are represented as t0 and t1, respectively. The buffering energy absorption level of the impact reduction element is controlled by changing the wall thickness t0 of the first-order cell and the wall thickness t1 of the second-order cell. The wall thickness parameters are designed as follows: t0 is 0.2 mm and t1 is 0.2 mm. Under this parameter condition, the buffering level of the impact reduction element is high, but the energy absorption level is weak.

[0042] In this embodiment, the number of the first-order cell main structures is not less than 15.

[0043] In this embodiment, the non-self-similar hybrid hierarchical honeycomb material is made of 316L steel.

[0044] In this embodiment, the non-self-similar hybrid hierarchical honeycomb is manufactured using selective laser melting additive technology.

[0045] Example 2: A lightweight impact reduction material for spacecraft pyrotechnic separation, including a non-self-similar hybrid hierarchical honeycomb, the non-self-similar hybrid hierarchical honeycomb includes a first-order cell and a second-order cell, the first-order cell is a regular hexagonal cell, and second-order cells are formed at the six vertices of the regular hexagonal cell, and the second-order cell is composed of an equilateral triangle and a circle located inside the equilateral triangle.

[0046] In this embodiment, the circle is located inside the equilateral triangle, and the inner surface of the equilateral triangle is tangent to the outer surface of the circular hole.

[0047] In this embodiment, the centroid of the regular triangle of the second-order cell and the center of the circular hole are both located at the vertices of the first-order regular hexagonal cell.

[0048] In this embodiment, the geometric constraints of the first-order cell and the second-order cell are set to 0 < γ = l1 / Among them, l0 and l1 are the initial side lengths of the first-order cell and the second-order cell, respectively, and γ is the hierarchical design factor; different γ values ​​can be selected to obtain hierarchical honeycomb cells with different buffering and energy absorption strokes. The side length parameters are designed as: l0 is 150mm, l1 is 120mm, and γ is 0.8. Under this parameter condition, the buffering stroke of the impact reduction element is small, while the energy absorption stroke is large.

[0049] In this embodiment, the wall thicknesses of the first-order cell and the second-order cell are represented as t0 and t1, respectively. The buffering energy absorption level of the impact reduction element is controlled by changing the wall thickness t0 of the first-order cell and the wall thickness t1 of the second-order cell. The wall thickness parameters are designed as: t0 is 5 mm and t1 is 5 mm. Under this parameter condition, the buffering level and energy absorption stroke of the impact reduction element are both high.

[0050] In this embodiment, the number of the first-order cell main structures is not less than 15.

[0051] In this embodiment, the non-self-similar hybrid hierarchical honeycomb material is made of AlSi10Mg alloy.

[0052] In this embodiment, the non-self-similar hybrid hierarchical honeycomb is manufactured using selective laser melting additive technology.

[0053] Embodiment 3: A lightweight impact reduction material for spacecraft pyrotechnic separation includes a non-self-similar hybrid hierarchical honeycomb, wherein the non-self-similar hybrid hierarchical honeycomb includes a first-order cell and a second-order cell, wherein the first-order cell is a regular hexagonal cell, and second-order cells are formed at the six vertices of the regular hexagonal cell, and the second-order cell is composed of an equilateral triangle and a circle located inside the equilateral triangle.

[0054] In this embodiment, the circle is located inside the equilateral triangle, and the inner surface of the equilateral triangle is tangent to the outer surface of the circular hole.

[0055] In this embodiment, the centroid of the regular triangle of the second-order cell and the center of the circular hole are both located at the vertices of the first-order regular hexagonal cell.

[0056] In this embodiment, the geometric constraints of the first-order cell and the second-order cell are set to 0 < γ = l1 / Among them, l0 and l1 are the initial side lengths of the first-order cell and the second-order cell respectively, and γ is the hierarchical design factor; different γ values ​​can be selected to obtain hierarchical honeycomb cells with different buffering and energy absorption strokes. The side length parameters are designed as: 5mm≤l0≤150mm, 0≤l1≤130mm.

[0057] In this embodiment, the wall thicknesses of the first-order cell and the second-order cell are represented as t0 and t1, respectively. The buffering and energy absorption level of the impact reduction element is controlled by changing the wall thickness t0 of the first-order cell and the wall thickness t1 of the second-order cell. The wall thickness parameters are designed as follows: t0 is 3 mm and t1 is 3 mm. Under this parameter condition, the buffering and energy absorption level of the impact reduction element is related to the cell side length.

[0058] In this embodiment, the number of the first-order cell main structures is not less than 15.

[0059] In this embodiment, the non-self-similar hybrid hierarchical honeycomb material is made of titanium alloy.

[0060] In this embodiment, the non-self-similar hybrid hierarchical honeycomb is manufactured using selective laser melting additive technology.

[0061] The present application is described in detail above in conjunction with specific implementation methods and exemplary examples, but these descriptions cannot be understood as limiting the present application. Those skilled in the art understand that, without departing from the spirit and scope of the present application, a variety of equivalent replacements, modifications or improvements can be made to the technical solution of the present application and its implementation methods, all of which fall within the scope of the present application. The scope of protection of the present application shall be subject to the attached claims.

Claims

1. A lightweight impact reduction material for spacecraft pyrotechnic separation, characterized in that: It includes a non-self-similar hybrid hierarchical honeycomb, which includes a first-order cell and a second-order cell. The first-order cell is a regular hexagonal cell, and a second-order cell is formed at the six vertices of the regular hexagonal cell. The second-order cell is composed of an equilateral triangle and a circle located inside the equilateral triangle; the circle is located inside the equilateral triangle, and the inner surface of the equilateral triangle is tangent to the outer surface of the circular hole.

2. The spacecraft pyrotechnic separation lightweight impact reduction material according to claim 1, characterized in that: The centroid of the regular triangle of the second-order cell and the center of the circular hole are both located at the vertices of the first-order regular hexagonal cell.

3. The spacecraft pyrotechnic separation lightweight impact reduction material according to claim 1, characterized in that: Set the geometric constraints of the first-order cell and the second-order cell as Among them, l0 and l1 are the initial side lengths of the first-order cell and the second-order cell respectively, and γ is the hierarchical design factor; by selecting different γ values, hierarchical honeycomb cells with different buffering and energy absorption strokes can be obtained, that is, the larger the γ, the smaller the buffering stroke of the hierarchical honeycomb, and the larger the energy absorption stroke.

4. The spacecraft pyrotechnic separation lightweight impact reduction material according to claim 1, characterized in that: The wall thicknesses of the first-order cell and the second-order cell are represented as t0 and t1, respectively. The buffering energy absorption level of the impact reduction element is controlled by changing the wall thickness t0 of the first-order cell and the wall thickness t1 of the second-order cell. That is, the smaller the t0 value is, the higher the buffering level of the impact reduction element is, and the larger the t1 value is, the higher the energy absorption level of the impact reduction element is.

5. The spacecraft pyrotechnic separation lightweight impact reduction material according to claim 3, characterized in that: The number of the first-order cell main structures is not less than 15, the side length of the first-order cell is 5mm≤l0≤150mm, and the side length of the second-order cell is 0≤l1≤130mm.

6. The spacecraft pyrotechnic separation lightweight impact reduction material according to claim 4, characterized in that: The wall thickness of the first-order cell is 0.2mm≤t0≤5mm, and the wall thickness of the second-order cell is 0.2mm≤t1≤5mm.

7. The spacecraft pyrotechnic separation lightweight impact reduction material according to claim 1, characterized in that: The non-self-similar hybrid hierarchical honeycomb material is selected from one or a combination of 316L steel, AlSi10Mg alloy, and titanium alloy.

8. The spacecraft pyrotechnic separation lightweight impact reduction material according to claim 1, characterized in that: The non-self-similar hybrid hierarchical honeycomb is manufactured by using a selective laser melting additive technology.

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