A precision compensation method for high temperature dynamic stress test of engine turbine rotor blades

Abstract

The present application provides a precision compensation method for high-temperature dynamic stress testing of engine turbine rotor blades, which belongs to the field of strength testing and testing technology of aircraft engines, and specifically includes: selection of contact high-temperature strain gauges; design of finite element simulation model and mechanical strain transmission path for high-temperature strain gauge measurement, and analysis of factors affecting high-temperature strain measurement accuracy based on high-temperature strain dynamic calibration, and obtaining the influence of factors such as fixing method, installation error, sensitive grid wire characteristics, sensitive grid shape, and measured material characteristics on measurement accuracy in the contact high-temperature strain measurement link; design of high-temperature strain measurement accuracy correction model, and accuracy compensation for contact high-temperature dynamic stress test results of aircraft engine turbine rotor blades. Through the processing scheme of the present application, the accuracy of high-temperature strain testing is improved.

Description

Technical Field

[0001] The present application relates to the field of aero-engine strength testing and measurement, and in particular to a precision compensation method for high-temperature dynamic stress testing of engine turbine rotor blades. Background Art

[0002] As a key working element, aircraft engine turbine rotor blades work in harsh environments. They are very prone to cracks, falling off, or even breakage due to fatigue under multiple loads such as mechanical loads, thermal loads, and aerodynamic loads. Therefore, based on the needs of design verification of the structure / strength of turbine rotor blades, acquisition of vibration characteristics, troubleshooting, and structural improvement, it is necessary to conduct high-temperature dynamic stress tests on turbine rotor blades during engine testing, so as to assess the strength and life of turbine rotor blades under the working environment of aircraft engines.

[0003] At present, the most commonly used and mature high-temperature dynamic stress test method is the contact resistance strain test method, which obtains the vibration parameters of the blades in working state by installing resistance high-temperature strain gauges on the turbine rotor blades. For high-temperature strain, the measurement accuracy of the resistance strain gauge is the focus of the entire test system. The test accuracy of the strain gauge is related to many factors, such as thermal output resistance dispersion, series wires, insulation resistance changes, contact resistance changes, strain gauge lateral effects, etc. At present, there is no research on the influence of related factors on the high-temperature strain test accuracy, and it is impossible to compensate for the high-temperature strain test accuracy of high-temperature components such as turbine rotor blades. Improving the existing high-temperature strain measurement accuracy cannot meet the needs of precise measurement in engineering. Summary of the invention

[0004] In view of this, the present application provides an accuracy compensation method for high-temperature dynamic stress testing of engine turbine rotor blades, which solves the problem of unclear strain transfer characteristics and accuracy influencing mechanism in the high-temperature strain detection link in the prior art, and improves the accuracy of high-temperature strain testing.

[0005] The present application provides an accuracy compensation method for high temperature dynamic stress testing of an engine turbine rotor blade, which adopts the following technical solution:

[0006] A precision compensation method for high temperature dynamic stress testing of an engine turbine rotor blade, comprising:

[0007] Step 1, selection of contact high temperature strain gauge;

[0008] Step 2, establishing a high temperature strain measurement finite element model;

[0009] Step 3, multi-parameter calibration of contact high temperature strain gauge;

[0010] Step 4, installation of contact high temperature strain gauge;

[0011] Step 5, establishing a high temperature strain data compensation model;

[0012] Step 6, high temperature strain test;

[0013] Step 7: Comprehensive accuracy compensation of high temperature dynamic stress.

[0014] Optionally, the step 1 specifically includes: determining the model, resistance, sensitivity coefficient, wire grid diameter of the sensing part, and material parameters of the contact high-temperature strain gauge based on the material, operating temperature, and installation space of the aircraft engine turbine rotor blade, which are used for establishing a high-temperature strain measurement finite element model in step 2 and a high-temperature strain data compensation model in step 5, providing basic parameters for the sensor of the high-temperature strain test in step 6 and the comprehensive accuracy compensation of high-temperature dynamic stress in step 7.

[0015] Optionally, in step 2, the transfer characteristics of mechanical strain in the test piece-glue / coating-strain sensor path are analyzed through a high-temperature strain measurement finite element model, and the influence of the fixing method, installation error, sensitive grid wire characteristics, sensitive grid shape, and measured material characteristics on the measurement accuracy in the contact high-temperature strain measurement link is studied. The specific parameters required for calibration in the contact high-temperature strain gauge multi-parameter calibration technology in step 3 are determined to provide data support for establishing a high-temperature strain data compensation model in step 5.

[0016] Optionally, step 3 includes:

[0017] 3.1, Design of multi-parameter calibration device for high temperature strain gauge;

[0018] 3.2, High temperature strain sensor characteristic parameter calibration software development;

[0019] 3.3, Calibration of characteristic parameters of high temperature strain gauges.

[0020] Optionally, the step 3.1 includes: a loading system, a measuring system and a temperature control system;

[0021] The working temperature of the calibration device is not less than 1200℃, the temperature control accuracy is ±1℃, the temperature difference in the thermal averaging zone is ±2℃, the measurement accuracy of the displacement sensor is 1μm, the temperature control device controls the high-temperature furnace by means of K-type thermocouple temperature measurement and resistance wire heating, the loading device uses weights as standard loads, and controls the size of the deformation through the loading mechanism, and the measuring device simultaneously collects the high-temperature strain gauge signal, thermocouple signal, and deflectometer displacement signal to be calibrated. The displacement signal calculates the standard strain value according to the calibration beam size, thereby realizing the calibration of multiple parameters such as the sensitivity coefficient, thermal output, zero drift, creep and limit strain of the high-temperature strain gauge.

[0022] Optionally, the step 3.2 includes a calibration control module, a parameter calibration module and a data measurement module;

[0023] The calibration control module sets the temperature and load program, and sends the temperature, load, stress and strain data to the parameter calibration module during the calibration experiment. The data measurement module collects sensor data, processes the data and sends it to the parameter calibration module.

[0024] Optionally, the step 3.3 includes conducting research on the calibration method of the high-temperature strain gauge characteristic parameters according to the material and temperature parameters of the high-temperature strain gauge and the test piece obtained by selecting the contact high-temperature strain gauge in step 1 and the high-temperature strain test influencing factors determined in establishing the high-temperature strain measurement finite element model in step 2, formulating the calibration device heating rate, holding time, stress / displacement loading value, loading rate and holding time program, forming a high-temperature strain gauge characteristic parameter calibration procedure, and obtaining calibration characteristic parameter data.

[0025] Optionally, step 5 includes obtaining the influence of the characteristic parameters of the strain gauge on the high-temperature strain measurement through multi-parameter calibration of the contact high-temperature strain gauge in step 3, and designing and determining the overall error correction model for the high-temperature strain measurement;

[0026]

[0027] Where ε' is the test strain data before correction, ε is the strain data after correction, and ε 热输出 is the heat output correction expression, ε 零漂 is the zero drift correction expression, Δε 蠕变 is the creep correction expression, K 仪 The sensitivity factor set for the strain gauge.

[0028] Optionally, step 6 includes: mainly including test system preparation, collection and recording of high-temperature dynamic stress of turbine rotor blades, turbine rotor blade temperature, rotation speed, and test time.

[0029] Optionally, step 7 includes: performing accuracy compensation on the high-temperature dynamic stress data of the turbine rotor blades obtained by the high-temperature strain test in step 6 through a high-temperature strain data compensation model, bringing the temperature, time, and strain gauge sensitivity coefficient during the test into the overall error correction model of the high-temperature strain measurement, and using the correction expressions of each parameter obtained by the multi-parameter calibration of the contact high-temperature strain gauge in step 3 to extract the true strain characteristics in the complex high-temperature strain signal of the turbine rotor blade, thereby realizing accurate measurement and accuracy compensation of the high-temperature strain signal.

[0030] In summary, this application includes the following beneficial technical effects:

[0031] This application designs a finite element simulation model and a mechanical strain transfer path for high-temperature strain gauge measurement. On the basis of high-temperature strain dynamic calibration, an analysis of factors affecting high-temperature strain measurement accuracy is carried out to obtain the influence of factors such as fixing method, installation error, sensitive grid wire characteristics, sensitive grid shape, and measured material characteristics on measurement accuracy in the contact high-temperature strain measurement link; a high-temperature strain measurement accuracy correction model is designed to perform accuracy compensation on the contact high-temperature dynamic stress test results of aircraft engine turbine rotor blades, thereby improving the high-temperature strain test accuracy and solving problems such as the unclear strain transfer characteristics and accuracy influencing mechanism in the high-temperature strain detection link. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0033] Figure 1 This is a flow chart of the accuracy compensation method for high temperature dynamic stress testing of engine turbine rotor blades in this application. DETAILED DESCRIPTION

[0034] The embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0035] The following describes the implementation methods of the present application through specific examples, and those skilled in the art can easily understand other advantages and effects of the present application from the contents disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The present application can also be implemented or applied through other different specific implementation methods, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present application. It should be noted that, in the absence of conflict, the following embodiments and the features in the embodiments can be combined with each other. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without making creative work belong to the scope of protection of the present application.

[0036] It should be noted that various aspects of the embodiments within the scope of the appended claims are described below. It should be apparent that the aspects described herein can be embodied in a wide variety of forms, and any specific structure and / or function described herein is merely illustrative. Based on the present application, it should be understood by those skilled in the art that an aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number of aspects described herein can be used to implement the device and / or practice the method. In addition, other structures and / or functionalities other than one or more of the aspects described herein can be used to implement this device and / or practice this method.

[0037] It should also be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present application. The drawings only show components related to the present application rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0038] Additionally, in the following description, specific details are provided to facilitate a thorough understanding of the examples. However, it will be understood by those skilled in the art that the aspects described may be practiced without these specific details.

[0039] An embodiment of the present application provides a method for compensating for the accuracy of high temperature dynamic stress testing of engine turbine rotor blades.

[0040] like Figure 1 As shown, a precision compensation method for high temperature dynamic stress testing of an engine turbine rotor blade comprises:

[0041] Step 1: Selection of contact high temperature strain gauge.

[0042] Step 2: Establish a high temperature strain measurement finite element model.

[0043] Step 3: multi-parameter calibration of contact high temperature strain gauge.

[0044] Step 4, installation of contact high temperature strain gauge. The contact high temperature strain gauge is installed on the turbine rotor blade. The installation of the high temperature strain gauge provides basic parameters for the high temperature strain test in step 6 and the comprehensive accuracy compensation of high temperature dynamic stress in step 7.

[0045] Step 5: Establish a high temperature strain data compensation model.

[0046] Step 6, high temperature strain test.

[0047] Step 7: Comprehensive accuracy compensation of high temperature dynamic stress.

[0048] The step 1 specifically includes: determining the model, resistance, sensitivity coefficient, wire grid diameter of the sensing part, material and other parameters of the contact high-temperature strain gauge according to the material, operating temperature and installation space of the aircraft engine turbine rotor blade, which are used for establishing a high-temperature strain measurement finite element model in step 2 and a high-temperature strain data compensation model in step 5, and providing basic parameters for the sensor of the high-temperature strain test in step 6 and the comprehensive accuracy compensation of the high-temperature dynamic stress in step 7.

[0049] In the step 2, a finite element model is used to design the transfer characteristics of mechanical strain in the test piece-glue / coating-strain sensor path, and the influence of factors such as fixing method, installation error, sensitive grid wire characteristics, sensitive grid shape, and measured material characteristics on the measurement accuracy in the contact high-temperature strain measurement link is studied. The influencing mechanism is explored, and the specific parameters required for calibration in the multi-parameter calibration technology of the contact high-temperature strain gauge in step 3 are determined, providing data support for establishing a high-temperature strain data compensation model in step 5.

[0050] The step 3 comprises:

[0051] 3.1. Design of multi-parameter calibration device for high-temperature strain gauges; 3.1 specifically includes: loading system, measurement system and temperature control system; the working temperature of the calibration device is not less than 1200℃, the temperature control accuracy is ±1℃, the temperature difference in the thermal average zone is ±2℃, and the measurement accuracy of the displacement sensor is 1μm. The temperature control device controls the high-temperature furnace by means of K-type thermocouple temperature measurement and resistance wire heating to form a uniform, stable and controllable temperature environment in the furnace. The loading device uses weights as standard loads and controls the deformation size through the loading mechanism to generate a uniform, stable and controllable stress-strain field on the calibration beam. The measuring device simultaneously collects the high-temperature strain gauge signal, thermocouple signal and deflectometer displacement signal to be calibrated. The displacement signal calculates the standard strain value according to the calibration beam size to realize the calibration of multiple parameters such as the sensitivity coefficient, thermal output, zero drift, creep and limit strain of the high-temperature strain gauge.

[0052] 3.2, High temperature strain sensor characteristic parameter calibration software development; including calibration control module, parameter calibration module and data measurement module; calibration control module sets temperature and load program, sends temperature, load, stress and strain data to parameter calibration module in calibration experiment, data measurement module collects sensor data and processes data, and sends it to parameter calibration module. The calibration control module, parameter calibration module and data measurement module work together to complete parameter calibration.

[0053] 3.3, Calibration of characteristic parameters of high temperature strain gauges. This includes, based on the material, temperature and other parameters of the high temperature strain gauge and the test piece obtained by selecting the contact high temperature strain gauge in step 1 and the high temperature strain test influencing factors determined in the establishment of the high temperature strain measurement finite element model in step 2, conducting research on the calibration method of characteristic parameters of high temperature strain gauges, formulating procedures such as the heating rate, holding time, stress / displacement loading value, loading rate and holding time of the calibration device, forming a calibration procedure for characteristic parameters of high temperature strain gauges, and obtaining calibration characteristic parameter data. Including but not limited to sensitivity coefficient, sensitivity coefficient change with temperature, thermal output, zero drift, creep, thermal hysteresis, mechanical hysteresis, lateral effect coefficient, and high temperature insulation resistance.

[0054] The step 4 of contact high temperature strain gauge installation is a high temperature ceramic cement glue installation process, and its process steps mainly include test piece cleaning → test piece protection → test piece surface roughening → test piece cleaning → scribing → substrate preparation → high temperature strain gauge installation → high temperature strain gauge installation glue curing → high temperature strain gauge pin transfer → protective glue installation → inspection and numbering. Other installation processes can refer to this process.

[0055] The step 5 includes obtaining the influence of the characteristic parameters of the strain gauge on the high-temperature strain measurement through the multi-parameter calibration of the contact high-temperature strain gauge in step 3, and designing and determining the overall error correction model of the high-temperature strain measurement;

[0056] Subtract the thermal output, zero drift, and creep value from the measured value, and then correct the sensitivity coefficient and lateral effect to obtain the corrected measured value.

[0057] Where ε' is the test strain data before correction, ε is the strain data after correction, and ε 热输出 is the heat output correction expression, ε 零漂 is the zero drift correction expression, Δε 蠕变 is the creep correction expression, K 仪 The sensitivity factor set for the strain gauge.

[0058] The step 6 includes: being carried out after the contact high temperature strain gauge in step 4 is installed, providing data support for the comprehensive accuracy compensation of high temperature dynamic stress in step 7, mainly including the preparation of the test system, the collection and recording of the high temperature dynamic stress of the turbine rotor blades, the temperature of the turbine rotor blades, the rotation speed, and the test time.

[0059] The step 7 includes: performing precision compensation on the high-temperature dynamic stress data of the turbine rotor blade obtained by the high-temperature strain test in step 6 through a high-temperature strain data compensation model, bringing the temperature, time, and strain gauge sensitivity coefficient in the test process into the overall error correction model of the high-temperature strain measurement, and using the correction expressions of each parameter obtained by the multi-parameter calibration of the contact high-temperature strain gauge in step 3 to extract the true strain characteristics in the complex high-temperature strain signal of the turbine rotor blade, so as to achieve accurate measurement and precision compensation of the high-temperature strain signal.

[0060] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A precision compensation method for high temperature dynamic stress testing of engine turbine rotor blades, characterized in that: include: Step 1, selection of contact high temperature strain gauge; Step 2, establishing a high temperature strain measurement finite element model; Step 3, multi-parameter calibration of contact high temperature strain gauge; Step 4, installation of contact high temperature strain gauge; Step 5, establishing a high temperature strain data compensation model; Step 6, high temperature strain test; Step 7, high temperature dynamic stress comprehensive accuracy compensation; The step 1 specifically includes: determining the model, resistance, sensitivity coefficient, wire grid diameter of the sensing part, and material parameters of the contact high-temperature strain gauge according to the material, operating temperature, and installation space of the turbine rotor blade of the aircraft engine, which are used for establishing a high-temperature strain measurement finite element model in step 2 and a high-temperature strain data compensation model in step 5, and providing basic parameters for the sensor of the high-temperature strain test in step 6 and the comprehensive accuracy compensation of high-temperature dynamic stress in step 7; In the step 2, the transmission characteristics of mechanical strain on the path of the tested piece-glue / coating-strain sensor are analyzed by the high-temperature strain measurement finite element model, and the influence of the fixing method, installation error, sensitive grid wire characteristics, sensitive grid shape, and measured material characteristics on the measurement accuracy in the contact high-temperature strain measurement link is studied, and the specific parameters required for calibration in the multi-parameter calibration technology of the contact high-temperature strain gauge in step 3 are determined, so as to provide data support for establishing a high-temperature strain data compensation model in step 5; The step 5 includes obtaining the influence of the characteristic parameters of the strain gauge on the high-temperature strain measurement through the multi-parameter calibration of the contact high-temperature strain gauge in step 3, and designing and determining the overall error correction model of the high-temperature strain measurement; in is the test strain data before correction, is the corrected strain data, is the heat output correction expression, is the zero drift correction expression, is the creep correction expression, The sensitivity coefficient set for the strain gauge, is the sensitivity coefficient of the strain gauge; The step 7 includes: performing precision compensation on the high-temperature dynamic stress data of the turbine rotor blade obtained by the high-temperature strain test in step 6 through a high-temperature strain data compensation model, bringing the temperature, time, and strain gauge sensitivity coefficient in the test process into the overall error correction model of the high-temperature strain measurement, and using the correction expressions of each parameter obtained by the multi-parameter calibration of the contact high-temperature strain gauge in step 3 to extract the true strain characteristics in the complex high-temperature strain signal of the turbine rotor blade, so as to achieve accurate measurement and precision compensation of the high-temperature strain signal.

2. The accuracy compensation method for high temperature dynamic stress testing of engine turbine rotor blades according to claim 1, characterized in that: The step 3 comprises: Step 3.1, design of multi-parameter calibration device for high temperature strain gauge; Step 3.2, high temperature strain sensor characteristic parameter calibration software development; Step 3.3, calibration of characteristic parameters of high temperature strain gauge.

3. The accuracy compensation method for high temperature dynamic stress testing of engine turbine rotor blades according to claim 2 is characterized in that: The step 3.1 includes: a loading system, a measuring system and a temperature control system; The working temperature of the calibration device is not less than 1200℃, the temperature control accuracy is ±1℃, the temperature difference in the thermal averaging zone is ±2℃, the measurement accuracy of the displacement sensor is 1μm, the temperature control device controls the high-temperature furnace by means of K-type thermocouple temperature measurement and resistance wire heating, the loading device uses weights as standard loads, and controls the size of the deformation through the loading mechanism. The measuring device simultaneously collects the high-temperature strain gauge signal, thermocouple signal, deflectometer displacement signal, and displacement signal to be calibrated, and calculates the standard strain value according to the calibration beam size to realize the calibration of multiple parameters such as high-temperature strain gauge sensitivity coefficient, thermal output, zero drift, creep and limit strain.

4. The accuracy compensation method for high temperature dynamic stress testing of engine turbine rotor blades according to claim 2, characterized in that: The step 3.2 includes a calibration control module, a parameter calibration module and a data measurement module; The calibration control module sets the temperature and load program. In the calibration experiment, the temperature, load, stress and strain data are sent to the parameter calibration module. The data measurement module collects the sensor data, processes the data and sends it to the parameter calibration module.

5. The accuracy compensation method for high temperature dynamic stress testing of engine turbine rotor blades according to claim 2, characterized in that: The step 3.3 includes conducting a study on the calibration method of the characteristic parameters of the high-temperature strain gauge according to the material and temperature parameters of the high-temperature strain gauge and the test piece obtained by selecting the contact high-temperature strain gauge in step 1 and the high-temperature strain test influencing factors determined in establishing the high-temperature strain measurement finite element model in step 2, formulating the calibration device heating rate, holding time, stress / displacement loading value, loading rate and holding time program, forming a high-temperature strain gauge characteristic parameter calibration procedure, and obtaining calibration characteristic parameter data.

6. The accuracy compensation method for high temperature dynamic stress testing of engine turbine rotor blades according to claim 1, characterized in that: The step 6 includes: preparing the test system, collecting and recording the high temperature dynamic stress of the turbine rotor blades, the temperature of the turbine rotor blades, the rotation speed, and the test time.

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