A variable stiffness flexible wing

Abstract

The present invention discloses a variable-stiffness flexible wing, which relates to the technical field of wing structures. The wing comprises a leading edge wing, a passive variable-stiffness structure, and a trailing edge wing, which are connected in sequence. The passive variable-stiffness structure and the trailing edge wing are externally connected by a skin. The passive variable-stiffness structure can swing up and down with the chord to change the wing's stiffness. During the wing deformation process, the present invention can change the wing's stiffness by causing the chord to swing up and down through contact with the passive variable-stiffness structure. This can increase the local stiffness of the wing, thereby ensuring that the wing maintains sufficient load-bearing stiffness and enabling the stiffness characteristics of the wing's trailing edge to bend upward or downward.

Description

Technical Field

[0001] The present invention relates to the technical field of wing structures, in particular to a variable-rigidity flexible wing. Background Art

[0002] With the rapid development of modern manufacturing technology, improving the aerodynamic efficiency of aircraft has been a long-standing focus of research for aeronautical engineering researchers. A variety of morphing structural designs have emerged for deformable wings. Using rigid structures can achieve variable camber-driven wing deformation, optimizing wing design to identify aerodynamically efficient airfoil structures, using flexible skin structures to achieve continuous wing deformation, and using artificial muscle drive units to achieve wing bending deformation. Morphing is a promising biomimetic technology that adjusts wing shape to achieve optimal efficiency under any flight conditions, potentially making aircraft more economical and sustainable. To further reduce flight costs and environmental pollution, a more radical departure from traditional aircraft design is necessary. One promising technology is active morphing, which enables aircraft to transform in flight and achieve continuous deformation.

[0003] The variable-camber flexible wing is a technology that adjusts the camber of the airfoil through active deformation of the wing structure. Compared to traditional wing designs, the variable-camber flexible wing can adjust the wing's camber in real time based on varying aerodynamic conditions during flight, replacing the functions of traditional flaps and ailerons. This design can effectively improve the aircraft's lift-to-drag ratio and enhance its aerodynamic efficiency.

[0004] However, traditional variable-camber wing designs face two conflicting demands when achieving airfoil deformation. First, the wing needs to balance load-bearing stiffness and drive flexibility when deforming. If the load-bearing stiffness is insufficient, the wing may produce excessive, uncommanded deformation during flight, affecting the aerodynamic shape stability, thereby affecting flight control accuracy and flight safety; if the wing stiffness is too high, the drive system will require greater energy input, thereby increasing the weight and volume of the actuator and reducing the energy efficiency of the aircraft. Therefore, how to ensure that the wing has sufficient stiffness to maintain stability while reducing energy consumption and ensuring drive flexibility has become a core issue in variable-camber wing design.

[0005] Some existing variable-camber flexible wings lack variable stiffness, resulting in a conflict between load-bearing stiffness and actuation flexibility. Insufficient wing load-bearing stiffness can lead to excessive, uncommanded deformation during flight, compromising aerodynamic shape stability, reducing flight control accuracy, and threatening flight safety. Excessive wing stiffness, on the other hand, requires greater energy input to drive the system, increasing the weight and volume of the actuators and reducing the vehicle's energy efficiency. Some wing designs also offer variable stiffness, such as those achieved through pneumatic actuation or electrostatic adsorption. However, these designs are considered active variable stiffness. Currently, most active variable stiffness wings require both wing control surfaces and additional actuation mechanisms to adjust stiffness, increasing the weight and energy consumption of the vehicle while also complicating the design and connection of the circuit system. Summary of the Invention

[0006] The purpose of the present invention is to provide a variable stiffness flexible wing to solve the problems existing in the above-mentioned prior art, so that the wing has sufficient stiffness while realizing flexible drive and passive drive.

[0007] To achieve the above object, the present invention provides the following solutions:

[0008] The present invention provides a variable-rigidity flexible wing, comprising a leading edge wing, a passive variable-rigidity structure, and a trailing edge wing connected in sequence. The passive variable-rigidity structure and the exterior of the trailing edge wing are connected via a skin. The passive variable-rigidity structure can swing up and down with the chord to form contact stiffness, thereby changing the stiffness of the wing.

[0009] Preferably, the passive variable stiffness structure includes a main beam plate and an auxiliary beam plate, one end of the main beam plate is fixedly connected to the leading edge wing, and the other end is fixedly connected to the trailing edge wing, and several groups of auxiliary beam plates are symmetrically arranged on both sides of the main beam plate, and an adjustable gap is arranged between adjacent auxiliary beam plates along the chord direction.

[0010] Preferably, the passive variable stiffness structure is provided with an active camber adjustment component, which is connected to the auxiliary beam plate and the trailing edge wing and can make the main beam plate swing up and down, and the active camber adjustment component includes a traction rope and a driving mechanism, and the two traction ropes are symmetrically arranged on both sides of the main beam plate, one end of each traction rope is connected to the trailing edge wing and the other end is connected to the driving mechanism, and the driving mechanism is arranged in the leading edge wing; the width of the adjustment gap on both sides of the main beam plate is different.

[0011] Preferably, the driving mechanism is a motor or a steering gear, and two traction ropes are wound around the rotating shaft of the motor or the steering gear, and the winding directions of the two traction ropes are opposite, and the ends of the traction ropes are fixed on the rotating shaft.

[0012] Preferably, the driving mechanism is a translation mechanism, the ends of the two traction ropes are respectively fixedly connected to one of the translation mechanisms, and the translation mechanism is a cylinder, a hydraulic cylinder, an electric push rod or a screw slider mechanism; the material of the traction rope includes steel wire rope.

[0013] Preferably, the material of the main beam plate includes a flexible non-metallic material or a memory alloy, and the thickness of the main beam plate is not greater than 1 / 100 of the chord length of the wing.

[0014] Preferably, the auxiliary beam plate includes a chord plate and a longitudinal rib plate, the cross-section of the connection between the chord plate and the longitudinal rib plate is cross-shaped, the inner ends of the longitudinal rib plate are vertically connected to the two sides of the main beam plate, and each of the chord plates is arranged in a straight line. The adjustment gap is set between adjacent chord plates, and when the main beam plate swings up and down, the adjacent chord plates can collide with each other; the angle between the arrangement line of the chord plates and the wing chord is not greater than 5°; the adjustment gap is not greater than 1 / 500 of the wing chord length; the outer end of the longitudinal rib plate is provided with a connecting plate, and the connecting plate is used to stick the skin.

[0015] Preferably, the auxiliary beam plate is a quadrilateral frame, and an adjustment gap is provided between the side plates of two adjacent quadrilateral frames. The adjustment gap is V-shaped, and the adjustment gap is not greater than 1 / 500 of the wing chord length.

[0016] Preferably, the leading edge wing, the main beam plate and auxiliary beam plate of the passive variable stiffness structure, and the trailing edge wing are 3D printed one-piece manufactured parts.

[0017] Preferably, the leading edge wing is a D-shaped wing box, and the driving mechanism of the active camber adjustment component is arranged on a flat plate of the D-shaped wing box; the cross section of the trailing edge wing is an acute-angled triangle.

[0018] Compared with the prior art, the present invention has achieved the following technical effects:

[0019] During the deformation process of the wing, the passive variable stiffness structure of the present invention can swing up and down with the chord to form contact stiffness and thus change the stiffness of the wing. It can increase the local stiffness of the wing, thereby ensuring that the wing maintains sufficient load-bearing stiffness and can adjust the stiffness characteristics of the wing trailing edge when bending upward or downward. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0021] Figure 1 Schematic diagram of the structure of the variable stiffness flexible wing in Example 1 of the present invention;

[0022] Figure 2 Schematic diagram of the cross-sectional structure of the variable stiffness flexible wing in Example 1 of the present invention;

[0023] Figure 3 Schematic diagram of a variable stiffness flexible wing structure using auxiliary beams and plates of a quadrilateral frame in the second embodiment of the present invention Figure 1 ;

[0024] Figure 4 Schematic diagram of the cross-sectional structure of a variable stiffness flexible wing using an auxiliary beam plate of a quadrilateral frame in the second embodiment of the present invention Figure 2 ;

[0025] In the figure: 1-leading edge wing, 2-trailing edge wing, 3-skin, 4-main beam plate, 5-auxiliary beam plate, 6-chord plate, 7-longitudinal rib plate, 8-adjusting gap, 9-traction rope, 10-motor, 11-quadrilateral frame. DETAILED DESCRIPTION

[0026] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0027] It should be noted that, in the description of the present invention, the terms "upper", "lower", "left", "right", "inside", "outside", "front", "back", "clockwise", "counterclockwise" and the like indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings. This is merely for the convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third" and "fourth" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, the features defined as "first", "second", "third" and "fourth" may explicitly or implicitly include one or more of the features. In the description of the present invention, "multiple" means two or more, unless otherwise clearly and specifically defined.

[0028] Furthermore, it should be noted that, in the description of the present invention, unless otherwise expressly specified or limited, the terms "disposed," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0029] The purpose of the present invention is to provide a variable stiffness flexible wing to solve the problems existing in the prior art, so that the wing has sufficient stiffness while realizing flexible drive and passive drive.

[0030] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0031] Example 1

[0032] like Figures 1 to 2 As shown, this embodiment provides a variable-stiffness flexible wing comprising a sequentially connected leading edge wing 1, a passive variable stiffness structure, and a trailing edge wing 2. The passive variable stiffness structure and the trailing edge wing 2 are externally connected via a skin 3. The passive variable stiffness structure can swing up and down with the chord to create contact stiffness, thereby varying the wing's stiffness. In this embodiment, the passive variable stiffness structure can deform under control loads (motor 10 or servo drive traction rope 9) or aerodynamic loads (aerodynamic forces on the wing surface during flight), causing gaps in the structure to close and contact, thereby varying the wing's stiffness.

[0033] As an optional solution, the passive variable stiffness structure in this embodiment includes a swing assembly, a main beam plate 4 and an auxiliary beam plate 5. One end of the main beam plate 4 is fixedly connected to the leading edge wing 1, and the other end is fixedly connected to the trailing edge wing 2. Several groups of auxiliary beam plates 5 are symmetrically arranged on both sides of the main beam plate 4, and an adjustment gap 8 is arranged along the chord direction between adjacent auxiliary beam plates 5.

[0034] As an optional solution, this embodiment incorporates an active camber adjustment assembly on the passive variable stiffness structure. This assembly is connected to the auxiliary beams 5 and the trailing wing 2 and is capable of causing the main beam 4 to swing up and down. This assembly comprises two traction ropes 9 symmetrically positioned on either side of the main beam 4, each connected at one end to the trailing wing 2 and at the other end to the drive mechanism, which is located within the leading wing 1. In this embodiment, the traction ropes 9 extend through the longitudinal ribs 7 of each auxiliary beam 5, ultimately connecting to the trailing wing 2.

[0035] As an optional solution, the widths of the adjustment gaps 8 on both sides of the main beam plate 4 in this embodiment can be the same or different. Specifically, the widths of the adjustment gaps 8 on the upper and lower sides of the wing can be set to different widths to allow independent design for both upward and downward wing deflection to meet design objectives and usage requirements.

[0036] As an optional solution, the driving mechanism in this embodiment is a motor 10 or a servo, and two traction ropes 9 are wound around the rotating shaft of the motor 10 or the servo, and the winding directions of the two traction ropes 9 are opposite, and the ends of the traction ropes 9 are fixed to the rotating shaft. This embodiment can achieve passive variable stiffness and no longer relies on additional driving devices, which greatly simplifies the driving system of the variable stiffness wing, and also avoids the energy consumption and weight burden caused by the complexity of the driving device. In this embodiment, the driving mechanism drives the deformation of the main beam to achieve the change of the wing curvature, realizing the replacement of the traditional rudder surface structure; wherein, after receiving the control signal, the motor 10 or the servo can quickly rotate forward or reverse to close the adjustment gap 8, and finally the torsional force of the motor 10 or the servo is balanced with the tension of the traction rope 9, thereby locking the deformation of the wing.

[0037] As an optional solution, in this embodiment, the drive mechanism is a translation mechanism. The ends of two traction ropes 9 are respectively fixedly connected to a translation mechanism, which can be a pneumatic cylinder, hydraulic cylinder, electric push rod, or screw-slider mechanism. The traction ropes 9 are made of steel wire rope. A set of traction ropes 9 is arranged at the position of the symmetry line of the wing section.

[0038] As an optional solution, in this embodiment, the material of the main beam plate 4 includes nylon, acrylonitrile-styrene-butadiene copolymer (ABS resin) or thermoplastic polyurethane, and the thickness of the main beam plate 4 is not greater than 1 / 100 of the wing chord length.

[0039] As an optional solution, in this embodiment, the auxiliary beam 5 includes chord-wise plates 6 and longitudinal ribs 7. The cross-section of the connection between the chord-wise plates 6 and the longitudinal ribs 7 is cross-shaped. The inner ends of the longitudinal ribs 7 are perpendicularly connected to the two sides of the main beam 4. The chord-wise plates 6 are arranged in a straight line, and an adjustable gap 8 is provided between adjacent chord-wise plates 6. When the main beam 4 swings up and down, adjacent chord-wise plates 6 can contact each other. In this embodiment, the wing can passively adjust the stiffness distribution of different regions under the action of aerodynamic loads. After the wing deforms to the point where the chord-wise plates 6 contact each other, the chord-wise plates 6 provide a portion of the wing's stiffness. At this point, the stiffness is jointly contributed by the chord-wise plates 6 and the main beam 4, resulting in increased stiffness and maintaining the wing's load-bearing stiffness. Within the wing's deformation and maneuvering range, the chord-wise plates 6 do not contact or partially contact each other, resulting in lower stiffness than when the chord-wise plates 6 are fully in contact, thus avoiding excessive driving force requirements.

[0040] As an optional solution, in this embodiment, the angle between the alignment line of the chord-wise plates 6 and the wing chord is no greater than 5°, and the distance between the alignment line and the wing chord is greater than half the cross-sectional length of the longitudinal ribs 7. This greater distance between the alignment line of the chord-wise plates 6 and the wing chord provides greater wing stiffness. The linear arrangement of the chord-wise plates 6 facilitates practical processing and manufacturing of the structure, as well as theoretical calculations of structural deformation. The adjustment gap 8 is no greater than 1 / 500 of the wing chord length. In this embodiment, when the adjustment gap 8 is not in contact with the passive variable stiffness structure, the stiffness is contributed solely by the main beam 4. Due to the small thickness of the main beam 4, the wing stiffness is low. When the adjustment gap 8 is in contact, the stiffness is contributed by both the chord-wise plates 6 and the main beam 4. Since the distance between the chord-wise plates 6 and the main beam 4 is greater than three times the thickness of the main beam 4, the wing stiffness can be increased to more than 27 times the original wing stiffness. The outer ends of the longitudinal ribs 7 are provided with connecting plates for attachment to the skin 3, ensuring a secure connection of the skin 3. In this embodiment, the frontmost auxiliary beam plate 5 only has a chord-wise plate 6 connected to the flat plate of the leading edge wing 1, and the rearmost auxiliary beam plate 5 is arranged in a C shape opening toward the leading edge wing 1 to facilitate connection with the middle auxiliary beam plate 5.

[0041] As an optional solution, the leading edge wing 1, the main beam plate 4 and auxiliary beam plate 5 of the passive variable stiffness structure, and the trailing edge wing 2 in this embodiment are 3D-printed, one-piece manufactured parts. In this embodiment, the leading edge wing 1, the main beam plate 4 and auxiliary beam plate 5 of the passive variable stiffness structure, and the trailing edge wing 2 can also be assembled structures, which can be connected by bonding, clamping, screwing, or welding.

[0042] As an optional solution, in this embodiment, the leading edge wing 1 is a D-shaped wing box, and the drive motor 10 or the servo of the variable stiffness mechanism is arranged on the flat plate of the D-shaped wing box; the cross-section of the trailing edge wing 2 is an acute triangle, which is convenient for pasting the skin 3.

[0043] Among them, Figure 1 This is the structural state when the wing is not driven, with all adjustment gaps 8 open. This is the state of lowest wing stiffness. Each adjustment gap 8 will adaptively adjust to the airflow pressure on the wing surface during flight, achieving adaptive adjustment of the wing stiffness. When the motor 10 or servo rotates clockwise, the wing trailing edge deflects downward due to the tension of the tow rope 9. As the deflection angle of the motor 10 or servo increases, the adjustment gaps 8 close sequentially from left to right, and the chord-wise plates 6 come into contact sequentially from left to right. This structural contact increases the wing's chord-wise bending stiffness to maintain the wing's load-bearing stiffness. Furthermore, the width of the adjustment gaps 8 on the upper and lower sides of the main beam plate 4 can be designed according to actual needs, enabling independent stiffness adjustment when the wing trailing edge bends upward or downward.

[0044] The variable stiffness flexible wing in this embodiment effectively reduces the aeroelastic instability problem that may occur during the deformation process of the deformable wing, and can effectively avoid the vibration problem caused by wing surface flutter and aeroelastic coupling, thereby improving the aerodynamic performance and flight stability of the wing; it solves the contradiction between the load-bearing stiffness and driving flexibility in the existing variable curvature flexible wing structure, and balances the structural stiffness and flexibility requirements while meeting the aerodynamic performance requirements of the wing.

[0045] Example 2

[0046] like Figures 3 and 4 As shown, different from the first embodiment, the auxiliary beam plate 5 in this embodiment is a quadrilateral frame 11. Specifically, the two side plates of the quadrilateral frame 11 are respectively connected to the main beam plate 4 and enclose a quadrilateral. A longitudinal rib 7 is connected to a side plate of the quadrilateral frame 11 opposite to the main beam plate 4. A connecting plate is provided at the outer end of the longitudinal rib 7. The connecting plate is used to stick the skin 3 to facilitate the firm connection of the skin 3. An adjustment gap 8 is provided between the side plates of two adjacent quadrilateral frames 11. The adjustment gap 8 is V-shaped, which becomes larger from the middle to the outside, and the adjustment gap 8 is not greater than 1 / 500 of the chord length of the wing. The wing stiffness is increased by the contact between the side plates of adjacent quadrilateral frames 11 in the structure.

[0047] Example 3

[0048] The variable stiffness flexible wing in this embodiment generally has two operating modes, as follows:

[0049] Working mode 1: During the aircraft's taxiing and takeoff, the motor 10 or the servo drives the traction rope 9 to change the curvature of the wing, and the trailing edge of the wing deflects downward, which increases the aerodynamic load on the wing, resulting in an increase in the wing lift. The aircraft leaves the ground due to the increase in lift; at this time, due to the deformation of the wing, the adjustment gap 8 inside the auxiliary beam plate 5 comes into contact, which increases the overall stiffness of the wing. Even when the aerodynamic load on the wing increases, the wing will not undergo significant non-command deformation, thereby ensuring the stability of the wing structure during flight, preventing the wing from diverging or fluttering, and ensuring the safety of the flight process.

[0050] Working mode 2: When the aircraft maintains a constant speed cruise state in the air, there is no need for the motor 10 or the servo to drive the traction rope 9. When the wing has a certain angle of attack, the wing will bend upward after being subjected to the upward aerodynamic load, causing the adjustment gap 8 inside the auxiliary beam plate 5 to contact, thereby increasing the wing stiffness. However, since the wing deformation is small, the aircraft can still maintain a constant speed cruise state.

[0051] In this embodiment, the swing amount of the wing is determined in real time by the aircraft's flight control system according to the current flight state, or is adaptively deformed under the action of aerodynamic loads on the wing surface.

[0052] This embodiment enables the wing to passively adjust its stiffness distribution during deformation, thereby maintaining the load-bearing stiffness while reducing the energy consumption of the drive system, avoiding aerodynamic shape instability caused by excessive deformation, and effectively improving the aerodynamic performance and flight stability of the wing; no additional drive device is required, and the stiffness is adjusted through the geometric structure of the wing itself, which simplifies the drive system, reduces energy consumption, and reduces the weight of the aircraft and the complexity of the system; by adjusting the width of the adjustment gap 8, a customized design can be made for different flight conditions and actual needs, thereby realizing independent adjustment of the stiffness characteristics of the wing trailing edge when bending upward or downward, and can be extended to various types of aircraft.

[0053] Throughout this specification, references to terms such as "one embodiment," "certain embodiments," "illustrative embodiments," "this embodiment," "specific examples," or "some examples" indicate that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, illustrative uses of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0054] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only intended to help understand the method and core concept of the present invention. At the same time, those skilled in the art will find that the specific implementation methods and application scopes may vary based on the concept of the present invention. In summary, the contents of this specification should not be construed as limiting the present invention.

Claims

1. A variable stiffness flexible wing, characterized by: The invention comprises a leading edge wing, a passive variable stiffness structure, and a trailing edge wing connected in sequence, wherein the passive variable stiffness structure and the outer portion of the trailing edge wing are connected via a skin, and the passive variable stiffness structure can swing up and down with the chord to form contact stiffness and thereby change the stiffness of the wing; The passive variable stiffness structure includes a main beam plate and an auxiliary beam plate, one end of the main beam plate is fixedly connected to the leading edge wing, and the other end is fixedly connected to the trailing edge wing, and several groups of auxiliary beam plates are symmetrically arranged on both sides of the main beam plate, and adjustment gaps are arranged between adjacent auxiliary beam plates along the chord direction; an active camber adjustment component is provided on the passive variable stiffness structure, and the active camber adjustment component is connected to the auxiliary beam plate and the trailing edge wing and can make the main beam plate swing up and down, and the active camber adjustment component includes a traction rope and a driving mechanism, two traction ropes are symmetrically arranged on both sides of the main beam plate, one end of each traction rope is connected to the trailing edge wing, and the other end is connected to the driving mechanism, and the driving mechanism is arranged in the leading edge wing; the widths of the adjustment gaps on both sides of the main beam plate are different.

2. The variable stiffness flexible wing according to claim 1, characterized in that: The driving mechanism is a motor or a steering gear, and two traction ropes are wound around the rotating shaft of the motor or the steering gear, and the winding directions of the two traction ropes are opposite, and the ends of the traction ropes are fixed on the rotating shaft.

3. The variable stiffness flexible wing according to claim 1, characterized in that: The driving mechanism is a translation mechanism, the ends of the two traction ropes are respectively fixedly connected to one of the translation mechanisms, and the translation mechanism is a cylinder, a hydraulic cylinder, an electric push rod or a screw slider mechanism; the material of the traction rope includes steel wire rope, nylon rope or carbon fiber.

4. The variable stiffness flexible wing according to claim 1, characterized in that: The material of the main beam plate includes nylon, acrylonitrile-styrene-butadiene copolymer or thermoplastic polyurethane, and the thickness of the main beam plate is not greater than 1 / 100 of the chord length of the wing.

5. The variable stiffness flexible wing according to claim 1, characterized in that: The auxiliary beam plate includes a chord plate and a longitudinal rib plate. The cross-section of the connection between the chord plate and the longitudinal rib plate is cross-shaped. The inner ends of the longitudinal rib plates are perpendicularly connected to the two sides of the main beam plate. The chord plates are arranged in a straight line. The adjustment gap is set between adjacent chord plates. When the main beam plate swings up and down, the adjacent chord plates can contact each other. The angle between the arrangement line of the chord-wise plates and the chord is no more than 5°; the adjustment gap is no more than 1 / 500 of the wing chord length; a connecting plate is provided at the outer end of the longitudinal rib, and the connecting plate is used to stick the skin.

6. The variable stiffness flexible wing according to claim 1, characterized in that: The auxiliary beam plate is a quadrilateral frame, and an adjustment gap is set between the side plates of two adjacent quadrilateral frames. The adjustment gap is V-shaped and is no more than 1 / 500 of the wing chord length.

7. The variable stiffness flexible wing according to claim 1, characterized in that: The leading edge wing, the main beam plate and auxiliary beam plate of the passive variable stiffness structure, and the trailing edge wing are 3D printed integrally formed parts.

8. The variable stiffness flexible wing according to claim 1, characterized in that: The leading edge wing is a D-shaped wing box, and the driving mechanism of the active camber adjustment component is arranged on a flat plate of the D-shaped wing box; the cross section of the trailing edge wing is an acute-angled triangle.

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