Aircraft wing lift-off strength test load reduction device and method

Abstract

This invention relates to the field of aircraft strength testing technology, and discloses a load reduction device and method for aircraft wing top-mounted strength testing. It utilizes the lever principle to apply a downward load reduction load to the wing to balance the upward top-mounted load borne by the wing top point, thus reducing the overall load on the aircraft to zero and achieving the purpose of load reduction. This invention uses the lever principle to reduce the output load of the hydraulic actuator, achieving small load balancing of extremely large loads. Furthermore, for extremely large single-point loads at a single top point, only a few load reduction load application points need to be applied, reducing the loading channels for the load reduction load and lowering the test complexity. By using the small load of the hydraulic actuator to balance the extremely large load at the top point, the safety and reliability of the test are improved, solving the reliability and safety problems of balancing extremely large single-point loads in wing top-mounted strength testing.

Description

Technical Field

[0001] This invention relates to the field of aircraft strength testing technology, and discloses an aircraft wing wing lifting strength test load reduction device and method. Background Technology

[0002] In aircraft strength testing, static load tests are required to assess the structural strength of each top point of the aircraft. In load-bearing strength tests, especially for wing load-bearing strength tests, the load on a single top point can reach over 90 tons. In wing load-bearing strength tests, because the load on a single top point is an extremely large single-point load, it is crucial to ensure a safe and reliable reduction of the overall aircraft load to zero when reducing this load. Current methods typically involve balancing the load and moment near the top point, such as on the fuselage, wing, and landing gear structures. However, due to the limited local load-bearing capacity of structures like the fuselage and wing spars, dozens of loading points are generally required to achieve load and moment balance. This increases the number of load-bearing channels, complicates the test loading process, and reduces the safety and reliability of the test. Summary of the Invention

[0003] The purpose of this invention is to provide a load reduction device and method for wing wing jacking strength testing, which can solve the reliability and safety problems of ultra-large single-point load balancing in wing jacking strength testing, reduce test complexity, and improve test safety and reliability.

[0004] To achieve the above-mentioned technical effects, the technical solution adopted by the present invention is as follows:

[0005] A load reduction device for testing the wing top strength of an aircraft, comprising:

[0006] A loading beam is located above the wing. The fulcrum end of the loading beam is hinged to a support member and connected to a fixed point through the support member. The force-applying end of the loading beam is connected to another fixed point through a hydraulic actuator.

[0007] A loading connector, wherein the loading connector block is fixed on the loading crossbeam;

[0008] A load transfer pad is attached to a preset position on the wing and connected to the loading connector. The load transfer pad is used to transfer the load reduction applied to the wing by the loading connector to the wing when the hydraulic actuator applies a downward force to the loading beam.

[0009] Furthermore, the loading joint includes an upper loading block and a lower loading block. The upper loading block is fixed on the loading beam, and the lower loading block is connected to the load transfer pad. The upper loading block and the lower loading block are engaged through a hinged surface.

[0010] Furthermore, the upper loading block is provided with an arc-shaped groove, and the lower loading block is provided with an arc-shaped protrusion concentric with the arc-shaped groove, the arc-shaped protrusion being fitted and hinged with the arc-shaped groove.

[0011] Furthermore, the axes of both the arc-shaped groove and the arc-shaped protrusion are perpendicular to the direction of flight of the aircraft.

[0012] Furthermore, the lower loading block is provided with a limiting block to limit the relative position between the load transfer pad block and the lower loading block.

[0013] Furthermore, a force sensor is provided between the hydraulic actuator cylinder and the force-applying end of the loading beam.

[0014] A method for reducing load during an aircraft wing top-mounted strength test, implemented using the aforementioned aircraft wing top-mounted strength test load reduction device, includes:

[0015] On the wing where the top point to be tested is located, the intersection of the wing front spars and wing ribs or the intersection of the wing rear spars and wing ribs within a preset distance range with the top point to be tested as the center is selected as the candidate point for load reduction.

[0016] Based on the preset lifting load value of the top point to be assessed and the design maximum bearing load of the candidate points for load reduction, determine the number of load reduction load application points required for load reduction.

[0017] Based on the number of load reduction points, select the load reduction point to be verified from the candidate load reduction points. Then, perform force balance verification and moment balance verification on the aircraft. If the verification result shows that the aircraft is in a balanced state, then determine the load reduction point to be verified as the load reduction point and output the load value of the load reduction point. Otherwise, add trim load to the aircraft for trimming and / or adjust the position of the load reduction point to be verified and / or adjust the load value of the load reduction point. Then, re-perform force balance verification and moment balance verification on the aircraft until the aircraft is in a balanced state.

[0018] Based on the load value of each load reduction point, and combined with the relative position of the loading joint corresponding to each load reduction point on the loading beam and the length of the loading beam corresponding to each load reduction point, the load value required to be applied by the hydraulic actuator corresponding to each load reduction point is obtained.

[0019] The aircraft wing lifting strength test is completed using the aircraft wing lifting strength test load reduction device, based on the load value required to be applied by the hydraulic actuator corresponding to each load reduction point.

[0020] Furthermore, methods for verifying the force balance and torque balance of an aircraft include:

[0021] The initial load value of the load shedding point to be verified is determined based on the preset jacking load value and the number of load shedding points to be verified.

[0022] Based on the preset jacking load value and the initial load value of each load reduction point to be verified, the resultant force and resultant moment of the aircraft are calculated. If the resultant force and resultant moment of the aircraft are both less than or equal to the corresponding preset threshold, the aircraft is determined to be in a balanced state. Otherwise, a trim load is added to the aircraft for trimming and / or the position of the load reduction point to be verified and / or the load value of the load reduction point is adjusted, and the resultant force and resultant moment of the aircraft are recalculated until the aircraft is in a balanced state.

[0023] Compared with the prior art, the beneficial effects of this invention are:

[0024] This invention employs a load reduction device for aircraft wing wing lift strength testing, consisting of a hydraulic actuator, a loading beam, a loading joint, and load transfer pads. Utilizing the lever principle, a downward load reduction load is applied to the wing to balance the upward lift load borne by the wing's top point, resulting in zero overall load on the aircraft and achieving load reduction. Compared to existing load reduction methods, this invention reduces the output load of the hydraulic actuator using the lever principle, achieving small load balancing of extremely large loads. Furthermore, for extremely large single-point loads at a single top point, only a few load reduction load application points need to be applied, reducing the loading channels and lowering the test complexity. By using the small load of the hydraulic actuator to balance the extremely large load at the top point, the safety and reliability of the test are improved, solving the reliability and safety issues of balancing extremely large single-point loads in wing lift strength testing. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the load reduction device for the aircraft wing jacking strength test in the embodiment.

[0026] Figure 2 This is a schematic diagram of the loading connector in the embodiment;

[0027] Figure 3 This is a schematic diagram of the structure of the lower loading block and the load transfer pad block in the embodiment;

[0028] Figure 4 This is a flowchart of the load reduction method for the aircraft wing wing lift strength test in the embodiment;

[0029] Among them, 1-loading crossbeam, 2-support component, 3-hydraulic actuator cylinder, 4-loading joint, 41-upper loading block, 411-arc groove, 42-lower loading block, 421-arc protrusion, 422-limiting block, 5-load transfer pad, 6-force sensor, 7-wing. Detailed Implementation

[0030] The present invention will now be described in further detail with reference to the embodiments and accompanying drawings. However, this should not be construed as limiting the scope of the above-described subject matter of the present invention to the following embodiments; all technologies implemented based on the content of the present invention fall within the scope of the present invention.

[0031] Example

[0032] See Figures 1 to 3 A load reduction device for testing the 7-pinch strength of an aircraft wing, comprising:

[0033] A loading beam 1 is located above the wing 7. The loading beam 1 is designed for maximum strength, and its length must be greater than the chord length of the wing 7. A support member 2 is hinged to the fulcrum end of the loading beam 1 and connected to a fixed point via the support member 2. The force-applying end of the loading beam 1 is connected to another fixed point via a hydraulic actuator 3. The support member 2 can be a steel structure, an I-beam, or other structure capable of supporting the fulcrum end of the loading beam 1 and withstanding a preset load. The fixed point can be a ground-based fixed point, such as an I-beam connected to a ground-based base by bolts, or a fixed location and structure selected according to actual needs.

[0034] Loading connector 4, the loading connector 4 pieces are welded and fixed on the loading beam 1.

[0035] Load transfer pad 5 is adhered to a predetermined position on the wing 7 and connected to the loading connector 4. When the hydraulic actuator 3 applies a downward force to the force-applying end of the loading beam 1, the load transfer pad 5 is used to transfer the load reduction applied to the wing 7 by the loading connector 4 to the wing 7. It should be noted that the load transfer pad 5 is made of polyurethane, and the polyurethane block is designed according to the load. The lower surface of the polyurethane block is shaped according to the outer skin of the aircraft rear beam structure. During processing and use, the load transfer pad 5 is adhered to the skin of the wing 7 to avoid damage to the skin during testing.

[0036] In some embodiments, the loading joint 4 includes an upper loading block 41 and a lower loading block 42. The upper loading block 41 is welded and fixed to the loading beam 1, and the lower loading block 42 is bonded to the load transfer pad 5. The upper loading block 41 and the lower loading block 42 are hinged together.

[0037] In some embodiments, the upper loading block 41 is provided with an arc-shaped groove 411, and the lower loading block 42 is provided with an arc-shaped protrusion 421 concentric with the arc-shaped groove 411. The arc-shaped protrusion 421 is fitted and hinged with the arc-shaped groove 411. The upper loading block 41 and the lower loading block 42 achieve a concave-convex fit using the arc-shaped groove 411 and the arc-shaped protrusion 421. The upper loading block 41 can rotate around the axis of the arc-shaped protrusion 421 within a preset angle range so that the loading joint 4 adapts to the loading angle with the loading beam 1, while not restricting the application of load.

[0038] In some embodiments, the axes of the arcuate groove 411 and the arcuate protrusion 421 are both perpendicular to the flight direction of the aircraft to prevent the loading joint 4 from sliding along the flight direction of the aircraft after being loaded.

[0039] In some embodiments, the lower loading block 42 is provided with a limiting block 422 to limit the relative position between the load transfer pad 5 and the lower loading block 42, so as to ensure that the load transfer pad 5 can accurately transfer the load reduction applied by the loading joint 4 to the wing 7 to the preset position of the wing 7.

[0040] In some embodiments, a force sensor 6 is provided between the hydraulic actuator 3 and the force-applying end of the loading beam 1, so as to monitor the magnitude of the force applied by the hydraulic actuator 3 to the loading beam 1 in real time during the test, and also to facilitate the determination of the magnitude of the load reduction applied to the wing 7.

[0041] Based on the same inventive concept, see [link to inventive concept] Figure 4 This embodiment also provides a method for reducing the load during the wing 7 lifting strength test of an aircraft, which is implemented using the wing 7 lifting strength test load reduction device of Embodiment 1, including:

[0042] Step 1: In the wing 7 strength test, for a single wing 7 apex point to be tested, select the intersection of the front spar and the wing rib or the rear spar and the wing rib within a preset distance range centered on the apex point as candidate points for load reduction. The preset distance range refers to the range of no more than four wing ribs centered on the apex point to be tested.

[0043] Step 2: Determine the number of load reduction points required for load reduction based on the preset jacking load value of the top point to be assessed and the design maximum bearing load of the candidate points for load reduction.

[0044] Specifically, firstly, the design maximum load-bearing capacity of the candidate points for load reduction can be calculated based on the structural design parameters of the aircraft wing 7, or determined through simulation or experimentation. Since all candidate points for load reduction are within a preset distance range, the design maximum load-bearing capacity of these candidate points may differ, but the difference is within the allowable range of the experiment. Then, the average design maximum load-bearing capacity of all candidate points for load reduction is calculated. By dividing the preset jacking load value by the average design maximum load-bearing capacity, the number of load reduction points required for load reduction is obtained.

[0045] Step 3: Based on the number of load reduction points, select the load reduction points to be verified from the candidate load reduction points; determine the initial load value for each load reduction point to be verified based on the preset jacking load value and the number of load reduction points to be verified.

[0046] Based on the preset jacking load value and the initial load value of each load reduction point to be verified, the resultant force and resultant moment of the aircraft are calculated. If the resultant force and resultant moment of the aircraft are both less than or equal to the corresponding preset threshold, the aircraft is determined to be in a balanced state. Otherwise, a trim load is added to the aircraft for trimming and / or the position of the load reduction point to be verified and / or the load value of the load reduction point is adjusted, and the resultant force and resultant moment of the aircraft are recalculated until the aircraft is in a balanced state.

[0047] Step 4: Based on the load value of each load reduction point, and combined with the relative position of the loading joint 4 corresponding to each load reduction point on the loading beam 1 and the length of the loading beam 1 corresponding to each load reduction point, the required load value to be applied by the hydraulic actuator 3 corresponding to each load reduction point is obtained.

[0048] Specifically, the load reduction device for the aircraft wing 7 lifting strength test described in Example 1 is used to apply a load to each load reduction point. Each load reduction point corresponds to one aircraft wing 7 lifting strength test load reduction device. The load value to be applied by the hydraulic actuator 3 in each aircraft wing 7 lifting strength test load reduction device is obtained based on the load value of the load reduction point, the distance between the loading joint 4 corresponding to the load reduction point and the support point of the loading beam 1, and the length of the loading beam 1 corresponding to the load reduction point, according to the lever principle.

[0049] Step 5: Based on the load value required to be applied by the hydraulic actuator 3 corresponding to each load reduction point, the aircraft wing 7 lifting strength test load reduction device is used to complete the aircraft wing lifting strength test.

[0050] It should be noted that when calculating the resultant force and resultant moment of the aircraft, the sum of the forces and moments acting on the aircraft along the X, Y, and Z axes are calculated separately in the aircraft's body coordinate system, which includes the X, Y, and Z axes. The body coordinate system is a three-dimensional Cartesian coordinate system with a pre-defined fuselage reference point as its origin and obeying the right-hand rule. In this system, the X-axis is set along the aircraft's heading, the Y-axis along a direction perpendicular to the heading, and the Z-axis along the aircraft's lateral direction. The formula for the sum of the forces acting on the aircraft along the X, Y, and Z axes when the aircraft is in equilibrium is as follows:

[0051] ;

[0052] in, , These represent the components of the lifting load at the top starting point in the X, Y, and Z axes, respectively. , , They represent the first The components of a single-point load reduction load at the point of application of the load reduction load in the X, Y, and Z axes. Indicates the number of points of application of the load reduction; , , They represent the first The components of the balancing load at each balancing point in the X, Y, and Z axes. This indicates the number of balancing points.

[0053] When an aircraft is in equilibrium, the formula for the sum of the moments along the X, Y, and Z axes is as follows:

[0054] ;

[0055] in, , , These represent the moments of the lifting load at the top starting point in the X, Y, and Z axes, respectively. , , They represent the first The moment of a single-point load reduction load at the point of application of the load reduction load in the X, Y, and Z axes. Indicates the number of points of application of the load reduction; , , They represent the first The moments of the balancing load at each balancing point in the X, Y, and Z axes. Indicates the number of balancing points; , , These represent the sum of the torques of the aircraft along the X, Y, and Z axes, respectively.

[0056] This invention employs a load reduction device for testing the wing 7's lifting strength, consisting of a hydraulic actuator 3, a loading beam 1, a loading connector 4, and a load transfer pad 5. Utilizing the lever principle, a downward load reduction load is applied to the wing 7 to balance the upward lifting load borne by the wing 7's top point, thus reducing the overall load on the aircraft to zero and achieving load reduction. Compared to existing load reduction methods, this invention reduces the output load of the hydraulic actuator by utilizing the lever principle. Simultaneously, it rationally selects the load reduction load application point on the wing 7, achieving small load balancing of ultra-large loads. Furthermore, for ultra-large single-point loads at a single top point, only a few load reduction load application points need to be applied, reducing the number of load reduction load application channels and lowering the test complexity. By using the small load of the hydraulic actuator to balance the ultra-large load at the top point, the safety and reliability of the test are improved, solving the reliability and safety issues of balancing ultra-large single-point loads in the wing 7 lifting strength test.

[0057] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A load reduction device for testing the wing apex strength of an aircraft, characterized in that, include: A loading beam (1) is located above the wing (7) and its length is greater than the chord length of the wing (7). The fulcrum end of the loading beam (1) is hinged to a support member (2) and connected to a fixed point through the support member (2). The force-applying end of the loading beam (1) is connected to another fixed point through a hydraulic actuator (3). The fixed point is set on the ground, and the support member (2) is connected to the fixed point through bolts. Loading connector (4), the loading connector (4) is fixed on the loading beam (1), and the loading connector (4) is located between the fulcrum end and the force application end of the loading beam (1); Load transfer pad (5) is bonded to a preset position on the wing (7) and connected to the loading connector (4). The load transfer pad (5) is used to transfer the load reduction load applied to the wing (7) by the loading connector (4) through the lever principle to the wing (7) when the hydraulic actuator (3) applies a downward force to the loading beam (1) end, so as to balance the upward lifting load borne by the top point of the wing (7).

2. The aircraft wing top-lift strength test load reduction device according to claim 1, characterized in that, The loading connector (4) includes an upper loading block (41) and a lower loading block (42). The upper loading block (41) is fixed on the loading beam (1), and the lower loading block (42) is connected to the load transfer pad (5). The upper loading block (41) and the lower loading block (42) are engaged by a hinged surface.

3. The aircraft wing top-lift strength test load reduction device according to claim 2, characterized in that, The upper loading block (41) is provided with an arc-shaped groove (411), and the lower loading block (42) is provided with an arc-shaped protrusion (421) concentric with the arc-shaped groove (411). The arc-shaped protrusion (421) is fitted and hinged with the arc-shaped groove (411).

4. The aircraft wing top-lift strength test load reduction device according to claim 3, characterized in that, The axes of the arc-shaped groove (411) and the arc-shaped protrusion (421) are both perpendicular to the direction of flight of the aircraft.

5. The aircraft wing top-lift strength test load reduction device according to claim 3, characterized in that, The lower loading block (42) is provided with a limiting block (422) to limit the relative position between the load transfer pad block (5) and the lower loading block (42).

6. The aircraft wing top-lift strength test load reduction device according to claim 1, characterized in that, A force sensor (6) is provided between the hydraulic actuator (3) and the force-applying end of the loading beam (1).

7. A method for reducing load during an aircraft wing top-up strength test, implemented using the aircraft wing top-up strength test load reduction device according to any one of claims 1-6, characterized in that, include: On the wing (7) where the top point to be tested is located, select the intersection of the front spar and the rib of the wing or the intersection of the rear spar and the rib of the wing within a preset distance range with the top point to be tested as the candidate point for load reduction. The preset distance range refers to the range centered on the top starting point to be assessed, not exceeding four wing ribs; Based on the preset lifting load value of the top point to be assessed and the design maximum bearing load of the candidate points for load reduction, determine the number of load reduction load application points required for load reduction. Based on the number of load reduction points, select the load reduction point to be verified from the candidate load reduction points. Then, perform force balance verification and moment balance verification on the aircraft. If the verification result shows that the aircraft is in a balanced state, then determine the load reduction point to be verified as the load reduction point and output the load value of the load reduction point. Otherwise, add trim load to the aircraft for trimming and / or adjust the position of the load reduction point to be verified and / or adjust the load value of the load reduction point. Then, re-perform force balance verification and moment balance verification on the aircraft until the aircraft is in a balanced state. Based on the load value of each load reduction point, and combined with the relative position of the loading joint corresponding to each load reduction point on the loading beam and the length of the loading beam corresponding to each load reduction point, the load value required to be applied by the hydraulic actuator corresponding to each load reduction point is obtained. The aircraft wing lifting strength test is completed using the aircraft wing lifting strength test load reduction device, based on the load value required to be applied by the hydraulic actuator corresponding to each load reduction point.

8. The method for reducing load during the wing apex strength test of an aircraft according to claim 7, characterized in that, Methods for performing force balance and moment balance checks on aircraft include: Based on the preset jacking load value and the number of load application points to be verified, determine the initial load value of each load application point to be verified; Based on the preset jacking load value and the initial load value of each load reduction point to be verified, the resultant force and resultant moment of the aircraft are calculated. If the resultant force and resultant moment of the aircraft are both less than or equal to the corresponding preset threshold, the aircraft is determined to be in a balanced state. Otherwise, a trim load is added to the aircraft for trimming and / or the position of the load reduction point to be verified and / or the load value of the load reduction point is adjusted, and the resultant force and resultant moment of the aircraft are recalculated until the aircraft is in a balanced state.

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