Composite elastic rod for deployable membrane mechanisms

Abstract

This invention relates to a composite material elastic rod for deployable film mechanisms, belonging to the field of aerospace technology. The cross-sectional shape of the composite material elastic rod of this invention adopts a symmetrical "V"-shaped structure, and uses multiple composite materials: carbon fiber unidirectional tapes and glass fiber orthogonal fabrics. The composite material layup consists of 0° carbon fiber unidirectional tapes, with 90° carbon fiber unidirectional tapes and ±45° glass fiber fabrics symmetrically laid on both sides. By employing multiple composite materials and designing the layup method between them, the cross-sectional dimensions of the composite material elastic rod can be designed to improve its rigidity and mechanical properties. Furthermore, corresponding molds are designed for the fabrication of composite material elastic rods of specific dimensions, and corresponding efficient fabrication processes are developed to improve fabrication efficiency and reduce fabrication time and cost.

Description

TECHNICAL FIELD

[0001] The application relates to a composite elastic rod for a deployable thin film mechanism, and belongs to the technical field of aerospace. BACKGROUND

[0002] Deployable thin film mechanisms have received extensive attention and research in the field of aerospace, and are often used in space probes, satellites or other aerospace vehicles. They are usually made of thin film materials and can be deployed or folded in space. Such mechanisms are often used to achieve attitude control, energy collection, antenna deployment and other tasks of space vehicles. The main feature of the deployable thin film mechanism is that it can be deployed after launch or deployment to meet the needs of space missions, and occupies less space in the folded state. The design of such mechanisms needs to consider factors such as materials, structures, deployment mechanisms, etc. to ensure reliability and performance. Compared with other material structures, composite deployable mechanisms have good application prospects in the field of aerospace due to their light weight, large stiffness, good folding effect, rapid and reliable deployment process, etc.

[0003] The current composite elastic rod is a support system component for a deployable thin film mechanism, which undergoes elastic deformation during folding and deployment. First, the composite elastic rod is deformed by applying an external force, and when it needs to be deployed, the elastic strain energy stored during the folding deformation process is used to complete the deployment deformation process, thereby restoring to the initial configuration. It has multiple features, including light weight, simple folding and deployment principle, high folding rate, strong repeatability and high precision. It is often used in deployable spacecraft such as solar sails and space thin film antenna arrays.

[0004] The main composite elastic rod used in deployable thin film mechanisms in the domestic aerospace field is a composite pod rod, which is usually made of carbon fiber resin-based composite materials. The cross section of this composite pod rod is left-right symmetrical, and its profile is composed of a middle convex arc, two side concave arcs and half of the horizontal edge. Corresponding to this, there are three parts of the composite pod rod, namely the middle convex shell, the two side concave shells and the bonding surface. In other words, the cross section shape is an upside-down "Ω" shape.

[0005] The cross-sectional size design of the composite pod rod commonly used in China is relatively complicated, and the size used in the design is usually large, which limits its application range and makes it difficult to use in some small or space-limited applications. Due to the upside-down "Ω" shape of the cross section of the pod rod, its cross-sectional inertia and packaging efficiency are low, which may not be sufficient to meet the rigidity and stability requirements of some applications, resulting in low reusability. At the same time, the preparation process of the current domestic composite elastic rod is relatively traditional and inefficient, resulting in long preparation time and high cost. SUMMARY

[0006] The application aims at solving the problems of the complicated material cross-section shape of the support part of the existing deployable structure, the complicated design, and the large size commonly used, thereby limiting the application range, and provides a composite elastic rod for a deployable membrane mechanism; the cross-section shape of the composite elastic rod adopts a left-right symmetrical structure like a "human" shape, and a plurality of composite materials are selected: carbon fiber unidirectional tape and glass fiber orthogonal fabric, the composite material layering mode is 0° carbon fiber unidirectional tape, 90° carbon fiber unidirectional tape and ±45° glass fiber fabric are symmetrically laid on both sides in sequence. By designing the cross-section size of the simple composite elastic rod, a plurality of composite materials are used, and the layering mode between the composite materials is designed to improve the rigidity and mechanical properties of the composite elastic rod, and the corresponding mold for preparing the composite elastic rod is used for the design of the composite elastic rod of a specific size, and the corresponding efficient preparation process is developed to improve the preparation efficiency, reduce the preparation time and cost. Therefore, the application has very good engineering application value in the field of aerospace.

[0007] The application aims at solving the problems of the complicated material cross-section shape of the support part of the existing deployable structure, the complicated design, and the large size commonly used, thereby limiting the application range, and provides a composite elastic rod for a deployable membrane mechanism; the cross-section shape of the composite elastic rod adopts a left-right symmetrical structure like a "human" shape, and a plurality of composite materials are selected: carbon fiber unidirectional tape and glass fiber orthogonal fabric, the composite material layering mode is 0° carbon fiber unidirectional tape, 90° carbon fiber unidirectional tape and ±45° glass fiber fabric are symmetrically laid on both sides in sequence. By designing the cross-section size of the simple composite elastic rod, a plurality of composite materials are used, and the layering mode between the composite materials is designed to improve the rigidity and mechanical properties of the composite elastic rod, and the corresponding mold for preparing the composite elastic rod is used for the design of the composite elastic rod of a specific size, and the corresponding efficient preparation process is developed to improve the preparation efficiency, reduce the preparation time and cost. Therefore, the application has very good engineering application value in the field of aerospace.

[0008] A composite elastic rod for a deployable membrane mechanism, the cross-section shape of the composite elastic rod adopts a left-right symmetrical structure like a "human" shape; the composite material is composed of carbon fiber unidirectional tape and orthogonal glass fiber fabric;

[0009] The layering mode of the composite material is 0° carbon fiber unidirectional tape in the center; 90° carbon fiber unidirectional tape and ±45° glass fiber fabric are symmetrically laid on both sides in sequence;

[0010] The two concave arcs of the "human" shape are symmetrical, and the upper straight line needs to be tangent to the two concave arcs;

[0011] The relationship among the radius of the lower concave arc of the "human" shape of the composite elastic rod, the opening angle and the length of the tangent straight line on the upper side is obtained by the following method:

[0012] Step one: according to the material properties of the composite elastic rod and the layering mode of the composite material, the tensile stiffness matrix A of the composite material laminate is obtained.

[0013]

[0014]

[0015]

[0016] Step two: formula (3) is obtained

[0017] E1 is the Young's modulus of the composite single layer plate along the fiber direction; E2 is the Young's modulus of the composite single layer plate perpendicular to the fiber direction; v 12 is the Poisson's ratio of the composite single layer plate along the fiber direction; v 21 is the Poisson's ratio of the composite single layer plate along the fiber direction; G 12 is the in-plane shear modulus of the composite single layer plate;

[0018] n is the number of layers of the composite laminate; θ is the ply angle of the composite single layer plate;

[0019] z k , z k-1 is the coordinate of the kth layer and the k-1th layer of the composite laminate along the Z direction;

[0020] z k -z k-1 is the ply thickness of the single layer composite; is the stiffness matrix of the composite laminate in the principal direction;

[0021] P is the rotation matrix of the composite with the ply angle θ in the principal direction; A is the tensile stiffness matrix of the composite laminate;

[0022] Step three: calculate the centroid position of the cross section of the composite elastic rod: as shown in the following formula (4) and Figure 2 .

[0023]

[0024] (X C ,Y C ) is the centroid position coordinate of the cross section shape of the composite elastic rod;

[0025] w is the length of the tangent line of the cross section of the composite elastic rod; r is the radius of the concave arc of the cross section of the composite elastic rod; θ f is the opening angle of the concave arc of the cross section of the composite elastic rod;

[0026] Step four: the cross section moment of inertia of the X, Y axis of the composite elastic rod: as shown in the following formula (5) and (6):

[0027]

[0028]

[0029] M X is the cross section moment of inertia of the X axis direction of the composite elastic rod; M Y is the cross section moment of inertia of the Y axis direction of the composite elastic rod; (EI) XLet EI be the bending stiffness of the composite elastic rod in the X-axis direction. Y ρ is the bending stiffness of the composite elastic rod along the Y-axis; ρ is the radius of curvature of the neutral layer; A 11 A 12 A 22 These are elements in the tensile stiffness matrix A of the composite elastic rod;

[0030] Step 5: Calculate the relationship between the bending stiffness of the composite elastic rod and its cross-sectional dimensions using formulas (5) and (6):

[0031]

[0032]

[0033] t is the thickness of the concave arc of the composite elastic rod, and t1 is the thickness of the tangent straight line of the composite elastic rod; this can be obtained from the layup method of the composite material.

[0034] Follow the steps above and Figure 8 As shown, if the bending stiffness (EI) of the composite elastic rod is given according to actual needs... X and (EI) Y Then, using formulas (7) and (8), the radius r of the concave arc below the "V"-shaped part of the composite elastic rod and the opening angle θ can be obtained. f The dimensional relationship between the length w of the line tangent to the line above and the line above.

[0035] The preparation process of the composite material elastic rod includes the following steps:

[0036] Step 1: Prepare a multi-layer prepreg of carbon fiber unidirectional tape and glass fiber positive interwoven fabric, lay it on two convex arc molds with release cloth, and brush epoxy resin adhesive on each layer.

[0037] Step 2: Place the pointed mold on top of the two convex arc molds, press and fix the whole mold, then put it in a vacuum bag to vacuum it, and then put it in an oven to heat and cure.

[0038] Step 3: After curing, remove the molded composite material elastic rod and then use a utility knife to cut off the excess curved and straight sections to obtain the required size composite material elastic rod for the expandable film mechanism.

[0039] The invention mainly includes the design of a composite material elastic rod for a deployable film mechanism and a method for preparing the composite material elastic rod;

[0040] The composite material used in the elastic rod of the expandable film mechanism consists of a reinforcing material and a matrix material. The reinforcing material is orthogonal glass fiber fabric and carbon fiber T700 unidirectional tape, and the matrix material is epoxy resin with a symmetrical cross-section. The outline of the cross-section is shaped like a "V", consisting of a straight line 1 tangent at the top and concave arcs 2 on both sides.

[0041] The composite material elastic rod of this invention for a deployable film mechanism is symmetrical from left to right. Based on the required bending stiffness and the selected composite material, the composite material layup of the elastic rod for the deployable film mechanism is designed according to its functional requirements and the selection of the composite material. Because the structure adopts a herringbone shape and is symmetrical from left to right, the layup of one half of the structure is as follows: Figure 3 As shown. According to... Figure 3 As shown in the layup diagram, the theoretical thickness of the concave arc segment of the composite material elastic rod of this invention is only 0.135 mm, while the theoretical thickness of the straight segment of the composite material elastic rod, which is symmetrical from left to right, is only 0.27 mm. Then, according to... Figure 8 The design flow for the cross-sectional dimensions of the composite elastic rod shown can be obtained as follows: Figure 2 The relationship between the cross-sectional dimensions of the composite elastic rod shown is used to obtain a composite elastic rod that meets the requirements for a deployable film mechanism.

[0042] Then, the invention designs relevant molds to meet the dimensional requirements of the composite material elastic rod used in the expandable film mechanism, such as... Figure 5 As shown, the mold is then used for processing and preparation. It mainly consists of three parts: a pointed-corner mold 3 and two convex arc-shaped molds 4. An isometric view of the mold used for preparing the composite material elastic rod of the developable film mechanism is shown below. Figure 5 As shown, the front view and cross-sectional view along the CC direction of the mold for preparing the composite elastic rod for the spreadable film mechanism are as follows. Figure 6 As shown.

[0043] Beneficial effects:

[0044] 1. Currently, most deployable thin-film mechanisms in the aerospace field still rely primarily on specially designed structures and hinge systems, while integrating motors and spring mechanisms to ensure the stability and reliability of the deployment process. To address the mass and storage efficiency issues in traditional deployable thin-film mechanisms, this invention utilizes the composite material elastic rod's property of storing elastic potential energy through bending deformation. Compared to traditional motor-driven mechanisms, the composite material elastic rod can self-deploy without a motor, significantly reducing overall weight. Simultaneously, its efficient winding characteristics optimize the space utilization of the central mechanism, improving overall storage efficiency.

[0045] 2. The cross-sectional geometry of commonly used composite pod rods in China is typically complex. In contrast, the cross-section of this invention adopts a herringbone shape, resulting in simpler geometry. The cross-sectional dimensions can be designed according to specific application requirements using a streamlined process, allowing for the creation of customized composite elastic rods. Furthermore, the cross-sectional dimensions can be adjusted to suit small spacecraft, such as CubeSats, thus increasing the flexibility of the composite elastic rod's applicability. Currently used composite pod rods have low cross-sectional inertia. Compared to composite pod rods, the herringbone-shaped cross-section of this invention, at the same encapsulation height, has a cross-sectional moment of inertia ten times greater. This results in greater bending stiffness and improved torsional stiffness after unfolding. As a support component, it exhibits less deflection under the same external force. In summary, this invention demonstrates superior mechanical properties after unfolding.

[0046] 3. This invention utilizes both glass fiber and carbon fiber. The combination of orthogonal glass fiber fabric and T700 carbon fiber unidirectional tape enhances the strength and stiffness of the structure, enabling it to better withstand external stress. Furthermore, the layup method of this invention, which designs the orthogonal glass fiber fabric to be laid at ±45° on both sides of the structure, reduces the shearing damage to the structure caused by the paper cutter during dimensional processing, improves the surface quality of the composite elastic rod after dimensional processing, reduces the risk of damage during dimensional processing, and can improve the manufacturing efficiency of the composite elastic rod, thereby saving time and costs.

[0047] 4. This invention first designs a composite material elastic rod with specific dimensions according to requirements, and then designs a corresponding manufacturing mold. Next, an efficient manufacturing process is developed. The manufacturing mold has a simple structure and is easy to manufacture, and the manufacturing process is clear, making the manufacturing of composite material elastic rods more efficient and easier, reducing manufacturing costs, and improving manufacturing efficiency. This invention effectively improves the manufacturing efficiency and consistency of composite material elastic rods by integrating customized design, simplified manufacturing molds, and an efficient manufacturing process, thereby reducing costs and increasing production efficiency. Attached Figure Description

[0048] Figure 1 Schematic diagram of the cross-sectional shape of a composite elastic rod used in a deployable film mechanism;

[0049] Figure 2 A schematic diagram showing the specific dimensional parameters of the cross-section of the composite elastic rod used in the deployable film mechanism;

[0050] Figure 3 A schematic diagram of the composite material layup for a composite elastic rod used in a spreadable film mechanism;

[0051] Figure 4Orthographic isometric view and enlarged view of end of composite elastic rod for deployable membrane mechanism

[0052] Figure 5 Orthographic isometric view of composite elastic rod preparation mold for deployable membrane mechanism

[0053] Figure 6 Front view and C-C sectional view of composite elastic rod preparation mold for deployable membrane mechanism

[0054] Figure 7 Flowchart of composite elastic rod preparation process for deployable membrane mechanism

[0055] Figure 8 Flowchart of cross-sectional dimension design of composite elastic rod for deployable membrane mechanism

[0056] Wherein, 1 is a tangent straight line segment of the composite elastic rod, 2 is a concave arc segment of the composite elastic rod, 3 is a sharp corner mold for preparing the composite elastic rod, and 4 is a convex arc mold for preparing the composite elastic rod. DETAILED DESCRIPTION

[0057] In order to better illustrate the purpose and advantages of the present application, the content of the application is further described below in combination with the drawings and examples.

[0058] A composite elastic rod for a deployable membrane mechanism, characterized in that the relationship among the radius of the concave arc below the "human" shape, the opening angle and the length of the tangent straight line above is obtained by the following method:

[0059] Step one: according to the material properties of the composite elastic rod and the lamination method of the composite material, the tensile stiffness matrix A of the composite laminate is obtained.

[0060]

[0061]

[0062]

[0063] Step two: then formula (3) is obtained

[0064] E1 is the Young's modulus of the composite single-layer plate along the fiber direction; E2 is the Young's modulus of the composite single-layer plate perpendicular to the fiber direction; v 12 is the Poisson's ratio of the composite single-layer plate along the fiber direction; v 21 is the Poisson's ratio of the composite single-layer plate along the fiber direction; G 12 is the in-plane shear modulus of the composite single-layer plate;

[0065] n is the number of layers of the composite laminate; θ is the ply angle of the composite single layer;

[0066] z k , z k-1 is the coordinate of the kth layer and the k-1th layer of the composite laminate along the Z direction;

[0067] z k -z k-1 is the ply thickness of the single layer composite; is the stiffness matrix of the composite laminate in the principal direction;

[0068] P is the rotation matrix of the composite with the ply angle θ in the principal direction; A is the tensile stiffness matrix of the composite laminate;

[0069] Step three: calculate the centroid position of the cross section of the composite elastic rod: as shown in the following formula (4) and Figure 2 .

[0070]

[0071] (X C ,Y C ) is the centroid position coordinate of the cross section shape of the composite elastic rod;

[0072] w is the length of the tangent line of the cross section of the composite elastic rod; r is the radius of the concave arc of the cross section of the composite elastic rod; θ f is the opening angle of the concave arc of the cross section of the composite elastic rod;

[0073] Step four: the cross-sectional moment of inertia of the X, Y axis of the composite elastic rod: as shown in the following formula (5) and (6):

[0074]

[0075]

[0076] M X is the cross-sectional moment of inertia of the X axis of the composite elastic rod; M Y is the cross-sectional moment of inertia of the Y axis of the composite elastic rod; (EI) X is the bending stiffness of the X axis of the composite elastic rod; (EI) Y is the bending stiffness of the Y axis of the composite elastic rod; ρ is the radius of curvature of the neutral layer; A 11 , A 12 , A 22 are the elements in the tensile stiffness matrix A of the composite elastic rod, respectively;

[0077] Step five: the relationship between the bending stiffness of the composite elastic rod and its cross-sectional size is calculated by formula (5) and (6):

[0078]

[0079]

[0080] t is the thickness of the concave arc of the composite elastic rod, t1 is the thickness of the tangent straight line of the composite elastic rod; the thicknesses of the concave arc and the tangent straight line can be obtained from the laying mode of the composite material

[0081] According to the above steps and Figure 8 , if the bending stiffness (EI) of the composite elastic rod is given according to the actual requirement X =(EI) Y =10N·m 2 , then the radius r of the lower concave arc of the composite elastic rod in the shape of a "human" figure, the opening angle θ and the length w of the tangent straight line on the upper side can be obtained from formula (7) and (8) f , if θ f =90°, w=10mm; that is, the required size r=15mm can be obtained.

[0082] A composite elastic rod for an expandable film mechanism, characterized in that the cross-sectional shape of the composite elastic rod adopts a left-right symmetrical structure in the shape of a "human" figure; the composite material is composed of carbon fiber unidirectional tape and glass fiber orthogonal fabric; and characterized in that, as shown in Figure 3 , the laying mode of the composite material is that the center is 0° carbon fiber unidirectional tape; the two sides are symmetrically laid with 90° carbon fiber unidirectional tape and ±45° glass fiber orthogonal fabric in sequence; a composite elastic rod for an expandable film mechanism, characterized in that, as shown in Figure 1 , the two concave arcs of the shape of a "human" figure are symmetrical on the lower side, and the upper straight line needs to be tangent to the two concave arcs.

[0083] Through the above selected composite material and laying mode, as shown in Figure 3 , and the size of the shape of a "human" figure of the composite elastic rod calculated, as shown in Figure 2 , then a mold of corresponding size is designed, as shown in Figure 5 , and the mold is processed and manufactured for preparation, and finally the preparation process shown in Figure 6 is used to prepare the composite elastic rod for an expandable film mechanism (as shown in Figure 4 ).

[0084] The present application discloses a preparation process of a composite elastic rod for an expandable film mechanism (as shown in Figure 7 ), characterized in that the preparation process of the composite elastic rod comprises the following steps:

[0085] Step one, make a multi-layer prepreg of carbon fiber unidirectional tape and orthogonal glass fiber fabric, lay on two convex arc-shaped molds with release cloth, and brush epoxy resin adhesive on each layer.

[0086] Step two, then place the sharp corner mold above the two convex arc-shaped molds, press and fix the whole mold, then put it into a vacuum bag to extract vacuum, and then put it into an oven for temperature curing.

[0087] Step three, after curing, take out the formed composite elastic rod, and cut off the excess arc segment and straight segment with a paper cutter to obtain a composite elastic rod of the required size for the deployable membrane mechanism.

[0088] The composite elastic rod of the application adopts a left-right symmetrical structure in the shape of a "human" cross section, and a variety of composite materials are selected: carbon fiber unidirectional tape and glass fiber orthogonal fabric, the composite material layering mode is 0° carbon fiber unidirectional tape, and 90° carbon fiber unidirectional tape and ±45° glass fiber fabric are symmetrically laid on both sides.

[0089] By using a variety of composite materials and designing the layering mode between the composite materials, and then designing the cross-sectional size of the composite elastic rod to improve the rigidity and mechanical properties of the composite elastic rod, and the corresponding mold for the design of the composite elastic rod of a specific size is used to prepare the composite elastic rod, and the corresponding efficient preparation process is developed to improve the preparation efficiency, reduce the preparation time and cost.

[0090] The above specific description further details the purpose, technical solution and beneficial effects of the application. It should be understood that the above description is only a specific embodiment of the application and is not used to limit the protection scope of the application. Any modification, equivalent replacement, improvement, etc. within the spirit and principles of the application should be included in the protection scope of the application.

Claims

1. A composite elastic rod for an unfoldable film mechanism, characterized by: The cross section shape of the composite elastic rod is a left-right symmetrical structure in the shape of a "human" figure; the composite material is composed of carbon fiber unidirectional tape and glass fiber orthogonal fabric; The two concave arcs of the lower part of the "human" figure are symmetrical, and the upper straight line is tangent to the two concave arcs; The relationship among the radius of the lower concave arc of the "human" figure, the opening angle and the length of the tangent straight line of the upper part is obtained by the following method: Step one: according to the material properties of the composite elastic rod and the lamination method of the composite material, the tensile stiffness matrix A of the composite laminate is obtained: Step two: Obtain from equation (3) E1 is the Young's modulus of the composite single ply along the fiber direction; E2 is the Young's modulus of the composite single ply perpendicular to the fiber direction; v 12 is the Poisson's ratio of the composite single ply along the fiber direction; v 21 is the Poisson's ratio of the composite single ply along the fiber direction; G 12 is the in-plane shear modulus of the composite single ply; n is the number of layers of the composite laminate; θ is the lamination angle of the composite single-layer plate; z k , z k-1 is the coordinate of the kth layer and the k-1th layer of the composite laminate along the Z direction; z k -z k-1 is the ply thickness of the single-ply composite material; is the stiffness matrix of the composite laminate in the principal directions. P is the rotation matrix of the composite material with a lamination angle θ of the main direction; A is the tensile stiffness matrix of the composite laminate; Step three: calculate the centroid position of the cross section of the composite elastic rod: as shown in the following formula (4): (X C ,Y C ) are the cross-sectional shape centroid position coordinates of the composite elastic rod; w is the length of the tangent line of the cross section of the composite elastic rod; r is the radius of the concave arc of the cross section of the composite elastic rod; θ f is the opening angle of the concave arc of the cross section of the composite elastic rod; Step four: the cross section inertia moment of the X, Y axis of the composite elastic rod: as shown in the following formula (5) (6): M X is the moment of inertia of the cross section of the composite elastic rod in the X-axis direction; M Y is the moment of inertia of the cross section of the composite elastic rod in the Y-axis direction;(EI) X is the bending stiffness of the composite elastic rod in the X-axis direction;(EI) Y is the bending stiffness of the composite elastic rod in the Y-axis direction; p is the radius of curvature of the neutral layer; A 11 , A 12 , A 22 are elements in the tensile stiffness matrix A of the composite elastic rod, respectively; Step five: the relationship between the bending stiffness of the composite elastic rod and its cross section size is shown in the following formula (7) and (8): t is the thickness of the concave arc segment of the composite elastic rod, t1 is the thickness of the tangent straight segment of the composite elastic rod; which can be obtained from the laying mode of the composite material As shown in the above steps, if the bending stiffness (EI) of the composite elastic rod is given according to the actual demand X and (EI) Y Then the radius r, the opening angle θ of the composite elastic rod of the "human”-shaped lower concave arc and the length w of the tangent line of the upper side can be obtained from the above formula (7) (8) f The size relationship of the three.

2. A composite elastic strand for use in a deployable membrane apparatus as defined in claim 1, characterized in that: The lamination method of the composite material is that the center is 0° carbon fiber unidirectional tape; the two sides are symmetrically laid with 90° carbon fiber unidirectional tape and ± 45° glass fiber orthogonal fabric in turn.

3. A composite elastic strand for use in a deployable film mechanism according to claim 1 or 2, wherein: The preparation process of the composite elastic rod includes the following steps: Step one, make a multi-layer prepreg of carbon fiber unidirectional tape and orthogonal glass fiber fabric, lay it on two convex arc molds with release cloth, and brush epoxy resin adhesive on each layer; Step two, then place the sharp corner mold above the two convex arc molds, press and fix the whole mold, then put it into a vacuum bag to extract vacuum, and then put it into an oven for heating and curing; Step three, after curing, take out the formed composite elastic rod, then cut off the excess arc segment and straight segment part with a paper cutter to obtain the required size of the composite elastic rod for the developable membrane mechanism.

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