General wing multi-point loading test bed

Abstract

The application discloses a kind of general wing multi-point loading test benches, including aluminum profile frame, 8 several fixed pulley groups, kevlar rope, sucking disc, weight and three movable clamps;The direction of force is changed by fixed pulley, the weight gravity is converted into the pulling force on the upper surface of wing, multi-point loading is realized, the application is applicable to aircraft ground structure strength test equipment field, use standard weight as force source, cooperate with low friction bearing pulley, high-strength low elongation kevlar rope and high-precision universal sucking disc, ensure the accuracy and repeatability of loading force value, loading point position and force value can be independently adjusted, pulley group 360 ° rotating mechanism makes that kevlar rope can be led out from any direction, can adapt to complex chordwise load distribution, avoid rope and frame or wing interference, canvas strip or sucking disc loading mode gets rid of the dependence on specific airfoil card plate, movable clamp adapts to different wings of different span, different installation form.

Description

Technical Field

[0001] This invention relates to the field of ground structural strength testing equipment for aircraft, and more particularly to a universal multi-point loading test bench for airfoils. Background Technology

[0002] Static testing of airfoils is a core physical testing method for verifying the structural design strength, stiffness, and safety margin of aircraft. For large aircraft, complex hydraulic or electric servo loading systems are commonly used, along with rigid clamps that fit perfectly against the airfoil surface. This approach offers high precision and advanced control, but it suffers from significant drawbacks such as high system cost, limited compatibility of specialized tooling, large footprint, and complex maintenance. It is unsuitable for small aircraft development, teaching experiments, or high-level amateur verification scenarios with limited budgets and rapid model iteration.

[0003] In the field of small aircraft, the current common alternative is the "inverted sandbag / water bag method," which involves directly stacking sandbags or placing water-filled bags on the underside of the wing to simulate loads. This method suffers from drawbacks such as coarse load quantification, uncontrollable load distribution, the introduction of localized compression effects through contact loading, and the inability to visualize the testing process. Therefore, there is an urgent need for a solution that combines the loading accuracy of specialized equipment with the low cost and high versatility of a simple method. Summary of the Invention

[0004] In view of the above problems, the present invention is proposed to provide solutions that overcome or at least partially solve the above problems.

[0005] According to one aspect of the present invention, a universal wing multi-point loading test bench is provided, comprising an aluminum profile frame, a wing mounting unit provided in the middle of the aluminum profile frame for fixing the wing, and a load application unit provided in the upper part of the aluminum profile frame, the load application unit comprising a plurality of loading modules distributed above the wing for applying loads to a plurality of points on the wing.

[0006] Preferably, the upper end of the aluminum profile frame is provided with several optical axis guide rails along the length of the wing, and the loading modules are all slidably mounted on their corresponding optical axis guide rails to change the load application position.

[0007] Preferably, the system includes a fixed pulley assembly, a Kevlar rope, a connector, and a set of weights. The fixed pulley assembly is slidably disposed below the optical axis guide rail. The Kevlar rope passes through the fixed pulley assembly, and its inner end is connected to a predetermined loading point on the wing via the connector. Its other end is connected to the corresponding weight.

[0008] Preferably, the fixed pulley assembly includes two fixed pulleys with parallel axes. The Kevlar rope passes around the two fixed pulleys in a C-shaped path. The fixed pulleys use deep groove ball bearings as pulleys and are integrated through a metal housing. A slider is provided on the top of the fixed pulley. The slider is slidably limited to the optical axis guide rail. A 360° rotation mechanism is provided between the slider and the fixed pulley, which includes a precision thrust bearing, a locking turntable, and a scale. After the locking handle is released, the fixed pulley as a whole can rotate continuously around the vertical axis, and the rotation angle can be read through the scale. After locking, the direction can be fixed.

[0009] Preferably, the connector is a vacuum suction cup with a flat bottom, which is connected to the Kevlar rope via a universal connector to adapt to the slight curvature changes of the wing surface.

[0010] Preferably, the connector is made of high-strength cotton canvas, which is circular with a diameter of 30mm. One end of the connector is coated with removable pressure-sensitive adhesive and is attached to a predetermined loading point on the upper surface of the wing before use. The other end of the canvas strip is connected to a Kevlar rope.

[0011] Preferably, the aluminum profile frame has a side beam on the middle side, the wing is fixed to the inside of the side beam, and the wing mounting unit is slidably mounted on the side beam.

[0012] Preferably, the wing mounting unit includes: A leading-edge clamp for holding the reinforcing structure or mounting hole on the leading edge of the wing; A spars clamp is used to hold the main spars or the strongest load-bearing structure of the wing. A trailing edge clamp for holding auxiliary structures or mounting holes on the trailing edge of the wing.

[0013] Preferably, the spar clamp is an inverted T-shaped 6061 aluminum alloy clamp, and the spar lugs are connected using M5 standard metric bolts; the leading edge clamp and the trailing edge clamp are L-shaped 6061 aluminum alloy clamps, and the clamping jaws are equipped with soft silicone pads.

[0014] Preferably, the trailing edge clamp, spar clamp, and leading edge clamp are all mounted on the T-slot of the side crossbeam via bottom sliders, and the spacing can be freely adjusted along the wingspan.

[0015] In this invention, standard weights are used as the force source, combined with low-friction bearing pulleys, high-strength, low-elongation Kevlar ropes, and high-precision universal suction cups to ensure the accuracy and repeatability of the applied force. The loading point position and force value can be adjusted independently. The 360° rotation mechanism of the pulley group allows the Kevlar rope to be led out from any direction, which can adapt to complex chordal load distributions and avoid interference between the rope and the frame or wing. The loading method of canvas strips or suction cups is free from dependence on specific airfoil clamps. The movable clamps can adapt to wings with different spans and different installation forms. The optical axis guide rail and T-slot work together to provide multi-degree-of-freedom positioning capabilities.

[0016] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and in order to make the above and other objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are described below. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a three-dimensional axonometric view of a preferred embodiment of the present invention, showing the overall layout of the test bench and the spatial relationship of its main components; Figure 2 This is a front view of the invention, showing the aluminum profile frame, the arrangement of loading modules on the top crossbeam, and the wing mounting height; Figure 3 This is a side view of the invention, showing the installation details of the fixed pulley block, the winding path of the Kevlar rope, and the structure of the rotating mechanism; Figure 4 This is a top view of the invention, showing the distribution of multiple loading points along the wing span and the clamping positions of the three clamps.

[0019] 1. Aluminum profile frame; 2. Kevlar rope; 3. Fixed pulley block; 4. Weights; 5. Suction cup; 6. Wing; 7. Trailing edge clamp; 8. Wing spars clamp; 9. Leading edge clamp. Detailed Implementation

[0020] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0021] The terms "comprising" and "having," and any variations thereof, in the specification, embodiments, claims, and drawings of this invention are intended to cover non-exclusive inclusion, such as including a series of steps or units.

[0022] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0023] Example 1: A general-purpose multi-point loading test bench for airfoils, such as Figures 1-4 As shown, it includes an aluminum profile frame 1, a wing mounting unit in the middle of the aluminum profile frame 1 for fixing the wing 6, and a load application unit on the upper part of the aluminum profile frame 1. The load application unit includes several loading modules, which are distributed above the wing 6 for applying loads to several points on the wing 6.

[0024] Furthermore, the upper end of the aluminum profile frame 1 is provided with several optical axis guide rails along the length of the wing 6, and the loading modules are all slidably mounted on their corresponding optical axis guide rails to change the load application position.

[0025] Furthermore, it includes a fixed pulley assembly 3, a Kevlar rope 2, a connector 5, and a set of weights 4. The fixed pulley assembly 3 is slidably positioned below the optical axis guide rail. The Kevlar rope 2 passes through the fixed pulley assembly 3, and its inner end is connected to the corresponding predetermined loading point of the wing 6 through the connector 5. Its other end is connected to its corresponding weight 4.

[0026] Furthermore, the fixed pulley assembly 3 includes two fixed pulleys with parallel axes. The Kevlar rope 2 passes around the two fixed pulleys in a C-shaped path. The fixed pulleys use deep groove ball bearings as pulleys and are integrated through a metal shell. A slider is provided on the top of the pulley, and the slider is slidably limited to the optical axis guide rail. A 360° rotation mechanism is provided between the slider and the fixed pulley, which consists of a precision thrust bearing, a locking turntable, and a scale. After the locking handle is released, the fixed pulley as a whole can rotate continuously around the vertical axis, and the rotation angle can be read through the scale. After locking, the direction can be fixed.

[0027] In one possible implementation, the connector 5 is a vacuum suction cup with a flat bottom, which is connected to the Kevlar rope 2 via a universal connector to adapt to minute curvature changes on the surface of the wing 6.

[0028] In one possible implementation, the connector 5 is made of high-strength cotton canvas, which is circular with a diameter of 30mm. One end of the connector is coated with removable pressure-sensitive adhesive and is attached to a predetermined loading point on the upper surface of the wing 6 before use. The other end of the canvas strip is connected to a Kevlar rope.

[0029] Furthermore, a side beam is provided on the middle side of the aluminum profile frame 1, the wing 6 is fixed to the inner side of the side beam, and the wing mounting unit is slidably mounted on the side beam.

[0030] Furthermore, the wing mounting unit includes: A leading edge clamp 9 is used to hold the reinforcing structure or mounting hole on the leading edge of the wing 6; A wing spar clamp 8 is used to clamp the main wing spar or the strongest load-bearing structure of the wing 6; A trailing edge clamp 7 is used to hold the auxiliary structure or mounting hole on the trailing edge of the wing 6.

[0031] Furthermore, the spar clamp 8 is an inverted T-shaped 6061 aluminum alloy clamp, which uses M5 standard metric bolts to connect the spar lugs; the leading edge clamp 9 and the trailing edge clamp 7 are L-shaped 6061 aluminum alloy clamps, with soft silicone pads on the clamping jaws.

[0032] Furthermore, the trailing edge clamp 7, spar clamp 8, and leading edge clamp 9 are all mounted on the T-slots of the side crossbeams via bottom sliders, allowing the spacing to be freely adjusted along the wing span.

[0033] Furthermore, wing 6 is a model wing used for static testing. Its interior is made of balsa wood or composite material, and its exterior is covered with transparent or semi-transparent heat-shrinkable plastic skin to facilitate direct observation of structural deformation, strain gauge working status, and final failure mode during loading.

[0034] Furthermore, the aluminum profile frame 1 is equipped with height-adjustable feet at the four bottom corners for leveling the entire test bench on non-level ground; at the same time, handles are installed on both sides of the frame for easy movement.

[0035] By adopting the above technical solution, the present invention has the following significant advantages: High cost performance: All parts and profiles are made of commercially available standard parts and profiles, resulting in low cost and easy processing and assembly.

[0036] High loading accuracy: Using standard weights as the force source, combined with low-friction bearing pulleys, high-strength, low-elongation Kevlar ropes, and high-precision universal suction cups, the accuracy and repeatability of the loading force value are ensured.

[0037] Flexible load distribution: The loading point position and force value can be adjusted independently. The 360° rotation mechanism of the pulley block allows the Kevlar rope to be led out from any direction, which can adapt to complex chordal load distribution and avoid interference between the rope and the frame or wing.

[0038] High versatility: The canvas strip loading method eliminates the dependence on specific airfoil clamps, and the movable clamps can adapt to wings with different spans and different installation forms; the optical axis guide rail and T-slot work together to provide multi-degree-of-freedom positioning capabilities.

[0039] Teaching and observation friendly: The transparent skin wing allows for direct observation of the internal structural deformation and failure process, and the canvas strip adhesive loading does not damage the skin, making it easy to conduct multiple tests and possessing extremely high teaching demonstration value.

[0040] Safe and easy to use: Mechanical loading, no dangerous sources such as high-pressure oil or electricity, and can be operated by a single person.

[0041] Example 2: Reference Figures 1 to 4The universal wing multi-point loading test bench of this embodiment uses 4040 series industrial aluminum profiles for its aluminum frame 1, which is approximately 1.6 meters long, 1 meter wide, and 1.2 meters high. All connections are secured with angle brackets and hex bolts. Two T-slot crossbeams are installed parallel to each other on the top of the frame, and two T-slot crossbeams are also installed at appropriate heights on the sides.

[0042] The load application unit consists of eight identical loading modules. Each module includes a fixed pulley assembly 3, a Kevlar rope 2, a canvas strip 5, and a set of weights 4. The fixed pulley assembly 3 is an integrated small component containing two deep groove ball bearings as pulleys, integrated through a metal housing. A slider that can slide along a T-slot is mounted at its bottom, and a 360° rotating mechanism is provided between the slider and the pulley assembly. This rotating mechanism consists of a precision thrust bearing, a locking dial, and a scale; after releasing the locking handle, the entire pulley assembly can rotate continuously around the vertical axis, and the rotation angle can be read through the scale. After locking, the direction is fixed. In this way, the direction of the Kevlar rope 2 can be set to any horizontal angle, such as 0° to 360°, thereby flexibly avoiding frame columns, measuring instruments, or other interference, and accurately aligning with the canvas strip attachment point at any chordal position on the upper surface of the wing.

[0043] The Kevlar rope 2 has a diameter of 1mm, and one end is connected to the canvas strip 5 via a stainless steel quick-release buckle. The canvas strip is made of high-strength cotton canvas, is circular with a diameter of 30mm, and one end is coated with removable pressure-sensitive adhesive, which is attached to the predetermined loading point on the upper surface of the wing 6 before use; the other end of the canvas strip is connected to the Kevlar rope. The Kevlar rope passes around two fixed pulleys in a "C" shaped path and then leads downwards, with the end connected to the weight 4 via a detachable hook. The weight 4 is a standard combination of 1kg, 2kg, and 5kg, which can be combined to create single-point loads ranging from 5kg to 50kg.

[0044] Wing mounting unit: Contains three clamps. Spall clamp 8 is an inverted T-shaped 6061 aluminum alloy clamp, using M5 standard metric bolts to connect to the spall lugs; leading edge clamp 9 and trailing edge clamp 7 are L-shaped 6061 aluminum alloy clamps with soft silicone pads at the clamping jaws. The three clamps are mounted on the T-slots of the side crossbeams via bottom sliders, allowing for free adjustment of the spacing along the wing span.

[0045] Test operation procedure: Leveling: Adjust the frame to be level using the adjustable feet at the bottom.

[0046] Install the wing: Place the balsa wood transparent skin wing 6 between the three clamps. First, lock the spar clamp 8 to hold the main spar at the position of 25%-30% of the chord. Then, adjust the leading and trailing edge clamps 9 and 7 for auxiliary positioning and clamp them in the leading and trailing edge reinforcement areas.

[0047] Arrange the loading points: According to the spanwise and chordwise coordinates determined in the static test task book, slide the eight fixed pulley groups 3 along the T-slot to the corresponding spanwise position, then adjust the chordwise position along the optical axis guide rail 10, and finally rotate the 360° rotating mechanism to make the Kevlar rope outlet direction perpendicular to the canvas strip pasting point, and lock all degrees of freedom.

[0048] Connection and Loading: Attach the adhesive side of canvas strip 5 to the predetermined position on the wing surface and press firmly; connect the other end to Kevlar rope 2. Check that all ropes are smooth and free of tangles. The operator hangs the weights 4 onto the corresponding hooks in sequence. Loading can be done incrementally or all at once.

[0049] Data Acquisition and Observation: Data is acquired using strain gauges and displacement sensors. Simultaneously, failure phenomena such as deformation of the internal balsa wood frame, cracking of glue joints, and bulging or tearing of the skin can be directly observed through the transparent skin. The entire failure process can be recorded using a camera.

[0050] Unloading and cleaning: After the test, remove the weights one by one, tear off the canvas strips or remove the residual glue with alcohol, loosen the clamps, remove the wings, and complete the test cycle.

[0051] Example 3: A general-purpose multi-point loading test bench for airfoils is similar in structure to Embodiment 2, except that it is configured with four loading modules according to the airfoil size and test requirements, and the canvas strips are replaced with vacuum suction cups or Velcro straps to accommodate different skin materials. The rotating mechanism is also equipped with an electric drive and an angle sensor to achieve remote automatic control.

[0052] Example 4: A general-purpose multi-point loading test bench for airfoils is similar in structure to Embodiment 2, except that it is configured with six loading modules according to the airfoil size and test requirements, and the canvas strips are replaced with vacuum suction cups or Velcro straps to accommodate different skin materials. The rotating mechanism is also equipped with an electric drive and an angle sensor to achieve remote automatic control.

[0053] Example 5: A general-purpose multi-point loading test bench for airfoils is similar in structure to Embodiment 2, except that twelve loading modules are configured according to the airfoil size and test requirements, and the canvas strips are replaced with vacuum suction cups or Velcro straps to accommodate different skin materials. The rotating mechanism is also equipped with an electric drive and an angle sensor to achieve remote automatic control.

[0054] Through the modular design described above, this invention achieves low-cost, high-precision, and highly flexible static testing of wings, making it particularly suitable for university aviation laboratories, UAV R&D teams, and model aircraft enthusiasts for wing strength verification and teaching demonstrations.

[0055] The above specific embodiments further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above are merely specific embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A universal multi-point loading test bench for airfoils, characterized in that: The aluminum profile frame (1) is provided with a wing mounting unit in the middle of the aluminum profile frame (1) for fixing the wing (6). The upper part of the aluminum profile frame (1) is provided with a load application unit, which includes several loading modules. The several loading modules are distributed above the wing (6) for applying loads to several points of the wing (6).

2. The universal wing multi-point loading test bench as described in claim 1, characterized in that: The upper end of the aluminum profile frame (1) is provided with several optical axis guide rails along the length of the wing (6), and the loading modules are all slidably mounted on their corresponding optical axis guide rails to change the load application position.

3. The universal wing multi-point loading test bench as described in claim 2, characterized in that: The device includes a fixed pulley assembly (3), a Kevlar rope (2), a connector (5), and a set of weights (4). The fixed pulley assembly (3) is slidably disposed below the optical axis guide rail. The Kevlar rope (2) passes through the fixed pulley assembly (3), and its inner end is connected to the corresponding predetermined loading point of the wing (6) through the connector (5). Its other end is connected to its corresponding weight (4).

4. The universal wing multi-point loading test bench as described in claim 3, characterized in that: The fixed pulley assembly (3) includes two fixed pulleys with parallel axes. The Kevlar rope (2) passes around the two fixed pulleys in a C-shaped path. The fixed pulleys use deep groove ball bearings as pulleys and are integrated through a metal shell. A slider is provided on the top of the slider, which is connected to the optical axis guide rail for sliding limit. A 360° rotation mechanism is provided between the slider and the fixed pulley, which includes a precision thrust bearing, a locking turntable and a scale. After the locking handle is released, the fixed pulley as a whole can rotate continuously around the vertical axis, and the rotation angle can be read through the scale. After locking, the direction can be fixed.

5. The universal wing multi-point loading test bench as described in claim 4, characterized in that: The connector (5) is a vacuum suction cup with a flat bottom, which is connected to the Kevlar rope (2) through a universal connector to adapt to the slight curvature changes on the surface of the wing (6).

6. The universal wing multi-point loading test bench as described in claim 4, characterized in that: The connector (5) is made of high-strength cotton canvas, which is a circle with a diameter of 30mm. One end of the connector is coated with removable pressure-sensitive adhesive and is pasted to the predetermined loading point on the upper surface of the wing (6) before use. The other end of the canvas strip is connected to a Kevlar rope.

7. The universal wing multi-point loading test bench as described in claim 1, characterized in that: The aluminum profile frame (1) has a side beam in the middle side, the wing (6) is fixed to the inside of the side beam, and the wing mounting unit is slidably mounted on the side beam.

8. The universal wing multi-point loading test bench as described in claim 7, characterized in that: The wing mounting unit includes: A leading edge clamp (9) for holding the reinforcing structure or mounting hole of the leading edge of the wing (6); A wing sparb clamp (8) is used to clamp the main wing sparb or the strongest load-bearing structure of the wing (6); A trailing edge clamp (7) is used to hold the auxiliary structure or mounting hole of the trailing edge of the wing (6).

9. A universal multi-point loading test bench for airfoils as described in claim 8, characterized in that: The wing beam clamp (8) is an inverted T-shaped 6061 aluminum alloy clamp, which uses M5 standard metric bolts to connect the wing beam lugs; the leading edge clamp (9) and the trailing edge clamp (7) are L-shaped 6061 aluminum alloy clamps with soft silicone pads at the clamping openings.

10. A universal multi-point loading test bench for airfoils as described in claim 8, characterized in that: The trailing edge clamp (7), spar clamp (8), and leading edge clamp (9) are all mounted on the T-slot of the side crossbeam via bottom sliders, and the spacing can be freely adjusted along the wingspan.

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