Method for testing mechanical property of inflatable wing

Abstract

The invention discloses a mechanical property testing method for an inflatable wing, and belongs to the technical field of aerospace testing. The method comprises the following steps: S1, wing installation: clamping an inflatable wing on a test board, and enabling a chord plane of the inflatable wing to be perpendicular to a loading direction; s2, applying a load: driving a loading mechanism to apply a vertical load to the inflatable wing through an external universal tester; s3, data acquisition: synchronously acquiring a deflection curve and stress distribution data by using a displacement measurement unit and a strain detection unit; and S4, failure judgment: when monitoring that the shape of the deflection curve suddenly changes or the strain data exceeds a threshold value, judging that the inflatable wing is subjected to buckling failure, stopping loading and recording the maximum load. The test bench serves as an expansion platform of a universal tester, can be adapted to a large-size inflatable wing, does not need special equipment, reduces the cost, realizes cooperative monitoring of displacement and strain data, realizes closed-loop control of inflation air pressure-deformation-load, and remarkably improves the test precision and the data reliability.

Description

Technical Field

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

[0002] In the aviation field, due to characteristics such as foldability, portability, and ease of deployment, inflatable wings have shown broad application prospects in unmanned aerial vehicles, small aircraft, etc. For flexible structures such as inflatable wings, bending stiffness and buckling failure load are key indicators for evaluating their performance. Accurately measuring these indicators is of great significance for the design, optimization, and safe use of inflatable wings.

[0003] Currently, there are some technical solutions related to loading tests, such as some patents disclosed in the prior art: 1. An invention patent with a publication number of CN221377027U and a patent name of a static loading test device for a stabilizing device can more intuitively simulate the true load-bearing situation of the stabilizing device when the aircraft is flying at high speed; 2. An invention patent with a publication number of CN112729893A and a patent name of a static loading test platform and test method for a rotary-wing unmanned aerial vehicle can monitor the force on the rotor arm in real time and has strong versatility; 3. An invention patent with a publication number of CN116448548A and a patent name of a wing static load test loading method and loading device can make the force on the wing more accurate and better simulate the loading situation of the wing.

[0004] However, the above-mentioned static loading test benches are difficult to accurately measure the relevant performance of inflatable wings. When measuring bending stiffness and buckling failure load, due to the limitations of the test bench structure design or loading method, there are large errors in the measurement results.

[0005] In addition, the standard working space width of the widely used universal testing machine (such as Instron 5967) is only 500 mm, and the fixture system is rigidly designed, which cannot accommodate large-size inflatable wings (typical span ≥ 1.5 m, typical wing width ≥ 0.6 m). Although the specially developed test bench for inflatable structures can expand the space, it has problems such as high cost and poor compatibility.

[0006] In view of the above problems, it is necessary to design a test device that can break through the space limitation and simultaneously achieve closed-loop control of inflation pressure - deformation - load, providing a high-cost-effective solution for the engineering testing of inflatable wings. Summary of the Invention

[0007] The present invention addresses the above problems existing in the prior art and proposes a method for testing the mechanical properties of an inflatable wing.

[0008] The present invention can be realized by the following technical solutions: A method for testing the mechanical properties of an inflatable wing, which is applied to a test bench connected to an external universal testing machine. The test bench includes: A base; A support assembly, with at least two groups provided. The support assembly can move along the length direction of the base to adjust the spacing; A fixed crossbeam, which is bridged across each group of the support assemblies; A loading beam, one end of which is connected to the fixed crossbeam through a rotating shaft, and the other end is provided with a loading conversion head for connecting to an external universal testing machine; A wing contact beam, which is connected to the bottom of the loading beam through a rotating shaft. The wing contact beam contacts the surface of the inflatable wing and applies a vertical load; The testing 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: Drive the loading beam through an external universal tester to apply a vertical load to the inflatable wing at a preset rate; S3. Data acquisition: a. Displacement measurement units are arranged along the surface of the inflatable wing. The displacement measurement units are used to capture the deflection changes of the wing surface under different loads and generate a deflection curve; b. Strain detection units are installed in the maximum bending moment area of the inflatable wing. The strain detection units are used to monitor the stress distribution in this area; S4. Failure determination: When it is monitored that the deflection curve has a sudden change in deformation or the strain data exceeds the threshold, it is determined that the inflatable wing has buckled and failed. Stop loading and record the maximum load value.

[0009] As a further improvement of the present invention, after step S4, it further includes: S5. Stiffness verification: After the test, compare the measured load-displacement curve with the theoretical model, calculate the relative error of the bending stiffness and control the error within ±3%.

[0010] As a further improvement of the present invention, in step S1, the inflatable wing realizes a fixed support constraint condition or a simply supported constraint condition on the test bench. Among them, In the fixed support constraint condition, the leading edge of the inflatable wing is fixed by a quick clamp, and the trailing edge is applied with a pre-tightening force through an adjustable jackscrew; In the simply supported constraint condition, the inflatable wing is supported distributively by multiple clamping beams. Pressure sensors are arranged on each clamping beam, and the pressure deviation at each clamping point does not exceed ±5%.

[0011] As a further improvement of the present invention, in step S2, the stress loading mechanism applies a vertical load to the position of the symmetry axis of the inflatable wing.

[0012] 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 through laser calibration.

[0013] As a further improvement of the present invention, the displacement measurement unit is set 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.

[0014] As a further improvement of the present invention, the strain detection unit is set as a three - strain rosette, the three - strain rosette is arranged on the surface of the inflatable wing, and the three - strain rosette is close to and symmetrically distributed on both sides of the symmetry axis of the inflatable wing.

[0015] As a further improvement of the present invention, the stress loading mechanism is embedded with a distributed fiber optic sensor, and the load distribution uniformity is measured through the fiber optic sensor.

[0016] As a further improvement of the present invention, the support assembly includes: A support frame, which forms a slide - rail connection structure with the base; Clamping beams, the number of which is multiple and are vertically installed on the opposite surfaces of the same group of support frames to form a parallel - arranged support structure.

[0017] As a further improvement of the present invention, the support assembly includes: A support frame, which forms a slide - rail connection structure with the base; Clamping beams, the number of which is multiple and are vertically installed on the opposite surfaces of the same group of support frames to form a parallel - arranged support structure.

[0018] Compared with the prior art, the present invention has the following beneficial effects: 1. The modular structure design improves adaptability and compatibility: The test bench is set as a modular assembly structure, enabling it to flexibly adapt to inflatable wings of various sizes and shapes (typical span length ≥ 1.5 m, width ≥ 0.6 m). This design not only solves the problem of limited space of traditional universal testing machines but also enhances the adaptability of the equipment to different boundary conditions (fixed support / simply supported), significantly improving the versatility and engineering practicability of the test system; 2. High-precision sensing system improves test accuracy: By integrating multiple types of high-precision measurement units such as laser displacement sensors, three-way strain rosettes, and distributed optical fiber sensors, synchronous monitoring of the macroscopic deflection changes and microscopic stress distributions of the inflatable wing during the loading process is achieved. These sensors cooperate with each other to form a closed-loop control mechanism for inflation pressure - deformation - load, significantly improving the accuracy of buckling failure determination and the reliability of experimental data; 3. Precise loading method enhances experimental authenticity and repeatability: Using laser calibration technology to ensure that the loading direction is strictly perpendicular to the wing chord plane and applying the load to the symmetric axis of the wing, avoiding torsional loads and asymmetric stress distributions caused by eccentric loading. This method is closer to the form of aerodynamic loads in actual flight, improving the authenticity and repeatability of experimental results and providing a scientific basis for material strength evaluation; 4. Low-cost expansion solution enables efficient resource utilization: The test bench is used as an expansion platform for the existing universal testing machine, eliminating the need to develop dedicated testing equipment separately. On the basis of retaining the high-precision loading system of the original model, its test range is effectively expanded, significantly reducing the R & D cost and cycle investment, and having good economic efficiency and promotion value; 5. Complete test process ensures data integrity and engineering usability: From wing installation, load application, data acquisition to failure determination and stiffness verification, the entire test process system is complete and logically clear. Especially by introducing a stiffness verification link (with an error control within ±3%), through the comparison of the measured curve and the finite element model, the scientific nature and credibility of the experimental data are further ensured, providing solid data support for the structural optimization, material selection of the inflatable wing, and the safety design of the aircraft. Description of the Drawings

[0019] Figure 1 is a schematic structural diagram of the test bench of the present invention; Figure 2 is a schematic structural diagram of the clamping system of the test bench of the present invention; Figure 3 is a schematic structural diagram of the loading mechanism of the test bench of the present invention; Figure 4 is a schematic structural diagram of the test bench after installing the inflatable wing (simply supported constraint condition); Figure 5 is a schematic structural diagram of the test bench after installing the inflatable wing (fixed support constraint condition); Figure 6 is a schematic diagram of the location of the laser displacement sensor of the present invention; Figure 7 is a schematic diagram of the positions of the measurement points of the laser displacement sensor and the three-way strain rosette on the inflatable wing.

[0020] In the figure, 100 is a test bench; 110 is a base; 120 is a support frame; 130 is a clamping beam; 140 is a fixed cross beam; 150 is a loading beam; 160 is a wing contact beam; 170 is a rotating shaft; 180 is a loading adapter; 200 is an inflatable wing; 210 is a laser displacement meter; 211 is a measuring point; 220 is a three - dimensional strain rosette. Detailed implementation mode

[0021] The following are specific embodiments of the present invention and in combination with the attached drawings, the technical methods of the present invention are further described, but the present invention is not limited to these embodiments.

[0022] As Figures 1-7 shown, the present invention provides a method for testing the mechanical properties of an inflatable wing, including the following steps: S1. Wing installation: Clamp the inflatable wing 200 on the test bench 100 and make its chord plane perpendicular to the stress loading direction, because any loading deviation from the vertical will cause additional moments, affecting the authenticity and accuracy of the experimental results; S2. Load application: Drive the stress loading mechanism on the test bench 100 through an external universal testing machine to apply a vertical load to the inflatable wing 200 at a preset rate; S3. Data acquisition: a. A displacement measurement unit is arranged along the surface of the inflatable wing 200. This displacement measurement unit is used to capture the deflection changes of the wing surface under different loads. In this way, the deflection curve between the load and the displacement can be accurately drawn, thereby evaluating the stiffness characteristics of the wing; b. A strain detection unit is installed in the maximum bending moment area of the inflatable wing 200. This strain detection unit is used to monitor the stress distribution in this area, which is crucial for analyzing the performance of the structure when bearing loads and helps predict possible failure modes; S4. Failure determination: When it is monitored that the deflection curve shows a sudden change in deformation or the strain data exceeds the threshold (the strain value suddenly changes by more than 10%), it is determined that the inflatable wing 200 has buckled and failed, stop loading and record the maximum load value, thereby evaluating the ultimate strength of the material.

[0023] It should be noted that the test bench 100 applied in this embodiment is only used as an extended platform of the universal testing machine. Its core role is to provide a stable and adjustable installation and support structure for the inflatable wing 200, while the load application is still provided by an external universal testing machine (such as standard equipment like Instron, MTS, etc.). The test bench 100 accurately transmits the force applied by the universal testing machine to the inflatable wing 200 through the loading mechanism to realize the mechanical property test of the specimen.

[0024] This extended test bench 100 functionally separates and coordinates 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 being unable to accommodate large-sized inflatable wings 200 (typical wingspan ≥ 1.5 m, width ≥ 0.6 m) through modular expansion.

[0025] Meanwhile, it avoids the high R & D costs and cycle investment brought about by developing dedicated test equipment for inflatable structures alone, and has good economic efficiency and engineering promotion value.

[0026] In addition, it is worth mentioning that by arranging displacement measurement units and strain detection units on the surface of the inflatable wing 200, a 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 conditions of the inflatable wing 200 during the loading process in real time. Thus, it can not only provide detailed deformation data but also help identify potential buckling failure points.

[0027] Based on the real-time feedback information provided by the displacement measurement units and strain detection units, researchers can accurately adjust the test conditions according to experimental requirements and make corresponding adjustments in a timely manner to avoid excessive damage or ineffective loading.

[0028] Generally speaking, the improvement of the test method for the mechanical properties of the inflatable wing 200 in this embodiment brings at least the following advantages: 1. Strong adaptability and cost reduction: The test bench 100 is used as an extended platform for the universal testing machine. It can not only accommodate large-sized inflatable wings 200 but also reduce R & D costs, and has high compatibility and flexibility. 2. Improved test accuracy: The combination of displacement measurement units and strain detection units realizes the coordinated monitoring of the macroscopic deformation - microscopic strain of the inflatable wing 200, improving the determination accuracy of the buckling failure load of the inflatable wing 200.

[0029] Preferably, after step S4, it further includes: S5. Stiffness verification: After the test, compare the measured load - displacement curve with the theoretical model. Specifically, construct a response model of the inflatable wing 200 under different load conditions through finite element analysis software, and predict its deformation behavior and bending stiffness based on this model. Then calculate the relative error between the measured result and the theoretical prediction to ensure that the measurement error of the bending stiffness is controlled within ±3%.

[0030] Step S5 can effectively verify the accuracy of the experimental results by comparing the actual test data with the theoretical model. This approach helps identify any potential systematic biases or anomalies, thereby enhancing the reliability of the overall test and providing a solid foundation for subsequent product development, design optimization, and scientific research.

[0031] Preferably, in step S1, the inflatable wing 200 is subjected to a fixed support constraint condition or a simply supported constraint condition on the test bench 100 through the clamping beam 130, where Under the fixed support constraint condition: The leading edge of the inflatable wing 200 is rigidly fixed using a quick clamp to ensure no displacement during the loading process, and the trailing edge is preloaded through an adjustable jackscrew structure to enhance the clamping stability and prevent local slippage. This clamping method can effectively simulate the root loading situation in the real flight state with one end fixed and the other end restricted; Under the simply supported constraint condition: The inflatable wing 200 is distributedly supported by multiple clamping beams 130, and appropriate spacing is maintained between the clamping beams 130 to accommodate wing structures of different spans. To ensure uniform distribution of the supporting force, each clamping beam 130 is integrated with a high-precision pressure sensor to monitor the pressure values at each support point in real time, and the feedback system is used to control the pressure deviation at each clamping point not to exceed ±5%, ensuring balanced forces at each support point and avoiding measurement errors caused by local stress concentration.

[0032] This design realizes precise control of the boundary conditions of the inflatable wing 200 through structural optimization of the clamping system and the introduction of a sensing feedback mechanism, thus more realistically reflecting its mechanical response under different working conditions.

[0033] Among them, the two typical constraint forms of fixed support and simply supported cover a variety of engineering application scenarios, making the test results more representative and practical. They can simulate the different support conditions that the wing bears during different stages such as takeoff, landing, and cruising of the aircraft, thereby improving the matching degree between the experimental data and the actual application.

[0034] Preferably, in step S2, the stress loading mechanism applies a vertical load to the symmetric axis position of the inflatable wing 200. It should be noted that applying the load on the symmetric axis can ensure uniform distribution of the force on the wing structure.

[0035] If the load deviates from the symmetric axis, it may lead to asymmetric stress distribution, thereby causing one side of the material to bear excessive stress while the other side may not fully utilize its bearing capacity. This not only affects the accuracy of the test results but also may lead to local damage or changes in the failure mode.

[0036] Moreover, since the same load conditions can be applied at the same position in each experiment, the repeatability of the experiment and the consistency of the results can be greatly improved, which is very important for scientific research and quality control in engineering applications.

[0037] In addition, during actual flight, the main external loads on the aircraft (such as aerodynamic loads) are usually symmetrically applied to the entire wing. By applying a vertical load at the axis of symmetry in the laboratory environment, these real flight load conditions can be better simulated, thus more accurately evaluating the design performance of the inflatable wing 200.

[0038] Preferably, in step S2, the chord plane of the inflatable wing 200 is made perpendicular to the stress loading direction through laser calibration. The method of laser calibration can provide extremely high precision to ensure that the loading direction is consistent with the expectation. And the perpendicularity of the chord plane of the inflatable wing 200 to the stress loading direction avoids the introduction of additional moments that may change the actual stress state, thereby improving the accuracy of the test results.

[0039] Preferably, the displacement measurement unit is set as the laser displacement meter 210. The measurement points 211 of the laser displacement meter 210 are distributed at intervals along the spanwise direction (i.e., from the wing root to the wing tip) of the inflatable wing 200. In this test scheme, since the symmetric axis vertical loading method 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 one side of the wing, the deformation state of the other side can be inferred without repeating the layout of sensors, thus realizing the efficient utilization of hardware resources.

[0040] In addition, it should be noted that during the use and testing of the inflatable wing 200, the deformation along the spanwise direction is a key index for evaluating its bending stiffness, structural stability, and failure mode. Therefore, arranging the laser displacement meter 210 in a straight line at intervals along the spanwise direction can accurately capture the deflection change trend in this direction, which helps to judge the material buckling behavior and stiffness distribution, and is convenient for drawing a complete deflection curve and conducting mechanical analysis.

[0041] Generally speaking, by arranging the laser displacement meter 210 at intervals unilaterally along the spanwise direction, the efficient and accurate monitoring of the deformation characteristics of the inflatable wing 200 is realized. This method makes full use of the symmetry of the structural stress, optimizes the resource allocation, and at the same time focuses on obtaining key mechanical indexes, providing a scientific and practical technical means for the mechanical performance evaluation of the inflatable wing 200.

[0042] Preferably, the strain detection unit is set as the three - dimensional strain rosette 220. The three - dimensional strain rosette 220 is arranged on the surface of the inflatable wing 200 and is symmetrically distributed on both sides of the axis of symmetry of the inflatable wing 200 and close to it.

[0043] It should be noted that the three - direction strain rosette 220 can simultaneously measure the strain values in three different directions. This enables it not only to capture the deformation in the principal stress direction but also to obtain the in - plane shear strain through calculation, thereby providing more comprehensive stress state information.

[0044] The vicinity of the symmetry axis of the inflatable wing 200 is usually the area that bears the maximum stress. Especially in the analysis of bending and buckling failures, the performance of this area is particularly important. Therefore, arranging high - sensitivity strain sensors at this position helps to capture the most significant stress changes and provides a direct basis for evaluating the ultimate strength of the material.

[0045] In addition, the initial occurrence of buckling is a local and asymmetric phenomenon. Therefore, three - direction strain rosettes 220 need to be arranged on both sides of the symmetry axis of the inflatable wing 200 simultaneously to ensure the accuracy of the test results.

[0046] Preferably, the stress loading mechanism is embedded with a distributed fiber optic sensor. The distributed fiber optic sensor is a sensing technology based on the transmission characteristics of light in an optical fiber. Its core principle relies on the change in the propagation characteristics of the optical signal in the optical fiber to sense changes in the external environment, such as strain.

[0047] Embed the distributed fiber optic sensor into the key parts of the stress loading mechanism, such as inside the wing contact beam 160, so that it can directly sense the force transmission during the loading process. Based on the data provided by the fiber optic sensor, the stress distribution at different positions during the loading process can be monitored in real - time, ensuring that the load is evenly distributed over the entire inflatable wing 200 and avoiding material damage or failure caused by local overload.

[0048] By real - time monitoring of the load distribution through the distributed fiber optic sensor, uneven load distribution problems can be detected 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.

[0049] The present invention also provides a test bench for the mechanical properties of an inflatable wing, which can implement the above - mentioned test method for the mechanical properties of an inflatable wing, including: A base 110, which is assembled by several T - shaped trough beams and serves as the basic framework of the entire test bench 100, providing a stable support platform; Support components, with at least two groups. The support components can move along the length direction of the base 110 to adjust the spacing to adapt to inflatable wings 200 of different sizes; A fixed cross - beam 140, which spans across each group of support components; The loading beam 150 has one end connected to the fixed cross beam 140 through a rotating shaft 170, and the other end is provided with a loading conversion head 180. The free end of the loading beam 150 is inserted into the guide sleeve of the loading conversion head 180, and the bottom of the loading conversion head 180 is connected to the actuator of an external universal testing machine through a flange plate; The wing contact beam 160 is connected to the bottom of the loading beam 150 through a rotating shaft 170. The wing contact beam 160 contacts the surface of the inflatable wing 200 and applies a vertical load.

[0050] 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 conduct a mechanical property test on the inflatable wing 200.

[0051] Furthermore, the support assembly includes: The support frame 120 forms a sliding rail connection structure with the base 110. In this embodiment, the support frame 120 is set as a U-shaped frame; The clamping beams 130 are provided in multiple numbers and are vertically installed on the opposite surfaces of the same group of support frames 120 to form a parallel arrangement of support structures.

[0052] The clamping beams 130 are used to clamp the wing root of the inflatable wing 200, and by adjusting the number and position layout of the clamping beams 130, the switching between fixed support constraint conditions and simply supported constraint conditions can be achieved. For example, with two left and right clamping beams 130 cooperating with a quick clamp with a pneumatic locking function and adjustable jackscrews, the inflatable wing 200 can be fixed and constrained, and with eight clamping beams 130, the inflatable wing 200 can be simply supported and constrained.

[0053] It is worth mentioning that the test bench 100 is set with a modular structure, allowing the positions and spacings 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 assembly can slide freely on the base 110 and be locked in the required position to adapt to inflatable wings 200 with different spans and widths, and the height of the entire test bench 100 can also be adjusted. Thus, the test bench 100 only needs simple assembly to adapt to inflatable wings 200 of different sizes, enhancing its versatility.

[0054] In addition, the bottom surface of the wing contact beam 160 is provided with an arc-shaped polyurethane buffer pad to ensure that a line contact with a width of 30 mm is formed with the surface of the inflatable wing 200, and the surface of each clamping beam 130 includes a silica gel anti-slip layer to enhance the fixing effect on the wing.

[0055] The technical means disclosed by the solution of the present invention are not limited to those disclosed by the above-mentioned technical means, but also include technical solutions composed of any combination of the above technical features. The above are the specific embodiments of the present invention. It should be noted that for those of ordinary skill in the art of this technology, without departing from the principle of the present invention, several improvements and retouches can be made, and these improvements and retouches are also regarded as the protection scope of the present invention.

[0056] It should be noted that all directional indications (such as up, down, left, right, front, back...) in the embodiments of the present invention are only used to explain the relative position relationship and movement conditions between components in a specific posture (as shown in the drawings). If the specific posture changes, the directional indications will also change accordingly.

[0057] In addition, in the present invention, descriptions such as "first", "second", "one" are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically defined. Terms such as "connection" and "fixation" should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and can be the communication inside two components or the interaction relationship between two components, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0058] The technical solutions between the various embodiments of the present invention can be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the protection scope required by the present invention.

[0059] The specific embodiments described herein are only illustrative of the spirit of the present invention. Those skilled in the art of the present invention can make various modifications or supplements to the described specific embodiments or use similar methods for substitution, but will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

Claims

1. A method for testing the mechanical properties of an inflatable wing, which is applied to a test bench connected to an external universal testing machine, and is characterized in that the test bench includes: a base; a support assembly, at least two groups of which are provided, and the support assembly can move along the length direction of the base to adjust the spacing; a fixed crossbeam, which is bridged across each group of the support assemblies; a loading beam, one end of which is connected to the fixed crossbeam through a rotating shaft, and the other end is provided with a loading conversion head, and the loading conversion head is used to connect to an external universal testing machine; a wing contact beam, which is connected to the bottom of the loading beam through a rotating shaft, and 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: Drive the loading beam through an external universal tester to apply a vertical load to the inflatable wing at a preset rate; S3. Data acquisition: a. Displacement measurement units are arranged on 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 condition in this area; S4. Failure determination: When it is monitored that the deflection curve shows a sudden change in deformation or the strain data exceeds the threshold, it is determined that the inflatable wing has buckled and failed, stop loading and record the maximum load value.

2. The mechanical property testing method of an inflatable wing according to claim 1, wherein After step S4, it further includes: S5. Stiffness verification: After the test, compare the measured load-displacement curve with the theoretical model, calculate the relative error of the bending stiffness and control the error within ±3%.

3. A method for testing the mechanical properties of an inflatable wing according to claim 1, characterized in that, In step S1, the inflatable wing realizes a fixed support constraint condition or a simply supported constraint condition on the test bench through a clamping beam. Among them, In the fixed support constraint condition, the leading edge of the inflatable wing is fixed by a quick clamp, and the trailing edge is applied with a pre-tightening force through an adjustable jackscrew; In the simply supported constraint condition, the inflatable wing is supported distributively by multiple clamping beams, pressure sensors are arranged on each clamping beam, and the pressure deviation at each clamping point does not exceed ±5%.

4. A method for testing the 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. A method for testing the 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 through laser calibration.

6. A method for testing the mechanical properties of an inflatable wing according to claim 1, characterized in that The displacement measurement unit is set 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. A method for testing the mechanical properties of an inflatable wing according to claim 1, characterized in that, The strain detection unit is set as a three-way strain rosette, and the three-way strain rosette is arranged on the surface of the inflatable wing, and the three-way strain rosette is close to and symmetrically distributed on both sides of the symmetry axis of the inflatable wing.

8. A method for testing the 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 through the optical fiber sensor.

9. A method for testing the mechanical properties of an inflatable wing according to claim 1, characterized in that The support assembly includes: a support frame, which forms a slide rail connection structure with the base; clamping beams, the number of which is multiple and are vertically installed on the opposite surfaces of the same group of support frames to form a parallel arranged support structure.

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