Multi-degree-of-freedom morphing wing based on zero Poisson's ratio superstructure

Abstract

The invention discloses a multi-degree-of-freedom morphing wing based on a zero poisson ratio superstructure, and belongs to the technical field of morphing wings. The wing comprises a front edge section, a wing body and a rear edge section which are sequentially connected, the front edge section comprises an inner side front edge plate, a middle front edge plate and an outer side front edge plate, the wing body comprises a plurality of zero-Poisson-ratio honeycomb structures, each zero-Poisson-ratio honeycomb structure is formed by arraying a plurality of zero-Poisson-ratio unit cell cubic structures, and the adjacent zero-Poisson-ratio unit cell cubic structures share a connecting rod; the rear edge section comprises an inner side rear edge plate, a middle rear edge plate and an outer side rear edge plate; the inner-side front edge plate and the inner-side rear edge plate, the middle front edge plate and the middle rear edge plate, and the outer-side front edge plate and the outer-side rear edge plate are respectively connected through zero-Poisson-ratio honeycomb structures which are arranged along the chord length direction of the wing; the two sides of the middle front edge plate are connected with the inner side front edge plate and the outer side front edge plate through zero-Poisson-ratio honeycomb structures arranged in the extension direction of the wing correspondingly, and the two sides of the middle rear edge plate are connected with the inner side rear edge plate and the outer side rear edge plate through zero-Poisson-ratio honeycomb structures arranged in the extension direction of the wing correspondingly. The wing has four deformation functions of variable elongation, chord length, dihedral angle and camber, so that the aircraft can adapt to different flight environments and tasks.

Description

Technical Field

[0001] The invention belongs to the technical field of variant wings, in particular to a multi-degree-of-freedom variant wing based on a zero Poisson's ratio superstructure. Background Art

[0002] During flight, the aircraft changes its flight attitude by changing the shape of its wings to adapt to different flight environments and missions, thereby achieving an efficient flight state. A morphing wing is a wing that can change its shape according to the flight environment and mission using deformable structures and metamaterials, aiming to optimize the flight performance of the aircraft.

[0003] The patent application with publication date of December 8, 2023 and publication number CN117184412A discloses a variant wing of an aircraft and its assembly method. The wing body includes a plurality of unit cell structures, each unit cell structure includes a chiral structure and a zero Poisson's ratio structure connected to each other. The chiral structure is located on the transverse section of the variant wing and has a tensile rotation characteristic, so that the variant wing changes its curvature when subjected to tensile and compressive loads; the zero Poisson's ratio structure is arranged on the longitudinal section of the variant wing, and the zero Poisson's ratio structure has a tensile deformation characteristic, so that the variant wing changes its span when subjected to tensile and compressive loads, solving the problems of small adjustable range of the wing and discontinuous shape change, but only has two degrees of freedom of variable curvature and span, and cannot meet the multi-degree-of-freedom adjustment requirements of the variant wing. To this end, the present invention proposes a multi-degree-of-freedom variant wing based on a zero Poisson's ratio superstructure. Summary of the invention

[0004] In view of the deficiencies in the prior art, the technical problem to be solved by the present invention is to provide a multi-degree-of-freedom variant wing based on a zero Poisson's ratio superstructure.

[0005] The present invention solves the technical problem by adopting the following technical solution:

[0006] A multi-degree-of-freedom variant wing based on a zero Poisson's ratio superstructure comprises a leading edge section, a wing body and a trailing edge section connected in sequence; the leading edge section comprises an inner leading edge plate, an intermediate leading edge plate and an outer leading edge plate, the wing body comprises a plurality of zero Poisson's ratio honeycomb structures, the zero Poisson's ratio honeycomb structures are formed by an array of a plurality of zero Poisson's ratio single-cell cubic structures, and adjacent zero Poisson's ratio single-cell cubic structures share a connecting rod; the trailing edge section comprises an inner trailing edge plate, an intermediate trailing edge plate and an outer trailing edge plate; the inner leading edge plate and the inner trailing edge plate, the intermediate leading edge plate and the intermediate trailing edge plate, the outer leading edge plate and the outer trailing edge plate are respectively connected by zero Poisson's ratio honeycomb structures arranged along the chord length direction of the wing, the two sides of the intermediate leading edge plate are respectively connected to the inner leading edge plate and the outer leading edge plate by zero Poisson's ratio honeycomb structures arranged along the wing span length direction, and the two sides of the intermediate trailing edge plate are respectively connected to the inner trailing edge plate and the outer trailing edge plate by zero Poisson's ratio honeycomb structures arranged along the wing span length direction.

[0007] Furthermore, the zero Poisson's ratio unit cell cubic structure includes arc-shaped connecting rods and vertical connecting rods; four vertical connecting rods are evenly arranged in a square shape, and the upper and lower ends of two adjacent vertical connecting rods are respectively connected together by arc-shaped connecting rods, and the arc-shaped connecting rods are concave toward the center of the surface on which they are located.

[0008] Furthermore, the left and right sides of the arc-shaped connecting rod are symmetrical, and a single side is divided into a first arc segment, a second arc segment, a straight line segment and a third arc segment; wherein, the first arc segment is close to the center line of the arc-shaped connecting rod, one end of a second arc segment is tangent to an end of the first arc segment away from the center line of the arc-shaped connecting rod, the other end of the second arc segment is tangent to one end of the straight line segment, the other end of the straight line segment is tangent to one end of another second arc segment, the other end of the second arc segment is tangent to one end of the third arc segment, and the other end of the third arc segment is connected to the vertical connecting rod.

[0009] Furthermore, when the inner leading edge panel and the inner trailing edge panel are fixed and a displacement load along the span direction is applied to the sides of the outer leading edge panel and the outer trailing edge panel, the span length of the wing is changed; when the inner leading edge panel, the middle leading edge panel and the outer leading edge panel are fixed and a displacement load along the chord length direction is applied to the roots of the inner trailing edge panel, the middle trailing edge panel and the outer trailing edge panel, the chord length of the wing is changed; when the inner leading edge panel and the inner trailing edge panel are fixed and a displacement load perpendicular to the wing surface is applied to the upper or lower surfaces of the outer leading edge panel and the outer trailing edge panel, the reverse angle of the wing is changed; when the inner leading edge panel, the middle leading edge panel and the outer leading edge panel are fixed and a displacement load perpendicular to the wing surface is applied to the roots of the inner trailing edge panel, the middle trailing edge panel and the outer trailing edge panel, the camber of the wing is changed.

[0010] Compared with the prior art, the present invention has the following beneficial effects:

[0011] The variant wing of the present invention adopts a split design. The entire wing is divided into a leading edge section, a wing body and a trailing edge section. The wing body is composed of a plurality of zero Poisson's ratio honeycomb structures arranged along the span and chord length directions. The zero Poisson's ratio honeycomb structure is used to realize the connection between the leading edge plate and the trailing edge plate, between the leading edge plates and between the trailing edge plates, so that the variant wing has four deformation functions of variable span, chord length, dihedral angle and camber, thereby enabling the aircraft to adapt to different flight environments and tasks.

[0012] Two arc-shaped connecting rods are arranged between two adjacent vertical connecting rods of the zero Poisson's ratio unit cell cubic structure. When the zero Poisson's ratio unit cell cubic structure is subjected to a displacement load perpendicular to the axial direction of the vertical connecting rod, the arc-shaped connecting rod produces bending deformation and gradually shrinks inward while the length of the vertical connecting rod remains unchanged, so that the zero Poisson's ratio honeycomb structure has a zero Poisson's ratio characteristic, thereby realizing the deformation of the wing. The segments of the arc-shaped connecting rod are tangent to each other, which increases the smoothness of the arc-shaped connecting rod, thereby increasing the continuity of the shape change, while reducing stress concentration, and can achieve greater deformation. The zero Poisson's ratio honeycomb structure has the characteristics of zero Poisson's ratio, variable stiffness, large elastic strain, and light weight, which effectively improves the aerodynamic performance of the aircraft. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0014] Figure 2 It is a schematic diagram of the zero Poisson's ratio unit cell cubic structure of the present invention;

[0015] Figure 3 It is a structural schematic diagram of the arc connecting rod of the present invention;

[0016] Figure 4 It is a simulation schematic diagram of variable length according to an embodiment of the present invention;

[0017] Figure 5 It is a simulation schematic diagram of a variable chord length according to an embodiment of the present invention;

[0018] Figure 6 It is a simulation schematic diagram of variable reverse angle according to an embodiment of the present invention;

[0019] Figure 7 It is a simulation schematic diagram of the variable curvature of an embodiment of the present invention;

[0020] In the figure, 1, inner leading edge plate; 2, middle leading edge plate; 3, outer leading edge plate; 4, inner trailing edge plate; 5, zero Poisson's ratio honeycomb structure; 6, middle trailing edge plate; 7, outer trailing edge plate; 51, arc-shaped connecting rod; 52, vertical connecting rod; 511, first circular arc segment; 512, second circular arc segment; 513, straight line segment; 514, third circular arc segment. DETAILED DESCRIPTION

[0021] Specific embodiments are given below in conjunction with the accompanying drawings. The specific embodiments are only used to further introduce the technical solution of the present invention and are not intended to limit the protection scope of the present application.

[0022] The present invention provides a multi-degree-of-freedom variant wing based on a zero Poisson's ratio superstructure (see Figure 1-7), including a leading edge section, a wing body and a trailing edge section connected in sequence; wherein, the leading edge section includes an inner leading edge panel 1, an intermediate leading edge panel 2 and an outer leading edge panel 3, the wing body includes a plurality of zero Poisson's ratio honeycomb structures 5 arranged along the wing span and chord length directions, and the trailing edge section includes an inner trailing edge panel 4, an intermediate trailing edge panel 6 and an outer trailing edge panel 7; the inner leading edge panel 1 and the inner trailing edge panel 4, the intermediate leading edge panel 2 and the intermediate trailing edge panel 6, the outer leading edge panel 3 and the outer trailing edge panel 7 are respectively connected together through the zero Poisson's ratio honeycomb structure 5 arranged along the wing chord length direction, the two sides of the intermediate leading edge panel 2 are respectively connected to the inner leading edge panel 1 and the outer leading edge panel 3 through the zero Poisson's ratio honeycomb structure 5 arranged along the wing span direction, and the two sides of the intermediate trailing edge panel 6 are respectively connected to the inner trailing edge panel 4 and the outer trailing edge panel 7 through the zero Poisson's ratio honeycomb structure 5 arranged along the wing span direction.

[0023] The zero Poisson's ratio honeycomb structure 5 is composed of a plurality of zero Poisson's ratio single-cell cubic structure arrays, and adjacent zero Poisson's ratio single-cell cubic structures share a connecting rod. The length of each zero Poisson's ratio honeycomb structure 5 connecting each leading edge plate and trailing edge plate gradually shortens from the inside to the outside to adapt to the change in the overall shape of the wing. In this embodiment, the zero Poisson's ratio honeycomb structure 5 between the leading edge plate and the trailing edge plate has multiple rows of zero Poisson's ratio single-cell cubic structures arrayed along the wing span direction, adapted to the width of the leading edge plate and the trailing edge plate. The zero Poisson's ratio honeycomb structure 5 between the leading edge plates and between the trailing edge plates includes at least one row of zero Poisson's ratio single-cell cubic structures.

[0024] The zero Poisson's ratio unit cell cube structure includes an arc-shaped connecting rod 51 and a vertical connecting rod 52; the four vertical connecting rods 52 are evenly arranged in a square shape, and the upper and lower ends of two adjacent vertical connecting rods 52 are respectively connected together by the arc-shaped connecting rod 51, and the arc-shaped connecting rod 51 is concave toward the center of the surface where it is located. When the zero Poisson's ratio unit cell cube structure is subjected to a displacement load perpendicular to the axial direction of the vertical connecting rod 52, the arc-shaped connecting rod 51 is bent and deformed and gradually shrinks inward while the length of the vertical connecting rod 52 remains unchanged, so that the zero Poisson's ratio unit cell cube structure has a zero Poisson's ratio characteristic.

[0025] The arc connecting rod 51 is a symmetrical structure on the left and right sides, and one side is divided into a first arc segment 511, a second arc segment 512, a straight segment 513 and a third arc segment 514; wherein the first arc segment 511 is close to the center line of the arc connecting rod 51, one end of a second arc segment 512 is tangent to one end of the first arc segment 511 away from the center line of the arc connecting rod 51, the other end of the second arc segment 512 is tangent to one end of the straight segment 513, the other end of the straight segment 513 is tangent to one end of another second arc segment 512, the other end of the second arc segment 512 is tangent to one end of the third arc segment 514, and the other end of the third arc segment 514 is connected to the vertical connecting rod 52. The segments of the arc connecting rod 51 are tangent to each other, so that the arc connecting rod 51 is smoother, stress concentration is reduced, and greater deformation can be achieved.

[0026] The zero Poisson's ratio honeycomb structure 5 is made of elastic materials with a certain rigidity, such as polymer materials such as nylon PA12, nylon PA11, TPU, photosensitive resin, or elastic metal materials such as spring steel. The connection between the zero Poisson's ratio honeycomb structure 5 and the corresponding plate can be welded, riveted, bolted, etc.

[0027] The working principle and workflow of the present invention are:

[0028] If the variable span function of the wing is to be realized, the inner leading edge panel 1 and the inner trailing edge panel 4 are fixed, and at the same time, a displacement load along the wing span direction is applied to the sides of the outer leading edge panel 3 and the outer trailing edge panel 7. Then, the zero Poisson's ratio honeycomb structure 5 between the middle leading edge panel 2 and the inner leading edge panel 1 and the outer leading edge panel 3, and between the middle trailing edge panel 6 and the inner trailing edge panel 4 and the outer trailing edge panel 7 is compressed along the wing span direction to achieve the purpose of variable span.

[0029] If the variable chord length function of the wing is to be realized, the inner leading edge panel 1, the middle leading edge panel 2 and the outer leading edge panel 3 are fixed, and at the same time, a displacement load along the chord length direction of the wing is applied to the roots of the inner trailing edge panel 4, the middle trailing edge panel 6 and the outer trailing edge panel 7. Then, the zero Poisson's ratio honeycomb structure 5 between each leading edge panel and the trailing edge panel is compressed along the chord length direction of the wing to achieve the purpose of variable chord length.

[0030] If the wing's variable angle function is to be realized, the inner leading edge panel 1 and the inner trailing edge panel 4 are fixed, and at the same time, a displacement load perpendicular to the wing surface is applied to the upper or lower surface of the outer leading edge panel 3 and the outer trailing edge panel 7. Then, the zero Poisson's ratio honeycomb structure 5 between the middle leading edge panel 2 and the inner leading edge panel 1 and the outer leading edge panel 3, and between the middle trailing edge panel 6 and the inner trailing edge panel 4 and the outer trailing edge panel 7 bends upward or downward to achieve the purpose of variable angle.

[0031] If the wing's camber changing function is to be realized, the inner leading edge panel 1, the middle leading edge panel 2 and the outer leading edge panel 3 are fixed, and at the same time, a displacement load perpendicular to the wing surface is applied to the roots of the inner trailing edge panel 4, the middle trailing edge panel 6 and the outer trailing edge panel 7. Then, the zero Poisson's ratio honeycomb structure 5 between each leading edge panel and the trailing edge panel bends upward or downward to achieve the purpose of camber changing.

[0032] Example

[0033] In order to verify that the variant wing can achieve multiple deformation functions, this embodiment performs quasi-static simulation on the wing based on Abaqus static simulation. The material of the zero Poisson's ratio honeycomb structure 5 is nylon PA12, with the wing chord length direction as the X axis, the wing span direction as the Z axis, and the Y axis perpendicular to the wing surface.

[0034] The inner front edge plate 1 and the inner rear edge plate 4 are fixed, and a displacement load of 16 mm along the Z direction is applied to the outer front outer edge plate 3 and the outer rear edge plate 7. Figure 4 As shown, the wing span changes.

[0035] The inner front edge plate 1, the middle front edge plate 2 and the outer front edge plate 3 are fixed, and a displacement load of 5 mm along the X direction is applied to the roots of the inner rear edge plate 4, the middle rear edge plate 6 and the outer rear edge plate 7, as shown in FIG. Figure 5 As shown, the chord length of the wing changes.

[0036] The inner front edge plate 1 and the inner rear edge plate 4 are fixed, and a displacement load of 16 mm along the Y direction is applied to the upper surfaces of the outer front edge plate 3 and the outer rear edge plate 7. Figure 6 As shown, the wing anhedral angle changes.

[0037] The inner front edge plate 1, the middle front edge plate 2 and the outer front edge plate 3 are fixed, and a displacement load of 5 mm along the Y direction is applied to the roots of the inner rear edge plate 4, the middle rear edge plate 6 and the outer rear edge plate 7. Figure 7 As shown, the camber of the wing changes.

[0038] In summary, the variant wing of the present invention has multiple degrees of freedom, and can realize four deformations of variable span, chord length, reverse angle and camber, and various deformations are independent of each other.

[0039] Any matters not described in the present invention are applicable to the prior art.

Claims

1. A multi-degree-of-freedom variant wing based on a zero Poisson's ratio superstructure, comprising a leading edge section, a wing body and a trailing edge section connected in sequence; characterized in that: The leading edge section includes an inner leading edge panel, an intermediate leading edge panel and an outer leading edge panel, and the wing body includes a plurality of zero Poisson's ratio honeycomb structures, which are formed by an array of a plurality of zero Poisson's ratio single-cell cubic structures, and adjacent zero Poisson's ratio single-cell cubic structures share a connecting rod; the trailing edge section includes an inner trailing edge panel, an intermediate trailing edge panel and an outer trailing edge panel; the inner leading edge panel and the inner trailing edge panel, the intermediate leading edge panel and the intermediate trailing edge panel, the outer leading edge panel and the outer trailing edge panel are respectively connected by zero Poisson's ratio honeycomb structures arranged along the chord length direction of the wing, and both sides of the intermediate leading edge panel are respectively connected to the inner leading edge panel and the outer leading edge panel through zero Poisson's ratio honeycomb structures arranged along the span length direction of the wing, and both sides of the intermediate trailing edge panel are respectively connected to the inner trailing edge panel and the outer trailing edge panel through zero Poisson's ratio honeycomb structures arranged along the span length direction of the wing.

2. The multi-degree-of-freedom morphing wing based on a zero Poisson's ratio superstructure according to claim 1, characterized in that: The zero Poisson's ratio unit cell cubic structure includes arc-shaped connecting rods and vertical connecting rods; four vertical connecting rods are evenly arranged in a square shape, and the upper and lower ends of two adjacent vertical connecting rods are respectively connected together by arc-shaped connecting rods, and the arc-shaped connecting rods are concave toward the center of the surface where they are located.

3. The multi-degree-of-freedom morphing wing based on a zero Poisson's ratio superstructure according to claim 2, characterized in that: The left and right sides of the arc-shaped connecting rod are symmetrical, and a single side is divided into a first arc segment, a second arc segment, a straight line segment and a third arc segment; wherein the first arc segment is close to the center line of the arc-shaped connecting rod, one end of a second arc segment is tangent to an end of the first arc segment away from the center line of the arc-shaped connecting rod, the other end of the second arc segment is tangent to one end of the straight line segment, the other end of the straight line segment is tangent to one end of another second arc segment, the other end of the second arc segment is tangent to one end of the third arc segment, and the other end of the third arc segment is connected to the vertical connecting rod.

4. The multi-degree-of-freedom morphing wing based on a zero Poisson's ratio superstructure according to any one of claims 1 to 3, characterized in that: When the inner leading edge panel and the inner trailing edge panel are fixed and a displacement load along the span direction is applied to the sides of the outer leading edge panel and the outer trailing edge panel, the span length of the wing is changed; when the inner leading edge panel, the middle leading edge panel and the outer leading edge panel are fixed and a displacement load along the chord length direction is applied to the roots of the inner trailing edge panel, the middle trailing edge panel and the outer trailing edge panel, the chord length of the wing is changed; when the inner leading edge panel and the inner trailing edge panel are fixed and a displacement load perpendicular to the wing surface is applied to the upper or lower surfaces of the outer leading edge panel and the outer trailing edge panel, the reverse angle of the wing is changed; when the inner leading edge panel, the middle leading edge panel and the outer leading edge panel are fixed and a displacement load perpendicular to the wing surface is applied to the roots of the inner trailing edge panel, the middle trailing edge panel and the outer trailing edge panel, the camber of the wing is changed.

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