Satellite antenna reflector and its processing method, design method of its main structure layer and reconstruction accuracy verification method

Abstract

The present invention provides a satellite antenna reflector, which is made of negative Poisson's ratio material or negative Poisson's ratio metamaterial; radial tension is applied to the reflector, so that the area size of the reflector becomes larger. Compared with the existing mechanically reconfigurable reflector, the in-plane stiffness is smaller under the condition of suitable bending stiffness, so the work done by the actuator is more converted into bending deformation outside the reflector, so the output force of the actuator is smaller, thereby reducing the size and weight of the actuator, and reducing the overall weight and launch cost of the reflector. The reflector of the present invention presents a negative Poisson's ratio form in the macroscopic sense. When a single actuator is actuated, the reflector has a larger out-of-plane deformation as a whole, rather than only affecting a local part. In particular, when the actuator is actuated, the reflector can be bent in the same direction in an orthogonal direction to form a "bowl" shape, which is more in line with the shape of a parabolic reflector.

Description

Technical Field

[0001] The present invention relates to the technical field of satellite antenna reflective surfaces, and in particular to a satellite antenna reflective surface and a processing method thereof, a design method for a main structural layer thereof, and a reconstruction accuracy verification method. Background Art

[0002] In satellite communication systems, it is hoped that the antenna beam has an on-orbit reconfiguration function, that is, the shaped beam that the antenna generates to cover the service area in normal times can be changed at any time according to changes in communication needs, and the on-orbit reconfiguration of the satellite antenna beam shape can be quickly realized. In addition, if necessary, a spot beam can be generated in any specific area within the service area. The spot beam antenna has a high effective omnidirectional radiated power, can accurately control the pointing area, and can avoid signal interference while obtaining high gain.

[0003] Traditional shaped antennas have only a fixed reflector geometry and can only provide a specific radiation pattern and a fixed target gain area, which cannot meet the needs of on-orbit reconstruction of antenna beams. The antenna can be reconfigured by changing some characteristic parameters of the antenna so that it can provide multiple target gain areas, thereby achieving multiple uses for one satellite. The on-orbit mechanical reconstruction of the antenna is to arrange an actuator array on the back of the antenna reflector, and change the geometric shape of the reflector by actuating each actuator in the array, thereby changing the radiation pattern.

[0004] Mechanically reconfigurable antennas require that the reflector surface has a sufficiently large deformation capacity in the out-of-plane direction, and that the deformation of the structure in the in-plane direction is limited to a local area and will not have a significant impact on other beams in the overall domain. Therefore, the reflector surface needs to have a certain bending stiffness, and at the same time, the tensile stiffness in the plane needs to be as small as possible, so that the work done by the actuator out of the plane is converted into out-of-plane bending deformation, reducing the energy loss due to in-plane deformation.

[0005] The current mechanically reconfigurable antenna reflectors mainly include: (1) metal mesh reflectors, which are reshaped and reconfigured by adjusting the force of the control points; (2) carbon fiber reinforced silicone fabric as the reflector material, which is connected to the reflector by a linear actuator to control the deformation of the reflector; (3) a sandwich structure material with an aluminum honeycomb as the middle core layer and the top and bottom layers of carbon fiber reinforced silicone fabric as the reflector. However, there are the following disadvantages:

[0006] The bending stiffness of the metal mesh reconfigurable reflector is too small. The deformation of the surface under the action of the actuator can only change part of the surface. To make the global surface deform and achieve the target surface reconstruction accuracy, a large number of actuators are required, which will increase the weight of the actuator system and thus increase the launch cost.

[0007] Carbon fiber reinforced silicone fabric reconfigurable reflective surface Since the Young's modulus of carbon fiber reinforced silicone fabric is small, to obtain appropriate bending stiffness, it is necessary to increase the thickness of the reflective surface, which also increases the mass of the reflective surface and also increases the weight of the entire reflective surface system;

[0008] In order to increase the bending stiffness of the sandwich structure reflective surface, the thickness of the aluminum honeycomb core layer is relatively large. However, a thicker reflective surface is not conducive to improving the accuracy of the reflective surface.

[0009] In the current reflective surface processing method, for carbon fiber reflective surfaces, a mold hot pressing molding method is adopted. The reprocessing process method for the reflective surface after hot pressing molding is mainly to grind the mold surface to improve the accuracy, while additive processing such as 3D printing technology is not suitable for large-area thin-walled curved surface processing. Summary of the invention

[0010] In order to overcome the above technical defects, the purpose of the present invention is to provide a satellite antenna reflecting surface capable of reconstructing the geometric shape of the reflecting surface, a processing method thereof, a design method of its main structural layer and a reconstruction accuracy verification method.

[0011] The invention discloses a satellite antenna reflecting surface, comprising a main structure layer and an electromagnetic wave reflecting layer, wherein the main structure layer and the electromagnetic wave reflecting layer are bonded by epoxy resin; the main structure layer is made of a negative Poisson's ratio material or a negative Poisson's ratio metamaterial; a radial tension is applied to the main structure layer so that the area size of the reflecting surface becomes larger; and the electromagnetic wave reflecting layer is a metal wire mesh.

[0012] Preferably, the unit body structure of the negative Poisson's ratio metamaterial includes a concave polygonal structure, a chiral structure, a rotational rigid body structure and a rotational semi-rigid body structure; a number of the concave polygonal structure unit bodies are interlocked to form the reflecting surface; the chiral structure includes a column and a belt body, the column is arranged at one end of the belt body, a number of the columns and the belt body are chirally arranged to form the chiral structure unit body, and a number of the chiral structure unit bodies are interlocked to form the reflecting surface; the rotating rigid body structure includes a sub-rigid body, a number of the sub-rigid bodies are flexibly connected to form the rotating rigid body structure unit body, and a number of the rotating rigid body structure unit bodies are interlocked to form the reflecting surface; the rotating semi-rigid body structure includes a sub-semi-rigid body, a number of the sub-semi-rigid bodies are flexibly connected to form the rotating semi-rigid body structure unit body, and a number of the rotating semi-rigid body structure unit bodies are interlocked to form the reflecting surface.

[0013] Preferably, the belt body is a rigid belt or a flexible belt; and the column body is a cylinder or a polygonal column.

[0014] Preferably, the four sub-rigid bodies are flexibly connected to form a quadrilateral hole in the middle; the connection between the sub-rigid bodies rotates, so that the angles of the corners of the quadrilateral hole change, thereby increasing or decreasing the area size of the reflecting surface; the four sub-semi-rigid bodies are flexibly connected to form a quadrilateral hole therebetween; the connection between the sub-semi-rigid bodies rotates, so that the angles of the corners of the quadrilateral hole change, thereby increasing or decreasing the area size of the reflecting surface.

[0015] Preferably, the flexible connection is a hinge connection; or the rotating rigid body structure and the rotating semi-rigid body structure are an integrated structure, the thickness of the connection of the sub-rigid body is less than the thickness of the sub-rigid body, and the thickness of the connection of the sub-semi-rigid body is less than the thickness of the sub-semi-rigid body.

[0016] Preferably, the four sub-rigid bodies are flexibly connected to form orthogonal holes therebetween, and the orthogonal holes are ellipses; the rotating rigid body is an integrated structure, and the thickness of the connection of the sub-rigid bodies is less than the thickness of the sub-rigid bodies, and each of the sub-rigid bodies includes a first connection, a second connection, a third connection and a fourth connection; the first connection is taken as a reference point and remains stationary, and a pulling force is applied to any side on both sides of the first connection, the second connection that shares the side with the reference point is displaced along the direction of the pulling force, and the third connection and the fourth connection are respectively displaced in a direction perpendicular to the pulling force, so that the sub-rigid body rotates along the first connection; the four sub-rigid bodies rotate separately, thereby increasing the surface area size of the rotating rigid body.

[0017] Preferably, the major axis of the ellipse is 2a, the minor axis is 2b, and b / a=0.1.

[0018] The present invention also discloses a design method for the main structural layer of a satellite antenna reflector, which is used to set the above-mentioned satellite antenna reflector, comprising the following steps: Calculate the Young's modulus of the rotating rigid body; by the formula Calculate the Poisson's ratio of the rotating rigid body; by the formula Calculate the bending stiffness of the rotating rigid body; obtain Young's modulus, Young's modulus and bending stiffness corresponding to different b / a values ​​respectively; take the b / a value within the first preset range of the Young's modulus as the first value range, the b / a value within the second preset range of the Poisson's ratio as the second value range, and the b / a value within the third preset range of the bending stiffness as the third value range, one of the boundaries of the first preset range is the minimum value of the Young's modulus, one of the boundaries of the second preset range is the minimum value of the Poisson's ratio, and one of the boundaries of the third preset range is the maximum value of the bending stiffness; take the value of the overlapping part of the first value range, the second value range and the third value range as the optimal value range.

[0019] The present invention also discloses a method for verifying the reconstruction accuracy of the main structural layer of the satellite antenna reflector, which is used to verify the accuracy of the above-mentioned satellite antenna reflector. Obtain the reconstruction accuracy of the reflective surface and determine whether the RMS is less than a preset RMS value; wherein n is the number of the actuators, is the actual displacement value of the reflection surface in the z direction after the actuator works, Z i It is the expected displacement value of the reflective surface in the z direction after the actuator works.

[0020] The present invention also discloses a method for processing a satellite antenna reflecting surface, which is used to process the above-mentioned satellite antenna reflecting surface, and includes the following steps: laying carbon fiber prepreg on a mold according to the main structure layer, and obtaining a main structure panel after vacuum heating; removing material from the main structure panel to obtain the main structure layer; the material removal includes laser cutting or multi-axis machine tool mechanical cutting; laying a metal mesh on the surface of the main structure layer, and bonding it with epoxy resin.

[0021] Compared with the prior art, the above technical solution has the following beneficial effects:

[0022] 1. Compared with the existing mechanically reconfigurable reflective surface, the reconfigurable reflective surface of the negative Poisson's ratio metamaterial structure used in the present invention has a smaller in-plane stiffness under the condition of having a suitable bending stiffness, so the work done by the actuator is more converted into the bending deformation outside the reflective surface, so the output force of the actuator is required to be smaller, thereby reducing the size and weight of the actuator, and reducing the overall weight and launch cost of the reflector;

[0023] 2. The reflective surface with the metamaterial structure of the present invention presents a negative Poisson's ratio in the macroscopic view. When a single actuator is actuated, the reflective surface as a whole has a larger out-of-plane deformation, rather than only affecting a part. In particular, when the actuator is actuated, the reflective surface can be bent in the same direction in an orthogonal direction to form a "bowl" shape, which is more in line with the shape of a parabolic reflective surface;

[0024] 3. The electromagnetic wave reflection layer formed by the metal wire mesh has small gaps, can reflect electromagnetic waves to a greater extent, has a high reflectivity, and is suitable for high-frequency electromagnetic waves. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 A schematic diagram of the structure of the satellite antenna reflector provided by the present invention;

[0026] Figure 2 The negative Poisson's ratio material structure in the form of a concave hexagonal structure provided by the present invention;

[0027] Figure 3The negative Poisson's ratio material structure of the "arrow" type structure provided by the present invention;

[0028] Figure 4 A negative Poisson's ratio material structure in the form of a diamond grid structure provided by the present invention;

[0029] Figure 5 A negative Poisson's ratio material structure in the form of a square grid structure provided by the present invention;

[0030] Figure 6 The negative Poisson's ratio material structure in the form of a triangular star structure provided by the present invention;

[0031] Figure 7 The negative Poisson's ratio material structure in the form of a four-pointed star structure provided by the present invention;

[0032] Figure 8 The negative Poisson's ratio material structure in the form of a hexagonal star structure provided by the present invention;

[0033] Fig. 9 The negative Poisson's ratio material structure of the chiral structure provided by the present invention;

[0034] Fig.10 The negative Poisson's ratio material structure in the form of a "three-handed" chiral structure provided by the present invention;

[0035] Fig.11 The negative Poisson's ratio material structure of the "concave three-handed" chiral structure provided by the present invention;

[0036] Fig.12 The negative Poisson's ratio material structure in the form of a "three-handed" reverse-handed structure provided by the present invention;

[0037] Fig.13 The negative Poisson's ratio material structure of the "concave three-handed" chiral structure provided by the present invention;

[0038] Fig.14 The negative Poisson's ratio material structure provided by the present invention has a chiral structure in which the central circle is a regular hexagon;

[0039] Fig.15 A negative Poisson's ratio material structure in the form of a rectangular rotating block structure provided by the present invention;

[0040] Fig.16 A negative Poisson's ratio material structure of a parallelogram rotating block provided by the present invention;

[0041] Fig.17 A negative Poisson's ratio material structure of orthogonally cut rectangular holes provided by the present invention;

[0042] Fig.18 A negative Poisson's ratio material structure of an orthogonally cut elliptical hole provided by the present invention;

[0043] Fig.19 A schematic diagram of the force acting on the negative Poisson's ratio material structure of the orthogonally cut elliptical hole provided by the present invention;

[0044] Fig. 20 A schematic diagram of the force of a single "blade" of a negative Poisson's ratio material structure with orthogonally cut elliptical holes provided by the present invention;

[0045] Fig.21 A schematic diagram of a simulated variant structure of a negative Poisson's ratio material structure for orthogonally cutting an elliptical hole provided by the present invention;

[0046] Fig. 22 The unit deformation curve diagram in the x and y directions of the negative Poisson's ratio material structure of the orthogonally cut elliptical hole provided by the present invention;

[0047] Fig.23 A curve diagram showing the relationship between the equivalent Poisson's ratio and the b / a value of the negative Poisson's ratio material structure of the orthogonally cut elliptical hole provided by the present invention;

[0048] Fig.24 A curve diagram showing the relationship between the Young's modulus and the b / a value of the negative Poisson's ratio material structure of the orthogonally cut elliptical hole provided by the present invention;

[0049] Fig.25 A curve diagram showing the relationship between the disturbance and the b / a value of the negative Poisson's ratio material structure of the orthogonally cut elliptical hole provided by the present invention;

[0050] Fig.26 A curve diagram showing the relationship between the bending stiffness and the b / a value of the negative Poisson's ratio material structure with orthogonally cut elliptical holes provided by the present invention;

[0051] Fig. 27 A curve diagram showing the relationship between the ratio D / E of the bending stiffness and the in-plane equivalent Young's modulus and the b / a value of the negative Poisson's ratio material structure with orthogonally cut elliptical holes provided by the present invention;

[0052] Fig.28 A curve diagram showing the relationship between the profile accuracy and the b / a value of the negative Poisson's ratio material structure of the orthogonally cut elliptical hole provided by the present invention;

[0053] Fig.29 A front view of a main structural layer of a negative Poisson's ratio material structure with orthogonally cut elliptical holes provided by the present invention;

[0054] Fig.30 A top view of the main structural layer of the negative Poisson's ratio material structure with orthogonally cut elliptical holes provided by the present invention.

[0055] Among them: 1-main structural layer, 2-electromagnetic wave reflection layer. DETAILED DESCRIPTION

[0056] The advantages of the present invention are further described below in conjunction with the accompanying drawings and specific embodiments.

[0057] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present disclosure. Instead, they are merely examples of devices and methods consistent with some aspects of the present disclosure as detailed in the appended claims.

[0058] The terms used in this disclosure are for the purpose of describing specific embodiments only and are not intended to limit the disclosure. The singular forms of "a", "said" and "the" used in this disclosure and the appended claims are also intended to include plural forms unless the context clearly indicates otherwise. It should also be understood that the term "and / or" used herein refers to and includes any or all possible combinations of one or more associated listed items.

[0059] It should be understood that although the terms first, second, third, etc. may be used in the present disclosure to describe various information, such information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of the present disclosure, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Depending on the context, the word "if" as used herein may be interpreted as "at the time of" or "when" or "in response to determining".

[0060] In the description of the present invention, it is necessary to understand that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0061] In the description of the present invention, unless otherwise specified and limited, it should be noted that the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a mechanical connection or an electrical connection, or it can be the internal connection between two components. It can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to the specific circumstances.

[0062] In the following description, the suffixes such as "module", "component" or "unit" used to represent elements are only used to facilitate the description of the present invention, and have no specific meanings. Therefore, "module" and "component" can be used interchangeably.

[0063] See attached Figure 1 The present invention discloses a satellite antenna reflector, comprising a main structure layer 1 and an electromagnetic wave reflector layer 2, wherein the main structure layer 1 and the electromagnetic wave reflector layer 2 are bonded by epoxy resin. The main structure layer 1 is made of a negative Poisson's ratio material or a negative Poisson's ratio metamaterial, that is, a radial tension is applied to the main structure layer 1, so that the area size of the main structure layer 1 becomes larger. By adopting the main structure layer 1, the in-plane stiffness is small under the condition of having a suitable bending stiffness, so that the work done by the actuator on the back of the reflector is more converted into the bending deformation outside the reflector, so the output force of the actuator required is smaller, thereby reducing the size and weight of the actuator, and reducing the overall weight and launch cost of the reflector. Moreover, the reflecting surface presents a negative Poisson's ratio on a macro scale. When a single actuator is actuated, the reflecting surface as a whole has a larger out-of-plane deformation instead of only affecting a local area. In particular, when the actuator is actuated, the reflecting surface can bend in the same direction in orthogonal directions to form a "bowl" shape, which is more in line with the shape of a parabolic reflecting surface, rather than a "saddle" shape formed by a positive Poisson's ratio material under the action of torque.

[0064] The electromagnetic wave reflecting layer 2 is made of a metal wire mesh with small gaps, which can reflect electromagnetic waves to a greater extent and has a high reflectivity.

[0065] Furthermore, the present invention has studied that the unit cell structure of the negative Poisson's ratio metamaterial includes a concave polygonal structure, a chiral structure, a rotational rigid body structure and a rotational semi-rigid body structure.

[0066] The concave polygonal structure is a polygon with a negative internal angle, and a number of concave polygonal structural units are interlocked to form a reflective surface. Figure 2 The concave hexagonal structure of (a) can also be regarded as a "bow tie" form. Figure 2 (b) When a force is applied in one direction to cause tensile deformation, the dimensions in the orthogonal direction increase simultaneously.

[0067] In addition to the concave hexagon, Figure 3 The "arrow" type structure, Figure 4 The diamond grille structure Figure 5 Square grille structure, Figure 6 The triangular star structure, Figure 7 The four-pointed star structure and Figure 8 Of course, the concave polygonal structure is not limited to the above-mentioned form.

[0068] The chiral structure is a central cylinder wrapped by a "belt" tangent to it, but these "belts" are not mirror-symmetrical. It can be understood that the chiral structure includes a cylinder and a belt. The cylinder is set at one end of the belt. Several cylinders and belts are arranged in a chiral manner to form a chiral structural unit body. Several chiral structural unit bodies are interlocked to form a reflection surface. The belt body is a rigid belt or a flexible belt, and the cylinder is a cylinder or a polygonal column.

[0069] See attached Fig. 9 , attached Fig. 9 (a) is a structural form without stress, Fig. 9 (b) is the structural form after being subjected to stress.

[0070] According to whether the band is left-handed or right-handed, the chiral structure can be divided into chiral and anti-chiral structures. Fig.10 The "three-handed" chiral structure form, attached Fig.11 The concave three-handed chiral structure form, attached Fig.12 The "three-hand" backhand structure, attached Fig.13 The concave "three-hand" reverse-handed structure. If the circle at the center of the unit is changed to a regular hexagon, the attached Fig.14 chiral structural form.

[0071] The rotating rigid body structure includes sub-rigid bodies, and several sub-rigid bodies are flexibly connected to form a rotating rigid body structure unit body, and several rotating rigid body structure unit bodies are interlocked to form a reflecting surface. The four sub-rigid bodies are flexibly connected to form a quadrilateral hole in the middle. The connection between the sub-rigid bodies rotates, expands or contracts according to the different types of loading forces, so that the angles of each corner of the quadrilateral hole change, thereby increasing or decreasing the area size of the reflecting surface. The rigid block can be a rectangle, a triangle, a parallelogram, etc. See the attached Fig.15 Rectangular rotating block structure, attached Fig.15 (a) is a structural form without stress, Fig.15 (b) is the structural form after being subjected to stress.

[0072] In addition to the rectangular rotation block, there is also Fig.16 The parallelogram rotation block.

[0073] By cutting a certain shape on the plane, a rotatable unit is generated. See the attached Fig.17 By orthogonally cutting rectangular holes, a negative Poisson's ratio structure of four rotating unit structures connected by hinges is obtained. Fig.18 The method is to cut an orthogonal elliptical hole.

[0074] The rotating semi-rigid structure is similar to the rotating rigid structure, and also includes sub-semi-rigid bodies, and several sub-semi-rigid bodies are flexibly connected to form a rotating semi-rigid structure unit body, and several rotating semi-rigid structure units are interlocked to form a reflecting surface. Similarly, four sub-semi-rigid bodies are flexibly connected to form a quadrilateral hole therebetween, and the connection between the sub-semi-rigid bodies rotates, so that the angles of each corner of the quadrilateral hole change, thereby increasing or decreasing the area size of the reflecting surface.

[0075] Usually, the flexible connection can be a hinge connection. Alternatively, the rotating rigid body structure and the rotating semi-rigid body structure are an integrated structure, the thickness of the connection of the sub-rigid body is smaller than the thickness of the sub-rigid body, and the thickness of the connection of the sub-semi-rigid body is smaller than the thickness of the sub-semi-rigid body.

[0076] A better structural form, namely Fig.18 The structural form of cutting orthogonal elliptical holes can be a rotating rigid body integrated structure formed by cutting four sub-rigid bodies, the thickness of the connection of the sub-rigid body is smaller than the thickness of the sub-rigid body, and each sub-rigid body includes a first connection, a second connection, a third connection and a fourth connection; the first connection is taken as a reference point and does not move, and a pulling force is applied to any side on both sides of the first connection, the second connection that shares the side with the reference point is displaced along the direction of the pulling force, and the third connection and the fourth connection are respectively displaced in a direction perpendicular to the pulling force, so that the sub-rigid body rotates along the first connection; the four sub-rigid bodies rotate respectively, thereby increasing the surface area size of the rotating rigid body.

[0077] See attached Figure 19-20 , or it can be composed of four "blades" (i.e., sub-rigid bodies) connected together. When a tensile force is applied to it in one direction, and the left and lower edges are simply supported, the "blades" are stretched and deformed in the direction of the force. Due to the action of the bending moment, they also bend and rotate. Therefore, the deformation of the entire unit in the direction of the force includes the tensile deformation and the deformation caused by the rotation of the "blades". The deformation caused by the rotation of the "blades" will also occur in the orthogonal direction of the force, and the orthogonal direction also appears as stretching, such as Fig.19 The deformed unit shape shown by the dotted line exhibits a "tension" phenomenon, which presents a negative Poisson's ratio on a macro scale.

[0078] See attached Fig. 20 Since the thickness of the connection between the "blades" is small and the bending stiffness is small, it is easy to rotate around the connection. Therefore, when an external force F acts, a bending moment M=FD / 2 is generated, where D=(ab) / 2. Therefore, M increases with the increase of the deviation of the major and minor axes of the elliptical hole, that is, the flatter the elliptical hole, the greater the bending moment, the larger the rotation angle of the "blade", and the larger the deformation size of the unit in two orthogonal directions, that is, the smaller the tensile stiffness within the surface.

[0079] The present invention also discloses a design method for the main structural layer 1 of the satellite antenna reflecting surface, which is used for designing the structural form of the main structural layer 1 of the satellite antenna reflecting surface.

[0080] Take an orthogonal elliptical hole and simulate the structure. Take L = 25mm, the width of the "blade" connection g = 1mm, the Young's modulus of the material is Emat = 50GPa, and the thickness is 0.5mm. The left edge and the lower edge are simply supported, and a unit force F is applied to the edge. After simulation, the deformation of the unit in the x and y directions is obtained, as shown in Fig.21 As shown, Fig.21 (a) is b / a=0.1, Fig.21 (b) is b / a=0.5, Fig.21 (c) is b / a=1. Fig. 22 , a graph showing the unit deformation in the x and y directions.

[0081] According to the formula Calculate the equivalent Poisson’s ratio and plot the results in a graph, see Appendix Fig.23 As can be seen from the figure, when the elliptical hole approaches a circle, the bending moment decreases to zero, and the "blade" has no bending or rotational deformation. Therefore, the deformation of the unit is mainly the tensile deformation of the material itself, and the deformation in the orthogonal direction is mainly determined by the Poisson's ratio of the material itself.

[0082] During design, the material suitability is evaluated by the ratio of the bending stiffness of the reflection surface to the Young's modulus in the plane (D / E). The larger the ratio, the less energy is consumed by the tensile deformation in the plane relative to the bending deformation, and the larger the ratio, the higher the accuracy of the surface reconstruction. According to the formula Calculate Young's modulus. According to the simulation results and the calculated in-plane equivalent Young's modulus Eeff under different b / a, the attached Fig.24 This is the relationship diagram between Eeff and b / a value. It can be seen from the figure that as the b / a value increases, the in-plane membrane stiffness increases. Therefore, when designing, it is necessary to reduce the membrane stiffness, that is, to make the elliptical hole flat.

[0083] The influence of the b / a parameter on the bending stiffness in the elliptical hole array structure is also calculated by the simulation model. The cantilever beam length of the model is H = 250 mm, F = 0.01 N. The disturbance δ of the cantilever beam under different b / a ratios is obtained according to the deformation simulation. See Appendix Fig.25 shown.

[0084] According to the formula Calculate the bending stiffness of the rotating rigid body and obtain the relationship curve between the bending stiffness and the b / a ratio, such as Fig.26 As shown in the figure, it can be seen that as the b / a value increases, the bending stiffness becomes smaller, that is, when the hole changes from a flat ellipse to a round hole, the bending stiffness becomes smaller.

[0085] joint Fig.24 and Fig.26 , plot the ratio of bending stiffness to in-plane equivalent Young's modulus, such as Fig. 27 As shown, when b / a is smaller, that is, when the ellipse is flatter, the D / E value is greatly improved relative to the non-porous structure, so that the reflective surface of the elliptical structure can make the work of the actuator more converted into the bending deformation required for the reconstruction of the reflective surface, less consumed in the tensile deformation within the surface, and improve the deformation accuracy of the surface.

[0086] Therefore, the orthogonal elliptical hole array structure of the present invention greatly reduces its in-plane stiffness while ensuring that it has a certain bending stiffness. In addition, the reflective surface using this structure has a negative Poisson's ratio and exhibits a tensile expansion effect, which makes the reconfigurable reflective surface bend in the same direction orthogonal to the direction when it is bent by a bending moment in one direction, thereby forming a "bowl" shape, while the reflective surface of the positive Poisson's ratio material is prone to reverse bending, thus forming a "saddle" shape. The "bowl" shape is more in line with the shape of the reflective surface, so the reconfigurable reflective surface using the negative Poisson's ratio material with tensile expansion effect has a higher reconstruction accuracy.

[0087] In this regard, the present invention further discloses a method for verifying the reconstruction accuracy of the main structural layer 1 of the satellite antenna reflection surface, which is used to verify the accuracy of the above-mentioned satellite antenna reflection surface.

[0088] The reflective surface of the orthogonal elliptical hole array structure is made of carbon fiber composite material, and the reconstruction accuracy is calculated by simulation. Among them, the initial profile is a standard parabola, the focal length f = 1m, the aperture D = 0.5m, and the target profile is a biased feed profile with a biased feed angle of 10°.

[0089] By evaluating the displacement of the point, the formula To evaluate the accuracy of reconstruction, where n is the number of actuators, is the actual displacement value of the reflection surface in the z direction after the actuator works, Z i is the expected displacement value of the reflection surface in the z direction after the actuator works. When the b / a parameters of the elliptical hole in the profile are different, the profile accuracy is as follows: Fig.28 At the same time, in the simulation calculation results, when the reflective surface has no opening structure, the reconstruction RMS of the reflective surface is 0.95mm. When b / a is smaller, the higher the surface accuracy is obtained. However, when the b / a value is 0.1, the reconstruction RMS of the surface drops to 0.45mm. It can be seen that setting this negative Poisson's ratio structure in the mechanical reconstruction reflective surface can improve the reconstruction accuracy of its surface.

[0090] The present invention also discloses a method for processing a satellite antenna reflective surface, which is used for processing the above-mentioned satellite antenna reflective surface, and comprises the following steps:

[0091] S100, laying prepreg on the mold of the reflective surface of the orthogonal elliptical hole array structure with a diameter of 1m, the prepreg can be Toray T300, and the single layer thickness is 0.03mm;

[0092] S200, placing the mold and the carbon fiber material of the upper layer thereof in an autoclave for heat drying;

[0093] S300, demoulding the heat-baked carbon fiber material from the mold to obtain a main structural panel of the parabolic carbon fiber reflective surface;

[0094] S400, laser etching or multi-axis machine tool mechanical cutting is used to process an orthogonal elliptical hole array on the carbon fiber reflective surface shell to obtain a reflective surface and obtain a main structure layer 1, see attached Fig.29 ;

[0095] S500, laying a metal mesh on the surface of the main structure layer 1 and bonding it with epoxy resin, after curing, the metal mesh is fixed on the main structure layer 1 to form a parabolic reflection surface, see attached Fig.30 .

[0096] It should be noted that the embodiments of the present invention have better practicability and do not impose any form of limitation on the present invention. Any technician familiar with the field may use the technical content disclosed above to change or modify it into an equivalent effective embodiment. However, any modification or equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A satellite antenna reflector, characterized in that: It comprises a main structure layer and an electromagnetic wave reflection layer, wherein the main structure layer and the electromagnetic wave reflection layer are bonded by epoxy resin; The reflecting surface is made of a negative Poisson's ratio material; a radial pulling force is applied to the reflecting surface so that the area size of the reflecting surface becomes larger; The electromagnetic wave reflecting layer is a metal wire mesh; The unit cell structure of the negative Poisson's ratio material includes a rotating rigid body structure; The rotating rigid body structure comprises a sub-rigid body, a plurality of the sub-rigid bodies are flexibly connected to form a rotating rigid body structure unit body, and a plurality of the rotating rigid body structure unit bodies are mutually embedded to form the reflecting surface; The four sub-rigid bodies are flexibly connected to form orthogonal holes therebetween, and the orthogonal holes are elliptical; The rotating rigid body is an integrated structure, the thickness of the connection of the sub-rigid body is smaller than the thickness of the sub-rigid body, and each of the sub-rigid bodies includes a first connection, a second connection, a third connection and a fourth connection; Taking the first connection as a reference point and keeping it stationary, a pulling force is applied to any side of both sides of the first connection, the second connection sharing the same side with the reference point is displaced along the pulling force direction, and the third connection and the fourth connection are respectively displaced along the direction perpendicular to the pulling force, so that the sub-rigid body rotates along the first connection; The four sub-rigid bodies rotate respectively, so that the surface area size of the rotating rigid body increases; and By formula Calculating Young's modulus of the rotating rigid body; By formula Calculating the Poisson's ratio of the rotating rigid body; By formula Calculating the bending stiffness of the rotating rigid body; Among them, E eff is Young's modulus, δ is perturbation, ε x is the strain of the element in the x direction, ε y is the strain of the unit in the y direction, F is the force applied in the x direction, Δx is the deformation of the unit in the x direction, Δy is the deformation of the unit in the y direction, g is the wall thickness between the elliptical holes, t is the thickness of the unit, the major axis of the ellipse is 2a, the minor axis is 2b, b / a=0.1, D is the bending stiffness, H is the length of the cantilever beam, Obtain the Young's modulus, Poisson's ratio and bending stiffness corresponding to different b / a values; The b / a value within the first preset range of the Young's modulus is taken as the first value range, the b / a value within the second preset range of the Poisson's ratio is taken as the second value range, and the b / a value within the third preset range of the bending stiffness is taken as the third value range. One of the boundaries of the first preset range is the minimum value of the Young's modulus, one of the boundaries of the second preset range is the minimum value of the Poisson's ratio, and one of the boundaries of the third preset range is the maximum value of the bending stiffness; the value of the overlapping part of the first value range, the second value range, and the third value range is taken as the optimal value range.

2. The satellite antenna reflector according to claim 1, characterized in that: The flexible connection is a hinge connection.

3. A method for designing a main structural layer of a satellite antenna reflector, used to set the satellite antenna reflector according to claim 1, characterized in that: The steps include: By formula Calculating Young's modulus of the rotating rigid body; By formula Calculating the Poisson's ratio of the rotating rigid body; By formula Calculating the bending stiffness of the rotating rigid body; Obtain the Young's modulus, Poisson's ratio and bending stiffness corresponding to different b / a values; The b / a value within the first preset range of the Young's modulus is taken as the first value range, the b / a value within the second preset range of the Poisson's ratio is taken as the second value range, and the b / a value within the third preset range of the bending stiffness is taken as the third value range. One of the boundaries of the first preset range is the minimum value of the Young's modulus, one of the boundaries of the second preset range is the minimum value of the Poisson's ratio, and one of the boundaries of the third preset range is the maximum value of the bending stiffness; the value of the overlapping part of the first value range, the second value range, and the third value range is taken as the optimal value range.

4. A method for verifying the reconstruction accuracy of the main structural layer of a satellite antenna reflector, used to verify the accuracy of the satellite antenna reflector according to claim 1, characterized in that: By formula Obtain the reconstruction accuracy of the reflective surface and determine whether the RMS is less than a preset RMS value; wherein n is the number of actuators, is the actual displacement value of the reflection surface in the z direction after the actuator works, Z i It is the expected displacement value of the reflective surface in the z direction after the actuator works.

5. A method for processing a satellite antenna reflective surface, characterized in that: The method for processing the satellite antenna reflector surface according to any one of claims 1 to 2 comprises the following steps: Laying carbon fiber prepreg on the mold of the main structure layer and performing vacuum heating to obtain a main structure panel; Performing material removal processing on the main structure panel to obtain the main structure layer; the material removal processing includes laser cutting or multi-axis machine tool mechanical cutting; A metal mesh is laid on the surface of the main structural layer and bonded with epoxy resin.

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