Hybrid honeycomb flexible skin of variable sweepback wing

Abstract

The invention discloses a hybrid honeycomb flexible skin of a variable sweepback wing, which belongs to the field of flexible structure design of a morphing aircraft, and comprises a frame, a deformable support structure and a flexible surface layer, the frame is divided into a parallelogram area and a trapezoidal area, and the corresponding deformable supporting structures are also divided into two types; the first rod, the second rod, the third rod and the fourth rod are rods with the same length, and the fifth rod is a nested structure rod with the variable length. The four rods are flexible skin front edges, and the five rods are flexible skin rear edges; the AC section of the first rod is as long as the BD section of the second rod; the AC section of the first rod, the BD section of the second rod, the fourth rod and the third rod form the edge of a parallelogram area; the CE section of the first rod, the DF section of the second rod, the third rod and the fifth rod form the edge of the trapezoidal area. According to the method, the flexible skin is divided into areas, different deformable supporting structures are used for filling according to the deformation characteristics of all the areas, and the bidirectional corrugated honeycombs meet the requirement for edge length change in the sweepback changing process.

Description

Technical Field

[0001] The invention belongs to the field of flexible structure design of variant aircraft, and in particular relates to a hybrid honeycomb flexible skin structure of a variable swept wing. Background Art

[0002] Variable swept wings enable the aircraft to meet the aerodynamic requirements of both high-speed and low-speed flight. In the process of changing the sweep angle of the wing, the skin surface undergoes shear deformation and also bears out-of-plane loads. Traditional skin forms are difficult to take into account the above characteristics. In order to meet the deformation and aerodynamic requirements of the wing and to ensure the smoothness of the outer surface of the wing skin, the variable swept wing must adopt a flexible skin structure.

[0003] The leading edge and rib lengths of the variable-sweep wing remain unchanged. When the sweep angle is changed, in order to keep the ribs in the direction of the airflow, the length of the trailing edge of the wing will change. Therefore, it is necessary to fill the flexible skin with a honeycomb structure that can adapt to the changing characteristics of the boundary. Summary of the invention

[0004] In view of the problems existing in the above-mentioned prior art, the present invention proposes a hybrid honeycomb flexible skin for a variable swept wing, which has the characteristics of being shear-deformable and capable of bearing out-of-plane loads, and is suitable for a variable swept wing.

[0005] The present invention is achieved in that: A hybrid honeycomb flexible skin of a variable swept wing comprises: a frame, a deformable support structure, and a flexible surface layer; the frame is divided into a parallelogram area and a trapezoidal area, and the corresponding deformable support structure is also divided into two types; the one rod, two rods, three rods, and four rods are rods of constant length, and the five rods are nested structure rods of variable length; the four rods are the leading edge of the flexible skin, and the five rods are the trailing edge of the flexible skin; the one rod, two rods, four rods, and five rods constitute a quadrilateral frame ABFE, and the two ends of the three rods are respectively connected to the C point on the rod and the D point on the two rods, so as to divide the frame into a parallelogram area ABDC and a trapezoidal area CDFE; the AC segment of the one rod is the same as the BD segment of the two rods; the AC segment of the one rod, the BD segment of the two rods, the four rods, and the three rods constitute the edge of the parallelogram area; the CE segment of the one rod, the DF segment of the two rods, the three rods, and the five rods constitute the edge of the trapezoidal area.

[0006] Furthermore, the parallelogram area is filled with quadrilateral honeycombs, and the chord-wise and span-wise lengths of the trapezoidal area are changed, so the trapezoidal area is filled with bidirectional corrugated honeycombs; when the wing sweep angle changes, in the parallelogram area of ​​the flexible skin structure, the lengths of the four sides remain unchanged, only the angle changes, and the honeycomb structure filled inside produces shear deformation; in the trapezoidal area, the lengths of the CE segment of the one-rod and the BD segment of the three-rod remain unchanged, and due to the change in angle, the length of the nested five-rod changes, the bidirectional corrugated honeycomb structure produces shear deformation, and the length of the wall panel also changes.

[0007] Furthermore, the one rod, the two rods and the four rods are hollow rods; the one rod and the two rods have different lengths, are arranged in the chord length direction and always remain parallel during the deformation process; ears with connecting holes are welded on both ends of the four rods, which are hinged to the upper ends of the one rod and the two rods, so that the angle between the four rods and the one rod and the two rods can be changed, which is used to change the leading edge sweep angle; the one rod is divided into an AC section and a CE section, and the two rods are divided into a BD section and a DF section, and the AC section of the one rod is the same length as the BD section of the two rods; the three rods are solid rods, the length of which is the same as that of the four rods, and the two ends are respectively hinged to the C point of the one rod and the D point of the two rods; the three rods divide the variable sweep wing flexible skin structure into a parallelogram area and a trapezoidal area.

[0008] Furthermore, since the first rod and the second rod need to remain parallel during the deformation process, the length of the fifth rod can be changed to form the edge of the trapezoidal area; the five rods are formed by nesting three hollow rods; when the sweep angle changes, the angles between the fourth rod, the third rod, the fifth rod and the first rod and the second rod change, and at the same time, in order to keep the first rod and the second rod parallel, the length of the fifth rod changes.

[0009] Furthermore, the three rods divide the variable swept wing flexible skin structure into a parallelogram region and a trapezoidal region; in the parallelogram region, the AC segment of the first rod and the BD segment of the second rod remain parallel, the fourth rod and the third rod remain parallel, the length of each boundary remains unchanged, and only the angle changes; according to the structural characteristics, a quadrilateral honeycomb is selected to be bonded to the inner side of the AC segment of the first rod, the inner side of the BD segment of the second rod, the inner side of the fourth rod and the upper side of the third rod, and when the wing changes the sweep angle, the honeycomb structure in the parallelogram region produces shear deformation; in the trapezoidal region, the length of the three rods remains unchanged, and in order to keep the CE segment of the first rod and the DF segment of the second rod parallel, the trailing edge length needs to be variable.

[0010] Furthermore, the five rods adopt a nested structure, and a bidirectional corrugated honeycomb is selected in the trapezoidal area to be bonded to the inner side of the CE section of the first rod, the inner side of the DF section of the second rod, the inner side of the fifth rod and the lower side of the third rod.

[0011] Furthermore, the five rods are composed of three rectangular hollow rods nested together, including one hollow thin rod and two hollow thick rods, with one thick rod nested at each end of the hollow thin rod. Joints are provided at both ends of the five rods, which are hinged to the lower ends of the first rod and the second rod. A limit baffle is provided on the inner wall of the thick rod to prevent excessive local length deformation of the five rods, which may cause the filling structure of the trapezoidal area to tear, and at the same time, the maximum deformation of the nested part is half of the maximum deformation of the five rods. The angles between the five rods and the first rod and the second rod, as well as the angles between the five rods and the third rod in the trapezoidal area are variable. When the sweep angle increases, the bidirectional corrugated honeycomb at the junction of the nested structure bends, and when the sweep angle decreases, the bidirectional corrugated honeycomb at the junction of the nested structure stretches.

[0012] Furthermore, the wall panels of the bidirectional corrugated honeycomb are corrugated and can be stretched and deformed in both the chordal and span directions. The chordal and spanwise wavelengths and wave heights are different. The change in chordal length is provided by the chordal wall panels, and the change in spanwise length is provided by the spanwise wall panels. There is a half-wave-shaped spanwise wall panel between two adjacent chordal wall panels, and the wave crests and troughs are arranged alternately to form a bidirectional corrugated honeycomb structure filling a trapezoidal area. The spanwise wall panels at the left and right boundaries are bonded to the CE segment of the first rod and the DF segment of the second rod, and the chordal wall panels at the upper and lower boundaries are bonded to the third rod and the fifth rod. At the junction of the nested structure of the five rods, the bidirectional corrugated honeycomb is connected to the five rods. In order to prevent the bidirectional corrugated honeycomb structure from being torn due to the change in the boundary length when deformed, the chordal wall panels within the length variation range of the nested structure at the junction are not bonded to the five rods.

[0013] Furthermore, when the sweep angle changes, the first rod and the second rod are in the chord length direction and remain parallel, the angle between the fourth rod and the first rod and the second rod changes, and the fourth rod and the third rod remain parallel; to meet the deformation of the structure, the length of the fifth rod changes through the nested structure, and the angle between the fifth rod and the first rod and the second rod also changes; the quadrilateral honeycomb filled in the parallelogram area produces shear deformation; in the trapezoidal area, the length of the fifth rod and the angle between the third rod and the fifth rod change, and the honeycomb filled inside changes in the chord direction and the span direction with the change of the angle, and the chord-wise wallboard at the nested junction is not bonded to the five rods, which avoids the tearing of the bidirectional corrugated honeycomb due to the change of the boundary length during deformation; When the sweep angle changes, the two areas of the flexible skin structure produce different deformations. A deformable support structure that meets the structural deformation characteristics is selected for filling, providing in-plane deformation and out-of-plane load-bearing capacity. Foam rubber is filled in the maximum sweep angle state, and a flexible film is covered on the skin surface to meet the surface smoothness requirements.

[0014] The beneficial effects of the present invention compared with the prior art are: 1. The present invention divides the flexible skin into regions and fills them with different deformable support structures according to the deformation characteristics of each region. The bidirectional corrugated honeycomb meets the requirement of edge length change during variable sweep.

[0015] 2. The hybrid honeycomb flexible skin of the variable swept wing of the present invention can be filled with suitable honeycombs according to the structural deformation characteristics of the divided areas, and has strong designability. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the structure of the hybrid honeycomb flexible skin of the variable sweep wing of the present invention.

[0017] Figure 2 A schematic diagram of the five-rod structure.

[0018] Figure 3Schematic diagram of a bidirectional corrugated honeycomb.

[0019] Figure 4 It is a schematic diagram of the connection method of the junction between the bidirectional corrugated honeycomb and the trailing edge nesting.

[0020] Among them, 1-one rod, 2-two rods, 3-three rods, 4-four rods, 5-five rods, 6-parallelogram area, 7-trapezoidal area, 8-chordal wall panel, 9-spanwise wall panel, 10-range of variation of nested structure length, 11-joint, 12-hollow thick rod, 13-hollow thin rod, 14-limit baffle. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solution and effect of the present invention clearer and more specific, the present invention is further described in detail by enumerating examples below. It should be noted that the specific implementation described here is only used to explain the present invention and is not used to limit the present invention.

[0022] During the deformation process of the variable-sweep wing, the leading edge and rib lengths remain unchanged, and when the leading edge sweep angle changes, the trailing edge length can change. Based on this deformation characteristic, the flexible skin structure between the two ribs can be divided into: (1) an area where the edge length remains unchanged and only the angle changes; (2) an area where both the angle and edge length change. In order to avoid tearing of the filling structure due to the change in edge length, in area (2), a deformable support structure that can adapt to the change in the edge of the area needs to be selected.

[0023] The hybrid honeycomb flexible skin of the variable sweep wing of the present invention is composed of a frame, a deformable support structure, and a flexible surface layer. The frame is divided into a parallelogram area 6 and a trapezoidal area 7, and the corresponding deformable support structure is also divided into two types, such as Figure 1As shown. One rod 1, two rods 2, three rods 3 and four rods 4 are rods of constant length, five rods 5 are nested structural rods of variable length, four rods 4 are the leading edge of the flexible skin, and five rods 5 are the trailing edge of the flexible skin. The AC segment of one rod 1 is the same length as the BD segment of two rods 2. The AC segment of one rod 1, the BD segment of two rods 2, four rods 4 and three rods 3 form the edge of the parallelogram area 6; the CE segment of one rod 1, the DF segment of two rods 2, three rods 3 and five rods 5 form the edge of the trapezoidal area 7. Quadrilateral honeycombs are filled in the parallelogram area 6, and the chord and span lengths of the trapezoidal area 7 are changed, so bidirectional corrugated honeycombs are filled in the trapezoidal area 7. When the wing sweep angle changes, in the parallelogram area 6 of the flexible skin structure, the lengths of the four sides remain unchanged, only the angle changes, and the honeycomb structure filled inside produces shear deformation. In the trapezoidal area 7, the lengths of the CE section of the one-rod 1 and the BD section of the three-rod 3 remain unchanged. Due to the change in angle, the length of the nested telescopic five-rod 5 changes, the bidirectional corrugated honeycomb structure undergoes shear deformation, and the length of the wall panel also changes. At the nested junction of the five-rod 5, in order to avoid honeycomb tearing, the honeycomb wall panel with the connection point within the length change range of the junction is not bonded to the five-rod 5. like Figure 1 As shown, the frame of the hybrid honeycomb flexible skin of the variable sweep wing is divided into a parallelogram area 6 and a trapezoidal area 7. One rod 1, two rods 2, four rods 4, and five rods 5 form a quadrilateral frame ABFE, and the two ends of the three rods 3 are respectively connected to the point C on the rod 1 and the point D on the two rods 2, dividing the frame into a parallelogram area 6ABDC and a trapezoidal area 7CDFE.

[0024] One rod 1, two rods 2 and four rods 4 are hollow rods. One rod 1 and two rods 2 have different lengths, are arranged in the chord length direction and remain parallel during the deformation process. Ears with connection holes are welded on both ends of the four rods 4, which are hinged to the upper ends of one rod 1 and two rods 2, so that the angle between the four rods 4 and one rod 1 and two rods 2 can be changed, which is used to change the leading edge sweep angle. One rod 1 is divided into AC segment and CE segment, and two rods 2 are divided into BD segment and DF segment. The AC segment of one rod 1 is the same length as the BD segment of two rods 2. Three rods 3 are solid rods with the same length as four rods 4, and their two ends are hinged to the C point of one rod 1 and the D point of two rods 2 respectively. Three rods 3 divide the variable sweep wing flexible skin structure into a parallelogram area 6 and a trapezoidal area 7. Since one rod 1 and two rods 2 need to remain parallel during the deformation process, the five rods 5 are variable in length to form the edge of the trapezoidal area 7. The five-rod 5 is formed by nesting three hollow rods, and joints 11 are arranged at both ends of the five-rod 5, which are hinged with the lower ends of the first rod 1 and the second rod 2. When the sweep angle changes, the angles between the four-rod 4, the three-rod 3, the five-rod 5 and the first rod 1 and the second rod 2 change, and at the same time, in order to keep the first rod 1 and the second rod 2 parallel, the length of the five-rod 5 changes.

[0025] The three rods 3 divide the variable swept wing flexible skin structure into a parallelogram area 6 and a trapezoidal area 7. In the parallelogram area 6, the AC segment of the first rod 1 and the BD segment of the second rod 2 remain parallel, the four rods 4 and the three rods 3 remain parallel, the length of each boundary remains unchanged, and only the angle changes. According to the structural characteristics, a quadrilateral honeycomb is selected to be bonded to the inner side of the AC segment of the first rod 1, the inner side of the BD segment of the second rod 2, the inner side of the four rods 4 and the upper side of the three rods 3. When the wing changes the sweep angle, the honeycomb structure in the parallelogram area 6 produces shear deformation. In the trapezoidal area 7, the length of the three rods 3 remains unchanged. At the same time, in order to keep the CE segment of the first rod 1 and the DF segment of the second rod 2 parallel, the trailing edge length needs to be variable. In order to meet the structural requirements, the five rods 5 adopt a nested structure, and the trapezoidal area 7 uses a bidirectional corrugated honeycomb to be bonded to the inner side of the CE segment of the first rod 1, the inner side of the DF segment of the second rod 2, the inner side of the five rods 5 and the lower side of the three rods 3. The change of the chord length is provided by the bending of the chord wall panel 8, and the change of the span length is provided by the span wall panel 9. The frame and the honeycomb structure deform together to realize the deformation of the flexible skin of the variable sweep wing.

[0026] like Figure 2 As shown, the five-rod 5 is composed of three rectangular hollow rods nested together. A thick rod is nested at each end of a thin rod, and joints 11 are provided at both ends of the rods, which are hinged to the lower ends of the first rod 1 and the second rod 2. A limit baffle 14 is provided on the inner wall of the thick rod to prevent the local length deformation of the five-rod 5 from being too large, which may cause the filling structure of the trapezoidal area 7 to tear, and at the same time, the maximum deformation of the nested part is half of the maximum deformation of the five-rod 5. The angle between the five-rod 5 and the first rod 1 and the second rod 2, as well as the angle between the five-rod 5 and the third rod 3 in the trapezoidal area 7, are variable. When the sweep angle increases, the bidirectional corrugated honeycomb at the junction of the nested structure bends, and when the sweep angle decreases, the bidirectional corrugated honeycomb at the junction of the nested structure stretches.

[0027] like Figure 3 As shown, the wall panels of the bidirectional corrugated honeycomb are corrugated and can be stretched and deformed in both the chord and span directions. The length and height of the wave in the chord and span directions are different. The change in the chord length is provided by the chord wall panel 8, and the change in the span length is provided by the span wall panel 9. There is a half-wave-shaped span wall panel 9 between two adjacent chord wall panels 8, and the wave crests and troughs are arranged alternately to form a bidirectional corrugated honeycomb structure filling the trapezoidal area 7. The span wall panels 9 at the left and right boundaries are bonded to the CE section of the first rod 1 and the DF section of the second rod 2, and the chord wall panels 8 at the upper and lower boundaries are bonded to the third rod 3 and the fifth rod 5. At the intersection of the nested structure of the five rods 5, the bidirectional corrugated honeycomb is connected to the five rods 5 as shown in the figure. Figure 4 As shown, in order to prevent the bidirectional corrugated honeycomb structure from being torn due to the change in boundary length during deformation, the chordal wall panels 8 and the five-bars 5 within the length variation range 10 of the nested structure at the junction are not bonded.

[0028] When the sweep angle changes, the first rod 1 and the second rod 2 are in the chord length direction and remain parallel, the angle between the fourth rod 4 and the first rod 1 and the second rod 2 changes, and the fourth rod 4 and the third rod 3 remain parallel. To meet the deformation of the structure, the fifth rod 5 changes in length through the nested structure, and the angle between the fifth rod 5 and the first rod 1 and the second rod 2 also changes. The quadrilateral honeycomb filled in the parallelogram area 6 produces shear deformation.

[0029] In the trapezoidal area 7, the length of the five-rod 5 and the angle between the three-rod 3 and the five-rod 5 change. The honeycomb filled inside changes in the chord direction and span direction as the angle changes. The chord-direction wallboard 8 at the nested junction is not bonded to the five-rod 5, which prevents the bidirectional corrugated honeycomb from tearing due to the change in boundary length during deformation. When the sweep angle changes, the two areas of the flexible skin structure produce different deformations. A deformable support structure that meets the structural deformation characteristics is selected for filling, providing in-plane deformation and out-of-plane bearing capacity. Foam rubber is filled in the state of maximum sweep angle, and a flexible adhesive film is covered on the skin surface to meet the surface smoothness requirements.

[0030] The specific implementation modes of the present invention are further described in detail below through specific data.

[0031] Assume that the length of the flexible skin rod 1 is L1=500mm, the length of the AC segment is LAC=300mm, the length of the CE segment is 200mm, the length of the second rod 2 is L2=430mm, the length of the BD segment is LBD=300mm, the length of the DF segment is 130mm, the length of the third rod 3 is L3=700mm, and the length of the fourth rod 4 is L4=700mm. The flexible skin frame material is selected as hard aluminum material. The maximum sweep angle of the flexible skin leading edge is 40° and the minimum is 3°. In the initial state, the sweep angle of the flexible skin leading edge is 3°, and the length of the flexible skin trailing edge is 700mm; when the sweep angle of the flexible skin leading edge changes to 40°, the length of the flexible skin trailing edge is 657mm.

[0032] One rod 1, two rods 2 and four rods 4 are hollow rods with a square cross section of 10mm×10mm and a wall thickness of 1mm. Three rods 3 are solid rods with a width of 4mm and a height of 10mm. Five rods 5 are composed of three nested square hollow rods, two of which are thick rods with a length of 250mm and a square cross section of 12mm×12mm, and the other is a thin rod with a length of 250mm and a square cross section of 10mm×10mm, and the wall thickness is 1mm. A limit baffle 14 is set inside the hollow thick rod 12. When the length of the five rods 5 is 700mm, the exposed length of the thin rod is 200mm; when the length of the five rods 5 is 657mm, the exposed length of the thin rod is 157mm, and the maximum length change at both ends of the thin rod is 21.5mm.

[0033] The material of the deformable support structure is 7 series aluminum alloy. The parallelogram area 6 is filled with a quadrilateral honeycomb. The quadrilateral honeycomb unit cell is 5mm long, 5mm wide, 0.05mm thick and 10mm high. The wall panels at the edge of the honeycomb are glued to the edge of the parallelogram area 6. The trapezoidal area 7 is filled with a bidirectional corrugated honeycomb, and the thickness of the honeycomb wall panel is 0.05mm. In the bidirectional corrugated honeycomb, the wavelength of the span-wise wall panel 9 is l1=10mm, the wave height is h1=4mm, the wavelength of the chord-wise wall panel 8 is l2=20mm, and the wave height is h2=2mm. The deformation stored in the corrugated wall panel can meet the length change requirements of the chord and span directions of the trapezoidal area 7. The chord-wise wall panel 8 is 199.5mm at the longest, and the length decreases from 0.5mm in sequence, and the shortest is 130.5mm. The chord-wise wall panel 8 and the span-wise wall panel 9 together constitute a bidirectional corrugated honeycomb structure.

[0034] The bars of the flexible skin frame are hinged, and the four-bar 4 sweep angle of 3° is used as the initial state to install the deformable support structure. The quadrilateral honeycomb is glued to the edge of the parallelogram area 6, and the quadrilateral honeycomb will produce corresponding shear deformation to adapt to the shape and size of the structure; the edges of the bidirectional corrugated honeycomb and the trapezoidal area 7 are glued, and during the bonding process, the span-wise wall panel 9 will bend or stretch according to the size, shape and size of the structure. In the nested part of the five-bar 5, there are 6 chord-wise wall panels 8 of bidirectional corrugated honeycombs at the left and right nesting junctions that are not bonded to the five-bar 5. The flexible skin is deformed to a four-bar 4 sweep angle of 40°. At this time, foam rubber is filled in the flexible skin and a layer of flexible film is covered on the outer surface of the skin, so that the foam rubber and the film are only tensile during the deformation process, which can keep the outer surface of the flexible skin smooth during the deformation process, and then this hybrid honeycomb flexible skin is covered on the corresponding position of the variable swept wing structure.

[0035] The above description is only a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several improvements without departing from the principle of the present invention, and these improvements should also be regarded as within the protection scope of the present invention.

Claims

1. A hybrid honeycomb flexible skin of a variable sweep wing, characterized in that: The hybrid honeycomb flexible skin comprises: a frame, a deformable support structure, and a flexible surface layer; The frame is divided into a parallelogram region (6) and a trapezoidal region (7), and the corresponding deformable support structures are also divided into two types; The one rod (1), two rods (2), three rods (3), and four rods (4) are rods of constant length, and the five rods (5) are nested structural rods of variable length; the four rods (4) are the leading edge of the flexible skin, and the five rods (5) are the trailing edge of the flexible skin; the one rod (1), two rods (2), four rods (4), and five rods (5) form a quadrilateral frame ABFE, and the two ends of the three rods (3) are respectively connected to point C on the rod (1) and point D on the two rods (2), so as to divide the frame into a parallelogram area (6) ABDC and a trapezoidal area (7) CDFE; the AC segment of the one rod (1) is the same as the BD segment of the two rods (2); the AC segment of the one rod (1), the BD segment of the two rods (2), the four rods (4), and the three rods (3) form the edge of the parallelogram area; the CE segment of the one rod (1), the DF segment of the two rods (2), the three rods (3), and the five rods (5) form the edge of the trapezoidal area.

2. The hybrid honeycomb flexible skin of a variable sweep wing according to claim 1, characterized in that: The parallelogram region (6) is filled with quadrilateral honeycombs, and the lengths of the trapezoidal region (7) in both the chord direction and the span direction are changed, so the trapezoidal region is filled with bidirectional corrugated honeycombs; when the wing sweep angle changes, the lengths of the four sides of the parallelogram region (6) of the flexible skin structure remain unchanged, only the angle changes, and the honeycomb structure filled inside undergoes shear deformation; in the trapezoidal region (7), the lengths of the CE section of the one rod (1) and the BD section of the three rods (3) remain unchanged, and due to the change in angle, the length of the nested five rods (5) changes, the bidirectional corrugated honeycomb structure undergoes shear deformation, and the length of the wall panel also changes.

3. The hybrid honeycomb flexible skin of a variable sweep wing according to claim 1, characterized in that: The one rod (1), the two rods (2) and the four rods (4) are hollow rods; the one rod (1) and the two rods (2) are of different lengths, arranged in the chord length direction and always remain parallel during the deformation process; ears with connection holes are welded on both ends of the four rods (4) and are hinged to the upper ends of the one rod (1) and the two rods (2), so that the angle between the four rods (4) and the one rod (1) and the two rods (2) can be changed, which is used to change the leading edge sweep angle; the one rod (1) is divided into an AC section and a CE section, and the two rods (2) are divided into a BD section and a DF section, and the AC section of the one rod (1) is the same length as the BD section of the two rods (2); the three rods (3) are solid rods, the length of which is the same as that of the four rods (4), and the two ends of which are respectively hinged to the C point of the one rod (1) and the D point of the two rods (2); the three rods (3) divide the variable sweep wing flexible skin structure into a parallelogram area and a trapezoidal area.

4. The hybrid honeycomb flexible skin of a variable sweep wing according to claim 1, characterized in that: Since the first rod (1) and the second rod (2) need to remain parallel during the deformation process, the length of the five rods (5) is variable to form the edge of the trapezoidal area; the five rods (5) are formed by three hollow rods being nested; when the sweep angle changes, the angles between the four rods (4), the three rods (3), the five rods (5) and the first rod (1) and the second rod (2) change, and at the same time, in order to keep the first rod (1) and the second rod (2) parallel, the length of the five rods (5) changes.

5. The hybrid honeycomb flexible skin of a variable sweep wing according to claim 1, characterized in that: The three rods (3) divide the variable swept wing flexible skin structure into a parallelogram region (6) and a trapezoidal region (7); in the parallelogram region (6), the AC segment of the first rod (1) and the BD segment of the second rod (2) remain parallel, the four rods (4) and the three rods (3) remain parallel, the length of each boundary remains unchanged, and only the angle changes; according to the structural characteristics, a quadrilateral honeycomb is selected to be bonded to the inner side of the AC segment of the first rod (1), the inner side of the BD segment of the second rod (2), the inner side of the four rods (4) and the upper side of the three rods (3); when the wing changes its swept angle, the honeycomb structure in the parallelogram region (6) produces shear deformation; in the trapezoidal region (7), the length of the three rods (3) remains unchanged, and in order to keep the CE segment of the first rod (1) and the DF segment of the second rod (2) parallel, the trailing edge length needs to be variable.

6. The hybrid honeycomb flexible skin of a variable sweep wing according to claim 5, characterized in that: The five rods (5) adopt a nested structure, and a bidirectional corrugated honeycomb is used in the trapezoidal area (7) to bond with the inner side of the CE section of the first rod (1), the inner side of the DF section of the second rod (2), the inner side of the fifth rod (5) and the lower side of the third rod (3).

7. The hybrid honeycomb flexible skin of a variable sweep wing according to claim 6, characterized in that: The five-rod (5) is composed of three rectangular hollow rods nested together, a hollow thin rod (13) and two hollow thick rods (12), one thick rod (12) being nested at each end of the hollow thin rod (13), and joints (11) being provided at both ends of the five-rod (5) and hinged to the lower ends of the first rod (1) and the second rod (2); a limit baffle (14) is provided on the inner wall of the thick rod to prevent the local length deformation of the five-rod (5) from being too large, thereby causing the filling structure of the trapezoidal area to tear, and at the same time making the maximum deformation of the nested part half of the maximum deformation of the five-rod (5); the angle between the five-rod (5) and the first rod (1) and the second rod (2) and the angle between the five-rod (5) and the third rod (3) in the trapezoidal area are variable; when the sweep angle increases, the bidirectional corrugated honeycomb at the junction of the nested structure bends, and when the sweep angle decreases, the bidirectional corrugated honeycomb at the junction of the nested structure stretches.

8. The hybrid honeycomb flexible skin of a variable sweep wing according to claim 7, characterized in that: The wall panels of the bidirectional corrugated honeycomb are corrugated and can be stretched and deformed in both the chordal and span directions. The chordal and spanwise wavelengths and wave heights are different. The change in chordal length is provided by the chordal wall panels (8), and the change in spanwise length is provided by the spanwise wall panels (9). A half-wave-shaped spanwise wall panel (9) is provided between two adjacent chordal wall panels (8). The wave crests and wave troughs are arranged alternately to form a bidirectional corrugated honeycomb structure filling a trapezoidal area. The spanwise wall panels at the left and right boundaries are bonded to the CE section of the first rod (1) and the DF section of the second rod (2). The chordal wall panels at the upper and lower boundaries are bonded to the third rod (3) and the fifth rod (5). At the junction of the nested structure of the five rods (5), the bidirectional corrugated honeycomb is connected to the five rods (5). In order to prevent the bidirectional corrugated honeycomb structure from being torn due to the change in the boundary length when deforming, the chordal wall panels within the length variation range (10) of the nested structure at the junction are not bonded to the five rods (5).

9. The hybrid honeycomb flexible skin of a variable sweep wing according to claim 1, characterized in that: When the sweep angle changes, the first rod (1) and the second rod (2) are always parallel in the chord length direction, the angle between the fourth rod (4) and the first rod (1) and the second rod (2) changes, and the fourth rod (4) and the third rod (3) always remain parallel; to meet the deformation of the structure, the length of the fifth rod (5) changes through the nested structure, and the angle between the fifth rod (5) and the first rod (1) and the second rod (2) also changes; the quadrilateral honeycomb filled in the parallelogram area undergoes shear deformation; in the trapezoidal area, the length of the fifth rod (5) and the angle between the third rod (3) and the fifth rod (5) vary, and the honeycomb filled inside varies in the chord direction and the span direction as the angle varies, and the chord-wise wallboard at the nested junction is not bonded to the fifth rod (5), thereby preventing the bidirectional corrugated honeycomb from being torn due to the change in boundary length during deformation; When the sweep angle changes, the two areas of the flexible skin structure produce different deformations. A deformable support structure that meets the structural deformation characteristics is selected for filling, providing in-plane deformation and out-of-plane load-bearing capacity.

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