阅读说明：本技术 一种复杂环境下桨叶应变测量试验系统及试验方法 (Blade strain measurement test system and method under complex environment ) 是由 王潇 佳欢 李博 夏品奇 于 2020-12-28 设计创作，主要内容包括：本发明提供一种复杂环境下桨叶应变测量试验系统及试验方法,属于桨叶应变测量技术领域。系统包括试验箱、桨叶、喷洒水系统、制冷系统、加热系统、风力系统、气压调控系统、解调仪、应变传感系统、温度湿度监测系统,应变传感系统和解调仪实时观察读取桨叶应变情况,通过喷水、释放液氮和风力的作用可以使桨叶结冰,打开加热装置可以在桨叶结冰的时候加热除冰,此外加真空泵用来调控试验箱内的压强。温度湿度计用来反映试验箱内的温度湿度信息。此桨叶应变测量系统简单易操作,可以模拟桨叶运行的复杂环境,应变传感器采用光纤光栅材质能更精确的测量出桨叶应变。(The invention provides a system and a method for testing blade strain measurement in a complex environment, and belongs to the technical field of blade strain measurement. The system comprises a test box, blades, a water spraying system, a refrigerating system, a heating system, a wind power system, an air pressure regulating system, a demodulator, a strain sensing system and a temperature and humidity monitoring system, wherein the strain sensing system and the demodulator observe and read the strain condition of the blades in real time, the blades can be frozen through the action of water spraying, liquid nitrogen releasing and wind power, a heating device is started to heat and deice the blades when the blades are frozen, and a vacuum pump is additionally arranged to regulate and control the pressure in the test box. The temperature and humidity meter is used for reflecting the temperature and humidity information in the test chamber. The blade strain measuring system is simple and easy to operate, can simulate the complex environment of blade operation, and the strain sensor can more accurately measure the blade strain by adopting the fiber grating material.)

1. The utility model provides a paddle measurement of strain test system under complex environment which characterized in that: the test system comprises a test box body, an icing system, a heating deicing system, a vacuum pump pressure regulating device and a strain measurement system;

the freezing system is used for rapidly reducing the temperature in the test box body, the heating deicing system vaporizes water mist to increase the humidity, and meanwhile, the cold air sinking into the bottom is blown upwards to take away the heat on the surface of the blade to accelerate cooling and freezing; the paddle is positioned in the test box body; the vacuum pump pressure regulating device is used for pumping out gas in the test box body to enable the internal air pressure to be close to vacuum or for pressurizing the inside of the test box body;

the strain measurement system adopts a fiber grating to collect the temperature and humidity conditions in the test box body, and the fiber grating measures the strain of the paddle.

2. The blade strain measurement testing system under the complex environment according to claim 1, characterized in that: the heating deicing system comprises a controllable water spraying device and a liquid nitrogen refrigerating device, wherein the controllable water spraying device is arranged at the top of the test box body, and the liquid nitrogen refrigerating device is introduced into the test box body from the top of the test box body;

and a heating device is arranged above the wind power device, and the wind power device is connected with a fan controller.

3. The blade strain measurement testing system under the complex environment according to claim 1 or 2, characterized in that: the test box body is made of transparent acrylic materials.

4. The blade strain measurement testing system under the complex environment according to claim 3, characterized in that: the temperature and humidity meter is respectively provided with one on the left and the right of the bottom of the box body of the test box, and one on the upper surface and the lower surface of the paddle.

5. The blade strain measurement testing system under the complex environment according to claim 2, characterized in that: the controllable water spraying device is positioned right above the paddle and comprises four adjustable water spraying mode nozzles and a water storage tank provided with a pressurizing device, and the spraying speed of water mist can be increased by pressurizing.

6. The blade strain measurement testing system under the complex environment according to claim 2, characterized in that: the vacuum pump pressure regulating device is provided with a pressure gauge, and the pressure gauge is used for reading the air pressure in the test box.

7. The blade strain measurement testing system under the complex environment according to claim 2, characterized in that: the strain measurement system comprises fiber gratings and a demodulator, wherein the fiber gratings are uniformly arranged on the surfaces of the blades, and the fiber gratings are externally connected with the demodulator to read the strain of the blades.

8. A blade strain measurement test method in a complex environment is characterized by comprising the following steps: the test method comprises the following steps:

designing a blade strain measurement test system under a complex environment according to claim 1;

step two, controlling the water outlet speed of the spray head, opening a switch of a liquid nitrogen refrigerating device to inject liquid nitrogen to rapidly refrigerate or opening a heating device; the fan controller adjusts the wind power of the fan below the paddle, the fan blows cold air or warm air which is sunk into the bottom to the surface of the paddle, and water mist is vaporized to increase the humidity in the box body of the test box and take away heat on the surface of the paddle to quickly freeze the paddle;

step three, pumping out air in the box body of the test box to be in a state close to vacuum, and controlling the air pressure to be at a target pressure level through the reading of a pressure gauge;

and step four, reading the degrees of air pressure, temperature and humidity, and reading the reading of the demodulator when the environmental requirements are met.

9. The blade strain measurement test method under the complex environment according to claim 8, characterized in that: various complex environments for the operation of the paddle and strain data of the paddle are manufactured and read through different matching methods of the heating device, the water spraying device, the liquid nitrogen refrigerating device and the air pressure regulating device.

10. The blade strain measurement test method under the complex environment according to claim 8, characterized in that: and when simulating severe hot environments such as gobi and the like, closing the liquid nitrogen and water spraying device, opening the heating device, observing the reading of the thermometer and the reading of the demodulator, starting the water spraying device to adjust to a spraying mode when simulating strain under a high-humidity environment on the sea surface, adjusting the wind power of the fan to be large, and observing the reading of the hygrometer and the reading of the demodulator.

Technical Field

The invention provides a system and a method for testing blade strain measurement in a complex environment, and belongs to the technical field of blade strain measurement.

Background

The working state and environment of the helicopter rotor blade are extremely complex, the helicopter rotor blade is in plateau, high altitude, gobi, desert, sea and the like, the temperature, the humidity and the air pressure change multiple ends, and the load identification is especially important for ensuring that the rotor blade is in a safe load interval, and the load identification of the rotor blade is one of the most complex and difficult problems in the helicopter technology. The identification of blade load is realized by identifying blade strain, the identification methods include a force analysis method, a composite force-modal analysis method and the like, and the identification method of the identification load of the helicopter rotor blade by using an acceleration sensor has the problems of low signal-to-noise ratio, poor precision, complicated measurement system, damage to blade surface smoothness and aerodynamic force and the like when measurement data are obtained. The fiber grating material has the advantages of high sensing measurement precision, strong interference resistance, good repeated stability, small volume and light weight, and is very suitable for measuring the structural strain of the aircraft. Blade strain measurements can be measured by field testing with a tester, but are expensive, time consuming, labor intensive, and present a certain risk. Other measurement and test methods also have the defects of complex equipment operation, high cost and the like.

Disclosure of Invention

In view of the defects of the prior art, the invention aims to provide a blade strain measurement test system in a complex environment, which can be used for manufacturing high-temperature, low-temperature, high-humidity, icing, low-pressure and other sealed environments, can better simulate various complex environments and measure the strain of the blades of a helicopter rotor during task execution, is simple and easy to operate, and can effectively improve the measurement efficiency and reduce the test cost.

The invention adopts the following technical scheme for realizing the purpose:

a blade strain measurement test system in a complex environment comprises a test box body, an icing system, a heating deicing system, a vacuum pump pressure regulating device and a strain measurement system;

the freezing system is used for rapidly reducing the temperature in the test box body, the heating deicing system vaporizes water mist to increase the humidity, and meanwhile, the cold air sinking into the bottom is blown upwards to take away the heat on the surface of the blade to accelerate cooling and freezing; the paddle is positioned in the test box body; the vacuum pump pressure regulating device is used for pumping out gas in the test box body to enable the internal air pressure to be close to vacuum or for pressurizing the inside of the test box body;

the strain measurement system adopts a fiber grating to collect the temperature and humidity conditions in the test box body, and the fiber grating measures the strain of the paddle.

Further, the heating deicing system comprises a controllable water spraying device and a liquid nitrogen refrigerating device, wherein the controllable water spraying device is installed at the top of the test box body, and the liquid nitrogen refrigerating device is introduced into the test box body from the top of the test box body;

and a heating device is arranged above the wind power device, and the wind power device is connected with a fan controller.

Furthermore, the box body of the test box is made of transparent acrylic materials.

Furthermore, the temperature and humidity meters are respectively arranged on the left and the right of the bottom of the box body of the test box, and are respectively arranged on the upper surface and the lower surface of the paddle.

As a preferred embodiment of the application, the controllable water spraying device is positioned right above the paddle and comprises four spray nozzles with adjustable water spraying modes and a water storage tank provided with a pressurizing device, and the water mist spraying speed can be accelerated by pressurizing.

Furthermore, the vacuum pump pressure regulating device is provided with a pressure gauge, and the pressure gauge is used for reading the air pressure in the test box.

Furthermore, the strain measurement system comprises fiber gratings and a demodulator, wherein the fiber gratings are uniformly arranged on the surfaces of the blades, and the fiber gratings are externally connected with the demodulator to read the strain of the blades.

The application also provides a blade strain measurement test method in a complex environment, which comprises the following steps:

step one, designing the test system;

step two, controlling the water outlet speed of the spray head, opening a switch of a liquid nitrogen refrigerating device to inject liquid nitrogen to rapidly refrigerate or opening a heating device; the fan controller adjusts the wind power of the fan below the paddle, the fan blows cold air or warm air which is sunk into the bottom to the surface of the paddle, and water mist is vaporized to increase the humidity in the box body of the test box and take away heat on the surface of the paddle to quickly freeze the paddle;

step three, pumping out air in the box body of the test box to be in a state close to vacuum, and controlling the air pressure to be at a target pressure level through the reading of a pressure gauge;

and step four, reading the degrees of air pressure, temperature and humidity, and reading the reading of the demodulator when the environmental requirements are met.

Furthermore, various complex environments for the blade to work and strain data of the blade to be read are manufactured by different matching methods of the heating device, the water spraying device, the liquid nitrogen refrigerating device and the air pressure regulating device.

Furthermore, when simulating a hot environment such as Gobi and the like, the liquid nitrogen and the water spraying device are turned off, the heating device is turned on, the reading of the thermometer and the reading of the demodulator are observed, when the strain is simulated under a high-humidity environment on the sea surface, the water spraying device is turned on, the spraying mode is adjusted, the wind power of the fan is increased, and the reading of the hygrometer and the reading of the demodulator are observed. .

Compared with the prior art, the invention has the following beneficial effects:

1. the vacuum pump is added into the blade strain measurement test system in the complex environment, so that the air pressure environments with different heights can be effectively simulated.

2. The system for testing the strain measurement of the blade in the complex environment designs a unique blade icing simulation mode, can control the blade icing speed by controlling the pouring amount of liquid nitrogen and the spraying and wind power sizes, and has the advantages of low cost, simple operation and good effect.

3. The blade strain measurement test system in the complex environment adopts the fiber bragg grating measurement system, is more accurate compared with the traditional measurement mode, has strong anti-interference, small volume and light weight, has little influence on the blade, and can quickly and accurately reflect the strain condition of the surface of the blade.

Drawings

In order to more clearly illustrate the technical solution of the present invention, the drawings needed to be used in the present invention will be briefly described below, and it is apparent that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained based on these drawings without inventive labor.

FIG. 1 is a schematic view of a fiber grating profile on the surface of a blade;

FIG. 2 is a schematic view of a blade strain measurement testing system;

in the figure: the device comprises a first temperature hygrometer 1-4, a first water mist sprayer 5-8, a fourth water mist sprayer 5-8, a water storage tank 9, a sprayer switch 10, a liquid nitrogen refrigerating device 11, a heating resistor 12, a pressure gauge 13, a vacuum pump 14, a first fan 15-16, a second fan controller 17, a blade 18, a fiber bragg grating 19 and a demodulator 20.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1

The invention discloses a paddle strain test system in a complex environment, which is shown in the attached drawing and comprises a test box body, a temperature and humidity meter 1-4, a water mist spray head 5-8, a water storage tank 9, a spray head switch 10, a liquid nitrogen refrigerating device 11, a heating resistor 12, a pressure gauge 13, a vacuum pump 14, fans 15-16, a fan controller 17, paddles 18, a fiber bragg grating 19 and a demodulator 20. The test box is used as a container and has the functions of isolating temperature, humidity and air pressure from the outside and providing adhesion and fixation for other systems, the paddle 18 is arranged at the central position of the box body, the root of the paddle is fixed on the left side wall, the water mist nozzles 5-8 are uniformly distributed on the top of the box right above the paddle, the fans 15-16 are arranged at the bottom of the box below the paddle, the temperature and humidity meters 1-4 are respectively arranged at the left and right ends of the bottom of the box body and the upper and lower surfaces of the paddle, the fiber bragg gratings are uniformly distributed on the surface of the paddle 18 and are connected with the demodulator 20 outside the box body through leads, the vacuum pump 14 is connected to the inside of the box body outside the box body through a pipeline, the pressure meter 13 is arranged on the pipeline, and the liquid nitrogen refrigerating device is arranged on. The heating resistor 12 is positioned at the bottom of the box body.

The water tank is provided with a pressurizing device, so that the water outlet speed can be controlled, the spray head has two modes of spraying water flowers and spraying water mist, and the fan controller 17 can adjust the wind power of the fans 15-16 below the blades. The fans 15-16 can blow cold air or warm air sunk into the bottom to the surface of the blade, and also have the functions of vaporizing water mist to increase the humidity in the box body and taking away the heat on the surface of the blade to quickly freeze the blade. High altitude plateau flight environment air is thin, and the atmospheric pressure is only about half of sea level when the height above sea level is 5000 meters, and is only about 1/3 to height above sea level 8000 meters, so in order to reflect the stress state of paddle when not co-altitude environment flight more really, connect a vacuum force pump 14, can take out the proof box air to near vacuum state at utmost, and the reading through manometer 13 can control atmospheric pressure to the target pressure position. When simulating blade strain of a helicopter in icing at high altitude and low temperature, fixing the root of the blade, uniformly sticking fiber gratings 19 on the surface of the blade 20, and connecting the fiber gratings to a demodulator 18; opening a liquid nitrogen switch to inject liquid nitrogen for rapid refrigeration, opening a spray switch 10 to adjust the spray size, starting a fan, blowing cold air at the bottom onto water mist on a blade to freeze the blade, opening a vacuum pump to pump out gas in a box, reading the value of a pressure gauge to maintain the gas pressure in the box at a certain size, controlling the liquid nitrogen injection and the size of the fan to read the reading of a thermometer hygrometer, and reading the reading of a demodulator at the moment when the gas pressure, the temperature, the humidity and the like meet the environmental requirements.

And when the high-humidity environment on the sea surface is simulated to be in strain, the water spraying device is started to be adjusted to be in a spraying mode, the wind power of the fan is increased, and the readings of the hygrometer and the demodulator are observed. By different matching methods of the heating device, the water spraying device, the liquid nitrogen refrigerating device and the air pressure regulating device, various complex environments for the rotor blade to work and the strain of the rotor blade can be manufactured.

The above description is only exemplary of the present application and should not be taken as limiting the present application, as any modification, equivalent replacement, or improvement made within the spirit and principle of the present application should be included in the protection scope of the present application.