A method and device for determining the center of pressure of a flat wing profile

Abstract

The application belongs to the field of aircraft structure strength test, and is a flat wing section center of rigidity position determination method and device. The weight of a loading device is recorded first, and then the loading device is controlled to load the test wing after checking and judging that each system or device is normal. The test wing is first loaded to an initial value, and then is loaded to different loading points according to settings. The variable amount of the test wing is fed back through a load sensor, and the average value of the load sensor is obtained through calculation. Then, the center of rigidity position of the test wing corresponding to the section can be determined according to the load ratio. The center of rigidity positions of different sections of the test wing can be obtained by loading different loading points of the test wing respectively. After the test is completed, unloading and pressure relief are performed. The electric drive actuator has the performance characteristics of high positioning accuracy, fast response speed, accurate control and high synchronism, and is better than the hydraulic actuator.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of aircraft structure strength test, and particularly relates to a method and device for determining the center of stiffness of a flat wing section. BACKGROUND

[0002] In aircraft structure strength test, stiffness test is one of important projects, which is used to obtain the stiffness characteristics of a wing, and the position of the center of stiffness on the wing is a very important parameter. The position of the center of stiffness has an important influence on the force transmission characteristics, vibration characteristics and structural deformation of the structure. The determination of the center of stiffness directly affects the internal force transmission and distribution of the wing structure, and is a key to ensure the matching of the wing structure and the aerodynamic load.

[0003] In aircraft stiffness test, the position of the center of stiffness of the wing section is usually obtained by using a numerical model theory calculation method. However, due to the influence of processing technology, loading equipment, measurement and control cable and the like, the position of the center of stiffness in the wing stiffness test is different from the theoretical calculation result. At this time, if the wing load is applied according to the theoretical center of stiffness position for stiffness test, the obtained wing stiffness characteristics are distorted.

[0004] Therefore, how to accurately determine the position of the center of stiffness of the aircraft wing is a problem to be solved. SUMMARY

[0005] The application aims to provide a method and device for determining the position of the center of stiffness of a flat wing section, so as to solve the problem that the calculation of the center of stiffness in the prior art easily leads to distortion of the wing stiffness characteristics.

[0006] The technical scheme of the application is: a method for determining the position of the center of stiffness of a flat wing section, comprising:

[0007] determining the section to be loaded, installing the test wing at the specified section on the loading equipment, weighing the loading equipment, and recording the weight of the loading equipment;

[0008] pressurizing and checking whether the control system, the measurement system and the loading equipment are normal, if normal, executing the next step;

[0009] controlling the loading equipment to apply load to the test wing, and loading to the initial reading, that is, the weight deduction value, and then controlling the loading equipment to keep the weight deduction value for the first time and then zeroing the micrometer;

[0010] setting different loading point positions of the wing, controlling the loading equipment to continue to apply load to the test wing, until the values on the micrometer respectively reach the positions of the loading points, and recording the feedback values of the force sensors on the electrically driven actuators at different loading points;

[0011] controlling the loading equipment to exit the initial reading of the micrometer;

[0012] The average of the feedback values on the plurality of sets of force sensors is obtained, and the centroid position of the section is calculated according to the load ratio;

[0013] The other wing sections that need to be loaded are determined, the test wing is controlled to be installed on the loading device according to different sections, and the centroid positions of different sections are tested and calculated respectively.

[0014] Unloading and pressure relief.

[0015] Preferably, the first time is 60s.

[0016] Preferably, the loading device controls the three loading points of the test wing to be loaded respectively, and the dial gauge positions corresponding to the three loading points are 20mm, 40mm and 60mm respectively.

[0017] As a specific embodiment, a straight wing section centroid position determination device adopts the above-mentioned method, including a loading device, a control system, a measurement system and an electric drive actuator, the loading device includes a clamping plate and a connecting column, the electric drive actuator is arranged on the ground or a support structure, the clamping plate is arranged horizontally in two groups, the connecting column is connected between the two groups of clamping plates in parallel, the test wing is connected to the connecting column, and the output end of the electric drive actuator is connected to the lower clamping plate; the measurement system includes a force sensor and a dial gauge, the force sensor is arranged between the clamping plate and the output end of the electric drive actuator, and the dial gauge is arranged at the loading position of the wing section.

[0018] The straight wing section centroid position determination method and device provided by the application record the weight of the loading device first, then control the loading device to load the test wing after checking that each system or device is normal, load to the initial value first, then load to different loading points according to the setting, obtain the average value of the force sensor through the variable amount of the test wing fed back by the force sensor, and then determine the centroid position of the corresponding section of the test wing according to the load ratio. By loading different loading points of the test wing respectively, the centroid positions of different sections of the test wing can be obtained, and unloading and pressure relief are performed after the test is completed. The electric drive actuator has the performance characteristics of high positioning accuracy, fast response speed, accurate control and high synchronicity, and is better than the hydraulic actuator. The clamping plate or the tension and compression pad-lever form is adopted for the loading device to reduce the influence of the gap between the loading devices on the test. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the technical solutions provided by the application, the following will briefly introduce the drawings. Obviously, the drawings described below are only some embodiments of the application.

[0020] Figure 1 This is a schematic diagram of the overall structure of this application, excluding the control system;

[0021] Figure 2 This is a schematic diagram of the cardboard loading process in this application;

[0022] Figure 3 This is a schematic diagram of the tension / compression pad-lever loading method in this application.

[0023] 1. Electric drive actuator; 2. Pallet; 3. Front beam; 4. Rear beam; 5. Dial indicator; 6. Force sensor; 7. Connecting column. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be described in more detail below with reference to the accompanying drawings.

[0025] A method for determining the position of the center of rigidity of a straight airfoil, such as Figure 1 As shown, it includes:

[0026] Step 1: Determine the section to be loaded, install the test wing onto the loading device at the designated section. The test wing includes a front spar 3 and a rear spar 4, which correspond to the installation positions of the dial indicator 5. Weigh the loading device and record its weight. This will allow you to remove the weight of the loading device during the test and accurately obtain the load applied to the test wing.

[0027] Step 2: Pressurize and check if the control system, measurement system and loading equipment are normal. If normal, proceed to the next step.

[0028] Step 3: Control the loading device to apply load to the test wing and load it to the initial reading, which is the tare value. Then, control the loading device to maintain the tare value for a period of time and then zero the dial indicator 5.

[0029] Preferably, the first time is 60 seconds, which can be adjusted as needed to ensure the accuracy of zeroing the dial indicator 5.

[0030] Step 4: Set different loading point positions on the wing, control the loading device to continue applying load to the test wing until the value on the dial indicator 5 reaches the position of each loading point, and record the feedback value of the force sensor 6 on the electric drive actuator 1 at different loading points.

[0031] The loading device includes an electrically driven actuator 1, which can specifically be an electric push rod. The electrically driven actuator 1 applies displacement through the loading device using a position control monitoring method. Considering the clearance of the loading device, a dial indicator 5 is installed at the loading position on the airfoil section to measure the actual deformation of the airfoil section. Simultaneously, the dial indicator 5 provides feedback as a command to the electrically driven actuator 1. For bending stiffness conditions, the deformation at the airfoil section is uniform, meaning the feedback from the dial indicator 5 is consistent.

[0032] Preferably, the loading device applies load to three loading points on the test wing separately, with the corresponding dial indicator 5 positions at 20mm, 40mm, and 60mm, respectively. The number of loading points can be adjusted as needed, while ensuring that the difference between the dial indicator 5 positions of any two adjacent loading points is the same to guarantee the accuracy of the test.

[0033] Step 5: Control the loading device to exit loading to the initial reading of dial gauge 5;

[0034] Step 6: Calculate the average value of the feedback values ​​from the multiple sets of force sensors 6, and calculate the position of the rigid center of the profile according to the load ratio.

[0035] Step 7: Determine other wing profiles that need to be loaded. Repeat steps 3-6, and control the test wings to be installed on the loading equipment according to different profiles. Test and calculate the position of the center of rigidity at different profiles.

[0036] Step 8: Unload and decompress.

[0037] The electrically driven actuator 1 is superior to the hydraulic actuator due to its high positioning accuracy, fast response speed, precise control, and high synchronization. The loading device uses a clamping plate 2 or a tension / compression pad-lever configuration to reduce the impact of loading device clearance on the test. The structure when using clamping plate 2 for loading is as follows... Figure 2 As shown, the structure when using tension / compression pad-lever loading is as follows: Figure 3 As shown.

[0038] As a specific embodiment, the device for determining the center of flat wing profile also includes a method, which comprises a loading device, a control system, a measuring system and an electrically driven actuator 1. The loading device includes a clamping plate 2 and a connecting column 7. The electrically driven actuator 1 is arranged on the ground or a support structure. The electrically driven actuator 1 has two groups and is arranged vertically and side by side. The clamping plate 2 has two groups and is arranged horizontally and vertically. The connecting column 7 has two groups and is connected to the two groups of clamping plates 2 side by side. A test wing is connected to the connecting column 7. The output end of the electrically driven actuator 1 is connected to the lower clamping plate 2. The measuring system includes a force sensor 6 and a micrometer 5. The force sensor 6 is arranged between the clamping plate 2 and the output end of the electrically driven actuator 1. The micrometer 5 is arranged at the loading position of the wing profile.

[0039] The control system is a controller or a computer, which can control the loading device, the measuring system and the electrically driven actuator 1. The control system controls the electrically driven actuator 1 to cooperate with the clamping plate 2 and the connecting column 7 to load the test wing, obtains the values of the force sensor 6 and the micrometer 5, and collects the deformation of the test wing, so as to realize simple and efficient loading of the test wing.

[0040] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited to this. Any changes or replacements within the technical range disclosed in the present application can be easily thought by those skilled in the art, which should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A method for determining the center of pressure of a flat wing section, characterized by, The method comprises the following steps: Determine the profile to be loaded, mount the test wing at the specified profile on the loading device, weigh the loading device, and record the weight of the loading device; Pressurize and check the control system, measurement system and loading device, if normal, proceed to the next step; Control the loading device to apply load to the test wing and load to the initial reading, i.e. the weight-off value, and then control the loading device to maintain the weight-off value for a first time and then zero the dial gauge (5); Set different loading point positions of the wing, control the loading device to continue to apply load to the test wing until the values on the dial gauge (5) reach the positions of the respective loading points, and record the feedback values of the force sensor (6) on the electric drive actuator (1) at different loading points; Control the loading device to exit the initial reading of the dial gauge (5); Calculate the center of stiffness position of the profile according to the load ratio by averaging the obtained feedback values of the force sensor (6) on the dial gauge (5); Determine other wing profiles to be loaded, control the test wing to be mounted on the loading device according to different profiles respectively, and test and calculate the center of stiffness positions of different profiles respectively; Unload and depressurize.

2. The method of claim 1, wherein: The first time is 60 seconds.

3. The method of claim 1, wherein: Control the loading device to apply load to the three loading points of the test wing, and the positions of the dial gauge (5) corresponding to the three loading points are 20mm, 40mm and 60mm respectively.

4. A device for determining the center of pressure of a flat wing profile, using a method according to any one of claims 1 to 3, characterized in that: The device comprises a loading device, a control system, a measurement system and an electric drive actuator (1), the loading device comprises a clamping plate (2) and a connecting column (7), the electric drive actuator (1) is arranged on the ground or a support structure, the clamping plate (2) has two groups and the two groups of clamping plates (2) are arranged horizontally above and below, the connecting column (7) has two groups and the two groups of connecting columns (7) are connected side by side between the two groups of clamping plates (2), the test wing is connected to the connecting column (7), and the output end of the electric drive actuator (1) is connected to the lower clamping plate (2); the measurement system comprises a force sensor (6) and a dial gauge (5), the force sensor (6) is arranged between the clamping plate (2) and the output end of the electric drive actuator (1), and the dial gauge (5) is arranged at the loading position of the wing profile.

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