Wing based on bistable composite material

Abstract

The invention relates to a wing based on a bistable composite material. The wing comprises a main body, a wingtip and a bistable deformation connecting section for connecting the main body and the wingtip, the bistable deformation connecting section comprises a bistable composite material plate and a driving assembly, and the bistable deformation connecting section can perform bistable jumping so as to change an included angle between the main body and the wingtip; the driving assembly is an SMA spring, the SMA spring drives steady-state jumping of the bistable-state composite material plate to achieve overall bending of the bistable-state deformation connecting section, and then the angle of the wingtip is changed. Compared with the prior art, the invention has the advantages of high deformation speed, stable configuration, high specific stiffness, strong bearing capacity and the like.

Description

Technical Field

[0001] The invention relates to the technical field of aircraft, and in particular to a wing based on a bistable composite material. Background Art

[0002] The variant winglet can be deformed according to the flight conditions to provide better aerodynamic benefits in different flight environments, thereby reducing the energy consumption cost required for flight. The structural design and drive scheme design of the variant winglet are the focus of current research.

[0003] There are many types of variant winglets designed with smart materials or new flexible structures. For example, piezoelectric ceramics, shape memory alloys, etc. are used as drivers, and shape memory polymers, grid or honeycomb structures, and inflatable structures are used as the deformation body of the winglet. These structures have low rigidity and are prone to deformation recovery and vibration when subjected to aerodynamic loads or other disturbances, which are not conducive to the performance of the winglet.

[0004] In summary, how to ensure that the structure has a certain load-bearing capacity while providing deformation capability is an urgent problem that needs to be solved in the practical application of the current intelligent variant winglet design. Summary of the invention

[0005] The purpose of the present invention is to overcome the defects of the above-mentioned prior art such as weak bearing capacity and to provide a wing based on a bistable composite material with fast deformation speed, stable configuration, high specific stiffness and strong bearing capacity.

[0006] The present invention provides a wing based on a bistable composite material, comprising: a main body, a wing tip and a bistable deformation connecting section connecting the main body and the wing tip;

[0007] The bistable deformation connection section includes a bistable composite material plate and a driving component. The bistable deformation connection section can perform a bistable jump to change the angle between the main body and the wing tip; the driving component is an SMA spring, and the SMA spring drives the bistable composite material plate to change the stable state to achieve the bending of the bistable deformation connection section as a whole, thereby achieving the change of the angle of the wing tip;

[0008] The bending of a bistable composite material plate is essentially the steady-state jump of the bistable composite material, that is, the bistable composite material plate made by an asymmetric layup method will produce residual stress between layers and show specific deformation trends in different directions. By applying a load in a specific direction, it can be deformed mainly in a certain direction to obtain different stable configurations. The bending curvature is related to the mechanical properties of the material itself and the thickness of the plate, and can be independently designed according to the required bending angle of the wingtip.

[0009] Furthermore, the bistable deformation connection section further comprises a flexible skin, the flexible skin is arranged outside the bistable deformation connection section, and the SMA spring is arranged between the flexible skin and the bistable composite material plate. The flexible skin is made to be corrugated to enhance the heat dissipation of the SMA spring and improve its own deformation ability.

[0010] Furthermore, the bistable deformation connection section further comprises a honeycomb sandwich or a corrugated plate; the bistable composite material plate is connected to the honeycomb sandwich or the corrugated plate by gluing, so as not to affect the deformation of the bistable composite material plate.

[0011] Furthermore, a concave space for accommodating the bistable deformable connecting section and a guide rail for pushing out and retracting the bistable deformable connecting section are provided inside the main body. The guide rail installed in the concave space is a controllable feed amount guide rail controlled by a motor, and the bistable deformable connecting section can be retracted into the concave space as needed. After retracting, the SMA spring and the flexible skin will be in a compressed state.

[0012] Furthermore, it also includes a heating power supply, which is arranged in the concave space.

[0013] Furthermore, the SMA spring is installed through a tension spring hook installed on the main body and the wing tip; the tension spring hook is connected to a wire of the SMA heating circuit.

[0014] Furthermore, the bistable composite material plate includes a bistable deformation section for deformation and a monostable installation section for installation on both sides. The bistable composite material plate with a monostable installation section is a special bistable composite material setting. When laying, several layers of continuous fiber layers are usually used as the base layer, which are divided into monostable installation sections at both ends and a bistable deformation section in the middle according to design requirements. The fiber laying method of the bistable composite material plate can adopt automatic fiber laying technology.

[0015] Furthermore, the bistable deformation section is made of long fiber reinforced composite material, and the laying method is anti-symmetric or asymmetric; the monostable installation section is made of long fiber reinforced composite material, and the laying method is unidirectional or symmetric.

[0016] Furthermore, the monostable mounting section is rigidly connected to the guide rail and the wing tip provided inside the main body, respectively, and the bistable deformation section is not directly connected to the main body or the wing tip.

[0017] Further, the SMA spring is a one-way or two-way shape memory alloy spring, and the SMA spring is installed along the span or oblique direction of the bistable deformation connection section. The specific reference may be made to the sweep angle of the main body or to generate sufficient bending moment.

[0018] Compared with the prior art, the present invention has the following advantages:

[0019] Fast deformation speed, stable configuration, high specific stiffness and strong bearing capacity. Bistable composite panels made by asymmetric layering will produce residual stress between layers and show specific deformation trends in different directions. By applying loads in specific directions, it can be deformed mainly in a certain direction to obtain different stable configurations. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the structure of a wing based on a bistable composite material;

[0021] Figure 2 It is a schematic diagram of the structure of the wing in the folded state based on the bistable composite material;

[0022] Figure 3 It is a schematic diagram of the structure of the wing tip tilted state of a wing based on a bistable composite material;

[0023] Figure 4 Schematic diagram of the installation details of the SMA spring of the wing based on the bistable composite material;

[0024] Figure 5 Schematic diagram of the layup scheme of the bistable composite panel of a wing based on the bistable composite material.

[0025] Figure markings: 1-main body; 2-wing tip; 3-bistable composite material plate; 4-SMA spring; 5-concave space; 6-guide rail; 7-flexible skin; 8-honeycomb core; 9-heating power supply; 10-tension spring hook; 11-bistable deformation section; 12-monostable installation section. DETAILED DESCRIPTION

[0026] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. Component models, material names, connection structures, control methods, algorithms and other features not clearly described in this technical solution are all considered to be common technical features disclosed in the prior art.

[0027] Example 1

[0028] This embodiment provides a wing based on a bistable composite material, such as Figure 1 , 2 , 3, and 4, comprising: a main body 1, a wing tip 2, and a bistable deformation connecting section connecting the main body 1 and the wing tip 2;

[0029] The bistable deformation connection section includes a bistable composite material plate 3 and a driving component. The bistable deformation connection section can perform a bistable jump to change the angle between the main body 1 and the wing tip 2; the driving component is an SMA spring 4, and the SMA spring 4 drives the bistable composite material plate 3 to change the stable state to achieve the bending of the bistable deformation connection section as a whole, thereby achieving the change of the angle of the wing tip 2;

[0030] The bending of the bistable composite material plate 3 is essentially the steady-state jump of the bistable composite material, that is, the bistable composite material plate made by an asymmetric lamination method will produce residual stress between layers and show specific deformation trends in different directions. By applying a load in a specific direction, it can be deformed mainly in a certain direction to obtain different stable configurations. Its bending curvature is related to the mechanical properties of the material itself and the thickness of the plate, and can be independently designed according to the required bending angle of the wing tip 2.

[0031] In a specific embodiment, the bistable deformation connection section further includes a flexible skin 7, which is arranged outside the bistable deformation connection section, and the SMA spring 4 is arranged between the flexible skin 7 and the bistable composite material plate 3. The flexible skin 7 is made to be corrugated to enhance the heat dissipation of the SMA spring 4 and improve its own deformation ability.

[0032] In a specific embodiment, the bistable deformation connection section further comprises a honeycomb core 8 or a corrugated plate; the bistable composite material plate 3 is connected to the honeycomb core or the corrugated plate 8 by gluing, so as not to affect the deformation of the bistable composite material plate 3.

[0033] In a specific embodiment, the main body 1 is provided with a concave space 5 for accommodating the bistable deformation connecting section and a guide rail 6 for pushing out and retracting the bistable deformation connecting section. Figure 2 As shown, the guide rail 6 installed in the concave space 5 is a controllable feed guide rail controlled by a motor, and the bistable deformable connecting section can be retracted into the concave space 5 as needed. After retracting, the SMA spring 4 and the flexible skin 7 will be in a compressed state.

[0034] In a specific embodiment, a heating power source 9 is further included, and the heating power source 9 is arranged in the concave space 5.

[0035] In a specific implementation, the SMA spring 4 is installed through a tension spring hook 10 installed on the main body 1 and the wing tip 2; the tension spring hook 10 is connected to the wire of the SMA heating circuit.

[0036] In a specific embodiment, the bistable composite material plate 3 includes a bistable deformation section 11 for deformation and a monostable installation section 12 for installation on both sides. Figure 5As shown, the bistable composite material plate 3 with the monostable installation section 12 is a special bistable composite material setting. When laying, several layers of continuous fiber layers are usually used as the base layer, which are divided into monostable installation sections 12 at both ends and bistable deformation sections 11 in the middle according to design requirements. The fiber laying method of the bistable composite material plate 3 can adopt automatic fiber placement technology.

[0037] In a specific embodiment, the bistable deformation section 11 is a long fiber reinforced composite material, and the laying method is anti-symmetric or asymmetric; the monostable installation section 12 is a long fiber reinforced composite material, and the laying method is unidirectional or symmetric.

[0038] In a specific implementation, when the bistable deformation section 11 and the monostable installation section 12 do not undergo bending jump, the geometric shape of the transverse cross section of the laminate is a circular arc or an airfoil arc line.

[0039] In a specific embodiment, the monostable mounting section 12 is rigidly connected to the guide rail 6 and the wing tip 2 provided inside the main body 1 , respectively, and the bistable deformation section 11 is not directly connected to the main body 1 or the wing tip 2 .

[0040] In a specific embodiment, the SMA spring 4 is a one-way or two-way shape memory alloy spring, and the SMA spring 4 is installed along the span or oblique direction of the bistable deformation connection section. Specifically, the sweep angle of the main body or sufficient bending moment may be used as the basis.

[0041] like Figure 1 , 2 As shown, the number of the bistable composite panels 3 is plural, and the size of each bistable composite panel 3 is not equal. The length of each panel can be determined according to the angle of the bent wing tip 2 and the curvature of the bistable composite panel 3. The size of the guide rail 6 and the concave space 5 is based on the size of the longest bistable composite panel 3.

[0042] In this wing, for the connection between the main body 1 and the wing tip 2, the functions of each part of the bistable deformation connection section are different. First, a rigid connection is made with the guide rail 6 and the wing tip 2 through the bistable composite material plate 3 and the honeycomb core 8 to ensure the stiffness and bearing capacity of the overall structure and prevent the wing tip 2 from detaching. The SMA spring 4 is installed on the outside of the bistable composite material plate 3 and the honeycomb core 8 to facilitate the transmission of driving force. The outermost side is covered with a flexible skin 7 to maintain the aerodynamic shape of the wing. Therefore, the flexible skin 7 is not required to be completely flexible, so as not to affect the steady-state deformation of the bistable composite material plate 3.

[0043] like Figure 3As shown, after the guide rail 6 pushes out the bistable deformation connection section, the SMA spring 4 generates tension to make the plurality of bistable composite material panels 3 bend in a jump manner. At this time, the honeycomb sandwich 8 and the flexible skin 7 bend together with the bistable composite material panels 3. When the bistable composite material panels 3 with longer dimensions bend, the remaining part contained in the concave space 5 is pushed out through the guide rail 6. The guide rail 6 fixes the feeding amount through the motor self-locking to keep the bistable deformation connection section in the pushed-out state.

[0044] The bending of the plurality of bistable composite material plates 3 may occur simultaneously or with a short gap, so that they can finally be in the second stable configuration simultaneously.

[0045] The main part of the SMA spring 4 is SMA (Shape Memory Alloy), where SMA is a smart metal material with shape memory effect (SME) and superelasticity / pseudoelasticity (SE). When the SMA spring 4 is heated to exceed the phase transition temperature, it will drive the structure or product to produce corresponding deformation. The SMA spring 4 is a shape memory alloy (SMA) spring, that is, when heated and excited, the SMA spring will return to the state it remembers before the pre-strain occurs, thereby interacting with the structure and driving the structure to deform. After cooling, it can return to the state before the drive under the action of the structural restoring force.

[0046] like Figure 4 As shown, the SMA spring 4 is connected between the main body 1 and the wing tip 2 through a spring hook 10 installed on the main body 1 and the wing tip 2, and is heated by a heating circuit. The heating power supply 9 is installed inside the main body 1, so as not to affect the normal movement of the guide rail 6 and the bistable composite material plate 3. A groove is dug inside the main body 1 and the spring hook 10 is installed in the groove, so as not to over-compress the SMA spring 4 when the guide rail is not pushed out. The number of SMA springs 4 can be one or more. It is based on generating sufficient bending moment.

[0047] Use more efficient heating equipment such as electromagnetic induction heating tubes.

[0048] A more efficient cooling method is used, such as building an air circulation system between the main body 1 and the wing tip 2, installing the SMA spring 4 in an air duct, and utilizing air cooling.

[0049] Components not described in detail in this embodiment are all existing components that can be purchased through public channels.

[0050] The above description of the embodiments is to facilitate the understanding and use of the invention by those skilled in the art. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the above embodiments, and improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be within the scope of protection of the present invention.

Claims

1. A wing based on a bistable composite material, characterized in that: include: A main body (1), a wing tip (2), and a bistable deformation connection section connecting the main body (1) and the wing tip (2); The bistable deformable connecting section comprises a bistable composite material plate (3) and a driving component, wherein the bistable deformable connecting section can perform a bistable jump to change the angle between the main body (1) and the wing tip (2); the driving component is an SMA spring (4), and the SMA spring (4) drives the bistable composite material plate (3) to perform a stable jump to achieve the bending of the entire bistable deformable connecting section, thereby achieving the change of the angle of the wing tip (2).

2. A wing based on a bistable composite material according to claim 1, characterized in that: The bistable deformation connection section further comprises a flexible skin (7), wherein the flexible skin (7) is arranged outside the bistable deformation connection section, and the SMA spring (4) is arranged between the flexible skin (7) and the bistable composite material plate (3).

3. The wing based on bistable composite material according to claim 1, characterized in that: The bistable deformation connection section also includes a honeycomb core (8) or a corrugated plate; the bistable composite material plate (3) is connected to the honeycomb core or the corrugated plate (8) by gluing.

4. The wing based on bistable composite material according to claim 1, characterized in that: The main body (1) is provided with a concave space (5) for accommodating the bistable deformation connecting section and a guide rail (6) for pushing out and retracting the bistable deformation connecting section.

5. The wing based on bistable composite material according to claim 4, characterized in that: It also comprises a heating power source (9), which is arranged in the concave space (5).

6. The wing based on bistable composite material according to claim 1, characterized in that: The SMA spring (4) is installed via a tension spring hook (10) installed on the main body (1) and the wing tip (2); the tension spring hook (10) is connected to a wire of the SMA heating circuit.

7. The wing based on bistable composite material according to claim 1, characterized in that: The bistable composite material plate (3) comprises a bistable deformation section (11) for deformation and a monostable installation section (12) for installation on both sides.

8. The wing based on bistable composite material according to claim 7, characterized in that: The bistable deformation section (11) is a long fiber reinforced composite material, and the laying method is anti-symmetric or asymmetric; the monostable installation section (12) is a long fiber reinforced composite material, and the laying method is unidirectional or symmetric.

9. The wing based on bistable composite material according to claim 7, characterized in that: The monostable mounting section (12) is rigidly connected to a guide rail (6) and a wing tip (2) provided inside the main body (1), respectively, and the bistable deformation section (11) is not directly connected to the main body (1) or the wing tip (2).

10. The wing based on bistable composite material according to claim 1, characterized in that: The SMA spring (4) is a one-way or two-way shape memory alloy spring, and the SMA spring (4) is installed in a span direction or an oblique direction along the bistable deformation connection section.

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