Wing skin health state detection method based on mechanoluminescent material

Abstract

The invention discloses a wing skin health state detection method based on a mechanoluminescent material. The method comprises the following steps: A) obtaining a stress-health state curve graph of a wing skin material; b) matching a persistent mechanoluminescence material suitable for detecting the health state of the wing skin material; c) obtaining a stress-wavelength curve graph of the mechanoluminescent material; d) uniformly coating the continuous mechanoluminescence material on the surface of the wing skin by adopting a spraying process; e) when the wing skin is subjected to stress excitation, shooting the light-emitting change of the wing skin in real time; and F) the airborne computer analyzes the health state of the wing skin according to the light-emitting images at different time points and the corresponding relation between the light-emitting color of the persistent mechanoluminescent material and the stress. By means of the method, the health state of the wing skin in the flight process can be monitored in real time, potential damage such as overlarge stress areas and cracks can be found in time, reliable guarantee is provided for safe flight of an airplane, the detection accuracy and real-time performance are effectively improved, and the detection cost is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of aircraft structural health monitoring, and particularly relates to a method for detecting the health status of wing skins based on force-induced luminescence materials. Background Art

[0002] With the rapid development of the aviation industry, the safety and reliability of aircraft have become crucial factors. As a key component of an aircraft, the wing skin is subjected to complex stress during flight, such as aerodynamic loads, structural vibrations, etc. The health status of the wing skin is directly related to the flight safety of the aircraft, and any potential damage or failure may lead to serious consequences.

[0003] Currently, traditional methods for detecting wing skins mainly include visual inspection and non-destructive testing techniques (such as ultrasonic testing, radiographic testing, etc.). Visual inspection is greatly affected by human factors and is difficult to detect minor damages and early health problems. Although non-destructive testing techniques can detect some defects, they often require the aircraft to be grounded for testing, the testing process is complex, the cost is high, and real-time monitoring cannot be achieved. During the flight of an aircraft, the health status of the wing skin is in a dynamic change, and traditional methods are difficult to meet the requirements of real-time and accurate monitoring. Therefore, it is of great practical significance to develop a method that is efficient, accurate and can monitor the health status of wing skins in real time. Summary of the Invention

[0004] The present invention aims to address the deficiencies of existing wing skin detection methods and provides a method for detecting the health status of wing skins based on force-induced luminescence materials. This method can monitor the health status of wing skins in real time during flight, timely detect potential areas with excessive stress and damages such as cracks, provide reliable guarantee for the safe flight of the aircraft, effectively improve the accuracy and real-time performance of detection, and reduce the detection cost.

[0005] Specific technical solution:

[0006] A method for detecting the health status of wing skins based on force-induced luminescence materials, comprising the following steps:

[0007] Step A: Obtain the stress-health status curve graph of the wing skin material;

[0008] The specific steps of Step A are as follows:

[0009] Step A1: Fabricate a test block with the same material and thickness as the wing skin.

[0010] Step A2: Apply a linearly varying pressure to the test block, and detect the health status of the test block in real time to obtain the pressure-health status curve graph of the wing skin material.

[0011] Step A3: Apply a linearly varying tensile force to the test block, and detect the health status of the test block in real time to obtain the tensile force - health status curve of the wing skin material.

[0012] Step B: Match a persistent force - induced luminescence material suitable for detecting the health status of the wing skin material;

[0013] Among them, the matching key points include the following parts:

[0014] Key point B1: The persistent force - induced luminescence material is an elastic force - induced luminescence material.

[0015] Key point B2: The stress response range of the persistent force - induced luminescence material covers the stress range of the wing skin material from healthy to fractured.

[0016] Key point B3: The persistent force - induced luminescence material has a fast response speed, and the luminescence color changes significantly with stress.

[0017] Step C: Obtain the stress - wavelength curve of the force - induced luminescence material; specifically, it includes the following steps:

[0018] Step C1: Fabricate a test block identical to the wing skin material, and spray the force - induced luminescence material on its surface.

[0019] Step C2: Apply a linearly varying pressure to the test block, collect and analyze the wavelength of the light emitted by the force - induced luminescence material in real time to obtain the compressive stress - light wavelength curve of the force - induced luminescence material.

[0020] Step C3: Apply a linearly varying tensile force to the test block, collect and analyze the wavelength of the light emitted by the force - induced luminescence material in real time to obtain the tensile stress - light wavelength curve of the force - induced luminescence material.

[0021] Step D: Use the spraying process to evenly coat the persistent force - induced luminescence material on the surface of the wing skin; the following key points need to be noted during the spraying process:

[0022] Key point D1: During the spraying process, it is necessary to control the thickness and uniformity of the material to ensure the consistency of stress response.

[0023] Step E: When the wing skin is stressed, a camera installed at the belly position of the aircraft takes pictures of the luminescence change of the wing skin in real time, and transmits the captured images to the on - board computer;

[0024] Use a high - speed camera to take pictures and transmit data using a high - speed transmission connection line to improve the authenticity and real - time performance of the data.

[0025] Step F: The on - board computer analyzes the health status of the wing skin according to the luminescence image and the corresponding relationship between the luminescence color of the persistent force - induced luminescence material and stress; specifically, it includes the following steps:

[0026] Step F1: The on-board computer analyzes the health status of the wing skin based on the luminescent image and the correspondence between the luminescent color of the persistent force-induced luminescent material and stress.

[0027] Step F2: If the stress is close to the damage threshold, the on-board computer displays the damage location and severity on the on-board screen to provide visual feedback.

[0028] Step F3: If the stress reaches the damage threshold, the on-board computer issues an alarm and displays the damage location and severity on the on-board screen to provide visual feedback.

[0029] Beneficial effects of the present invention:

[0030] Real-time monitoring: By coating the surface of the wing skin with a persistent force-induced luminescent material and combining it with a high-speed camera at the belly of the aircraft and the on-board computer, the health status of the wing skin can be monitored in real time during the flight of the aircraft, and stress abnormal areas can be detected in a timely manner, providing real-time guarantee for the safe flight of the aircraft.

[0031] High accuracy: By using the correspondence between the luminescent characteristics of the force-induced luminescent material and stress, as well as the stress-health status curve and stress-wavelength curve obtained from various stress tests on test blocks, the health status of the wing skin can be accurately analyzed, improving the accuracy of detection.

[0032] Visual feedback: The on-board computer displays the damage location and severity on the on-board screen, providing intuitive visual feedback for pilots and maintenance personnel, facilitating the timely adoption of corresponding measures, reducing maintenance costs and flight risks.

[0033] High cost-effectiveness: Compared with traditional non-destructive testing methods, the present invention does not require shutdown testing, reducing the testing time and cost, and at the same time improving the usage efficiency of the aircraft. Brief description of the drawings

[0034] Figure 1 is a flowchart of the present invention;

[0035] Figure 2 is a flowchart of the test for the damage threshold of the wing skin material in step A of the present invention;

[0036] Figure 3 is a flowchart of the test for the correspondence between the luminescent color of the force-induced luminescent material and stress in step C of the present invention. Detailed implementation manners

[0037] The specific technical solutions of the present invention are described in conjunction with the accompanying drawings.

[0038] As Figure 1 shown, a method for detecting the health status of a wing skin based on a force-induced luminescent material includes the following steps:

[0039] As Figure 2 shown, step A: Obtain the stress - health status curve of the wing skin material;

[0040] Step A1: Select a material that is exactly the same as the actual wing skin and make a specimen according to the actual thickness of the wing skin. For example, if the wing skin is made of aluminum alloy with a thickness of 5 mm, then make an aluminum alloy specimen with the same material and thickness.

[0041] Step A2: Place the made specimen on the pressure testing equipment and apply a linearly varying pressure to the specimen through this equipment. The pressure change range covers the pressure range that the wing skin may withstand during actual flight. At the same time, use high - precision health status detection instruments, such as ultrasonic flaw detectors, strain gauges, etc., to detect the health status of the specimen in real - time, including whether micro - cracks appear, deformation conditions, etc. Record and analyze the pressure data and the corresponding health status data, and finally obtain the pressure - health status curve of the wing skin material.

[0042] Step A3: Replace the testing equipment and use a tensile testing equipment to apply a linearly varying tensile force to the specimen, also covering the tensile force range during actual flight. During the application of the tensile force, continuously use the health status detection instrument to monitor the health status of the specimen, record the tensile force data and the health status data, and then obtain the tensile - health status curve of the wing skin material.

[0043] Step B: Match a persistent force - induced luminescence material suitable for detecting the health status of the wing skin material;

[0044] Key point B1: Screen out elastic force - induced luminescence materials from various force - induced luminescence materials. Elastic force - induced luminescence materials can return to their original state after being deformed by force, and there is a stable relationship between their luminescence characteristics and stress, which is more suitable for structures like wing skins that need to withstand complex stresses for a long time.

[0045] Key point B2: Conduct a stress response range test on the selected elastic force - induced luminescence material. Through experimental means, apply different magnitudes of stress to the material and observe the changes in its luminescence characteristics to ensure that the stress response range of this material can fully cover the stress interval from the healthy state to fracture of the wing skin material. For example, if the wing skin material fractures when the stress reaches 100 MPa, then the selected force - induced luminescence material should have an obvious luminescence response within the stress range of 0 - 100 MPa.

[0046] Key Point B3: Test the response speed and luminescence color change of the stress-induced luminescence material. Using high-speed photography equipment and spectral analysis instruments, observe the change speed and obviousness of the luminescence color when the material is subjected to rapidly changing stress. Select materials with fast response speed, which can quickly change the luminescence color when the stress changes, and the color changes are easy to distinguish, so as to more accurately reflect the stress state of the wing skin.

[0047] As Figure 3 shown, Step C: Obtain the stress-wavelength curve of the stress-induced luminescence material;

[0048] Step C1: Make a test block of the same material as the wing skin, and evenly spray the selected stress-induced luminescence material on the surface of the test block. During the spraying process, strictly control the spraying process parameters, such as spraying pressure, distance between the spray gun and the test block, etc., to ensure that the stress-induced luminescence material evenly covers the surface of the test block.

[0049] Step C2: Place the test block sprayed with the stress-induced luminescence material on the pressure loading device, and apply a linearly changing pressure to the test block through this device. During the pressure application process, use optical detection equipment, such as a spectrometer, to collect the wavelength of the light emitted by the stress-induced luminescence material in real time. At the same time, record the corresponding pressure data, and after data processing and analysis, obtain the compressive stress-light wavelength curve of the stress-induced luminescence material.

[0050] Step C3: Replace the loading device and use a tensile loading device to apply a linearly changing tensile force to the test block. Similarly, during the tensile force application process, use a spectrometer to collect the wavelength of the light emitted by the stress-induced luminescence material in real time, and record the tensile force data, and finally obtain the tensile stress-light wavelength curve of the stress-induced luminescence material.

[0051] Step D: Use the spraying process to evenly coat the persistent stress-induced luminescence material on the surface of the wing skin;

[0052] Key Point D1: When performing the spraying operation on the surface of the wing skin, use professional spraying equipment and technology. By precisely controlling the parameters of the spraying equipment, such as spraying flow rate, spraying angle, spray gun moving speed, etc., ensure that the persistent stress-induced luminescence material can be evenly coated on the surface of the wing skin, and the coating thickness remains consistent. For example, set the coating thickness to 0.5 mm, and through multiple tests and adjustments of the spraying parameters, control the coating thickness error of each part of the wing skin within ±0.05 mm to ensure the consistency of stress response.

[0053] Step E: When the wing skin is subjected to stress excitation, a camera installed at the belly position of the aircraft takes real-time pictures of the luminescence change of the wing skin and transmits the taken images to the on-board computer;

[0054] Select a high-speed camera and install it at the belly position to ensure that the shooting field of view of the camera can cover the area of the wing skin that needs to be monitored. The high-speed camera features a high frame rate and can quickly capture the luminescence changes of the stress-induced luminescence material on the wing skin surface. For example, a high-speed camera with a frame rate of 1000 fps is selected to clearly record the luminescence of the wing skin under rapid stress changes.

[0055] Connect the high-speed camera to the on-board computer using a high-speed transmission cable to ensure that the captured images can be transmitted to the on-board computer quickly and accurately. The high-speed transmission cable has the characteristics of low latency and high bandwidth, which can ensure the authenticity and real-time nature of data transmission. For example, using an optical fiber high-speed transmission line, its data transmission rate can reach more than 10 Gbps, which can meet the rapid transmission requirements of a large amount of image data.

[0056] Step F: The on-board computer analyzes the health status of the wing skin based on the luminescence image and the corresponding relationship between the persistent stress-induced luminescence material's luminescence color and stress.

[0057] Step F1: The on-board computer uses image processing algorithms and a pre-established corresponding relationship model between the stress-induced luminescence material's luminescence color and stress to analyze the luminescence image transmitted by the high-speed camera. By identifying the luminescence colors of different regions in the image and combining with the corresponding relationship model, the stress magnitudes borne by each region of the wing skin are calculated.

[0058] Step F2: Compare the calculated stress values with the pre-set damage thresholds. If the stress in a certain region is close to the damage threshold, the on-board computer marks the damage location on the schematic diagram of the wing skin through a graphical interface and displays its severity with different colors or warning symbols, providing intuitive visual feedback for pilots and maintenance personnel.

[0059] Step F3: If the stress in a certain region reaches the damage threshold, the on-board computer immediately issues an alarm signal and prominently displays the damage location and severity on the on-board screen. For example, mark the damage location with a flashing red icon and display the specific stress value and damage level to remind pilots and maintenance personnel to take measures in a timely manner.

Claims

1. A method for detecting the health status of a wing skin based on mechanoluminescent materials, characterized in that: The following steps are involved: Step A, obtaining a stress-health state curve diagram of the wing skin material; Step B, matching a continuous mechanoluminescent material suitable for detecting the health status of the wing skin material; Step C, obtaining a stress-wavelength curve of the mesoluminescent material; Step D, uniformly coating the continuous electroluminescent material on the surface of the wing skin by a spraying process; Step E: When the wing skin is subjected to stress excitation, a camera installed at the belly of the aircraft captures the luminous changes of the wing skin in real time, and transmits the captured images to an onboard computer; Step F: The onboard computer analyzes the health status of the wing skin according to the luminescent image and the corresponding relationship between the luminescent color of the continuous mechanoluminescent material and the stress.

2. The method for detecting the health status of a wing skin based on a mechanoluminescent material according to claim 1, characterized in that: The step A specifically comprises the following steps: Step A1, preparing a test block with the same material and thickness as the wing skin; Step A2, applying a linearly varying pressure to the test block, detecting the health status of the test block in real time, and obtaining a pressure-health status curve diagram of the wing skin material; Step A3: applying a linearly varying tension to the test block, detecting the health status of the test block in real time, and obtaining a tension-health status curve diagram of the wing skin material.

3. The method for detecting the health status of a wing skin based on a mechanoluminescent material according to claim 1, characterized in that: The matching key points in step B include the following parts: Point B1, the continuous mesoluminescent material is an elastic mesoluminescent material; Point B2: The stress response range of the continuous force-induced luminescence material covers the stress range of the wing skin material from healthy to fracture; Point B3: The continuous force-induced luminescence material has a fast response speed and the luminescent color changes significantly with stress.

4. The method for detecting the health status of a wing skin based on a mechanoluminescent material according to claim 1 is characterized in that: The step C specifically comprises the following steps: Step C1, preparing a test block with the same material as the wing skin, and spraying a mechanoluminescent material on its surface; Step C2, applying a linearly varying pressure to the test block, collecting and analyzing the wavelength of light emitted by the mechanoluminescent material in real time, and obtaining a compressive stress-light wavelength curve of the mechanoluminescent material; Step C3, applying a linearly varying tensile force to the test block, collecting and analyzing the wavelength of light emitted by the mesoluminescent material in real time, and obtaining a tensile stress-light wavelength curve of the mesoluminescent material.

5. The method for detecting the health status of a wing skin based on mechanoluminescent materials according to claim 1, characterized in that: The step E is filmed with a high-speed camera and data is transmitted using a high-speed transmission connection line.

6. The method for detecting the health status of a wing skin based on mechanoluminescent materials according to claim 1, characterized in that: The step F specifically comprises the following steps: Step F1, the onboard computer analyzes the health status of the wing skin according to the luminous image and the corresponding relationship between the luminous color of the continuous mechanoluminescent material and the stress; Step F2: If the stress is close to the damage threshold, the onboard computer displays the damage location and severity on the onboard screen to provide visual feedback; Step F3: If the stress reaches the damage threshold, the onboard computer will sound an alarm and display the damage location and severity on the onboard screen to provide visual feedback.

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