A dynamic simulation method for a wheel-track variable morphing wing structure design

Abstract

The application provides a dynamic simulation method for a wheel-rail variable telescopic wing structure design. The structure suitable for the dynamic simulation method comprises a base, fixed wings symmetrically arranged on the base, a movable wing provided with a wheel set, the movable wing being used to move along the fixed wings through the wheel set, a driving and transmission mechanism assembly used to drive the movable wing to extend and retract relative to the fixed wings, and the driving and transmission mechanism assembly being connected with the movable wing. The change of the lift area is realized through the extension and retraction of the movable wing relative to the fixed wings, so that the limitations of the traditional fixed configuration wing are overcome, the aspect ratio of the wing and the change of the lift area are realized, and the multi-working condition adaptation capability of the aircraft is greatly improved.

Description

Technical Field

[0001] This application relates to the field of aircraft technology, specifically to a dynamic simulation method for the design of a wheel-rail type variator telescopic wing structure. Background Technology

[0002] The aerospace industry is placing increasingly stringent demands on the flight adaptability, mission suitability, and maneuverability of aircraft. The diverse flight missions and complex flight environments are making the limitations of traditional fixed-configuration wings increasingly prominent. The aerodynamic parameters of traditional fixed-configuration wings, such as aspect ratio and lift area, are fixed and cannot be dynamically adjusted according to flight conditions, thus failing to meet the multi-condition service requirements of modern aircraft. Summary of the Invention

[0003] In view of this, this application provides a wheel-rail variable telescopic wing structure, which overcomes the limitations of traditional fixed-configuration wings, realizes changes in the wing's aspect ratio and lifting area, and significantly improves the aircraft's multi-condition adaptability. In addition, this application also provides a dynamic simulation method applicable to the design of wheel-rail variable telescopic wing structures.

[0004] To achieve the above objectives, this application provides the following technical solution:

[0005] A wheel-rail type variable telescopic wing structure includes:

[0006] Base;

[0007] Fixed wings, symmetrically arranged on the base;

[0008] The movable wing is equipped with a set of running wheels, which are used to move along the fixed wing.

[0009] A drive and transmission mechanism assembly is used to drive the movable wing to extend and retract relative to the fixed wing, and the drive and transmission mechanism assembly is connected to the movable wing;

[0010] The lifting area is changed by extending and retracting the movable wing relative to the fixed wing, thereby improving the aircraft's adaptability to various operating conditions.

[0011] Optionally, in the above-mentioned wheel-rail type variant telescopic wing structure, the fixed wing includes T-shaped guide rails arranged vertically opposite to each other and spaced apart. The rail surfaces of the T-shaped guide rails arranged opposite to each other are arranged in opposite directions. The rail surface is the surface adjacent to the protrusion of the T-shaped guide rail. The running wheel set includes running wheels arranged vertically opposite to each other, and the spacing between the vertically arranged running wheels is adapted to the spacing between the oppositely arranged rail surfaces.

[0012] Optionally, the above-mentioned wheel-rail type variant telescopic wing structure further includes a limiting mechanism, the limiting mechanism comprising:

[0013] An end-limiting wheel assembly is provided at the end of the fixed wing away from the base. The end-limiting wheel assembly can slide along the longitudinal beam of the movable wing to prevent the movable wing from jamming or wearing when it extends or retracts due to vertical deformation.

[0014] Lateral limiting wheel assembly is provided on the movable wing to limit the lateral displacement of the movable wing;

[0015] A vertical limiting wheel is provided on the running wheel assembly to limit the vertical displacement of the movable wing.

[0016] Optionally, in the above-mentioned wheel-rail type variant telescopic wing structure, the movable wing includes a longitudinal beam and a wheel assembly mounting plate arranged in the longitudinal direction. The wheel assembly mounting plate is arranged parallel to the longitudinal beam and has multiple mounting holes.

[0017] Optionally, in the above-mentioned wheel-rail type variant telescopic wing structure, the surface on which the movable wing allows the end limiting wheel assembly to slide is the movable wing rail surface, and the net dimension between the movable wing rail surface and the end limiting wheel assembly is A, 0≤A≤2mm.

[0018] A dynamic simulation method for designing a wheel-rail type variant telescopic wing structure includes:

[0019] S1: Construct a three-dimensional geometric model of the wheel-rail type variant telescopic wing structure, and mesh the three-dimensional geometric model to form a finite element model;

[0020] S2: Construct a rigid-flexible coupling dynamic model, designate the fixed wing and movable wing of the wheel-rail type variant telescopic wing structure as flexible bodies, and the remaining components of the wheel-rail type variant telescopic wing structure as rigid bodies, and introduce the structural elasticity of the movable wing and the fixed wing through modal synthesis method, and use a polygonal contact model to simulate the nonlinear dynamic contact behavior between the running wheel assembly and the T-shaped guide rail.

[0021] S3: Establish a random vibration environment model based on virtual excitation, and simulate the random vibration of the movable wing and the fixed wing through a PID control strategy;

[0022] S4: Construct a scale prototype and conduct calibration tests, free modal tests, static loading tests, dynamic expansion and contraction tests, and random vibration tests on the running wheel assembly of the scale prototype to obtain measured data. Compare the measured data with the simulation data obtained in steps S1-S3 to correct the parameters of the rigid-flexible coupling dynamic model. The calibration test is configured to attach strain gauges to the running wheel assembly, apply stepped force, and collect data to calibrate the strain-load mapping relationship of the running wheel assembly. The free modal test is configured to use an elastic suspension method to achieve free boundary constraints on the scale prototype and use a vibrator to sweep the frequency of the wheels. The wheel-rail variant telescopic wing structure is excited, and the vibration response of the wheel-rail variant telescopic wing structure is collected to obtain the natural frequency, mode shape and damping ratio of the scale prototype. The static loading test is configured to apply graded static loads to the end of the movable wing to obtain the static load transfer characteristics of the structure. The dynamic telescopic test is configured to drive the movable wing to reciprocate telescopic motion under a set load condition and collect dynamic wheel-rail force and traction force data throughout the telescopic process. The random vibration test is configured to apply random vibration excitation based on a given power spectral density function and collect vibration acceleration, dynamic load and displacement data of the scale prototype under combined vibration and telescopic conditions.

[0023] Optionally, in the above dynamic simulation method for the design of the wheel-rail type variant telescopic wing structure, the three-dimensional geometric model is divided into regions and meshed. The T-shaped guide rail, the end plate of the fixed wing, the middle plate of the movable wing, and the longitudinal beam of the movable wing are divided into hexahedral elements using Solid185 elements, and the remaining components of the wheel-rail type variant telescopic wing structure are divided into quadrilateral elements using Shell181 plate shell elements.

[0024] Optionally, in the above-mentioned dynamic simulation method for the design of the wheel-rail type variant telescopic wing structure, the free modal test includes the free modal test of the movable wing and the free modal test of the fixed wing, in order to obtain the first ten natural frequencies, mode shapes and damping ratios of the scale prototype.

[0025] This application provides a wheel-rail type variant telescopic wing structure. Two fixed wings are provided and are symmetrical about the center line of the base. The movable wings are arranged one-to-one with the fixed wings. The drive and transmission mechanism assembly includes a servo motor, a universal joint, and a ball screw. The servo motor transmits the output speed and torque to the ball screws on both sides evenly through bevel gear transmission. The universal joint and the ball screws realize the synchronous telescopic movement of the movable wings on both sides that correspond to the fixed wings. At the same time, the movable wings are provided with a set of running wheels. The running wheels move on the fixed wings to realize the telescopic movement of the movable wings relative to the fixed wings, thus realizing the change of the lift area and display ratio. The cooperation between the running wheel assembly and the fixed wing transforms the sliding friction between the movable wing and the fixed wing into rolling friction, significantly reducing motion drag during the extension and retraction process, reducing structural wear, and extending the service life of the telescopic wing. At the same time, it ensures the flexibility of the extension and retraction action, enabling rapid adjustment of the telescopic wing. By flexibly extending and retracting the movable wing relative to the fixed wing, the lifting area and aspect ratio of the wing can be changed, allowing the wing to dynamically adapt to aerodynamic requirements according to different flight conditions. During low-speed flight, the movable wing extends to increase the lifting area to improve the lift-to-drag ratio and increase range. During high-speed cruise or maneuvering flight, the movable wing retracts to reduce flight drag and improve maneuverability. This breaks through the performance limitations of traditional fixed-configuration wings and greatly improves the multi-condition adaptability of the aircraft. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of the structure of the wheel-rail type variant telescopic wing provided in this application;

[0028] Figure 2 This is a schematic diagram of the fixed wing structure provided in this application;

[0029] Figure 3 A schematic diagram of the structure of the movable wing provided in this application;

[0030] Figure 4 A schematic diagram of the drive and transmission mechanism assembly provided in this application;

[0031] Figure 5 This is a schematic diagram of the structure of the running wheel assembly provided in this application;

[0032] Figure 6 A schematic diagram of the structure of the lateral limiting wheel assembly provided in this application;

[0033] Figure 7This is a schematic diagram of the structure of the traveling wheel assembly and the lateral limiting wheel assembly provided in this application on the T-shaped guide rail;

[0034] Figure 8 This is a schematic diagram of the end-limiting wheel assembly provided in this application;

[0035] Figure 9 The scaled prototype finite element model provided for this application;

[0036] Figure 10 A schematic diagram of the bolts and wheel assembly; Figure 10 (a) Schematic diagram simulating a bolt; Figure 10 (b) Schematic diagram of the simulated wheelset;

[0037] Figure 11 Flowchart for modeling the rigid-flexible coupling dynamics of a scaled prototype;

[0038] Figure 12 This is a dynamic model of a scaled-down sample structure;

[0039] Figure 13 A schematic diagram for selecting the main node of a fixed-wing aircraft.

[0040] Figure 14 A schematic diagram for selecting the main node of the active wing;

[0041] Figure 15 This is a random vibration model for the airfoil.

[0042] Figure 16 Here is the PID control flowchart for the fixed section of the wing surface;

[0043] Figure 17 To control the comparison between the expected and actual simulated signals; Figure 17 (a) Comparison of accelerated time domains; Figure 17 (b) Acceleration comparison chart;

[0044] Figure 18 This is a static strength stress contour diagram of the wheelset;

[0045] Figure 19 This is a schematic diagram of the strain gauge mounting method;

[0046] Figure 20 A diagram illustrating the definition of wheel group numbers;

[0047] Figure 21 A schematic diagram of the calibration coefficients for the running wheels;

[0048] Figure 22 A schematic diagram showing the layout of measurement points for the movable wing;

[0049] Figure 23 A schematic diagram of the fixed-wing measurement point layout;

[0050] Figure 24 To compare wheel load results with experimental and simulation results;

[0051] Figure 25 This is a schematic diagram showing the test results of the wheel assembly load during the dynamic expansion and contraction process;

[0052] Figure 26 This is a schematic diagram of the simulation results of the wheel assembly load during the dynamic expansion and contraction process;

[0053] Figure 27 This is a schematic diagram showing the test results of the motor traction force during the telescopic process;

[0054] Figure 28 This is a schematic diagram showing the simulation results of the motor traction force during the telescopic process;

[0055] Figure 29 A schematic diagram of the loading fixture;

[0056] Figure 30 This is a schematic diagram of the experimental loading method;

[0057] Figure 31 This is a schematic diagram of the loading process for a random vibration test.

[0058] Figure 32 This is a schematic diagram showing the time-frequency comparison of wingtip vibration acceleration;

[0059] Figure 33 This is a schematic diagram showing the test results of the wheel assembly load during the dynamic expansion and contraction process;

[0060] Figure 34 This is a schematic diagram of the simulation results of the wheel assembly load during the dynamic expansion and contraction process;

[0061] Figure 35 This is a schematic diagram comparing the traction forces under dynamic expansion and contraction test conditions.

[0062] 1. Base; 2. Fixed wing; 3. Movable wing; 4. Running wheel assembly; 5. T-shaped guide rail; 6. End limit wheel assembly; 7. Lateral limit wheel assembly; 8. Vertical limit wheel; 9. Wheel assembly mounting plate; 10. Drive and transmission mechanism assembly; 11. Motor; 12. Universal joint; 13. Ball screw; 14. Weight; 15. Large mass body; 16. Excitation application point; 17. Connecting hole; 18. Counterweight connecting rod; 19. Counterweight block; 20. Counterweight baffle; 21. Prototype; 22. Fixed support fixture; 23. Vibration table surface; 24. Elastic rope; 25. Force gauge; 26. Strain gauge; 27. Vibration table; 28. Bolt. Detailed Implementation

[0063] This application provides a wheel-rail variable telescopic wing structure that overcomes the limitations of traditional fixed-configuration wings, enabling changes in the wing's aspect ratio and lifting area, and significantly improving the aircraft's multi-condition adaptability. Furthermore, this application also provides a dynamic simulation method applicable to the design of wheel-rail variable telescopic wing structures.

[0064] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0065] like Figures 1-8 As shown, this application provides a wheel-rail type variant telescopic wing structure, including: a base 1; a fixed wing 2, symmetrically arranged on the base 1; a movable wing 3, provided with a running wheel assembly 4, the movable wing 3 being used to move along the fixed wing 2 via the running wheel assembly 4; and a drive and transmission mechanism assembly 10, used to drive the movable wing 3 to extend and retract relative to the fixed wing 2, the drive and transmission mechanism assembly being connected to the movable wing 3; wherein, the change in lift area is achieved by extending and retracting the movable wing 3 relative to the fixed wing 2.

[0066] Specifically, there are two fixed wings 2, symmetrically arranged about the center line of the base 1. The movable wings 3 are arranged one-to-one with the fixed wings 2. The drive and transmission mechanism assembly 10 includes a servo motor 11, a universal joint 12, and a ball screw 13. The servo motor 11 transmits the output speed and torque to the ball screws 13 on both sides through bevel gear transmission. The universal joint 12 cooperates with the ball screw 13 to realize the synchronous extension and retraction of the movable wings 3 on both sides that correspond to the fixed wings 2. At the same time, the movable wings 3 are equipped with a set of traveling wheels 4. The set of traveling wheels 4 moves on the fixed wings 2 to realize the extension and retraction of the movable wings 3 relative to the fixed wings 2, thus realizing the change of the flying area and display ratio.

[0067] The fixed wing 2 and the movable wing 3 are arranged in a symmetrical one-to-one correspondence, which meets the symmetry requirements of the aircraft's aerodynamic layout, effectively avoiding flight attitude deviation caused by uneven force on the wing surface and improving the stability of the aircraft during flight. The drive and transmission mechanism adopts a design of bevel gear transmission combined with universal joint 12 and ball screw 13, which ensures the synchronicity of the extension and retraction of the two movable wings 3 from the transmission structure, completely solving the problems of wing surface yaw and local stress concentration on the wheel and rail caused by unilateral extension and retraction deviation, and greatly improving the smoothness and reliability of the telescopic wing movement. The cooperation between the running wheel assembly 4 and the fixed wing 2 converts the sliding friction between the movable wing 3 and the fixed wing 2 into rolling friction. Dynamic friction significantly reduces motion drag during extension and retraction, reduces structural wear, and extends the service life of the telescopic wing. At the same time, it ensures the flexibility of extension and retraction, enabling rapid adjustment of the telescopic wing 3. By flexibly extending and retracting the telescopic wing 3 relative to the fixed wing 2, the lifting area and aspect ratio of the wing can be changed, allowing the wing to dynamically adapt to aerodynamic requirements according to different flight conditions. During low-speed flight, the telescopic wing 3 is extended to increase the lifting area to improve the lift-to-drag ratio and increase range. During high-speed cruise or maneuvering flight, the telescopic wing 3 is retracted to reduce flight drag and improve maneuverability. This breaks through the performance limitations of traditional fixed-configuration wings and greatly improves the multi-condition adaptability of the aircraft.

[0068] The fixed wing 2 includes T-shaped guide rails 5 arranged vertically opposite each other and spaced apart. The rail surfaces of the T-shaped guide rails 5 are arranged opposite each other and the rail surface is the surface adjacent to the protrusion of the T-shaped guide rail 5. The running wheel set 4 includes running wheels arranged vertically opposite each other, and the spacing between the vertically arranged running wheels is adapted to the spacing between the oppositely arranged rail surfaces.

[0069] Specifically, the single-sided fixed wing 2 is enclosed by transverse beams and longitudinal beams to form a rectangular structure. Multiple parallel T-shaped guide rails 5 are arranged longitudinally within the rectangular structure. The multiple T-shaped guide rails 5 are divided into multiple groups. Each group includes two T-shaped guide rails 5 that are opposite to each other and spaced apart. The protrusions of the two T-shaped guide rails 5 are arranged opposite to each other, and the surface adjacent to the protrusions is the track surface on which the traveling wheel group 4 travels. Each traveling wheel group 4 is provided with two traveling wheels, and one of the two traveling wheels moves along one of the oppositely arranged T-shaped guide rails 5, while the other traveling wheel moves along the other of the oppositely arranged T-shaped guide rails 5.

[0070] Thus, the T-shaped guide rails 5 are symmetrically arranged in groups, with the protrusions of two T-shaped guide rails 5 in each group arranged back to back to form a rail surface that matches the running wheel assembly 4. The vertical double wheels of the running wheel assembly 4 are precisely matched with the rail surface, ensuring that the running wheels and the rail surface always maintain a stable contact state, avoiding problems such as wheel-rail separation and jamming, and ensuring the smoothness of the telescopic movement of the movable wing 3. In addition, multiple groups of T-shaped guide rails 5 are distributed longitudinally along the fixed wing 2, and cooperate with the corresponding running wheel assemblies 4 to evenly distribute the vertical load of the movable wing 3 to each T-shaped guide rail 5 and running wheel assembly 4, effectively reducing the local stress of a single set of wheel rails, avoiding rail surface wear and running wheel deformation, improving the overall load-bearing capacity of the telescopic wing structure, and adapting to the complex load conditions during aircraft flight.

[0071] Furthermore, the wheel-rail type variable telescopic wing structure also includes a limiting mechanism, which includes: an end limiting wheel assembly 6 disposed at the end of the fixed wing 2 away from the base 1, the end limiting wheel assembly 6 being able to slide along the longitudinal beam of the movable wing 3 to prevent the movable wing 3 from jamming or wearing during telescopic movement when the movable wing 3 undergoes vertical deformation; a lateral limiting wheel assembly 7 disposed on the movable wing 3 to limit the lateral displacement of the movable wing 3; and a vertical limiting wheel 8 disposed on the traveling wheel assembly 4 to limit the vertical offset of the movable wing 3.

[0072] Specifically, each fixed wing 2 has four end-limiting wheel sets 6 at its end, with two of the four end-limiting wheel sets 6 forming a group and arranged vertically opposite each other to move along the upper and lower surfaces of the longitudinal beams of the movable wing 3. The ends of the movable wing 3 near the base 1 are connected by connecting plates to the longitudinal beams of multiple movable wings 3. The movable wing 3 is divided longitudinally into a first region and a second region. The first region includes multiple parallel longitudinal beams, and the second region includes parallel wheel mounting plates 9 and longitudinal beams extending from the first region to the second region. It should be noted that the number of longitudinal beams extending from the first region to the second region is the same as the number of end-limiting wheel sets 6.

[0073] Four sets of end-limiting wheels 6 are provided at the end of a single fixed wing 2, and are arranged in pairs facing each other. They can slide against the upper and lower surfaces of the longitudinal beam of the movable wing 3. When the movable wing 3 is subjected to aerodynamic load and undergoes vertical deformation, it can form symmetrical auxiliary support and limit from the upper and lower sides. This not only limits the excessive vertical deformation of the movable wing 3, but also ensures uniform contact force and avoids wing surface sway caused by unilateral limiting. At the same time, the rolling and sliding contact method further reduces end friction loss.

[0074] The lateral limiting wheel assembly 7 is arranged laterally on the wheel assembly mounting plate 9 located at the end, and each lateral limiting wheel assembly 7 includes two lateral limiting wheels arranged vertically opposite each other, which are in contact with the side wall of the T-shaped guide rail 5.

[0075] Each lateral limiting wheel assembly uses two vertically opposite lateral limiting wheels that make precise contact with the side wall of the T-shaped guide rail 5. The vertically symmetrical layout of the two wheels can form a uniform contact force with the T-shaped guide rail 5, avoiding local hard contact between the single limiting wheel and the side wall of the guide rail. At the same time, it allows the lateral limiting force to be evenly distributed vertically, improving the stability of the lateral limiting and effectively preventing problems such as vertical tipping and swaying during the extension and retraction of the movable wing 3.

[0076] Each set of T-shaped guide rails 5 on the fixed wing 2 is arranged vertically at intervals. The vertical limiting wheel 8 slides perpendicularly to the side wall of the T-shaped guide rail 5, and the vertical limiting wheel 8 is arranged at both ends of the traveling wheel in the vertical direction. In this way, the vertical limiting wheel 8 slides along the surface of the T-shaped guide rail 5 and limits the vertical movement of the movable wing 3. The back side of the T-shaped guide rail 5 refers to the side facing away from the protrusion.

[0077] This layout allows the vertical limiting wheel 8 and the T-shaped guide rail 5 to form a vertical limiting engagement, limiting the movable wing 3 throughout its entire movement from the vertical gap of each set of guide rails. This achieves complete coverage of the vertical limiting along the extension and retraction path of the movable wing 3, thoroughly preventing the movable wing 3 from vertically shifting or deviating.

[0078] In summary, the limiting mechanism integrates the end limiting wheel assembly 6, the lateral limiting wheel assembly 7, and the vertical limiting wheel 8, which respectively constrain the movable wing 3 in three dimensions: vertical at the end, lateral as a whole, and vertical throughout the entire process. This effectively limits various offsets and deformations during the extension and retraction of the movable wing 3, fundamentally preventing unintended contact between the movable wing 3 and the fixed wing 2, completely solving the industry pain points of extension jamming and wear of guide rails and wheel assemblies, and significantly improving the reliability of structural movement.

[0079] In an optional embodiment, the movable wing 3 includes a longitudinal beam and a wheel assembly mounting plate 9 arranged longitudinally. The wheel assembly mounting plate 9 is parallel to the longitudinal beam and has multiple mounting holes. The wheel assembly mounting plate 9 is used for mounting the running wheel assembly 4 and the lateral limiting wheel assembly 7.

[0080] Multiple mounting holes provide multiple mounting options for the running wheel assembly 4 and the lateral limit wheel assembly 7. The longitudinal and lateral spacing of the wheel assembly can be adjusted as needed, and the wheel-rail stress distribution can be optimized for the load characteristics of different flight conditions, avoiding stress concentration in local wheel assemblies and improving the structure's adaptability to diverse flight scenarios.

[0081] In an optional embodiment, the surface on which the movable wing 3 allows the end limit wheel assembly 6 to slide is the track surface of the movable wing 3, and the net dimension between the track surface of the movable wing 3 and the end limit wheel assembly 6 is A, where 0≤A≤2mm.

[0082] The millimeter-level gap design allows the end limit wheel assembly to quickly engage the limit when the movable wing 3 undergoes slight excessive deformation. This can promptly correct the vertical attitude of the wing surface, avoid a chain reaction of problems such as uneven wheel-rail force and wing surface sway caused by the continuous expansion of deformation, improve the response speed and protection accuracy of the end vertical limit, and enhance the stability of the extension and retraction attitude of the movable wing 3.

[0083] In one example, the wheel-rail type variant telescopic wing structure has a width of 1216mm, a height of 185mm, a length of 5632mm when extended, and a length of 3632mm when fully retracted.

[0084] The length of the single-sided fixed wing 2 is 1680mm, the width is 1216mm, and the height is 185mm. It is made of 7075 high-strength aluminum alloy material, taking into account both structural rigidity and lightweight requirements. The distance between the end limit wheel and the rail surface of the movable wing 3 is 0mm~2mm, with a reference design value of 1.5mm. This is to prevent the movable wing 3 from undergoing excessive deformation under large vertical loads, avoid jamming or guide rail wear during the extension and retraction process, and provide auxiliary vertical support and limit position protection for the movable wing 3.

[0085] The single-sided movable wing 3 is 1400mm long, 1000mm wide, and 60mm high. It is constructed from 7075 high-strength aluminum alloy and housed within the fixed wing 2 assembly. It can reciprocate by extending and retracting along the T-shaped guide rail 5 of the fixed wing 2, with a maximum unidirectional extension stroke of 660mm. The single-sided movable wing 3 is enclosed by transversely arranged crossbeams and longitudinally arranged longitudinal beams, forming a rectangular structure. It is further divided longitudinally into a first region and a second region. The first region includes multiple parallel longitudinal beams, and the second region includes parallel wheel mounting plates 9 and longitudinal beams extending from the first region to the second region.

[0086] The single-sided movable wing 3 is equipped with three sets of wheel mounting plates 9. Each set of wheel mounting plates 9 includes two relatively spaced and parallel wheel mounting plates 9. Each set of wheel mounting plates 9 has two traveling wheel sets 4 symmetrically arranged along the transverse direction about the T-shaped guide rail 5, totaling twelve on one side. The traveling wheels act on the upper and lower rail surfaces of the T-shaped guide rail 5 of the fixed wing 2, converting the sliding friction between the movable wing 3 and the fixed wing 2 into rolling friction, realizing the vertical bearing and low-resistance rolling motion of the movable wing 3. Each traveling wheel set 4 is equipped with two vertical limiting wheels 8 on the upper and lower sides, totaling twenty-four vertical limiting wheels 8. The vertical limiting wheels 8 act on the back of the T-shaped guide rail 5 of the fixed wing 2, constraining the vertical jump of the movable wing 3. The single-sided movable wing 3 is equipped with four sets of lateral limiting wheel sets 7, two in each set, totaling eight lateral limiting wheels. The lateral limiting wheel sets 7 are installed longitudinally at both ends of the longitudinal beam of the movable wing 3, acting on the side of the T-shaped guide rail 5 of the fixed wing 2, constraining the lateral displacement and sway of the movable wing 3. The longitudinal spacing of the running wheel assembly 4 is adjustable from 90mm to 240mm, with a base design value of 180mm and an optimal value of 150mm to 180mm; the lateral spacing is adjustable from 260mm to 340mm, with a base design value of 260mm and an optimal value of 300mm to 340mm; the running wheel diameter is selectable from 28mm to 36mm, with a base design value of 32mm.

[0087] The servo motor 11 of the drive and transmission mechanism assembly 10 has a power of 1KW and a rated output speed of 2000rpm. The planetary reducer has a reduction ratio of 10, and the ball screw 13 has a diameter of 25mm and a lead of 10mm. Calculations show that the actual push-pull load of the movable wing 3 can reach about 18000N, and the extension speed can reach 2000mm / min. The stroke of the ball screw 13 meets the requirement that the movable wing 3 can extend outward by 660mm.

[0088] In addition, such as Figures 9-35 As shown, this application also provides a dynamic simulation method for the design of a wheel-rail type variator telescopic wing structure, including the following steps:

[0089] S1: Construct a three-dimensional geometric model of the wheel-rail type variant telescopic wing structure, and mesh the three-dimensional geometric model to form a finite element model.

[0090] Specifically, based on the aforementioned wheel-rail type variant telescopic wing structure, a three-dimensional geometric model is established, and the detailed structure described above is fully reproduced.

[0091] In one example, a finite element model of a scale prototype 21 (described later, and the scale of the scale prototype 21 and the 3D geometric model is 1:1) was built using Hypermesh. A gradient mesh size control strategy of 5mm-15mm was adopted (this application does not limit the specific mesh generation accuracy). 1D elements (rigids) were used to simulate bolt connections, and rigids + beam elements were used to simulate the running wheel assembly 4, which facilitates the extraction of the axial contact force of the wheel assembly. Finally, the finite element model was constructed, with a total of 1,509,612 meshes and 1,133,192 nodes. The mesh Jacobian ratio was greater than 0.7, which met the quality requirements of finite element calculation.

[0092] In this study, considering the computational accuracy and efficiency of the model, the T-shaped guide rail 5, the end plate of the fixed wing 2 (understood here as a plate set laterally at the end of the fixed wing 2), the middle plate of the movable wing 3 (understood here as a plate set laterally at the non-end of the movable wing 3), and the longitudinal beam of the movable wing 3 of the finite element model of the scale prototype 21 were divided into hexahedral elements using Solid185 elements, while the remaining parts were divided into quadrilateral elements using Shell181 shell elements. This fully reproduced the real geometric relationships and dimensional details of the fixed wing 2, movable wing 3, T-shaped guide rail 5, wheel assembly frame and connecting structure, providing a simulation basis that is closest to the physical prototype for subsequent finite element analysis, ensuring that the simulation results can truly reflect the mechanical behavior of the actual structure, and greatly improving the credibility of the model prediction.

[0093] In summary, differentiated element types are used to divide key load-bearing components and plate-like components. This ensures the calculation accuracy of stress concentration areas and complex stress parts, while using relatively large meshes for areas with relatively simple structures and gradual load changes. This effectively balances calculation accuracy and solution efficiency, avoiding the waste of computational resources and excessively long simulation cycles caused by over-refinement of the entire model, and meeting the design requirements of rapid iteration in engineering. The innovative use of 1D element rigids (such as...) Figure 10The solid blue conical structure (b) in the middle simulates the bolt connection, accurately reproducing the rigid constraints and load transfer characteristics of the bolt connection. Simultaneously, rigids+beam (as shown by the vertical green line on the right) beam elements are used to simulate the running wheel assembly 4. This ensures the overall rigidity of the wheel assembly structure and allows for the flexible extraction of key dynamic data such as axial contact force through the beam elements, realistically reproducing the nonlinear contact mechanics between the wheel and rail. This provides high-precision data support for analyzing the wheel-rail stress, wear risk, and motion stability during the expansion and contraction process. The final finite element model contains 1,509,612 meshes and 1,133,192 nodes, with a mesh Jacobian greater than 0.7, meeting the quality standards for finite element analysis. The high mesh quality effectively avoids problems such as computational divergence and stress distortion caused by element distortion, ensuring the stability and accuracy of subsequent simulation calculations such as modal analysis, static stiffness analysis, and dynamic contact analysis. This provides a solid data guarantee for the accurate correction of the dynamic model and structural optimization.

[0094] S2: Construct a rigid-flexible coupling dynamic model, designating the fixed wing 2 and movable wing 3 of the wheel-rail type variant telescopic wing structure as flexible bodies, and the remaining components of the wheel-rail type variant telescopic wing structure as rigid bodies. Introduce the structural elasticity of the movable wing 3 and the fixed wing 2 through modal synthesis, and use a polygonal contact model to simulate the nonlinear dynamic contact behavior between the running wheel assembly 4 and the T-shaped guide rail 5.

[0095] Based on the above example, considering the influence of the elastic deformation of the movable wing on the vibration response at key locations of the scale prototype 21, a rigid-flexible coupled dynamic model of the scale prototype 21 was established. First, based on the three-dimensional geometric model of the scale prototype 21, a mesh was generated using finite element method (FE) software. Then, appropriate principal nodes were selected, and substructure analysis was performed on the finite element model using Guyan's shrinkage theory (Guyan's static shrinkage theory). Finally, the rigid-flexible coupled dynamic model of the scale prototype 21 was generated in the dynamics software. The rigid-flexible coupled dynamic modeling process of the scale prototype 21 is as follows: Figure 11 As shown, the multiple degrees of freedom in the scaled prototype 21 finite element model are reduced to a finite number of master degrees of freedom using Guyan's reduction theory. This method preserves the transmitted forces of the master degrees of freedom and ignores the inertial forces of the slave degrees of freedom, thereby significantly reducing the computational load of the model.

[0096] It should be noted that the following principles should be followed when selecting master nodes: the hinge points at the corresponding positions in the dynamic model should be used as master degrees of freedom; the positions with larger structural vibration and deformation should be used as master degrees of freedom; and the selected master nodes should be able to characterize the geometric features of the model as much as possible.

[0097] A rigid-flexible coupling dynamic model of the telescopic wing was built in SIMPACK software. This model mainly consists of a fixed wing (2), a movable wing (3), a weight (14), a loading fixture, a wheel assembly, end limit wheels, and a large mass body (15). Figure 12 As shown. It should be noted that during the aircraft's ascent, the air exerts a downward force on the real wing. The weight 14 in the prototype model simulates the uniformly distributed downward load exerted by the air on the wing under real conditions, and the loading fixture is the fixture connecting weight 14. Through its large mass characteristic, which is much greater than the overall mass of the prototype, it can accurately reproduce the random vibration excitation under flight environment and test conditions, avoiding interference from the prototype's reaction force on vibration control accuracy, ensuring the stability of PID closed-loop control and the tracking accuracy of the acceleration target spectrum. It can also replicate the installation boundary conditions of the real fuselage, achieving complete unification of excitation and constraint benchmarks between simulation and physical experiments. Simultaneously, it isolates the coupling interference between static load and dynamic vibration excitation of the structure, ultimately achieving unbiased benchmarking between simulation and test data, providing reliable benchmark support for the accurate correction of the rigid-flexible coupling dynamic model of the telescopic wing. Among them, the fixed wing 2 and the movable wing 3 are flexible bodies, while the rest are rigid bodies.

[0098] To maximize the use of principal nodes to characterize the geometric features of the model and to designate locations of significant structural vibration and deformation as primary degrees of freedom, the principal nodes for fixed wing 2 and movable wing 3 are selected as follows: Figure 13 , Figure 14 As shown, the fixed wing 2 contains 95 main nodes, and the movable wing 3 contains 140 main nodes. The structural elasticity of the fixed wing 2 and the movable wing 3 is introduced by modal synthesis to restore the influence of structural flexible deformation on dynamic behavior. A polygonal contact model is used to simulate the nonlinear dynamic contact behavior between the wheel assembly and the T-shaped guide rail 5, which solves the problem of insufficient accuracy of the traditional single-point contact model in conformal contact scenarios, while avoiding the defect of excessive computation of finite element contact algorithm.

[0099] It's important to explain why a polygonal contact model is used: In multibody system dynamics calculations, contact problems are typically simplified to point-to-point interactions. While this method is widely used, single-point contact analysis has limitations, making it difficult to simulate multi-point and conformal contacts on complex surfaces. Finite element analysis, another method with higher accuracy, requires significant computational resources. The polygonal contact model can be seen as a compromise between point contact and finite element methods. The rigid body surface is modeled using polygons, the contact area is determined by the polygons and discretized, and finally, the contact force is solved using an elastic foundation model. Conformal contact is a core concept in contact mechanics and multibody system dynamics. It refers to two contacting objects whose contact surfaces have highly matched or even perfectly aligned geometric curvatures. The contact occurs on a continuous surface region of a certain area, rather than discrete point or line contact. In contrast, non-conformal contact (such as point contact between a steel ball and a steel plate, or line contact in the initial stage of gear meshing) is the default scenario for traditional contact algorithms.

[0100] When the telescopic wing is not in operation and is unloaded, the cylindrical surface of the running wheel and the plane of the T-shaped guide rail 5 are in ideal line contact (non-conformal); however, after being loaded, the wheel body and the rail surface undergo elastic deformation, forming a continuous rectangular contact band several millimeters wide, which becomes a typical surface-to-surface conformal contact.

[0101] The main parameter settings in the Simpack dynamics model are shown in Table 1.

[0102] It should be noted that flexible rail surfaces refer to all rail surfaces that come into contact with the wheels of the wheelset, while rigid rollers refer to all wheels of the wheelset.

[0103] Table 1. Main Connections in the Dynamic Model

[0104]

[0105] It should be noted that Joint 6 DOF by Input Functions (No. 35) can be understood as a drive joint with 6 degrees of freedom (3 translations and 3 rotations) that can be fully controlled by a custom time function. In this model, it is used to apply random vibration loads to the structural base 1 to reproduce the vibration environment of actual operation. Force Element Spring-Damper Parallel cmp (No. 5) can be understood as an elastic force element with spring and damper in parallel. It is used to simulate the elastic connection characteristics of fasteners such as bolts, transmit the force between components and buffer vibration, and fit the mechanical state of actual assembly. Joint 6DOF al-be-ga (No. 29) can be understood as a 6-DOF joint driven by active marker point displacement. The motion trajectory of the driven component can be controlled by a preset motion function. In this model, it is used to drive the movable wing 3 to complete the telescoping and deployment actions according to the design requirements. Force Element Poly-Contact (No. 199) (PCM) can be understood as a general-purpose multibody contact force element, which can accurately simulate the contact, friction and force transmission between contact surfaces of arbitrary shapes. In this model, it is used to reproduce the real contact working state between the rail surface and the roller in the wheel-rail telescopic mechanism; Joint 0 Degrees of Freedom can be understood as a fully constrained rigid fixed joint, which can realize a rigid connection between two parts without relative motion. In this model, it is used to simulate the fixed assembly state of the counterweight 14 and the movable wing 3; Connection Revolute 11 can be understood as a revolute pair that retains only the degree of freedom of rotation around the axis. Combined with dynamic Coulomb friction, it can restore the real rolling friction resistance. In this model, it is used to simulate the actual rotation characteristics of the running wheel.

[0106] The polygonal contact model consists of a polygonal contact surface and an elastic layer model. The running wheel adopts a three-dimensional geometric model, and the T-shaped guide rail 5 adopts a finite element flexible body mesh model. The contact area is determined by polygons and discretized. The normal contact force is solved based on the elastic basic model.

[0107] The Polygonal Contact Modeling Method (PCM) in Multibody Dynamics can be seen as a compromise between the point contact method and the finite element method. Specifically, the rigid body surface is modeled with polygons, the contact area is determined by the polygons and discretized, and finally the contact force is solved by the elastic foundation model.

[0108] The elastic fundamental model assumes the existence of a very thin elastic layer on the surface of a rigid (or flexible) body. If the tangential stress component within the elastic layer is ignored, the normal displacement can be derived. u n and pressure P n The relationship between them is:

[0109] In the formula, b For the thickness of the elastic layer, K This refers to the stiffness of the elastic layer.

[0110] For very thin elastic layer stiffness K It can be characterized by Young's modulus and Poisson's ratio: In the formula, E The Young's modulus of the material. The material's Poisson's ratio.

[0111] If the thin-layer assumption is not met, but the stiffness of the elastic layer satisfies the following relationship: In the formula, c 1 is a constant. Therefore, this structure can be considered to be applicable to the elastic basic model.

[0112] By strategically designing fixed wing 2 and movable wing 3 as flexible bodies, and other components as rigid bodies, the model closely matches the actual stress and deformation characteristics of a wheel-rail variant telescopic wing—fixed wing 2 and movable wing 3 are the main load-bearing and easily deformable structures, while the wheel assembly, tooling, etc., are rigid support components. This modeling method accurately reproduces the influence of the elastic deformation and vibration response of the flexible wing surface on the overall dynamic behavior, while avoiding the computational redundancy caused by the flexible modeling of non-critical components, ensuring a high degree of consistency between the model and the dynamic characteristics of the physical prototype. Substructure analysis of the finite element model is performed using Guyan's state condensation theory, by precisely selecting the locations of large vibration deformation in fixed wing 2 and movable wing 3 (i.e., the main... The selection of nodes significantly reduces the computational load. Furthermore, by incorporating the structural elasticity of the flexible body into the dynamic model through modal synthesis, the modal characteristics and deformation patterns of the fixed wing 2 and the movable wing 3 are perfectly reproduced, meeting the iterative requirements of engineering simulation. A polygonal contact model is used to simulate the nonlinear dynamic contact between the wheel assembly and the T-shaped guide rail 5. Compared to the traditional single-point contact model, this model can determine and discretize the contact area through polygons, accurately adapting to the actual scenario of conformal wheel-rail contact and solving the problems of insufficient accuracy and distorted contact force calculation in single-point contact. Simultaneously, compared to the pure finite element contact algorithm, this model significantly reduces the computational load, balancing contact analysis accuracy and simulation efficiency. Moreover, the contact setting of "flexible rail surface as the main surface and rigid roller as the secondary surface" better reflects the actual contact force state of the wheel and rail, enabling accurate calculation of the normal contact force and providing high-precision data support for analyzing wheel-rail wear, uneven force distribution, and other problems.

[0113] S3: Establish a random vibration environment model based on virtual excitation, and simulate the random vibration of the movable wing 3 and the fixed wing 2 through a PID control strategy;

[0114] Based on the above example, in order to establish a random vibration model of the airfoil based on virtual excitation and reproduce the airfoil vibration environment, the power spectral density function of the random vibration environment is used as the load input (refer to Table 2). The random vibration phenomenon of the airfoil is simulated by PID control strategy, and the frequency domain power spectral density distribution and contact force range between the main load transfer pulley and the slide rail of the airfoil extension section are calculated.

[0115] Table 2 Power spectral density function of random vibration environment

[0116]

[0117] Control systems that follow proportional, integral, and derivative control laws are called proportional-integral-derivative (PID) control. The transfer function of a PID controller is: ,in, This is the proportionality coefficient. This is called the integration time constant. is the differential time constant, and all three are adjustable parameters, with s being the Laplace complex frequency.

[0118] The output signal of the PID controller is: The above formula For signal deviation, Adjust parameters for PDI. This is the output signal of the controller. The proportional term controls the proportional relationship between the input and output, the integral term eliminates steady-state error, and the derivative term reduces the excess.

[0119] The transfer function of a PID controller can be written as: , where U(S) is the Laplace transform of the error signal e(t), representing the deviation between the system's expected output and the actual output.

[0120] E(S) is the Laplace transform of the controller output signal u(t), representing the control quantity that the PID controller outputs to the actuator after calculating based on the error.

[0121] More specifically, to simulate the vibration of the wing surface as realistically as possible, two force elements need to be defined at the connection between the large mass 15 and the ground. One element balances all the weight, while the other controls the large mass 15 to vibrate according to the expected acceleration signal. The model is as follows: Figure 15 As shown in the diagram. First, an initial force is applied to the large mass 15 to cause it to vibrate, and its acceleration signal is transmitted to the PID control system. By comparing the difference between this signal and the desired signal, a decision is made, and then the actuator adjusts the force applied to the large mass 15, thereby controlling the large mass 15 to vibrate according to the target acceleration. A schematic diagram is shown below. Figure 16 As shown.

[0122] Using the acceleration power spectral density function given in Table 2, the project team was able to reproduce the random vibration environment of the wing well using the established virtual excitation model, such as... Figure 17 As shown.

[0123] Using the power spectral density function of the random vibration environment as the load input, and combining it with the virtual excitation method to construct a vibration model, the random aerodynamic vibration load characteristics of the aircraft wing during actual flight can be accurately reproduced. This overcomes the limitation of traditional fixed-frequency vibration simulation in failing to reproduce the real random vibration environment. Simultaneously, the vibration load directly matches the power spectral density parameters of actual flight, ensuring a high degree of consistency between the simulation environment and the actual service conditions of the telescopic wing, guaranteeing the engineering reference value of subsequent simulation results such as contact force and dynamic response. A PID proportional-integral-derivative control strategy is introduced to regulate the vibration of the large mass body 15. Through the synergistic effect of matching the input-output relationship with the proportional term, eliminating steady-state errors with the integral term, and reducing the excess with the derivative term, the deviation between the actual acceleration signal and the desired signal of the large mass body 15 can be compared in real time, and the applied force can be dynamically adjusted. This achieves high-precision, closed-loop control of vibration acceleration, effectively avoiding problems such as amplitude deviation and frequency distortion during vibration, ensuring that the simulation effect of the random vibration of the wing surface is consistent with reality, and providing a basis for subsequent... The analysis of wheel-rail contact behavior under vibration provides a stable and reliable load environment. Two independent force elements are defined at the connection between the large mass body 15 and the ground to balance the weight and control the vibration, respectively. This decouples the structural gravity balance from the vibration excitation control. This not only offsets the overall structural weight through dedicated force elements, avoiding interference from gravity loads with the accurate transmission of vibration signals, but also allows the vibration control force element to focus on driving the vibration of the large mass body 15 according to the target acceleration, greatly improving the accuracy and flexibility of vibration control. This ensures the accuracy of random vibration simulation from the structural design level. The proportional coefficient, integral time constant, and derivative time constant of the PID controller are adjustable parameters. The control parameters can be flexibly adjusted according to the vibration characteristics of different flight scenarios (such as low-speed takeoff and landing, high-speed cruise, and harsh aerodynamic environments) to match the corresponding target acceleration signal. At the same time, the power spectral density function load input can be replaced as needed, allowing the model to adapt to random vibration simulation of all flight conditions of the retractable wing, greatly improving the model's versatility and scenario adaptability.

[0124] S4: Construct a scale prototype 21. Conduct calibration tests, free modal tests, static loading tests, dynamic expansion and contraction tests, and random vibration tests on the running wheel assembly 4 of the scale prototype 21 to obtain measured data. Compare the measured data with the simulation data obtained in steps S1-S3 to correct the parameters of the rigid-flexible coupling dynamic model. Specifically, the calibration test involves attaching strain gauges 26 to the running wheel assembly 4, applying a stepped force, and collecting data to calibrate the strain-load mapping relationship of the running wheel assembly 4. The free modal test involves using an elastic suspension method to achieve free boundary constraints on the scale prototype 21 and sweeping the frequency using an exciter. The system applies excitation to the wheel-rail type variator telescopic wing structure and collects the vibration response of the wheel-rail type variator telescopic wing structure to obtain the natural frequency, mode shape and damping ratio of the scale prototype 21. The static loading test is configured to apply graded static loads to the end of the movable wing 3 to obtain the static load transfer characteristics of the structure. The dynamic telescopic test is configured to drive the movable wing 3 to reciprocate telescopic motion under a set load condition and collect the dynamic wheel-rail force and traction force data of the entire telescopic process. The random vibration test is configured to apply random vibration excitation based on a given power spectral density function and collect the vibration acceleration, dynamic load and displacement data of the scale prototype under the combined vibration and telescopic conditions.

[0125] It should be noted that when applying excitation by sweeping the frequency of the exciter to collect the vibration response of the wheel-rail type variant telescopic wing structure, since the test site diagram is not shown, the model can be used as a reference. Figure 12 The excitation application point 16 is the midpoint of the upper surface of the base 1.

[0126] Based on the above example, in order to provide reliable support for subsequent structural parameter analysis and optimization, a full-condition test was conducted on the scale prototype 21 to obtain the measured true values ​​of the dynamic behavior of the telescopic wing structure, complete the benchmark verification of the simulation model and the iterative correction of parameters, and finally form a high-precision, engineering-applicable benchmark dynamic model, as detailed below.

[0127] Calibration tests were conducted on wheel assembly 4 of the running wheels. Due to the compact structure of the scale prototype 21, the wheel-rail contact force is difficult to collect directly using existing sensors. Therefore, load calibration tests were performed before the formal testing. For the running wheel calibration, static strength analysis was conducted on the running wheels, and the simulation results are as follows: Figure 18 As shown in the simulation results, the stress gradient is large and the area near both sides of the running wheel is relatively sensitive to stress. To ensure the sensitivity of the strain gauge bridge to stress / strain detection, this area is selected as the bonding area for strain gauge 26. Figure 19 As shown. Four strain gauges 26 are attached axially to the upper and lower surfaces of the running wheel axles, forming the entire bridge roadway.

[0128] The variant telescopic wing contains a total of 24 sets of running wheels, and the wheel set numbering is defined as follows: Figure 20 As shown, Figure 20 The number can be referenced Figure 1 The location of the middle running wheel assembly 4, and the single-sided movable wing 3, for example, the left movable wing 3, are as follows: Figure 3 As shown, it is equipped with 6 sets of running wheels 4, and the installation positions of the 6 sets of running wheels 4 are the same as those of the running wheels 4. Figure 20 In the numbering, the running wheel assembly 4 in the left movable wing 3 has the same installation position. Here, X represents longitudinal, Y represents transverse, L represents left, the inner side refers to the side closer to motor 11, and the outer side refers to the side farther from motor 11. L1-1 and L1-2 are positioned opposite each other and used for movement along the T-shaped guide rail 5. The calibration test uses a stepped loading method, with a load range of 1000N-8000N. After each loading, the wheels are allowed to rest for 15 seconds. The calibration wheelsets are then fixed to the test bench fixture using calibration tooling. Simultaneously with the stepped loading of the wheelsets, the strain of the wheel assembly bridge is collected using a Donghua data acquisition device, and the wheel assembly calibration coefficient is calculated. The calibration data for each wheelset obtained through the calibration test are presented.

[0129] like Figure 21 As shown, the average calibration coefficient is about 4.5 N / uε, and the load and strain have good linearity.

[0130] A linear conversion relationship between wheel axle strain and wheel-rail contact force was established, and accurate stress-load calibration coefficients for the wheel assembly were obtained. This provides a unified load calculation benchmark for subsequent static loading, dynamic expansion and contraction, and random vibration tests. Finally, the wheel-rail contact force calculation benchmark and stress-load mapping relationship in the simulation model were corrected to ensure the force measurement accuracy of the dynamic model.

[0131] Based on the above example, the free modal test is as follows.

[0132] The modal tests are divided into free modal tests for the movable wing 3 and free modal tests for the fixed wing 2. For the free modal tests of the movable wing 3, the constraint and loading method involves suspending it at one end using an elastic rope 24, and using a vibrator at the middle of the other end to provide excitation for frequency sweeping. The first-order natural frequency of the elastic rope 24 used in the modal tests is less than one-third of that of the scale prototype 21, meeting the test requirements. For the free modal tests of the fixed wing 2, the constraint and loading method involves suspending it in the middle of the cage using an elastic rope 24, and applying multi-point frequency sweeping excitation at the midpoints of both ends of the fixed wing 2. The vibrator and the force gauge 25 are connected by a flexible rod with sufficient axial stiffness to ensure effective transmission of the excitation force and safe use of the vibrator.

[0133] Considering the limitations on the number of sensors and data acquisition channels, the free modal test of the movable wing 3 divided the 25 measurement points into two groups: the first group consisted of measurement points C1-C11, and the second group consisted of measurement points C12-C25; the free modal test of the fixed wing 2 divided the 100 measurement points into five groups, with 20 measurement points in each group. Figure 22 , Figure 23 As shown.

[0134] The modal test conditions are set as shown in Table 3.

[0135] Table 3 Modal test conditions

[0136]

[0137] This experiment can obtain the first ten natural frequencies, mode shapes, and damping ratios of the movable wing 3 and the fixed wing 2, which can be used to correct the natural frequencies, mode shapes, and damping ratios of the flexible body in the simulation model. After comparing the experiment with the simulation, the maximum error of the modal frequency of the movable wing 3 is 3.67%, and the maximum error of the modal frequency of the fixed wing 2 is 10.04%, which provides a dynamic benchmark for subsequent dynamic expansion and random vibration simulation and experiment, making the overall dynamic simulation more accurate.

[0138] Based on the above example, the static loading experiment is as follows.

[0139] The test employed a tooling method to lift weights, which were bolted to the end of the movable wing 3 for loading. For example, a single weight weighed 25 kg, and the tooling weighed 14 kg. With safety supports and measures in place beforehand, the test was started according to the operating conditions selected in Table 4.

[0140] First, extend the movable wing 3 to the test extended state. Then, perform a balance reset operation on the wing model in this state. Once the reset is complete, begin signal acquisition. After the signal stabilizes, begin loading.

[0141] After ensuring adequate safety supports at the ends, select the appropriate load based on the operating conditions. Use an overhead crane to apply the load at the ends, ensuring consistent loading at both ends, perpendicular angles, and no significant deflection, tilting, or displacement of the movable wing 3 and the loading fixture. Once loading is complete at both ends, ensure the wing model is static and the sensor signals are stable after loading. After verifying that the loading process signals are correct, stop data acquisition and label the relevant test signal information.

[0142] After signal acquisition, the signal is pre-processed to obtain signal dynamics information for preliminary model analysis and adjustment of experimental details.

[0143] As shown in Table 4, the test covered 12 sets of engineering conditions, fully covering 6 load modes, 3 expansion / contraction states (full contraction / semi-extension / full extension), and 4 levels of vertical load from 25kg to 100kg.

[0144] Table 4 Static Loading Test Condition Settings

[0145]

[0146] Simulation and experimental results are as follows Figure 24 As shown, 1-2 and Figure 20 The left and right movable wings 3 correspond to 1-2, and so on.

[0147] Simulation calculations show that the loads on wheel sets 1-2 and 4-1 on both sides of the wing are basically the same as those on wheel sets 3-2 and 6-1, while wheel sets 2-2 and 5-1 in the middle do not participate in load bearing, and the simulation model basically does not show any off-center loading. However, in the experimental results, the loads on wheel sets 1-2 on both the left and right wings are significantly less than those on wheel set 3-2, the loads on wheel set 4-1 and 6-1 are basically the same, and the middle wheel sets 2-2 and 5-1 participate in load bearing, indicating a certain degree of off-center loading. This is mainly due to manufacturing tolerances and installation deviations of the test parts, which lead to inconsistencies between the wheel-rail clearance and the simulation model, and the impact of bolt preload on the wheel set calibration results after installation.

[0148] To eliminate the influence of wheel eccentric loading, the loads of each row of wheels are summed to obtain the total force of each row. ΔF1 represents the total load of the three lower outer wheel sets (1-2, 2-2, 3-2); ΔF2 represents the total load of the three upper inner wheel sets (4-1, 5-1, 6-1). The simulation and experimental errors are shown in Table 5. The maximum error is the sum of the loads of the lower outer wheels on the right wing, while the errors on the left wing are all within 1%. This indicates that the theoretical load calibration results can accurately reflect the stress on the wheel sets and can support load identification in dynamic expansion and contraction tests and random vibration tests.

[0149] Table 5 Comparison of the sum of theoretical and experimental wheel loads

[0150]

[0151] In summary, this experiment, under different loads and expansion / contraction states, obtained calibration coefficients through calibration tests and bridge strain acquired by a dynamic data acquisition device, yielded the true wheel-rail force distribution and end displacement of the movable wing 3 under static load. This provides a static benchmark for the simulation model, and can further correct the wheel-rail contact stiffness and boundary constraint parameters in the simulation model. Finally, it provides a reliable static benchmark and load calibration basis for subsequent dynamic expansion / contraction tests and random vibration tests.

[0152] Based on the above example, the dynamic stretching test is as follows.

[0153] After the static tests were completed, dynamic expansion and contraction tests were conducted on the model. This part of the test mainly focused on the expansion and contraction process of the movable wing 3 under different loads. The stress on each wheel set's running wheels was calculated using calibration data and bridge strain data acquired by the dynamic data acquisition device. The loading conditions for the dynamic expansion and contraction tests were the same as those for the static loading tests.

[0154] The experimental methods and procedures are as follows, and the specific parameter settings are shown in Table 6.

[0155] With safety support and measures in place in advance, select the appropriate operating condition from the operating condition table to begin the test.

[0156] First, retract the movable wing 3 to its fully retracted state. Then, perform a balance reset on the wing model in this state. Once the reset is complete, begin signal acquisition. After the signal stabilizes, begin the loading process.

[0157] After ensuring safety support at the ends, select the appropriate load based on the working conditions. Use an overhead crane to perform loading at the ends, ensuring consistent loading at both ends, vertical angles, and no significant deflection, tilting, or displacement of the movable wing 3 and the loading fixture.

[0158] After loading is complete at both ends, the dynamic extension and retraction process of movable wing 3 begins. Once the extension and retraction process is complete, the signal stabilizes normally. After verifying that the loading process signal is correct, data acquisition is stopped and relevant test signal information is labeled.

[0159] After signal acquisition, the signal is pre-processed to obtain signal dynamics information for preliminary model analysis and adjustment of experimental details.

[0160] Table 6 Dynamic Expansion Test Condition Settings

[0161]

[0162] The wheel load results obtained from experiments and simulations are as follows: Figure 25 and Figure 26 As shown. During a complete contraction and extension process, the simulated and experimental results of the wheel assembly load exhibit a W-shaped trend, with the maximum load occurring in the fully extended state. According to the experimental results, the load curves of the two tests are basically consistent, indicating good repeatability. During the test, an off-center loading phenomenon was clearly observed, with the middle wheel assemblies 2-2 and 5-1 participating in the load-bearing process and the load direction changing. This indicates that after wheel-rail separation, the change in the direction of the wheel frame opening leads to a change in the bending direction of the wheel axle. The simulation results show that the middle wheel assembly does not bear the load, and the loads of the wheel assemblies in the same row are basically the same.

[0163] By extracting traction forces from experiments and simulations, such as 27 and Figure 28As shown. The force is around 200N. When the variator telescopic wing starts, it needs to overcome static friction, resulting in a relatively large traction force. Due to the relatively poor deformation coordination ability of the lead screw mechanism in the prototype variator wing's telescopic mechanism, the test results show that the traction force is still relatively large in the retracted state.

[0164] This experiment can obtain the real dynamic wheel-rail force and traction force variation laws of the telescopic wing 3 during continuous telescopic motion, providing a dynamic behavior benchmark for the simulation model and correcting boundary conditions such as dynamic friction coefficient and end-position limit triggering conditions in the simulation model. It provides dynamic performance basis for structural parameter optimization, ensuring that the telescopic wing meets design requirements under actual motion conditions.

[0165] Based on the above example, the random vibration test is as follows.

[0166] Random vibration test loading method as follows Figure 31 As shown. The prototype was fixed to the vibration table 27 using a fixture, and an upward vertical tension was applied to the middle position of the end of the movable wing 3 of the prototype using an elastic rope 24.

[0167] The random vibration test can set multiple working conditions. In a certain example, nine working conditions are set as shown in Table 7. All working conditions have the same constraint method. The fixture is designed according to the vibration table surface 23 and bolts are used for constraint. The loading methods of the nine working conditions are different. The loading methods of working conditions one to eight are the same, and the fixture is used for loading. Working condition nine is loaded with elastic rope 24.

[0168] The tooling loading method involves using a designed tooling to lift weights and then fixing them to the ends of the movable wing 3 with bolts. The loading tooling is as follows: Figure 29 As shown, the fixture comprises a counterweight lifting rod, a counterweight baffle 20, and lifting rings. The connecting hole 17 of the counterweight lifting rod serves to connect, position, and fix the wing to the counterweight connecting rod 18. The counterweight connecting rod 18 connects the wing to the counterweight block 19 and can bear the load. The counterweight block 19 is used to apply accurate loads, simulating the vertical load exerted by air on the wing during takeoff. The counterweight baffle 20 supports the counterweight block 19, preventing it from falling off.

[0169] The counterweight lifting rod and the counterweight baffle 20 are connected by bolts, and the lifting ring is directly installed on the counterweight lifting rod. After the counterweight is installed onto the loading fixture, it is assembled onto the end of the movable wing 3 using an overhead crane. The installation and loading method is as follows: Figure 30 As shown, it includes a base 1, a fixed support fixture 22, a vibration table surface 23, a weight 14, and a vibration table 27, wherein the weight of a single weight is 25kg and the weight is 14kg.

[0170] The elastic rope 24 is used to vertically constrain the middle of the end of the movable wing 3 when the prototype 21 is fully extended. A force gauge 25 is needed to connect to the middle to ensure loading accuracy. The loading method is as follows: Figure 31 As shown.

[0171] Considering the vibration characteristics and response features of the scale prototype 21, vibration tests were conducted based on the power spectral density function of the random vibration environment as shown in Table 2.

[0172] The operating conditions are set as shown in Table 7.

[0173] Table 7 Random Vibration Test Conditions

[0174]

[0175] Simulation and experimental results of wingtip acceleration in full extension state are as follows: Figure 32 As shown, the vibration acceleration amplitudes of the two are basically the same (4g), and the first three main frequencies are around 16.9Hz, 76.6Hz, and 125.9Hz.

[0176] Figure 33 and Figure 34 This refers to the dynamic load of the wheel load during the expansion and contraction process under random vibration. Analysis shows that the load trends of the wheel sets in the test and simulation results are consistent. Both the test and simulation results indicate that the main load-bearing wheels are the two outer wheel sets (1-2, 3-2, 4-1, 6-1), while the middle wheel sets (1-2, 5-1) do not participate in the load-bearing or bear very little load, and there is a transition from constant contact to collision at the middle position. Under random vibration, the amplitude of wheel load variation is significantly larger, especially for the rear wheel sets L4-1 and L6-1 in the fully contracted state.

[0177] like Figure 35 The figure shows the experimental and simulation results of the traction force of the telescopic wing motor 11 under random vibration conditions. The results indicate that the simulation calculation results of the traction force of motor 11 are in good agreement with the experimental results. Both simulation and experimental results show that the traction force gradually decreases during retraction and gradually increases during extension. Therefore, the traction force of motor 11 is greater in the fully extended state than in the fully retracted state.

[0178] The experiment obtained the vibration acceleration, dynamic wheel-rail force, dynamic displacement, and dynamic traction force of the wing under flight vibration environment, verifying the correctness of the dynamic model.

[0179] A scaled-down prototype of 21 was constructed and subjected to five full-condition physical tests: calibration, modal analysis, static loading, dynamic extension / retraction, and random vibration. The prototype's structure maintains the same mechanical properties as a real telescopic wing. The test conditions comprehensively cover conditions including end-limited and telescopic states, multi-level loads, and vibrations. This approach closely mirrors the complex operating conditions of actual aircraft service while reducing the engineering complexity of test benches and load application through scaled-down design, achieving an optimal balance between test costs and simulation reference value. To address the challenge of directly measuring wheel-rail contact forces due to the prototype's compact structure, strain gauges of 26 were selected from stress-sensitive areas of the wheel axle through static strength analysis and bonded to form a full-bridge circuit. A 1000N-800N strain gauge was used. Twelve wheelsets were calibrated using a 0N stepped loading method, yielding an average linear calibration coefficient of 4.5N / με, achieving indirect and precise quantification of wheel-rail contact force. The full-bridge design effectively counteracted stress interference in non-measurement directions. The stepped loading and 15-second pressure holding operation ensured the stability and linearity of the calibration data, providing a high-precision benchmark for load identification in subsequent dynamic tests. Free modal tests were conducted on the movable wing 3 and fixed wing 2, using a free constraint method with elastic rope 24 suspension and multi-point frequency sweep excitation, matching the vibration characteristics of the scale prototype 21. Due to sensor channel limitations, measurement points were grouped for testing, and the first ten natural frequencies, mode shapes, and damping ratios were fully acquired. The test and simulation modal frequencies were compared. The maximum error is controllable, accurately capturing the inherent dynamic characteristics of different structures of the telescopic wing. This provides a direct benchmark for correcting inherent parameters such as stiffness and damping in the rigid-flexible coupled dynamic model, significantly improving the model's prediction accuracy for structural vibration response. Static loading tests completely replicate the installation boundary conditions of the simulation model, applying vertical loads using weights and specialized tooling while eliminating structural self-weight interference. The tests cover 12 engineering conditions, each corresponding to a simulation condition. Through experiments, the difference in wheel assembly off-center loading between simulation and actual conditions (caused by manufacturing and installation tolerances) was discovered and quantified. The effect of off-center loading was eliminated by summing the total load of the wheel assembly, verifying the effectiveness of the calibration coefficients and accurately obtaining data under different conditions. The wheel-rail load distribution and structural static deformation data provide a core basis for targeted correction of the wheel-rail contact stiffness and structural static stiffness parameters of the model, making the model more consistent with the actual load transfer law. The scale prototype 21 was fixed on the vibration table 27 and two loading methods, tooling and elastic rope 24, were designed. The power spectral density function was reasonably scaled according to the test bench capacity and prototype strength, and nine sets of random vibration tests were carried out. The test accurately reproduced the random vibration environment of the aircraft wing surface. The test results of wingtip acceleration, wheel group dynamic load, and motor 11 traction force are consistent with the trend and amplitude, which verifies the multi-physics field coupling simulation capability of the rigid-flexible coupled dynamic model combined with the random vibration environment model.

[0180] In addition, the above-mentioned calibration tests establish strain-load mapping to achieve indirect and accurate measurement of wheel-rail forces; free modal tests: obtain multi-state inherent characteristics and correct model stiffness and damping; static loading tests: verify load transfer and static stiffness and correct contact stiffness parameters; dynamic expansion and contraction tests: obtain load and traction force during motion and correct dynamic friction and transmission parameters; random vibration tests: simulate real vibration environment and correct vibration coupling and dynamic contact parameters.

[0181] In addition, simulation provides direction and reduces costs for experiments, while experiments verify simulations and correct deviations. The combination of the two achieves a complete closed loop from theoretical design to simulation analysis, then to experimental verification and model correction, and finally back to structural optimization. This ensures that the structural design and dynamic simulation methods of the telescopic wing are always based on scientific quantitative data, rather than simple theoretical derivation or empirical judgment. Simulation completes the early-stage rapid design and iteration, while experiments verify and correct the model, ensuring both R&D efficiency and the engineering feasibility of the design scheme. The corrected high-precision simulation model can replace a large number of subsequent physical experiments, providing a reliable simulation basis for subsequent product modifications and multi-specification designs. Ultimately, this supports the industrialization and practical application of this orbital variator telescopic wing technology. The high-precision simulation model based on experimental verification can conduct dynamic performance simulation analysis under different flight conditions and after aging and wear during the later stages of product use, predicting performance changes and failure risks during product service, providing a scientific basis for the maintenance, upkeep, and life assessment of the telescopic wing, and ensuring the reliability of the product throughout its entire life cycle.

[0182] Based on the above example, the experimental data are compared with the simulation to complete the iterative correction of the model and form a high-precision simulation system. Based on the corrected high-precision model, further variable parameter analysis of the telescopic mechanism is carried out.

[0183] Specifically, using the longitudinal spacing of the wheel set, the lateral spacing of the wheel set, the diameter of the running wheel, the distance between the end limit wheel and the rail surface, the wheel-rail friction coefficient, and the bearing friction coefficient as core variables, multiple sets of variable parameter simulation conditions were set up. Each time, the variable was one of the following: longitudinal spacing of the wheel set, lateral spacing of the wheel set, diameter of the running wheel, distance between the end limit wheel and the rail surface, wheel-rail friction coefficient, or bearing friction coefficient. The influence of each parameter on the wheel-rail force distribution, traction force, vibration response, and end displacement of the telescopic wing was quantified, as follows:

[0184] (1) Influence of longitudinal spacing of running wheel set 4: As the longitudinal spacing of the wheel set decreases, the wheel-rail force shows a trend of first increasing and then decreasing;

[0185] (2) Influence of the lateral spacing of the running wheel set 4: As the lateral spacing of the wheel set increases, the vibration acceleration of the fixed wing 2 and the displacement of the ends of the fixed wing 2 and the movable wing 3 decrease accordingly, which can effectively suppress structural vibration and deformation, and at the same time alleviate the adverse effects of the eccentric load.

[0186] (3) Influence of running wheel diameter: Within a certain range, the change in wheel diameter has little effect on wheel-rail force, traction force, structural vibration and displacement;

[0187] (4) The influence of the distance between the end limit wheel assembly 6 and the longitudinal beam of the rolling movable wing 3: When the distance increases, the wheel-rail force first increases and then remains unchanged when there is no extension or retraction. At 0 mm, the wheel bears part of the load. When the distance increases, the rear limit wheel stops bearing the load, and the wheel-rail force rises and stabilizes. During the retraction process, the larger the distance, the later the end limit wheel participates in bearing the load. When the distance increases, the vibration acceleration at the end of the movable wing 3 decreases accordingly. (5) The influence of the friction coefficient: The wheel-rail friction coefficient and the bearing friction coefficient only have a significant impact on the traction force, and the traction force is much more sensitive to the bearing friction coefficient than the wheel-rail friction coefficient.

[0188] (6) Effects of off-center loading: Off-center loading leads to increased wheel-rail force and displacement near the loading side and decreased force and displacement away from the loading side. Vibration and traction fluctuations are significantly aggravated when the movable wing 3 is close to the fully retracted position. Increasing the lateral spacing of the running wheel set 4 can effectively suppress the adverse effects of off-center loading. Based on the above influence patterns, combined with engineering constraints such as structural bearing capacity, motion smoothness, drive power consumption, and vibration suppression, the key parameters of the telescopic wing structure are quantitatively optimized to determine the optimal design scheme.

[0189] The basic principles of this application have been described above with reference to specific embodiments. However, it should be noted that the advantages, benefits, and effects mentioned in this application are merely examples and not limitations, and should not be considered as essential features of each embodiment of this application. Furthermore, the specific details disclosed above are for illustrative and facilitative purposes only, and are not limitations. These details do not limit the application to the necessity of employing the aforementioned specific details for implementation.

[0190] The block diagrams of devices, apparatuses, devices, and systems involved in this application are merely illustrative examples and are not intended to require or imply that they must be connected, arranged, or configured in the manner shown in the block diagrams. As those skilled in the art will recognize, these devices, apparatuses, devices, and systems can be connected, arranged, and configured in any manner. Words such as “comprising,” “including,” “having,” etc., are open-ended terms meaning “including but not limited to,” and are used interchangeably with them. The terms “or” and “and” as used herein refer to the terms “and / or,” and are used interchangeably with them unless the context clearly indicates otherwise. The term “such as” as used herein refers to the phrase “such as but not limited to,” and is used interchangeably with it.

[0191] It should also be noted that in the apparatus, equipment, and housing of this application, each component or step can be disassembled and / or reassembled. These disassemblies and / or reassemblies should be considered as equivalent solutions of this application.

[0192] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use this application. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein can be applied to other aspects without departing from the scope of this application. Therefore, this application is not intended to be limited to the aspects shown herein, but rather to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0193] It should be understood that the qualifiers “first,” “second,” “third,” “fourth,” “fifth,” and “sixth” used in the description of the embodiments of this application are only used to more clearly illustrate the technical solutions and are not intended to limit the scope of protection of this application.

[0194] The above description has been given for purposes of illustration and description. Furthermore, this description is not intended to limit the embodiments of this application to the forms disclosed herein. Although numerous exemplary aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, alterations, additions, and sub-combinations thereof.

Claims

1. A dynamic simulation method for the design of a wheel-rail type variant telescopic wing structure, characterized in that, include: S1: Construct a three-dimensional geometric model of the wheel-rail type variant telescopic wing structure, and mesh the three-dimensional geometric model to form a finite element model; S2: Construct a rigid-flexible coupling dynamic model, designate the fixed wing and movable wing of the wheel-rail type variant telescopic wing structure as flexible bodies, and the remaining components of the wheel-rail type variant telescopic wing structure as rigid bodies, and introduce the structural elasticity of the movable wing and the fixed wing through modal synthesis method, and use a polygonal contact model to simulate the nonlinear dynamic contact behavior between the running wheel assembly and the T-shaped guide rail. S3: Establish a random vibration environment model based on virtual excitation, and simulate the random vibration of the movable wing and the fixed wing through a PID control strategy; S4: Construct a scale prototype and conduct calibration tests, free modal tests, static loading tests, dynamic expansion and contraction tests, and random vibration tests on the running wheel assembly of the scale prototype to obtain measured data. Compare the measured data with the simulation data obtained in steps S1-S3 to correct the parameters of the rigid-flexible coupling dynamic model. The calibration test is configured to attach strain gauges to the running wheel assembly, apply stepped force, and collect data to calibrate the strain-load mapping relationship of the running wheel assembly. The free modal test is configured to use an elastic suspension method to achieve free boundary constraints on the scale prototype and use a vibrator to sweep the frequency of the wheels. The wheel-rail variant telescopic wing structure is excited, and the vibration response of the wheel-rail variant telescopic wing structure is collected to obtain the natural frequency, mode shape and damping ratio of the scale prototype. The static loading test is configured to apply graded static loads to the end of the movable wing to obtain the static load transfer characteristics of the structure. The dynamic telescopic test is configured to drive the movable wing to reciprocate telescopic motion under a set load condition and collect dynamic wheel-rail force and traction force data throughout the telescopic process. The random vibration test is configured to apply random vibration excitation based on a given power spectral density function and collect vibration acceleration, dynamic load and displacement data of the scale prototype under combined vibration and telescopic conditions.

2. The dynamic simulation method for designing a wheel-rail type variator telescopic wing structure according to claim 1, characterized in that, The three-dimensional geometric model is divided into regions and meshed. The T-shaped guide rail, the end plate of the fixed wing, the middle plate of the movable wing, and the longitudinal beam of the movable wing are divided into hexahedral elements using Solid185 elements. The remaining components of the wheel-rail type variant telescopic wing structure are divided into quadrilateral elements using Shell181 plate shell elements.

3. The dynamic simulation method for designing a wheel-rail type variator telescopic wing structure according to claim 1, characterized in that, The free modal test includes free modal tests of the movable wing and the fixed wing, in order to obtain the first ten natural frequencies, mode shapes, and damping ratios of the scale prototype.

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