CN115560937A - Strain gauge fatigue life measuring device - Google Patents
Strain gauge fatigue life measuring device Download PDFInfo
- Publication number
- CN115560937A CN115560937A CN202210014899.7A CN202210014899A CN115560937A CN 115560937 A CN115560937 A CN 115560937A CN 202210014899 A CN202210014899 A CN 202210014899A CN 115560937 A CN115560937 A CN 115560937A
- Authority
- CN
- China
- Prior art keywords
- strain gauge
- test piece
- fatigue life
- vibration
- engine blade
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
- G01M7/00—Vibration-testing of structures; Shock-testing of structures
- G01M7/02—Vibration-testing by means of a shake table
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
- G01M7/00—Vibration-testing of structures; Shock-testing of structures
- G01M7/02—Vibration-testing by means of a shake table
- G01M7/022—Vibration control arrangements, e.g. for generating random vibrations
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
- G01M7/00—Vibration-testing of structures; Shock-testing of structures
- G01M7/02—Vibration-testing by means of a shake table
- G01M7/025—Measuring arrangements
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Investigating Strength Of Materials By Application Of Mechanical Stress (AREA)
Abstract
The invention discloses a strain gauge fatigue life measuring device, belonging to the technical field of aero-engine tests, the strain gauge fatigue life measuring device comprises: an engine blade test piece provided with a strain gauge; the piezoelectric vibration table is used for applying vibration with preset frequency to the engine blade test piece; a switching tool is arranged at the top of the piezoelectric vibration table, a clamp is arranged in the switching tool, and the clamp is used for clamping the engine blade test piece; the controller is used for generating vibration signals and controlling the device to operate, and is connected with the power amplifier to drive the piezoelectric vibration table. The strain gauge on the blade is subjected to vibration test through the arranged piezoelectric vibration table, the test frequency range is 5-22000Hz and even can reach 25kHz or above, and the vibration excitation test frequency is wider than that of a conventional electromagnetic vibrator, the size is small, and the cost is low.
Description
Technical Field
The invention belongs to the technical field of aero-engine tests, relates to the field of blade high cycle fatigue tests, and particularly relates to a strain gauge fatigue life measuring device.
Background
The aircraft engine is the core of the whole aircraft, and the performance of the aircraft engine directly determines the overall performance of the aircraft, so the aircraft engine is also called as the pearl on the industrial crown. The most severe working environment and the most complicated stress in an aircraft gas turbine engine are turbine blades, and the turbine blades are also the key points for achieving high performance under the condition of small size and light weight of the aircraft engine.
In the dynamic strain measurement of the blade, a resistance strain gauge is adopted to measure the dynamic strain, the dynamic response characteristic of the strain gauge needs to be considered, and meanwhile, the strain gauge is required to have longer fatigue life.
During dynamic strain measurement, if the strain change frequency of a measuring point is high, the measurement time is long, and the strain cycle number of the strain gauge is large.
In this case, the strain gauge selected and the mounting process thereof are required to have a high fatigue life.
Generally, a fatigue life test is carried out on a strain gauge body and the bonding and adhering capacity of the strain gauge body, the mode is adopted, the strain gauge is installed on a blade, the working condition of the blade is simulated by carrying out high-frequency vibration on the blade, test data corresponding to the strain gauge is obtained, an electromagnetic vibration exciter is usually adopted for carrying out the high-frequency vibration test on the blade, the vibration exciting frequency range of the electromagnetic vibration exciter is narrow, the vibration exciting frequency range of a conventional electromagnetic vibration table is limited to thousands of hertz, for example, the device for carrying out the vibration fatigue test on the blade by using the aircraft engine compressor blade fatigue cycle test device provided by the publication No. CN104062104B, for the blade high-frequency vibration test device, the adopted electromagnetic high-frequency vibration device can reach higher vibration exciting frequency, but for testing the strain gauge or a smaller blade sample, the manufacturing cost is high, the device is mainly used in a large displacement vibration test system for carrying out the vibration test, and a device or a system for carrying out the fatigue life measurement on the strain gauge or the smaller blade sample is lacked.
Disclosure of Invention
The present invention is to provide a strain gauge fatigue life measuring device, which solves the problems of the conventional fatigue life measuring device in the use process in the background art.
In order to achieve the purpose, the invention provides the following technical scheme: a strain gauge fatigue life measuring device comprising:
an engine blade test piece provided with a strain gauge;
the piezoelectric vibration table is used for applying vibration with preset frequency to the engine blade test piece;
a switching tool is arranged at the top of the piezoelectric vibration table, a clamp is arranged in the switching tool, and the clamp is used for clamping the engine blade test piece;
the controller is used for generating a vibration signal and controlling the device to operate, and is connected with the power amplifier to drive the piezoelectric vibration table;
the device is characterized by comprising an engine blade test piece, an optional heater, an infrared thermometer and a control unit, wherein the optional heater is positioned at the outer edge of the engine blade test piece and used for heating the engine blade test piece through heat conduction;
and the laser vibration measuring system is used for measuring the vibration displacement and the acceleration of the engine blade test piece and transmitting the feedback signals of the displacement and the acceleration to the controller to form closed-loop control.
Preferably, the range of the excitation frequency of the operation of the piezoelectric vibration table is 5-22000Hz.
Preferably, the maximum excitation frequency of the piezoelectric vibration table is 25khz.
Preferably, the power amplifier is a variable frequency power amplifier.
Preferably, the heater is a high frequency/very high frequency electromagnetic eddy current heating device.
Preferably, the piezoelectric vibration table is further provided with a wind cooling joint.
Preferably, the piezoelectric vibration table comprises a piezoelectric excitation system and a workbench for packaging the piezoelectric excitation system, and the piezoelectric excitation system comprises a piezoelectric ceramic ring.
Preferably, the inner diameter of the piezoelectric ceramic ring is 20mm, the outer diameter of the piezoelectric ceramic ring is 50mm, and the thickness of the piezoelectric ceramic ring is 6mm.
Preferably, the piezoelectric ceramic rings are stacked and provided in number.
A method for measuring the fatigue life of a strain gauge comprises the following steps:
s1, clamping and fixing the engine blade test piece provided with the strain gauge by the clamp;
s2, the controller controls the vibration frequency of the piezoelectric vibration table, a control signal of the controller is output to the power amplifier, and the control signal is further transmitted to the piezoelectric vibration table;
s3, the piezoelectric vibration table applies vibration with a preset specific frequency to the engine blade test piece, displacement or acceleration is measured through a laser vibration measurement system, and measurement data are fed back to the controller for closed-loop control;
and S4, if a high-temperature working condition is to be created, heating the engine blade test piece through the heater, carrying out non-contact measurement on the temperature of the engine blade test piece through the infrared thermometer, monitoring the temperature of the engine blade test piece, and feeding back the temperature to the heater.
Compared with the prior art, the invention has the beneficial effects that:
the piezoelectric vibration table is arranged to carry out vibration test on the strain gauge on the blade, the working frequency range of the test is 5-22000Hz, the device provided by the invention can even reach 25kHz and above, the vibration excitation test frequency is wider than that of a conventional electromagnetic vibrator, the piezoelectric vibration exciter is low in cost and small in size, and the device can adapt to the test condition of the strain gauge, carry out high-frequency vibration test on a small test piece and carry out fatigue life test on the strain gauge.
And can carry out non-contact heating through the heater, simulate the actual use operating mode of blade, help carrying out dynamic strain measurement to the blade.
Drawings
FIG. 1 is a schematic diagram of a vibration testing system of the present invention;
FIG. 2 is a schematic diagram of the system of the present invention;
fig. 3 is a schematic structural view of a piezoelectric ceramic ring according to the present invention.
In the figure: 1. a piezoelectric vibrating table; 11. a piezoelectric ceramic ring; 12. a clamp; 13. transferring a tool; 2. a power amplifier; 3. a controller; 4. a heater; 5. an engine blade test piece; 6. air cooling joints; 7. a laser vibration measurement system; 8. an infrared thermometer.
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 obtained by a person skilled in the art without making any creative effort based on the embodiments in the present invention, belong to the protection scope of the present invention.
Referring to fig. 1-3, the present invention provides a technical solution: a strain gauge fatigue life measuring device comprising:
an engine blade test piece 5 provided with a strain gauge;
the piezoelectric vibration table 1 is used for applying vibration with preset frequency to the engine blade test piece 5;
the top of the piezoelectric vibration table 1 is provided with a switching tool 13, a clamp 13 is arranged in the switching tool 13, and the clamp 13 is used for clamping the engine blade test piece 5;
the controller 3 is used for generating a vibration signal and controlling the device to operate, and is connected with the power amplifier 2 to drive the piezoelectric vibration table 1;
the device is optionally provided with a heater 4 which is positioned at the outer edge of the engine blade test piece 5 and used for heating the engine blade test piece 5 through heat conduction, and further provided with an infrared thermometer 8 for monitoring the heating temperature and heating the engine blade test piece 5 to form closed-loop control;
and the laser vibration measurement system 7 is used for measuring the vibration displacement and the acceleration of the engine blade test piece 5 and transmitting feedback signals of the displacement and the acceleration to the controller 1 to form closed-loop control.
The fixture 13 is a device capable of stably clamping the engine blade test piece 5, such as a retention clamping device for a high-frequency circumferential small tenon blade vibration fatigue test proposed in CN 106840561B.
The controller 3 is used for sending signals and controlling the device, and is connected with the power amplifier 2 to drive the piezoelectric vibrating table 1.
A force sensor and an acceleration sensor are optionally arranged on the piezoelectric vibration table 1, so that the vibration quantity can be monitored in real time conveniently, and the damage to the vibration table caused by the fact that the vibration quantity exceeds a rated value is avoided.
The range of the excitation frequency of the operation of the piezoelectric vibration table 1 is 5-20000Hz, the resonance frequency of the piezoelectric vibration table 1 is 21kHz, the range of the excitation frequency of the conventional electromagnetic vibration table is limited to a few kHz, the highest excitation frequency of the piezoelectric vibration exciter can exceed 25kHz, and the performance of the piezoelectric vibration exciter far exceeds that of the conventional electromagnetic vibration table when the piezoelectric vibration table vibrates at high frequency above 4 kHz.
Further, the closed-loop control of the test conditions is realized by the laser vibration measuring system 7 and the infrared thermometer 8.
In the embodiment, in consideration of the vibration characteristics of other devices, the operating range of the excitation frequency is set to 5-22000kHz, the actual vibration frequency can even reach 25kHz or even higher, and the stacked piezoelectric ceramic rings 11 cannot be used at the resonance frequency because of the limitation of the piezoelectric ceramic response time, i.e., the step time, the power, the dynamic force and other factors.
The piezoelectric vibration table 1 comprises a piezoelectric excitation system and a workbench for packaging the piezoelectric excitation system, wherein the piezoelectric excitation system comprises a piezoelectric ceramic ring 11.
The piezoelectric excitation system can also be called as a piezoelectric vibration exciter, can generate high-order sound wave and ultrasonic excitation based on the characteristics of piezoelectric ceramic crystal materials, and can be used in the fields of vibration testing, analysis, high-frequency dynamic calibration and the like. According to the piezoelectric vibration exciter, the height of the main body of the device comprising the transfer tool 13 part is 300mm, the diameter of the cylindrical part is 170mm, and the size is small, so that the piezoelectric vibration exciter can meet the size and detection requirements of a small strain gauge.
Specifically, the piezoelectric ceramic rings 11 are stacked and provided in number.
The dimensions of the piezoceramic ring 11 chosen here are: the inner diameter was 20mm, the outer diameter was 50mm, and the thickness was 6mm, and a high-frequency vibration test was carried out.
In this embodiment, the piezoelectric ceramic rings 1 are stacked to realize high-frequency vibration.
Specifically, the power amplifier 2 is a variable frequency power amplifier.
Specifically, the heater 4 is a high frequency/very high frequency electromagnetic eddy current heating apparatus.
In this embodiment, the heater 4 is an eddy current heating device, and fig. 1 herein only shows a partial schematic view of a coil, and the piece to be tested is surrounded by the eddy current coil, so that non-contact heating can be performed, where the heater 4 can also be connected to the controller 3 for control, and the controller 3 is connected to the infrared thermometer 8 for temperature data acquisition.
Furthermore, the heater 4 is a DSP numerical control induction heating device, and can perform display control through a touch screen.
Specifically, the piezoelectric vibration table 1 is further provided with an air-cooled joint 6.
In this embodiment, the air-cooled joint 6 can be connected into the air current here, carries out cooling to the device.
In another embodiment, a low-frequency vibration exciter is selected for the vibration test, and the controller 3 is electrically connected to the low-frequency power amplifier and controls the low-frequency vibration exciter to perform the low-frequency vibration test.
In another embodiment, the testing system composed of the device can adjust the scale parameters of the device and also can perform the high cycle fatigue test of the blade.
The working principle and the using process of the invention are as follows: the engine blade test piece 5 provided with the strain gauge is clamped and fixed by the clamp 5, the vibration frequency of the piezoelectric vibration table 1 is controlled by the controller 3, a control signal of the piezoelectric vibration table is output to the power amplifier 2, the control signal is further transmitted to the piezoelectric vibration table 1, the piezoelectric vibration table 1 applies specific frequency vibration to the engine blade test piece 5, the strain gauge is determined under which vibration frequency the strain gauge can be loosened and dropped, or the strain gauge is electrically connected, dynamic strain measurement is carried out, the fatigue life of the strain gauge is detected, the vibration frequency is measured through the laser vibration measuring system 7, the engine blade test piece 5 is heated through the heater 4, the working condition of the engine blade test piece 5 during specific use is simulated, and the infrared thermometer 8 carries out non-contact measurement on the temperature of the engine blade test piece 5 so that the engine blade test piece 5 reaches a preset temperature.
Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.
Claims (10)
1. A strain gauge fatigue life measuring device is characterized in that: the method comprises the following steps:
an engine blade test piece (5) provided with a strain gauge;
the piezoelectric vibration table (1) is used for applying vibration with a preset frequency to the engine blade test piece (5);
a switching tool (13) is arranged at the top of the piezoelectric vibration table (1), a clamp (13) is arranged in the switching tool (13), and the clamp (13) is used for clamping the engine blade test piece (5);
the controller (3) is used for generating a vibration signal and controlling the device to operate, and is connected with the power amplifier (2) to drive the piezoelectric vibration table (1);
the device is characterized by comprising an optional heater (4) which is positioned at the outer edge of the engine blade test piece (5) and used for heating the engine blade test piece (5) through heat conduction, and an infrared thermometer (8) which is used for monitoring the heating temperature and enabling the engine blade test piece (5) to be heated to form closed-loop control;
and the laser vibration measuring system (7) is used for measuring the vibration displacement and the acceleration of the engine blade test piece (5) and transmitting feedback signals of the displacement and the acceleration to the controller (1) to form closed-loop control.
2. The strain gauge fatigue life measurement device according to claim 1, characterized in that: the vibration exciting frequency range of the piezoelectric vibration table (1) is 5-22000Hz.
3. The strain gauge fatigue life measurement device according to claim 1, characterized in that: the maximum excitation frequency of the piezoelectric vibration table (1) is 25khz.
4. The strain gauge fatigue life measurement device according to claim 1, characterized in that: the power amplifier (2) is a variable frequency power amplifier.
5. The strain gauge fatigue life measurement device according to claim 1, characterized in that: the heater (4) is a high-frequency/very high-frequency electromagnetic eddy current heating device.
6. The strain gauge fatigue life measurement device according to claim 1, characterized in that: and an air cooling joint (6) is also arranged on the piezoelectric vibration table (1).
7. The strain gauge fatigue life measuring apparatus according to claim 1, characterized in that: the piezoelectric vibration table (1) comprises a piezoelectric vibration excitation system and a workbench for packaging the piezoelectric vibration excitation system, wherein the piezoelectric vibration excitation system comprises a piezoelectric ceramic ring (11).
8. The strain gauge fatigue life measurement device according to claim 7, characterized in that: the inner diameter of the piezoelectric ceramic ring (11) is 20mm, the outer diameter is 50mm, and the thickness is 6mm.
9. The strain gauge fatigue life measurement device according to claim 8, characterized in that: the piezoelectric ceramic rings (11) are stacked and are provided in a plurality.
10. A strain gauge fatigue life measuring method comprising the strain gauge fatigue life measuring apparatus according to any one of claims 1 to 9, characterized in that: the method comprises the following steps:
s1, clamping and fixing the engine blade test piece (5) provided with the strain gauge by the clamp (5);
s2, the controller (3) controls the vibration frequency of the piezoelectric vibration table (1), a control signal of the controller is output to the power amplifier (2), and the control signal is further transmitted to the piezoelectric vibration table (1);
s3, the piezoelectric vibration table (1) applies vibration with a preset specific frequency to the engine blade test piece (5), displacement or acceleration is measured through a laser vibration measuring system (7), and measurement data are fed back to the controller (1) to be subjected to closed-loop control;
s4, if a high-temperature working condition is to be created, the heater (4) is used for heating the engine blade test piece (5), the infrared thermometer (8) is used for carrying out non-contact measurement on the temperature of the engine blade test piece (5), monitoring the temperature of the engine blade test piece (5) and feeding back the temperature to the heater (4).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210014899.7A CN115560937A (en) | 2022-01-07 | 2022-01-07 | Strain gauge fatigue life measuring device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210014899.7A CN115560937A (en) | 2022-01-07 | 2022-01-07 | Strain gauge fatigue life measuring device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115560937A true CN115560937A (en) | 2023-01-03 |
Family
ID=84737980
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210014899.7A Pending CN115560937A (en) | 2022-01-07 | 2022-01-07 | Strain gauge fatigue life measuring device |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115560937A (en) |
-
2022
- 2022-01-07 CN CN202210014899.7A patent/CN115560937A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US6732591B2 (en) | Device and method for fatigue testing of materials | |
| CN112577686B (en) | High-temperature vibration characteristic test system for composite material aero-engine flame tube | |
| US6286361B1 (en) | Method and apparatus for remotely detecting pressure, force, temperature, density, vibration, viscosity and speed of sound in a fluid | |
| CN108717026A (en) | A kind of small-sized piezoelectric ceramic driving in situ fatigue test machine considering temperature gradient | |
| CN111649926B (en) | Axial and vibration high-low cycle composite fatigue test device | |
| CN102840968B (en) | Detection device and detection method for wide-range vibration amplitude of blade of aviation engine | |
| CN101424666A (en) | Method and apparatus for testing and evaluating machine components under simulated in-situ thermal operating conditions | |
| CN105181734A (en) | Shape memory alloy thermal mechanical fatigue test device | |
| CN113295359B (en) | Simulation test device for inhibiting ejector supporting plate vibration and vibration inhibition method | |
| Jiang et al. | Determining the optimal pre-tightening force of a sandwich transducer by measuring resonance resistance | |
| CN115560937A (en) | Strain gauge fatigue life measuring device | |
| CN112665844B (en) | System and method for testing high-frequency vibration reduction characteristics of turbine blade with friction damping device | |
| CN101438130A (en) | Surface measurement probe | |
| CN110987595B (en) | Method and device for measuring elastic modulus and internal loss of material in high and low temperature environment | |
| Kluk et al. | Measurement system for parameter estimation and diagnostic of ultrasonic transducers | |
| CN116078560A (en) | Temperature correcting device for in-situ heating of centrifugal machine under high rotation speed and high temperature | |
| CN113514352B (en) | Micro-nano material and structural force thermal coupling high cycle fatigue test method and test device | |
| CN112945476B (en) | Small pressure container trace gas leakage emergency ultrasonic detection system and method | |
| CN112985794A (en) | Thermal fatigue test device and method for single engine cylinder cover | |
| CN113804379B (en) | Composite material ultra-high temperature vibration fatigue test method | |
| CN208156086U (en) | A kind of direct current cables space charge measuring system | |
| CN214149741U (en) | High-temperature environment vibration fatigue test system | |
| CN117451548A (en) | High-temperature high-low cycle composite fatigue test method applied to single-crystal superalloy | |
| CN220323357U (en) | Sensor high temperature performance test system | |
| CN220716233U (en) | Temperature correcting device for in-situ heating of centrifugal machine under high rotation speed and high temperature |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |