A method for testing mechanical properties of inflatable wings

Abstract

The present invention discloses a method for testing the mechanical properties of an inflatable wing, which belongs to the field of aerospace testing technology. The method comprises: S1, wing installation: clamping the inflatable wing on a test bench so that its chord plane is perpendicular to the loading direction; S2, load application: applying a vertical load to the inflatable wing by driving a loading mechanism through an external universal tester; S3, data acquisition: synchronously acquiring deflection curve and stress distribution data using a displacement measurement unit and a strain detection unit; S4, failure determination: when a sudden change in the shape of the deflection curve is detected or the strain data exceeds a threshold, it is determined that the inflatable wing has buckled and failed, loading is stopped, and the maximum load is recorded. As an expansion platform of the universal tester, the test bench can be adapted to large-sized inflatable wings, does not require special equipment, reduces costs, and coordinates monitoring of displacement and strain data to achieve closed-loop control of inflation pressure-deformation-load, significantly improving test accuracy and data reliability.

Description

Technical Field

[0001] The invention belongs to the technical field of aerospace testing, and in particular relates to a method for testing the mechanical properties of an inflatable wing. Background Art

[0002] In the aviation field, inflatable wings, due to their foldability, portability, and deployment, have shown broad application prospects in drones and small aircraft. For flexible structures like inflatable wings, bending stiffness and buckling failure load are key performance indicators. Accurately measuring these parameters is crucial for the design, optimization, and safe use of inflatable wings.

[0003] At present, there are some technical solutions related to loading tests, such as some patents disclosed in the prior art:

[0004] 1. An invention patent with publication number CN221377027U, entitled "A Static Loading Test Device for Stabilizers," which can intuitively simulate the actual load-bearing conditions of a stabilizer during high-speed flight.

[0005] 2. An invention patent with publication number CN112729893A, entitled "A static loading test platform and test method for a rotorcraft unmanned aerial vehicle," which can monitor the force on the rotor arm in real time and has strong versatility;

[0006] 3. A patent with publication number CN116448548A and patent name is "A Wing Static Load Test Loading Method and Loading Device Invention Patent", which can make the wing force more accurate and better simulate the wing loading conditions.

[0007] However, the above-mentioned static loading test bench is difficult to accurately measure the relevant performance of the inflatable wing. When measuring the bending stiffness and buckling failure load, the measurement results have large errors due to the limitations of the test bench structural design or loading method.

[0008] In addition, the standard working space width of the currently widely used universal testing machines (such as the Instron 5967) is only 500mm, and the fixture system is rigidly designed, which cannot accommodate large-sized inflatable wings (typical span ≥1.5m, typical wing width ≥0.6m). Although the independently developed inflatable structure-specific test bench can expand the space, it has problems such as high cost and poor compatibility.

[0009] To address the above problems, it is necessary to design a testing device that can break through space limitations and simultaneously achieve closed-loop control of inflation pressure-deformation-load, providing a cost-effective solution for the engineering testing of inflatable wings. Summary of the Invention

[0010] The present invention aims to solve the above problems in the prior art and proposes a method for testing the mechanical properties of an inflatable wing.

[0011] The present invention can be achieved through the following technical solutions:

[0012] A method for testing the mechanical properties of an inflatable wing is applied to a test bench connected to an external universal testing machine, the test bench comprising:

[0013] base;

[0014] Support assemblies, at least two of which are provided, and the support assemblies are movable along the length direction of the base to adjust the spacing;

[0015] a fixed crossbeam spanning each set of the support assemblies;

[0016] A loading beam, one end of which is connected to the fixed beam via a rotating shaft, and the other end of which is provided with a loading conversion head, the loading conversion head being used to connect to an external universal testing machine;

[0017] a wing contact beam connected to the bottom of the loading beam via a rotating shaft, wherein the wing contact beam contacts the surface of the inflatable wing and applies a vertical load;

[0018] The test method includes the following steps:

[0019] S1. Wing installation: clamp the inflatable wing on the support assembly and make its chord plane perpendicular to the stress loading direction;

[0020] S2. Load application: driving the loading beam through an external universal tester to apply a vertical load to the inflatable wing at a preset rate;

[0021] S3. Data collection:

[0022] a. Displacement measurement units are arranged along the surface of the inflatable wing, and the displacement measurement units are used to capture the deflection changes of the wing surface under different loads and generate a deflection curve;

[0023] b. A strain detection unit is installed in the maximum bending moment area of ​​the inflatable wing, and the strain detection unit is used to monitor the stress distribution in this area;

[0024] S4. Failure determination: When a sudden deformation change is detected in the deflection curve or the strain data exceeds a threshold, the inflatable wing is determined to have buckled and failed, and loading is stopped and the maximum load value is recorded.

[0025] As a further improvement of the present invention, after step S4, the following steps are further included:

[0026] S5. Stiffness verification: After the test, the measured load-displacement curve is compared with the theoretical model, and the relative error of the bending stiffness is calculated and controlled within ±3%.

[0027] As a further improvement of the present invention, in step S1, the inflatable wing is subjected to a clamped constraint condition or a simply supported constraint condition on the test bench by a clamping beam, wherein:

[0028] Under the fixed support constraint condition, the leading edge of the inflatable wing is fixed with a quick clamp, and the trailing edge is preloaded with an adjustable top screw.

[0029] Under the simply supported constraint condition, the inflatable wing is distributedly supported by a plurality of clamping beams, each of which is provided with a pressure sensor, and the pressure deviation of each clamping point does not exceed ±5%.

[0030] As a further improvement of the present invention, in step S2, the stress loading mechanism applies a vertical load to the symmetry axis position of the inflatable wing.

[0031] As a further improvement of the present invention, in step S2, the chord plane of the inflatable wing is made perpendicular to the stress loading direction by laser calibration.

[0032] As a further improvement of the present invention, the displacement measuring unit is configured as a laser displacement meter, and the measuring points of the laser displacement meter are distributed at intervals along the span direction of the inflatable wing.

[0033] As a further improvement of the present invention, the strain detection unit is configured as a three-dimensional strain rosette, which is arranged on the surface of the inflatable wing and is close to and symmetrically distributed on both sides of the symmetry axis of the inflatable wing.

[0034] As a further improvement of the present invention, the stress loading mechanism is embedded with a distributed optical fiber sensor, and the load distribution uniformity is measured by the optical fiber sensor.

[0035] As a further improvement of the present invention, the support assembly includes:

[0036] A supporting frame, which forms a slide rail connection structure with the base;

[0037] The clamping beams are provided in a plurality and are vertically mounted on opposite surfaces of the same group of support frames to form a parallel arrangement of support structures.

[0038] As a further improvement of the present invention, the support assembly includes:

[0039] A supporting frame, which forms a slide rail connection structure with the base;

[0040] The clamping beams are provided in a plurality and are vertically mounted on opposite surfaces of the same group of support frames to form a parallel arrangement of support structures.

[0041] Compared with the prior art, the present invention has the following beneficial effects:

[0042] 1. Modular structural design improves adaptability and compatibility: The test bench is designed with a modular assembly structure, making it flexible to accommodate inflatable wings of various sizes and shapes (typical span ≥1.5m, width ≥0.6m). This design not only solves the space limitations of traditional universal testing machines, but also enhances the equipment's adaptability to different boundary conditions (clamped / simply supported), significantly improving the test system's versatility and engineering practicality.

[0043] 2. High-precision sensing system improves test accuracy: The system integrates multiple high-precision measurement units, including laser displacement meters, three-dimensional strain gauge rosettes, and distributed fiber optic sensors, enabling simultaneous monitoring of the macroscopic deflection changes and microscopic stress distribution of the inflatable wing during loading. These sensors work together to form a closed-loop control mechanism of inflation pressure, deformation, and load, significantly improving the accuracy of buckling failure determination and the reliability of experimental data.

[0044] 3. Precise loading enhances experimental authenticity and repeatability: Laser calibration technology ensures that the loading direction is strictly perpendicular to the wing chord plane and applies the load along the wing's symmetry axis, avoiding torsional loads and asymmetric stress distribution caused by eccentric loading. This method more closely reflects the aerodynamic loads experienced during actual flight, improving the authenticity and repeatability of experimental results and providing a scientific basis for material strength assessment.

[0045] 4. Low-cost expansion solution achieves efficient resource utilization: The test bench is used as an expansion platform for existing universal testing machines, eliminating the need to develop dedicated test equipment. While retaining the high-precision loading system of the original model, it effectively expands its test range, significantly reducing R&D costs and cycle time investment, and has excellent economic efficiency and promotion value.

[0046] 5. A comprehensive testing process ensures data integrity and engineering usability: From wing installation, load application, data collection, failure determination, and stiffness verification, the entire testing process is comprehensive and logically clear. In particular, the introduction of stiffness verification (with an error controlled within ±3%) further ensures the scientific nature and credibility of the experimental data by comparing measured curves with the finite element model, providing solid data support for the structural optimization, material selection, and aircraft safety design of the inflatable wing. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 It is a structural schematic diagram of the test bench of the present invention;

[0048] Figure 2 It is a structural schematic diagram of the clamping system of the test bench of the present invention;

[0049] Figure 3 It is a structural schematic diagram of the loading mechanism of the test bench of the present invention;

[0050] Figure 4 2. It is a schematic diagram of the structure of the test bench of the present invention after installing the inflatable wing (simply supported and constrained working condition);

[0051] Figure 5 2. This is a schematic diagram of the structure of the test bench of the present invention after installing the inflatable wing (fixed support and restraint working condition);

[0052] Figure 6 is a schematic diagram of the location of the laser displacement meter of the present invention;

[0053] Figure 7 It is a schematic diagram of the positions of the laser displacement meter measuring points and the three-dimensional strain rosette on the inflatable wing of the present invention.

[0054] In the figure, 100, test bench; 110, base; 120, support frame; 130, clamping beam; 140, fixed beam; 150, loading beam; 160, wing contact beam; 170, rotating shaft; 180, loading conversion head; 200, inflatable wing; 210, laser displacement meter; 211, measuring point; 220, three-dimensional strain rosette. DETAILED DESCRIPTION

[0055] The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical method of the present invention, but the present invention is not limited to these embodiments.

[0056] like Figure 1-Figure 7 As shown, the present invention provides a method for testing the mechanical properties of an inflatable wing, comprising the following steps:

[0057] S1. Wing installation: Clamp the inflatable wing 200 onto the test bench 100 with its chord plane perpendicular to the stress loading direction. This is because any deviation from the vertical loading will cause additional torque, affecting the authenticity and accuracy of the test results.

[0058] S2. Load application: The stress loading mechanism on the test bench 100 is driven by an external universal tester to apply a vertical load to the inflatable wing 200 at a preset rate;

[0059] S3. Data collection:

[0060] a. Displacement measurement units are arranged along the surface of the inflatable wing 200. These displacement measurement units are used to capture the changes in the deflection of the wing surface under different loads. In this way, a deflection curve between load and displacement can be accurately plotted, thereby evaluating the stiffness characteristics of the wing;

[0061] b. A strain detection unit is installed in the maximum bending moment area of ​​the inflatable wing 200. The strain detection unit is used to monitor the stress distribution in this area, which is crucial for analyzing the performance of the structure under load and helps predict possible failure modes;

[0062] S4. Failure determination: When a sudden deformation change is detected in the deflection curve or the strain data exceeds a threshold value (the strain value sudden change exceeds 10%), the inflatable wing 200 is determined to have buckling failure, loading is stopped, and the maximum load value is recorded to evaluate the ultimate strength of the material.

[0063] It should be noted that the test bench 100 used in this embodiment is only used as an expansion platform of the universal testing machine. Its core function is to provide a stable and adjustable installation and support structure for the inflatable wing 200. The load application is still provided by an external universal testing machine (such as Instron, MTS and other standard equipment). The test bench 100 accurately transmits the force applied by the universal testing machine to the inflatable wing 200 through the loading mechanism, thereby realizing the mechanical property test of the specimen.

[0064] This extended test bench 100 functionally realizes the separation and coordination of the main loading system and the auxiliary support system. It not only retains the advantages of the universal testing machine's high-precision loading and control system, but also solves the space limitation problem of its inability to accommodate large-sized inflatable wings 200 (typical span ≥1.5m, width ≥0.6m) through modular expansion.

[0065] At the same time, it avoids the high R&D costs and cycle investment brought about by the separate development of special testing equipment for inflatable structures, and has good economic efficiency and engineering promotion value.

[0066] It is also worth mentioning that by arranging displacement measurement units and strain detection units on the surface of the inflatable wing 200, closed-loop control of inflation pressure-deformation-load is achieved. This design utilizes high-precision displacement measurement units and strain detection units, which are precisely arranged in specific areas of the inflatable wing 200 to monitor the deformation and strain of the inflatable wing 200 during loading in real time. This not only provides detailed deformation data, but also helps identify potential buckling failure points.

[0067] Based on the real-time feedback information provided by the displacement measurement unit and the strain detection unit, researchers can precisely control the test conditions according to experimental requirements and make timely adjustments to avoid excessive damage or ineffective loading.

[0068] In general, this embodiment improves the test method for the mechanical properties of the inflatable wing 200, thereby bringing at least the following advantages:

[0069] 1. Strong adaptability and reduced costs: The test bench 100 is used as an expansion platform for the universal testing machine. It can accommodate large-sized inflatable wings 200, while reducing R&D costs and having high compatibility and flexibility.

[0070] 2. Improve test accuracy: The combination of the displacement measurement unit and the strain detection unit realizes the coordinated monitoring of the macro deformation and micro strain of the inflatable wing 200, thereby improving the accuracy of determining the buckling failure load of the inflatable wing 200.

[0071] Preferably, after step S4, the method further includes:

[0072] S5. Stiffness Verification: After the test, the measured load-displacement curve is compared with the theoretical model. Specifically, a response model of the inflatable wing 200 under different load conditions is constructed using finite element analysis software. Based on the model, its deformation behavior and bending stiffness are predicted. The relative error between the measured results and the theoretical prediction is then calculated to ensure that the measurement error of the bending stiffness is controlled within ±3%.

[0073] Step S5 effectively verifies the accuracy of the experimental results by comparing the actual test data with the theoretical model. This helps identify any possible systematic deviations or anomalies, thereby improving the reliability of the overall test and providing a solid foundation for subsequent product development, design optimization, and scientific research.

[0074] Preferably, in step S1, the inflatable wing 200 is clamped on the test bench 100 to achieve a fixed support constraint condition or a simply supported constraint condition through the clamping beam 130, wherein:

[0075] Under the clamped-support constraint condition, the leading edge of the inflatable wing 200 is rigidly fixed with a quick-action clamp to ensure it does not move during loading. The trailing edge is preloaded using an adjustable top screw structure to enhance clamping stability and prevent local slippage. This clamping method can effectively simulate the root loading conditions under real-world flight conditions, where one end is fixed and the other end is constrained.

[0076] Under the simply supported constraint condition: the inflatable wing 200 is distributedly supported by multiple clamping beams 130, and appropriate spacing is maintained between each clamping beam 130 to adapt to wing structures of different spans. In order to ensure uniform distribution of supporting force, each clamping beam 130 is integrated with a high-precision pressure sensor to monitor the pressure value of each support point in real time, and control the pressure deviation of each clamping point to no more than ±5% through the feedback system, ensuring that each support point is balanced in force and avoiding measurement errors caused by local stress concentration.

[0077] This design achieves precise control of the boundary conditions of the inflatable wing 200 by optimizing the structure of the clamping system and introducing a sensor feedback mechanism, thereby more realistically reflecting its mechanical response under different working conditions.

[0078] Among them, the two typical constraint forms of fixed support and simple support cover a variety of engineering application scenarios, making the test results more representative and practical. They can simulate the different support conditions that the wings bear during different stages of aircraft take-off, landing, cruising, etc., thereby improving the matching degree between experimental data and actual applications.

[0079] Preferably, in step S2, the stress loading mechanism applies a vertical load to the symmetry axis of the inflatable wing 200. It should be noted that applying the load to the symmetry axis can ensure uniform distribution of force on the wing structure.

[0080] If the load deviates from the axis of symmetry, it may lead to asymmetric stress distribution, causing one side of the material to be subjected to excessive stress, while the other side may not fully utilize its load-bearing capacity. This not only affects the accuracy of the test results, but may also cause local damage or changes in failure mode.

[0081] And because the same load conditions can be applied at the same location in each experiment, the repeatability of the experiment and the consistency of the results can be greatly improved. This is very important for quality control in scientific research and engineering applications.

[0082] In addition, during actual flight, the main external loads (such as aerodynamic loads) on the aircraft usually act symmetrically on the entire wing. By applying vertical loads at the axis of symmetry in a laboratory environment, these real flight load conditions can be better simulated, thereby more accurately evaluating the design performance of the inflatable wing 200.

[0083] Preferably, in step S2, the chord plane of the inflatable wing 200 is made perpendicular to the stress loading direction through laser calibration. The use of laser calibration can provide extremely high precision and ensure that the loading direction is consistent with the expectation. The chord plane of the inflatable wing 200 is perpendicular to the stress loading direction, which avoids the introduction of additional torque and causes changes in the actual stress state, thereby improving the accuracy of the test results.

[0084] Preferably, the displacement measuring unit is configured as a laser displacement meter 210, and the measuring points 211 of the laser displacement meter 210 are spaced apart along the span direction (i.e., from the wing root to the wing tip) of the inflatable wing 200. In this test scheme, since a vertical loading method of a symmetrical axis is adopted, under ideal loading conditions, the deflections generated on both sides of the inflatable wing 200 after loading are symmetrically distributed. Therefore, by measuring the deflection change of the wing on one side, the deformation state of the other side can be inferred without the need for repeated deployment of sensors, thereby achieving efficient utilization of hardware resources.

[0085] It should also be noted that during the use and testing of the inflatable wing 200, the deformation along the span direction is a key indicator for evaluating its bending stiffness, structural stability and failure mode. Therefore, distributing the laser displacement meter 210 in a linear spacing along the span direction can accurately capture the deflection change trend in this direction, which helps to judge the material buckling behavior and stiffness distribution, and facilitates the drawing of a complete deflection curve and mechanical analysis.

[0086] In general, by arranging the laser displacement meters 210 on one side along the spanwise interval, efficient and accurate monitoring of the deformation characteristics of the inflatable wing 200 is achieved. This method fully utilizes the symmetry of the structural force, optimizes resource allocation, and focuses on the acquisition of key mechanical indicators, providing a scientific and practical technical means for the mechanical performance evaluation of the inflatable wing 200.

[0087] Preferably, the strain detection unit is configured as a three-dimensional strain rosette 220 , which is disposed on the surface of the inflatable wing 200 and is symmetrically distributed close to and on both sides of the symmetry axis of the inflatable wing 200 .

[0088] It should be noted that the three-axis strain gauge rosette 220 can simultaneously measure strain values ​​in three different directions. This allows it to not only capture deformation in the principal stress direction, but also obtain shear strain in the plane through calculation, thereby providing more comprehensive stress state information.

[0089] The area near the symmetry axis of the inflatable wing 200 is usually subject to the greatest stress, and its performance is particularly important in bending and buckling failure analysis. Therefore, arranging a highly sensitive strain sensor at this location helps capture the most significant stress changes and provides a direct basis for evaluating the ultimate strength of the material.

[0090] In addition, the initial buckling is a localized and asymmetric phenomenon, so it is necessary to simultaneously arrange the three-dimensional strain rosette 220 on both sides of the symmetry axis of the inflatable wing 200 to ensure the accuracy of the test results.

[0091] Preferably, the stress loading mechanism is embedded with a distributed optical fiber sensor, which is a sensing technology based on the transmission characteristics of light in optical fiber. Its core principle relies on changes in the propagation characteristics of optical signals in optical fiber to sense changes in the external environment, such as strain.

[0092] Distributed fiber optic sensors are embedded in key parts of the stress loading mechanism, such as inside the wing contact beam 160, so that they can directly sense the transmission of force during the loading process. Based on the data provided by the fiber optic sensors, the stress distribution at different positions during the loading process can be monitored in real time to ensure that the load is evenly distributed on the entire inflatable wing 200, avoiding material damage or failure caused by local overload.

[0093] By monitoring the load distribution in real time through distributed fiber optic sensors, uneven load distribution problems can be discovered and adjusted in a timely manner, thereby ensuring that the experimental conditions meet the expected design requirements and improving the accuracy and reliability of the loading process.

[0094] The present invention also provides an inflatable wing mechanical performance test bench, which can implement the above-mentioned inflatable wing mechanical performance test method, including:

[0095] The base 110 is assembled from a number of T-shaped slot beams and serves as the basic framework of the entire test bench 100, providing a stable support platform;

[0096] Support components, which are provided in at least two groups, and the support components can be moved along the length direction of the base 110 to adjust the spacing to adapt to inflatable wings 200 of different sizes;

[0097] A fixed crossbeam 140 , which spans each set of support assemblies;

[0098] The loading beam 150 has one end connected to the fixed beam 140 via a rotating shaft 170 and a loading adapter 180 at the other end. The free end of the loading beam 150 is inserted into the guide sleeve of the loading adapter 180. The bottom of the loading adapter 180 is connected to the actuator of the external universal testing machine via a flange.

[0099] The wing contact beam 160 is connected to the bottom of the load beam 150 via a rotating shaft 170 . The wing contact beam 160 contacts the surface of the inflatable wing 200 and applies a vertical load.

[0100] When the universal testing machine is started, its actuator drives the loading beam 150 to move downward, and the wing contact beam 160 can gradually increase the pressure on the inflatable wing 200 to perform a mechanical performance test on the inflatable wing 200.

[0101] Furthermore, the support assembly includes:

[0102] The support frame 120 forms a slide rail connection structure with the base 110. In this embodiment, the support frame 120 is configured as a U-shaped frame;

[0103] There are multiple clamping beams 130 and they are vertically mounted on opposite sides of the same set of support frames 120 to form a parallel support structure.

[0104] The clamping beam 130 is used to clamp the root of the inflatable wing 200, and by adjusting the number and position of the clamping beams 130, the switching between the fixed support constraint condition and the simply supported constraint condition can be achieved. For example, two left and right clamping beams 130 can be used in combination with a quick clamp with a pneumatic locking function and an adjustable top screw to fix the inflatable wing 200, and eight clamping beams 130 can be used to simply support the inflatable wing 200.

[0105] It is worth mentioning that the test bench 100 adopts a modular structure, which allows the position and spacing of each component to be adjusted according to the specific size and shape of the inflatable wing 200 to be tested. For example, the support component can slide freely on the base 110 and lock in the required position to accommodate inflatable wings 200 of different lengths and widths, and the height of the entire test bench 100 can also be adjusted. As a result, the test bench 100 can be adapted to inflatable wings 200 of different sizes through simple assembly, thereby enhancing its versatility.

[0106] In addition, the bottom surface of the wing contact beam 160 is provided with a curved polyurethane cushion to ensure that it forms a 30mm wide line contact with the surface of the inflatable wing 200. The surface of each clamping beam 130 includes a silicone anti-slip layer to enhance the fixing effect on the wing.

[0107] The technical means disclosed in the solutions of the present invention are not limited to the technical means disclosed in the above technical means, but also include technical solutions composed of any combination of the above technical features. The above is a specific embodiment of the present invention. It should be noted that for those skilled in the art, without departing from the principles of the present invention, various improvements and modifications can be made, and such improvements and modifications are also considered to be within the scope of protection of the present invention.

[0108] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0109] In addition, in the present invention, descriptions such as "first", "second", "one", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise clearly defined. The terms "connected", "fixed", etc. should be understood in a broad sense. For example, "fixed" can be a fixed connection, a detachable connection, or an integral whole; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0110] The technical solutions between the various embodiments of the present invention can be combined with each other, but they must be based on the fact that ordinary technicians in this field can implement them. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0111] The specific embodiments described herein are merely illustrative of the spirit of the present invention. Persons skilled in the art may make various modifications, additions, or substitutions to the described specific embodiments without departing from the spirit of the present invention or exceeding the scope of the appended claims.

Claims

1. A method for testing the mechanical properties of an inflatable wing, applied to a test bench connected to an external universal testing machine, characterized in that: The test bench includes: base; Support assemblies, at least two of which are provided, and the support assemblies are movable along the length direction of the base to adjust the spacing; a fixed crossbeam spanning each set of the support assemblies; A loading beam, one end of which is connected to the fixed beam via a rotating shaft, and the other end of which is provided with a loading conversion head, the loading conversion head being used to connect to an external universal testing machine; a wing contact beam connected to the bottom of the loading beam via a rotating shaft, wherein the wing contact beam contacts the surface of the inflatable wing and applies a vertical load; The test method includes the following steps: S1. Wing installation: clamp the inflatable wing on the support assembly and make its chord plane perpendicular to the stress loading direction; S2. Load application: driving the loading beam through an external universal tester to apply a vertical load to the inflatable wing at a preset rate; S3. Data collection: a. Displacement measurement units are arranged along the surface of the inflatable wing, and the displacement measurement units are used to capture the deflection changes of the wing surface under different loads and generate a deflection curve; b. A strain detection unit is installed in the maximum bending moment area of ​​the inflatable wing, and the strain detection unit is used to monitor the stress distribution in this area; S4. Failure determination: When a sudden deformation change is detected in the deflection curve or the strain data exceeds a threshold, the inflatable wing is determined to have buckled and failed, and loading is stopped and the maximum load value is recorded.

2. The method for testing the mechanical properties of an inflatable wing according to claim 1, characterized in that: After step S4, the method further includes: S5. Stiffness verification: After the test, the measured load-displacement curve is compared with the theoretical model, and the relative error of the bending stiffness is calculated and controlled within ±3%.

3. The method for testing the mechanical properties of an inflatable wing according to claim 1, characterized in that: In step S1, the inflatable wing is subjected to a fixed support constraint condition or a simply supported constraint condition on the test bench by means of a clamping beam, wherein: Under the fixed support constraint condition, the leading edge of the inflatable wing is fixed with a quick clamp, and the trailing edge is preloaded with an adjustable top screw. Under the simply supported constraint condition, the inflatable wing is distributedly supported by a plurality of clamping beams, each of which is provided with a pressure sensor, and the pressure deviation of each clamping point does not exceed ±5%.

4. The method for testing mechanical properties of an inflatable wing according to claim 1, characterized in that: In step S2, the stress loading mechanism applies a vertical load to the symmetry axis position of the inflatable wing.

5. The method for testing mechanical properties of an inflatable wing according to claim 1, characterized in that: In step S2, the chord plane of the inflatable wing is made perpendicular to the stress loading direction by laser calibration.

6. The method for testing mechanical properties of an inflatable wing according to claim 1, characterized in that: The displacement measuring unit is configured as a laser displacement meter, and the measuring points of the laser displacement meter are distributed at intervals along the span direction of the inflatable wing.

7. The method for testing mechanical properties of an inflatable wing according to claim 1, characterized in that: The strain detection unit is configured as a three-dimensional strain rosette, which is arranged on the surface of the inflatable wing and is close to and symmetrically distributed on both sides of the symmetry axis of the inflatable wing.

8. The method for testing mechanical properties of an inflatable wing according to claim 1, characterized in that: The stress loading mechanism is embedded with a distributed optical fiber sensor, and the load distribution uniformity is measured by the optical fiber sensor.

9. The method for testing mechanical properties of an inflatable wing according to claim 1, characterized in that: The support assembly comprises: A supporting frame, which forms a slide rail connection structure with the base; The clamping beams are provided in a plurality and are vertically mounted on opposite surfaces of the same group of support frames to form a parallel arrangement of support structures.

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