Thermal protection structure based on shape memory material and aircraft

Abstract

The invention provides a thermal protection structure based on a shape memory material and an aircraft, and relates to the technical field of aircraft protection, the thermal protection structure is applied to the aircraft, and the thermal protection structure based on the shape memory material comprises a thermal protection assembly, the thermal protection assembly comprises a center piece and a plurality of cell elements arranged in the circumferential direction of the center piece, the cell elements are movably connected with the center piece, and every two adjacent cell elements in the cell elements are movably connected. Wherein each cell element deforms or restores relative to the central piece after meeting a set condition, so that the thermal protection assembly is switched between a folded contraction state and an unfolded state; and the thermal protection assembly is movably connected with the aircraft through the telescopic rod. According to the thermal protection assembly, good thermal protection is provided for the aircraft, and meanwhile the strength, rigidity and shock resistance of the thermal protection assembly can be remarkably improved.

Description

Technical Field

[0001] The present invention relates to the technical field of aircraft protection, and in particular to a thermal protection structure based on shape memory materials and an aircraft. Background Art

[0002] With the development of aerospace technology, the flight speed of aircraft is getting faster and faster, and the operating environment is becoming more and more harsh. An effective thermal protection structure is one of the key conditions to ensure the safe flight of aircraft.

[0003] Existing thermal protection structures can generally be divided into three types: flexible thermal protection structure, rigid ceramic tile thermal protection structure and metal thermal protection structure. The flexible thermal protection structure is a quilt-like thermal protection structure with excellent deformation ability, light weight, good thermal shock resistance and other characteristics, but it is difficult to withstand external impact loads; rigid ceramic tile thermal protection structure and metal thermal protection structure have better thermal protection effects, but they are difficult to deform and cannot adapt to more complex environments. Summary of the invention

[0004] The present invention aims to solve the problem that the existing thermal protection structure is difficult to take into account both the impact load resistance and the deformation capacity.

[0005] To solve the above problems, in a first aspect, the present invention provides a thermal protection structure based on shape memory material, which is applied to an aircraft, comprising:

[0006] A heat protection component, the heat protection component comprising a center piece and a plurality of cells arranged circumferentially along the center piece, the plurality of cells being movably connected to the center piece, and each two adjacent cells in the plurality of cells being movably connected;

[0007] Wherein, each of the cells deforms or recovers relative to the central piece after satisfying the set conditions, so that the thermal protection component switches between a folded and contracted state and an unfolded state;

[0008] The telescopic rod is used for movably connecting the heat protection component to the aircraft, so that the heat protection component can be aligned with sunlight at a set angle when in an unfolded state.

[0009] Optionally, the cell includes a folded active metamaterial portion, a heat protection portion, a crease portion, and a plurality of substrates distributed at intervals on one side of the thickness direction of the folded active metamaterial portion, the heat protection portion is at least arranged on both sides of the thickness direction of the substrate, and the crease portion is arranged adjacent to every two adjacent substrates among the plurality of substrates.

[0010] Optionally, the folded active metamaterial portion includes a sandwich portion and a skin that uniformly wraps the sandwich portion, and the skin on at least one side of the sandwich portion is connected to the substrate through the heat protection portion.

[0011] Optionally, the core portion includes one or more of a concave hexagonal, star-shaped, double-arrow-shaped, four-ligament chiral, and six-ligament chiral honeycomb structures.

[0012] Optionally, the heat protection portion includes a first heat protection portion and a second heat protection portion, the first heat protection portion is arranged on a side of the substrate away from the folded active metamaterial portion, the second heat protection portion includes a flexible heat protection portion and a rigid heat protection portion, the rigid heat protection portion is used to connect the skin and the substrate and matches the shape and quantity of the substrate, and the fold portion includes the flexible heat protection portion.

[0013] Optionally, a fold is formed between the plurality of cells and the center piece, and a fold is formed between every two adjacent cells. The fold portion of each cell includes a first fold portion and a plurality of second fold portions. The first fold portion is used for folding, contraction and expansion between the cells, and the plurality of second fold portions are used for folding, contraction and expansion within the cell.

[0014] Optionally, the first fold portion is inclined at a set angle along the circumference of the center piece, a plurality of second fold portions are provided, and are symmetrically distributed on both sides of the first fold portion with the first fold portion as the axis of symmetry, and the second fold portions are evenly spread outward in a radial shape along the first fold portion.

[0015] Optionally, the manufacturing material of the folded active metamaterial portion includes shape memory polymers and / or shape memory polymer composite materials, wherein a plurality of the cells are formed by integrated printing, or each of the cells is formed by individual printing, and each two adjacent cells are connected by a slide rail and a protrusion, and an elastic locking component is provided at the connection point for limiting the relative movement of the two cells.

[0016] Optionally, the set conditions include the temperature of the folded active metamaterial portion reaching the glass transition temperature, and the set conditions correspond to one or more set driving modes, and the set driving modes include thermal drive, electrical drive, radio frequency drive, microwave drive and optical drive.

[0017] The present invention arranges a plurality of cells along the circumference of the center piece, and the plurality of cells are movably connected to the center piece, and an movably connected arrangement is arranged between each two adjacent cells in the plurality of cells, so that after the set conditions are met, the cells can be synchronously deformed and reversely deformed relative to the center piece, for example, gathering and unfolding can be achieved respectively. Correspondingly, the thermal protection component presents a folded and contracted state and an unfolded state, and cooperates with the arrangement of the telescopic rod to meet the thermal protection requirements of the aircraft when it is in orbit. When on the ground or not in orbit, the thermal protection component can be deformed to a gathered state, and when the aircraft reaches the designated orbit, the thermal protection component can be deformed to an unfolded state to meet the deformation requirements in a complex environment, and the unfolded thermal protection component can face the sunlight directly, thereby providing better thermal protection for the aircraft. In addition, since the plurality of cells in the thermal protection component are arranged along the center piece, the plurality of cells are tightly connected around the center piece, which can significantly improve the strength, stiffness and seismic resistance of the thermal protection component.

[0018] In a second aspect, the present invention further provides an aircraft, comprising a thermal protection structure based on a shape memory material as described in any one of the above schemes.

[0019] The beneficial effects of the aircraft provided by the present invention relative to the prior art are the same as the beneficial effects of the thermal protection structure relative to the prior art, which will not be described in detail here. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 An expanded view of a thermal protection structure of an aircraft in an embodiment of the present invention is shown;

[0021] Figure 2 A folding diagram of a thermal protection structure of an aircraft according to an embodiment of the present invention is shown;

[0022] Figure 3 A side view of a thermal protection structure of an aircraft in an embodiment of the present invention is shown;

[0023] Figure 4 The single deployment configuration of the heat protection structure based on shape memory material in the embodiment of the present invention is shown. Figure 1 ;

[0024] Figure 5 The single deployment configuration of the heat protection structure based on shape memory material in the embodiment of the present invention is shown. Figure 2 ;

[0025] Figure 6 The single deployment configuration of the heat protection structure based on shape memory material in the embodiment of the present invention is shown. Figure 3 ;

[0026] Figure 7A diagram showing an intermediate state of folding of a heat protection structure based on a shape memory material in an embodiment of the present invention;

[0027] Figure 8 The single folded configuration of the heat protection structure based on shape memory material in the embodiment of the present invention is shown. Figure 2 ;

[0028] Fig. 9 A rear view of a heat protection structure based on a shape memory material according to an embodiment of the present invention is shown;

[0029] Fig.10 A diagram showing a state in which a heat protection structure based on a shape memory material in an embodiment of the present invention faces sunlight;

[0030] Fig.11 A unit cell diagram of a heat protection structure based on a shape memory material in an embodiment of the present invention is shown;

[0031] Fig.12 A schematic diagram of the structure of a folded active metamaterial portion in an embodiment of the present invention is shown;

[0032] Fig.13 A front view schematic diagram of a heat protection structure based on a shape memory material in an embodiment of the present invention is shown;

[0033] Fig.14 It shows a schematic structural diagram of a sandwich structure of a six-ligament chiral honeycomb structure in an embodiment of the present invention;

[0034] Fig.15 It shows a schematic structural diagram of a sandwich structure in an embodiment of the present invention as a double-arrow honeycomb structure;

[0035] Fig.16 A schematic diagram showing a structure in which the sandwich structure in an embodiment of the present invention is a concave hexagonal honeycomb structure;

[0036] Fig.17 It shows a schematic structural diagram of a sandwich structure of a four-ligament chiral honeycomb structure in an embodiment of the present invention;

[0037] Fig.18 It shows a schematic structural diagram of a sandwich structure in an embodiment of the present invention that is a star-shaped honeycomb structure;

[0038] Fig.19 A separate folding diagram of a heat protection structure in an embodiment of the present invention is shown;

[0039] Fig. 20 A schematic diagram showing the connection between cells in an embodiment of the present invention is shown;

[0040] Fig.21 Schematic diagram showing the connection position of the cell in the embodiment of the present invention Figure 1;

[0041] Fig. 22 Schematic diagram showing the connection position of the cell in the embodiment of the present invention Figure 2 ;

[0042] Fig.23 A schematic structural diagram of a latch assembly in an embodiment of the present invention is shown.

[0043] Explanation of the reference numerals in the accompanying drawings: 1. aircraft; 2. thermal protection assembly; 3. telescopic rod; 4. ball hinge; 5. protrusion; 6. cell; 7. center piece; 8. thermal protection part; 9. base; 10. crease part; 101. first crease part; 102. second crease part; 11. folded active metamaterial part; 111. skin; 112. core part; 12. solar panel; 13. elastic locking assembly; 131. elastic latch; 1311. latch part; 1312. base; 1313. spring; 132. latch hole; 14. slide rail; 15. flexible thermal protection part; 16. rigid thermal protection part. DETAILED DESCRIPTION

[0044] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0045] It should be noted that, in the present invention, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0046] In the description of this specification, the description with reference to the terms "embodiment", "one embodiment" and "one implementation" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or implementation are included in at least one embodiment or implementation of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or implementation. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or implementations in a suitable manner.

[0047] Reference Figure 1 , Figure 2 and Figure 3 As shown, an embodiment of the present invention proposes a heat protection structure based on a shape memory material, which is applied to an aircraft 1. The heat protection structure based on a shape memory material comprises: a heat protection component 2, wherein the heat protection component 2 comprises a center piece 7 and a plurality of cells 6 arranged circumferentially along the center piece 7, wherein the plurality of cells 6 are movably connected to the center piece 7, and each two adjacent cells 6 in the plurality of cells 6 are movably connected;

[0048] Exemplarily, the heat protection component 2 includes six cells 6 and a center piece 7. The center piece 7 is in the form of a plate. The center piece 7 includes a center plate. A plurality of cells 6 are arranged in an array around the center plate.

[0049] Wherein, each of the cells 6 deforms or recovers relative to the central piece 7 after satisfying the set conditions, so that the heat protection component 2 switches between the folded and contracted state and the unfolded state;

[0050] Since the plurality of cells 6 are movably connected to the central piece 7 and each two adjacent cells 6 in the plurality of cells 6 are movably connected, the cells 6 can be folded, contracted and unfolded relative to the central piece 7 .

[0051] Exemplarily, the heat protection component 2 may be made of a shape memory polymer material to meet the requirements of deformation and deformation recovery.

[0052] Exemplarily, the aircraft may be a satellite platform or a space station, and the thermal protection structure may be installed on the outer bulkhead of the satellite platform / space station.

[0053] Specifically, the setting condition may be that a mechanical drive component (such as a hydraulic drive) is provided on the cell 6 to drive the folding, contraction and unfolding of the cell 6 relative to the center piece 7; alternatively, the cell 6 may be made of a shape memory polymer composite material, thereby achieving deformation and shape memory recovery at a certain temperature, thereby completing the switching of the thermal protection component 2 between the folded, contracted state and the unfolded state.

[0054] The telescopic rod 3, the heat protection component 2 is movably connected to the aircraft 1 through the telescopic rod 3, so that when the heat protection component 2 is in the unfolded state, it is aligned with the sunlight at a set angle.

[0055] The thermal protection component 2 is movably connected to the aircraft 1 via the telescopic rod 3, so that the telescopic length of the telescopic rod 3 can be adjusted, so that the protection component in the unfolded state can face the sunlight at a set angle, for example, the unfolded plane of the cell 6 is kept perpendicular to the sunlight, thereby providing better thermal protection for the on-orbit flight of the aircraft 1.

[0056] When this embodiment is applied in practice, through the multiple cells 6 arranged circumferentially along the center piece 7, and the multiple cells 6 are movably connected to the center piece 7, and the movably connected setting is set between each adjacent two of the multiple cells 6, so that after the set conditions are met, each cell 6 can be synchronously deformed and reversely deformed relative to the center piece 7, for example, gathering and unfolding are achieved respectively. Correspondingly, the thermal protection component 2 presents a folded and contracted state and an unfolded state, and cooperates with the setting of the telescopic rod 3 to meet the thermal protection requirements of the aircraft 1 when it is flying on the orbit. When on the ground or not flying on the orbit, the thermal protection component 2 can be deformed to a gathered state, and when the aircraft reaches the designated orbit, the thermal protection component 2 can be driven to deform to an unfolded state to meet the deformation requirements in a complex environment, and the unfolded thermal protection component 2 can face the sunlight directly, providing better thermal protection for the aircraft 1, and because the multiple cells 6 in the thermal protection component 2 are arranged along the center piece 7, the multiple cells 6 are tightly connected around the center piece 7, which can significantly improve the strength, stiffness and seismic resistance of the thermal protection component 2.

[0057] like Figure 4 , Figure 5 and Figure 6 and Fig. 9 As shown, as an optional embodiment of the present invention, two groups of telescopic rods 3 are provided, one group of telescopic rods 3 is fixedly mounted on the outer wall of the aircraft 1, and its extended end is connected to the center piece 7 through a ball hinge 4, and the other group of telescopic rods 3 is hingedly mounted on the outer wall of the aircraft 1, and its extended end is connected to the center piece 7 through a ball hinge 4, so that the control end of the aircraft 1 can adjust the angle of the thermal protection assembly with the sunlight when it is unfolded.

[0058] like Fig.11 and Fig.12 As shown, as an optional embodiment of the present invention, the cell 6 includes a folded active metamaterial portion 11, a heat protection portion 8, a crease portion 10, and a plurality of substrates 9 distributed at intervals on one side of the thickness direction of the folded active metamaterial portion 11, the heat protection portion 8 is at least arranged on both sides of the thickness direction of the substrate 9, and the crease portion 10 is arranged adjacent to every two adjacent substrates 9 among the plurality of substrates 9.

[0059] Specifically, the heat protection part 8 has the function of reducing the influence of high temperature or other heat sources on the substrate 9 and the folded active metamaterial part 11. It is located at least on both sides of the substrate 9, and can provide all-round heat protection, gradually reducing the heat from the sun-facing side. The substrate 9 serves as the main supporting part of the cell 6.

[0060] like Fig.12As shown, as an optional embodiment of the present invention, the folded active metamaterial portion 11 includes a core portion 112 and a skin 111 that uniformly wraps the core portion 112, and the skin 111 on at least one side of the core portion 112 is connected to the base 9 through the thermal protection portion.

[0061] Specifically, the folded active metamaterial part 11 can be made of shape memory polymer material to meet the requirements of deformation and deformation recovery. The sandwich panel is arranged in the skin 111 to protect the sandwich panel, so that the sandwich panel and the skin 111 are used as a whole to meet the use requirements of the thermal protection structure on the track.

[0062] like Fig.14 , Fig.15 , Fig.16 , Fig.17 and Fig.18 As shown, as an optional embodiment of the present invention, the sandwich part 112 includes one or more of concave hexagonal, star-shaped, double-arrow-shaped, four-ligament chiral, and six-ligament chiral honeycomb structures.

[0063] Specifically, multiple types of honeycomb structures of the sandwich part 112 can be selected in practice. The above types of honeycomb structures not only improve the buffering and shock absorption capabilities of the cell 6, thereby improving the overall stiffness and strength of the thermal protection structure, but can also further improve the heat absorption capacity, thereby improving the thermal protection capability.

[0064] like Fig.11 and Fig.12 As shown, as an optional embodiment of the present invention, the heat protection part 8 includes a first heat protection part and a second heat protection part, the first heat protection part is arranged on the side of the substrate 9 away from the folding active metamaterial part 11, the second heat protection part includes a flexible heat protection part 15 and a rigid heat protection part 16, the rigid heat protection part 16 is used to connect the skin 111 and the substrate 9 and match the shape and quantity of the substrate 9, the fold part 10 includes the flexible heat protection part 15, of course, the fold part 10 can also be made of other materials (such as flexible materials) to effectively resist folding damage, the flexible heat protection part 15 is arranged on the side of the fold part 10 away from the folding active metamaterial part 11, and the substrate 9 provides the main mechanical support.

[0065] Specifically, the first heat protection part is arranged on the side of the substrate 9 away from the folded active metamaterial part 11, that is, the side away from the aircraft 1 when unfolded. The rigid heat protection part 16 of the second heat protection part is arranged between the skin 111 and the substrate 9. The flexible protection part is capable of bending to adapt to the crease and plays a role in heat protection. The rigid protection part matches each substrate 9, that is, the number and area of ​​the two are equal.

[0066] The cell 6 can also be used as a radar antenna of the aircraft 1. As the aircraft 1 is in orbit, the radar antenna is unfolded, and the base 9 provides a platform for the radar antenna.

[0067] Through the structural setting of the above heat protection part, it is possible to block the heat of the cell 6 in which it is located when it is unfolded, and then absorb the heat through the folded active metamaterial part 11 to achieve layer-by-layer decomposition of heat, thereby providing better thermal protection for the aircraft 1.

[0068] like Figure 6 , Figure 7 , Figure 8 , Fig.13 and Fig.19 As shown, as an optional embodiment of the present invention, a fold is formed between the plurality of cells 6 and the central piece 7, a fold is formed between every two adjacent cells 6, the fold portion 10 of each cell 6 includes a first fold portion 101 and a plurality of second fold portions 102, the first fold portion 101 is used for folding, contraction and unfolding between the cells 6, and the plurality of second fold portions 102 are used for folding, contraction and unfolding within the cell 6.

[0069] When this embodiment is applied in practice, at least one first crease portion 101 is provided in the cell 6, and the first crease portion 101 divides the cell 6 equally, that is, the substrate 9 is distributed along the first crease portion 101 and the second crease portion 102, and the first crease portion 101 and the second crease portion 102 are creases between the substrate 9, and these creases facilitate the folding, contraction and expansion in the cell 6 (the folding active metamaterial portion 11 folds, contracts and expands along the substrate 9), and the creases between the cells 6 facilitate the folding, contraction and expansion between the cells 6. In the process of folding and deformation, with the folding and contraction between the cells 6 along the creases and the folding and expansion of each cell 6 along the creases, With the folding with the center piece 7, it is mainly accompanied by the folding and contraction along the first crease portion 101 in the cell 6. After the folding and contraction reaches a certain degree, not only the folding and contraction along the creases between the cells 6 and the folding and contraction along the first crease portion 101 in the cell 6 occur, but also the folding and contraction along the second crease portion 102 in the cell 6, and finally a folded and contracted state is formed, and the unfolding process is the reverse process. This method is similar to origami (folding or unfolding), the deformation of the cell 6 along the center piece 7, the deformation within the cell 6 and the deformation between the cells 6, so that the thermal protection structure can obtain a larger storage ratio.

[0070] like Fig.13As shown, as an optional embodiment of the present invention, the first fold portion 101 is inclined at a set angle along the circumferential direction of the center piece 7, a plurality of second fold portions 102 are provided, and are symmetrically distributed on both sides of the first fold portion 101 with the first fold portion 101 as the axis of symmetry, and the second fold portions 102 are evenly spread outward in a radial shape along the first fold portion 101.

[0071] When this embodiment is applied in practice, the first crease portion 101 and the second crease portion 102 are creases in the cell 6, and during the folding, contraction or unfolding process, the cell 6 folds along the center piece 7, contracts within the cell 6, and folds and contracts between the cells 6. The folding and contraction process is as follows: each cell 6 is simultaneously gathered along the crease between every two cells 6, and the cell 6 is folded along the crease with the center piece 7. At the same time, it is mainly accompanied by the contraction and gathering of the first crease portion 101 in each cell 6. Since the first crease portion 101 is inclined at a set angle along the circumference of the center piece 7, the gathering will reduce the distance from the center piece 7 to the edge of the cell 6. After gathering to a set radius (the minimum distance from the center piece 7 to the edge of the cell 6), each cell 6 further moves in the same direction (such as counterclockwise or clockwise, such as) along the second crease portion 102. Figure 7 The cells 6 are folded together along the first folding line 101, and the cells 6 are fitted together. The outermost part of each cell 6 is fitted with the second outermost part of the next cell 6 in the folding direction, and finally the outermost part of the cell 6 is at a certain angle (such as vertical) to the center piece 7. The unfolding process is the reverse process of the process, which will not be described here. For the folding process, see Figure 6 , Figure 7 and Figure 8 .

[0072] like Fig.13 , Fig.19 and Fig. 20 As shown, as an optional embodiment of the present invention, as an optional embodiment of the present invention, the manufacturing material of the folded active metamaterial part 11 includes shape memory polymer, and / or, shape memory polymer composite material, wherein the plurality of cells 6 are formed by integrated printing, or each of the cells 6 is formed by separate printing, and each two adjacent cells 6 are connected to the protrusion 5 via a slide rail 14, and an elastic locking component 13 for limiting the relative movement of the two is provided at the connection.

[0073] Specifically, in one embodiment, a shape memory composite material is printed using 4D printing technology to form a folding active metamaterial portion 11, and the resin used in the composite material is an epoxy-based shape memory polymer or a cyanate-based shape memory polymer; the reinforcement items in the composite material are carbon fibers, nanoparticles, carbon nanotube-grafted carbon fibers, chopped fibers, and the like; the material used in the matrix 9 can be a C / C composite material, a rigid fiber thermal protection material, or a high-performance ceramic foam, and the matrix 9 can be pasted or printed on the surface of the folding active metamaterial portion 11; the material used in the thermal protection portion can be a rigid fiber thermal protection material, and / or a high-performance ceramic, and the flexible thermal protection portion 15 uses a SiOC aerogel / flexible ceramic fiber composite material, and the rigid thermal protection material can use a C / C composite material or a rigid fiber thermal protection material, and each of the cells 6 is formed by integrated printing to form a thermal protection structure;

[0074] like Fig.21 , Fig. 22 and Fig.23 As shown, in another embodiment, only the folding active metamaterial portion 11 is formed by integrated printing, and the printed folding active metamaterial portion 11 is fixed to the thermal protection portion, the folding portion 10 and the substrate 9 by a setting method, and the setting method can be pasting or hot melting, etc. In this way, each single cell 6 is isolated and connected to the protrusion 5 through a slide rail 14, and the slide rail 14 and the protrusion 5 are respectively arranged at the connection between two adjacent cells 6, and the slide rail 14 is engaged with the protrusion 5 and can adapt to folding. During the folding process, the elastic locking component 13 can limit the relative movement of each two adjacent cells 6, and the elastic locking component 13 includes a fixed The base 1312 is fixed at a certain position of the cell 6 (such as the side edge of the folded active metamaterial part 11). The base 1312 can be a right angle. The bottom of the right angle is connected to the cell 6, and the top is connected to the latch part 1311 through the spring 1313. The base 1312, the spring 1313 and the latch part 1311 constitute an elastic latch 131, which can adapt to folding and limit the cell 6. In addition, the elastic latch 131 cooperates with the latch hole 132, and the elastic latch 131 and the latch hole 132 are respectively arranged on two adjacent cells 6. In addition, a strong magnetic layer or a snap-on part can be provided in the latch hole 132 to strengthen the fixation of the latch part 1311.

[0075] The integrated printing method provided above, or the method of printing part of the part first and then fixing the other parts, realizes the folding connection between the cells 6. The printing method forms the connection within the cell 6, which can be selected in practical applications and ensures the realization of the state of the thermal protection structure.

[0076] The set condition includes that the temperature of the folded active metamaterial portion 11 reaches the glass transition temperature, and the set condition corresponds to one or more of the set driving modes, and the set driving modes include thermal drive, electrical drive, radio frequency drive, microwave drive and optical drive.

[0077] Specifically, the glass transition temperature is the temperature corresponding to the phase change of the shape memory polymer, and / or the shape memory polymer composite material, which can be determined according to the actual material in practice, so as to achieve the temperature of deformation or deformation recovery, that is, to achieve that the folding active metamaterial portion 11 remains in a folded and contracted state, and when the temperature of the folding active metamaterial portion 11 reaches the glass transition temperature, the heating is stopped after the state is changed to the unfolded state, or, the unfolded state is maintained, and when the temperature of the folding active metamaterial portion 11 reaches the glass transition temperature, the heating is stopped after the state is changed to the folded and contracted state.

[0078] For example, if thermal drive is adopted, a resistive thin film heater is attached to the lower surface of the thermal protection structure (the side of the cell 6 close to the aircraft 1 ).

[0079] If electric drive is adopted, the shape memory composite material should be doped with one or more conductive reinforcing phases such as single-walled or multi-walled carbon nanotubes, graphene, carbon black, carbon nanopaper, carbon nanofibers, chopped carbon fibers, continuous carbon fibers or mixed particle fillings, and an external power source should be connected to the above-mentioned doped phases to form a loop.

[0080] If microwave driving is adopted, the shape memory polymer composite material should be doped with nanoparticles such as carbon nanotubes, graphene oxide and silicon carbide.

[0081] If radio frequency driving is adopted, radio frequency sensitive particles such as carbon nanotubes should be doped into the shape memory polymer composite material.

[0082] If light driving is adopted, materials such as optical fibers should be embedded in the shape memory polymer composite material.

[0083] If a combined driving mode is adopted, the enhancement phase of doping in the shape memory polymer composite material should include two or more combinations (from the corresponding doping materials in the electric driving mode to the optical driving mode).

[0084] The driver described is:

[0085] For example, a thermal drive method is used: the film heater is powered on, and when the temperature reaches above the glass transition temperature, the heat protection structure is deformed from the folded and contracted state to the unfolded state and then stops heating. The power can be supplied by the solar panel 12 .

[0086] If an electric drive method is adopted: power is supplied to the shape memory composite material, and when the temperature reaches above the glass transition temperature, the thermal protection structure is deformed from a folded and contracted state to an unfolded state and then the heating is stopped.

[0087] For example, if a microwave drive method is adopted: a microwave field is applied to the shape memory composite material, and when the temperature reaches above the glass transition temperature, the thermal protection structure is deformed from a folded and contracted state to an unfolded state and then the heating is stopped.

[0088] For example, when radio frequency driving is adopted: a radio frequency field is applied to the shape memory composite material, and when the temperature reaches above the glass transition temperature, the thermal protection structure is deformed from a folded and contracted state to an unfolded state and then the heating is stopped.

[0089] For example, if light driving is adopted: a light field is applied to the shape memory composite material, and when the temperature reaches above the glass transition temperature, the thermal protection structure is deformed from a folded and contracted state to an unfolded state and then heating is stopped.

[0090] If a combined driving method is adopted: a corresponding excitation is applied to the combined driving method selected for the shape memory composite material. When the temperature reaches above the glass transition temperature, the thermal protection structure is deformed from a folded and contracted state to an unfolded state and then the heating is stopped.

[0091] The various shape memory materials and corresponding driving methods in the above embodiments can be selected for practical applications, and can provide reliable protection for the folding, contraction and unfolding of the thermal protection structure of the aircraft 1 .

[0092] like Fig.10 As shown, the present invention also provides an aircraft 1, including the thermal protection structure as described in any of the above embodiments. The aircraft 1 can be a satellite or a space station, etc. By configuring the thermal protection structure based on shape memory material, the aircraft 1 has good thermal protection function.

[0093] The specific implementation of this embodiment can refer to the corresponding implementation method mentioned above and will not be described again here.

[0094] The above description is only a specific embodiment of the present invention, so that those skilled in the art can understand or implement the present invention. Various modifications to these embodiments will be 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 will not be limited to the embodiments shown herein, but should conform to the widest scope consistent with the principles and novel features invented herein.

[0095] Although the present invention is disclosed as above, the protection scope of the present invention is not limited thereto. Those skilled in the art may make various changes and modifications without departing from the spirit and scope of the present invention, and these changes and modifications will fall within the protection scope of the present invention.

Claims

1. A thermal protection structure based on shape memory material, characterized in that: Application to aircraft (1), including: A heat protection component (2), the heat protection component (2) comprising a center piece (7) and a plurality of cells (6) arranged circumferentially along the center piece (7), the plurality of cells (6) being movably connected to the center piece (7), and any two adjacent cells (6) in the plurality of cells (6) being movably connected to each other; Wherein, each of the cells (6) deforms or recovers its deformation relative to the central component (7) after satisfying a set condition, so that the thermal protection component (2) switches between a folded and contracted state and an unfolded state; A telescopic rod (3), wherein the heat protection component (2) is movably connected to the aircraft (1) via the telescopic rod (3), so that when the heat protection component (2) is in an unfolded state, it is aligned with sunlight at a set angle.

2. The heat protection structure based on shape memory material according to claim 1, characterized in that: The cell (6) comprises a folded active metamaterial portion (11), a heat protection portion (8), a folding portion (10), and a plurality of substrates (9) arranged at intervals on one side of the folded active metamaterial portion (11) in the thickness direction, wherein the heat protection portion (8) is arranged at least on both sides of the substrate (9) in the thickness direction, and the folding portion (10) is arranged adjacent to each two adjacent substrates (9) among the plurality of substrates (9).

3. The heat protection structure based on shape memory material according to claim 2, characterized in that: The folded active metamaterial portion (11) comprises a core portion (112) and a skin (111) that uniformly wraps the core portion (112); the skin (111) on at least one side of the core portion (112) is connected to the base (9) via the heat protection portion (8).

4. The heat protection structure based on shape memory material according to claim 3, characterized in that: The core part (112) comprises one or more of a concave hexagonal, star-shaped, double-arrow-shaped, four-ligament chiral, and six-ligament chiral honeycomb structures.

5. The heat protection structure based on shape memory material according to claim 3, characterized in that: The heat protection part (8) comprises a first heat protection part and a second heat protection part, wherein the first heat protection part is arranged on a side of the substrate (9) away from the folded active metamaterial part (11), and the second heat protection part comprises a flexible heat protection part (15) and a rigid heat protection part (16), wherein the rigid heat protection part (16) is used to connect the skin (111) and the substrate (9) and matches the shape and quantity of the substrate (9), and the folding part (10) comprises the flexible heat protection part (15).

6. The heat protection structure based on shape memory material according to any one of claims 2 to 5, characterized in that: A fold is formed between the plurality of cells (6) and the center piece (7), a fold is formed between each two adjacent cells (6), and the fold portion (10) of each cell (6) includes a first fold portion (101) and a plurality of second fold portions (102).

7. The heat protection structure based on shape memory material according to claim 6, characterized in that: The first fold portion (101) is inclined at a set angle along the circumference of the center piece (7), a plurality of second fold portions (102) are provided, and are symmetrically distributed on both sides of the first fold portion (101) with the first fold portion (101) as a symmetry axis, and the second fold portions (102) are evenly spread outward in a radial shape along the first fold portion (101).

8. The heat protection structure based on shape memory material according to any one of claims 2 to 5, characterized in that: The manufacturing material of the folded active metamaterial part (11) includes a shape memory polymer and / or a shape memory polymer composite material, wherein the plurality of cells (6) are formed by integrated printing, or each of the cells (6) is formed by individual printing, and each two adjacent cells (6) are connected to the protrusion (5) via a slide rail (14), and an elastic locking component (13) is provided at the connection point for limiting the relative movement of the two.

9. The heat protection structure based on shape memory material according to any one of claims 2 to 5, characterized in that: The set condition includes that the temperature of the folded active metamaterial portion (11) reaches the glass transition temperature, and the set condition corresponds to one or more of the set driving modes, and the set driving modes include thermal driving, electrical driving, radio frequency driving, microwave driving and optical driving.

10. An aircraft, characterized in that: A heat protection structure based on a shape memory material as claimed in any one of claims 1 to 9.

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