Friction and wear test method and system for typical motion pairs of aviation tail nozzles under high temperature and heavy load conditions

Abstract

The present invention provides a method and system for testing friction and wear of typical moving pairs of aviation tail nozzles under high temperature and heavy load conditions, including: S1 realizing the deconstruction of the tribological system of typical moving pairs of aviation tail nozzles; S2 realizing the material-level friction and wear test of typical moving pairs of aviation tail nozzles; S3 realizing the sample-level friction and wear test of typical moving pairs of aviation tail nozzles; S4 realizing the prediction modeling of friction and wear life of typical moving pairs of aviation tail nozzles. The present invention can establish a wear life prediction model of typical moving pairs of aviation tail nozzles suitable for high temperature and heavy load conditions, reveal the wear mechanism under special motion forms, and thus support the maintenance and replacement of typical moving pairs of tail nozzles.

Description

Technical Field

[0001] The present invention relates to the technical field of friction and wear testing, and in particular to a method and system for testing the friction and wear of typical kinematic pairs of an aviation tail nozzle under high temperature and heavy load conditions. Background Art

[0002] The latest generation of advanced fighter aircraft require that the engine tail nozzle movement adjustment speed is greater than 30° / s for hypersonic cruise and high maneuverability. The movement adjustment mechanism is subjected to aerodynamic loads exceeding 10,000 Newtons and high temperatures of nearly 1,000 degrees Celsius for a long time. In order to avoid the degradation or even failure of the service performance of key motion parts of the movement adjustment mechanism during the design life cycle, thereby limiting the adjustment accuracy, response performance, life and reliability of the overall equipment system, and even causing major engineering disasters, it is urgent to clarify the degradation mechanism of the tribological performance of moving parts and optimize the surface interface tribological design. However, there is no high-temperature and heavy-load simulated working condition tribological test system suitable for the research of aviation tail nozzle movement adjustment mechanism at home and abroad, which cannot provide experimental support for the above research, limiting technological breakthroughs.

[0003] Among the existing friction and wear testing machines, the universal friction and wear testing machine is the most widely used. This type of testing machine can only test the friction and wear performance of the material level, with limited loading forms and simple motion forms. It is confined to a certain point, line, or surface of the material sample to perform specific reciprocating, rotational, and micro-motion motions. However, the actual motion mechanism has multiple components and moving pairs, a single part has multiple moving pairs, and multiple points of force are applied. In addition, the parts have tolerance matching characteristics and the friction and heat generated by mutual motion are obvious. The material-level test and analysis conditions based on the universal friction and wear testing machine are too simplified, and the results obtained are significantly different from the friction and wear conditions of the moving pairs of the moving parts of the actual mechanism, and are only suitable for basic theoretical research and analysis.

[0004] In order to overcome the testing capability defects of material-level general friction and wear testing machines, it is necessary to design a high-temperature and heavy-load friction and wear testing machine for the research of typical motion pairs of aviation tail nozzle motion adjustment mechanisms, and at the same time improve the friction and wear testing methods to ensure that the testing process goes smoothly and that the corresponding performance index tests can be completed.

[0005] Patent application number: 201510009043.0 discloses a mold optimization method based on friction and wear CAE analysis. Its optimization idea is to verify the feasibility of the CAE analysis method through actual test methods, but there is no simulation of the test conditions, which is different from the idea of ​​directly conducting experimental tests in the present invention. Patent application number: 202010109593.0 discloses an industrial robot cable wear test method and device under composite motion. It conducts two forms of sliding and rotational friction tests on the sample-cable, but does not establish friction and wear evaluation indicators and prediction models. Patent application number: 201810481121.0 discloses a textured friction pair vibration noise and friction and wear performance test device and test method. This test method is mainly aimed at vibration and noise detection during the friction and wear process of the friction pair, and its evaluation method is different from that of the present invention. Summary of the invention

[0006] In view of the defects in the prior art, the purpose of the present invention is to provide a method and system for testing the friction and wear of typical kinematic pairs of aviation tail nozzles under high temperature and heavy load conditions.

[0007] The friction and wear test method of typical moving pairs of aviation tail nozzles under high temperature and heavy load conditions provided by the present invention includes:

[0008] Step S1: Deconstructing the tribological system of typical kinematic pairs of aviation tail nozzles, including analyzing the tail nozzle motion adjustment mechanism, establishing a kinematic simulation model of the tail nozzle motion adjustment mechanism, conducting dynamic simulation of the tail nozzle throat area and vector direction adjustment process, and studying the loading mode of typical kinematic pairs and their relative motion form characteristics;

[0009] Step S2: Conducting a friction and wear test on a typical moving pair material level of an aviation tail nozzle, including calculating the equivalent working conditions of the material level test, carrying out experimental design, processing and preparing a pin-on-disc test piece for a friction and wear test on a typical moving pair material level of an aviation tail nozzle, and conducting a pin-on-disc test based on an Rtec multifunctional testing machine, and conducting a friction and wear analysis after the test;

[0010] Step S3: Conducting a friction and wear test at the sample level of a typical moving pair of an aviation tail nozzle, including calculating the equivalent working conditions of the sample level test, carrying out experimental design, preparing the actual equipment of the typical moving pair test piece of the aviation tail nozzle, carrying out a sample level test based on a friction and wear test system for simulating working conditions of the typical moving pair of the aviation tail nozzle, measuring the vibration and strain data of the sample during the test online, measuring the surface wear morphology in situ, and carrying out offline wear measurement and analysis after the test;

[0011] Step S4: Conduct friction and wear life prediction modeling for typical moving parts of aviation tail nozzles, including establishing moving part wear life evaluation indicators, exploring factors affecting the wear life of typical moving parts through correlation analysis, and establishing a sample wear life prediction model suitable for heavy-load and high-temperature conditions based on neural network and machine learning algorithms.

[0012] Preferably, in step S1, the kinematic simulation model of the tail nozzle motion adjustment mechanism includes a cam, a roller, an adjustment plate, a tripod and a tail pipe outer ring, and the motion adjustment mechanism includes three types of typical motion pairs, the typical motion pairs include a cam pair between the cam and the roller, a ball pair between the cam and the adjustment plate, and a pin pair between the tripod and the tail pipe outer ring;

[0013] Studying the loading mode and relative motion characteristics of typical kinematic pairs requires quantitative analysis of the working conditions of typical kinematic pairs of aviation tail nozzles and tribological decoupling analysis of the motion adjustment mechanism of aviation tail nozzles.

[0014] The quantitative analysis of the working conditions of the typical motion pair of the aviation tail nozzle includes the following steps:

[0015] Step S11: convert the gas pressure on the regulating plate of the aviation tail nozzle motion regulating mechanism into the force it receives, divide the regulating plate into multiple micro-elements, and calculate the force on each micro-element. The force is perpendicular to the regulating plate. The calculation formula of the force is as follows:

[0016]

[0017] Step S12: Calculate the sum of the resultant force on the regulating plate of the aviation tail nozzle motion regulating mechanism, which is expressed as the integral sum of the regulating plate area. The calculation formula of the resultant force is:

[0018] F 合 (S) = ∫ΔPdS

[0019] Where ΔS / dS is the area of ​​each microelement; F is the force on each microelement, F 合 is the resultant force on the regulating plate of the aviation tail nozzle movement regulating mechanism; ΔP is the pressure on each unit;

[0020] Step S13: The pressure P on the regulating plate of the aviation tail nozzle motion regulating mechanism is simplified to be equally distributed along the Y axis by considering the symmetric characteristics, and the fitting formula along the X axis is established as follows:

[0021] P=Y*(aX 6 +bX 5 +cX 4 +dX 3 +eX 2 +fX+g)

[0022] Among them, a, b, c, d, e, f, g are fitting parameters, Y is the horizontal size of the adjustment piece, and X is the vertical distance from the left end of the adjustment piece;

[0023] Step S14: Simulate and calculate the working temperature of the typical kinematic pair of the aviation tail nozzle motion regulating mechanism. According to the measured ambient temperature of the aviation tail nozzle when it is working, the actual working temperature of the typical kinematic pair of the aviation tail nozzle motion regulating mechanism is obtained through simulation calculation. The heat generated by friction is fitted and calculated using the following formula:

[0024] Q=μF N Se

[0025] Where Q is the heat generated by friction; μ is the friction coefficient; F N is the normal pressure perpendicular to the surface of the object; S is the actual contact area between the two surfaces of the object; e is the effective energy conversion rate between the surfaces;

[0026] Then, the temperature rise of the typical motion pair of the aviation tail nozzle motion adjustment mechanism is calculated based on the heat generated by friction. The formula is:

[0027]

[0028] Among them, Q is the heat generated by friction; m is the mass of the kinematic pair; and c is the specific heat capacity of the kinematic pair matrix material.

[0029] Preferably, the step S2 comprises:

[0030] Step S21: Calculate the equivalent working condition of the material level test. According to the deconstruction results of the tribological system of the typical kinematic pair of the aviation tail nozzle in step S1, determine the load form, motion trajectory, actual working temperature and contact form of the typical kinematic pair. Take the force F when the force amplitude of the typical kinematic pair is the largest in a motion trajectory. max 、Position (X, Y, Z) max and the actual operating temperature T actual_max As the input condition for stress distribution simulation modeling, static simulation is carried out, and the average pressure of the contact area is calculated based on the VonMises stress result under the setting of Avg:75% as the equivalent contact pressure σ of the pin-disc test. equivalent , based on the Hertz contact theory, the equivalent load F applied to the pin in the material level test is calculated equivalent , calculate the equivalent rotation speed of the test plate in the material grade test rpm equivalent Make the relative linear velocity of the pin-disk equal to the average velocity of a typical kinematic pair in a motion trajectory, and the motion loading time t in the material level test equivalent Keep the same as the sample level test time, the test temperature T in the material level test equivalentThe actual working temperature T when the force amplitude of a typical kinematic pair in a motion trajectory is the maximum actual_max Consistency;

[0031] Step S22: Conduct experimental design, based on central composite design, and set equivalent load F according to actual working condition simulation requirements. equivalent and test temperature T equivalent Two factors, the response surface analysis method of 2 factors and 5 levels was used to generate the experimental plan, -α is the test equivalent load of the tail nozzle under the cruise working state, α is the test equivalent load of the tail nozzle under the full afterburner working state, -β is the test temperature of the tail nozzle under the cruise working state, β is the test temperature of the tail nozzle under the full afterburner working state, considering the influence of random errors in operation, four tests were carried out on the central point working condition, and two tests were carried out on each of the other working conditions to determine the deviation caused by other irrelevant factors in the test system, and at the same time, the order of the working conditions was disrupted and all tests were randomly carried out, and the average value of the test data under the same working condition was taken;

[0032] Step S23: Processing and preparing a pin-disc test piece for a material level test, according to the analysis of the kinematic pair contact form in the deconstruction results of the tribological system of a typical kinematic pair of an aviation tail nozzle in step S1, it is divided into point contact, line contact and surface contact, and a hemispherical surface, an arc surface and a plane are processed in sequence. The base material of the pin and the disk is the base material of a typical kinematic pair, and the contact surface has the same coating;

[0033] Step S24: Carry out material level pin-disc test. First, set the test accuracy index, adjust the reset of each execution module, and set the test parameters. The test parameters include: test disk rotation speed rpm equivalent 、Motor load F equivalent , proposed loading time t equivalent and test environment temperature T equivalent ; Then the test is carried out according to the setting. The time is judged during the test. If the set test time is reached, the loading motor and pin sample are lifted, and the other components are reset. At the same time, wear information identification and wear amount offline measurement are carried out; finally, the test is evaluated. If it meets the expected test, the test ends, otherwise the test is reset and re-tested;

[0034] Step S25: After the test, friction and wear analysis is carried out, including friction analysis and wear analysis, and wear surface morphology characterization analysis is carried out, the surface roughness of the wear scar is measured, the surface morphology is measured based on white light interferometry to extract periodic features, and the EDS energy spectrum analysis of the adhered wear debris particles is performed using a scanning electron microscope;

[0035] For friction analysis, the time-varying characteristics of the friction coefficient COF are analyzed, and the average value of the friction coefficient after stabilization is taken to qualitatively analyze the influence of temperature, load and speed on the average friction coefficient. Considering the Stribeck effect, an average friction coefficient prediction model with speed and temperature as prediction variables is established:

[0036] COF=c1+c2rpm+c3T

[0037] Wherein, c1, c2, c3 are fitting coefficients; T is temperature; rpm is speed;

[0038] For wear analysis, the test pin and test plate were weighed again, the wear amount was calculated, the friction coefficient distribution, load distribution, temperature distribution and speed distribution curves of the test process were derived, the wear coefficient K was solved using the Archard wear model, and a wear coefficient fitting model that integrates temperature, load and speed factors was established:

[0039]

[0040] Among them, d1, d2, d3, d4, d5, d6, and d7 are fitting coefficients; T is temperature; F is load; and rpm is speed.

[0041] Preferably, step S3 comprises:

[0042] Step S31: Calculate the equivalent working condition of the sample-level test, determine the load form, motion trajectory, actual working temperature and contact form of the typical kinematic pair according to the deconstruction results of the tribological system of the typical kinematic pair of the aviation tail nozzle in step S1, and directly set the test conditions equivalent to the actual working conditions based on the sample-level friction and wear test device, including the force position of the kinematic pair, the force magnitude, the change law of the direction with the movement, the kinematic pair movement form and the ambient temperature of the kinematic pair;

[0043] Step S32: Conduct experimental design, using the same central composite design as step S22, and set the actual load F actual and the actual temperature T actual Two factors, the response surface analysis method of 2 factors and 5 levels was used to generate the experimental plan, -α is the actual load of the tail nozzle in the cruise working state, α is the actual load of the tail nozzle in the full afterburner working state, -β is the actual temperature of the tail nozzle in the cruise working state, β is the actual temperature of the tail nozzle in the full afterburner working state, considering the influence of random errors in operation, four tests were conducted on the central point working condition, and two tests were conducted on each of the other working conditions to determine the deviation caused by other irrelevant factors in the test system, and at the same time, the order of the working conditions was disrupted and all tests were randomly conducted, and the average value of the test data under the same working condition was taken;

[0044] Step S33: preparing a typical kinematic pair test piece of an actual equipment aviation tail nozzle, marking the visual recognition features of the typical kinematic pair test piece of an actual equipment aviation tail nozzle, spraying ArUco marks on the surfaces of the rotating pair, ball and socket pair, and cam pair test pieces respectively, so that the visual module of the friction and wear test system for the simulated working condition of the typical kinematic pair of the aviation tail nozzle can track the target during the test, and randomly engraving scratches of varying depths on the contour of the test piece to distinguish the test piece with the same metallic luster from the background, so that the friction and wear test system for the simulated working condition of the typical kinematic pair of the aviation tail nozzle can recognize the contour features during the test;

[0045] Step S34: Conducting a sample-level test, based on the friction and wear test system of the typical kinematic pair of the aviation tail nozzle simulating working conditions, conduct a sample-level test, first set the test accuracy index, adjust the reset of each execution module, and set the test parameters at the same time, the test parameters include: displacement load relationship, data acquisition frequency, ambient heating temperature and planned loading time; then carry out heating in the temperature control box according to the setting to reach the preset ambient temperature, and then start the test according to the setting, during the test, based on the built-in high-resolution and high-frame rate visual module of the test system, perform online test piece strain measurement, and based on the motion amplification algorithm, perform online vibration characteristic measurement of the typical kinematic pair motion process, and according to the experimental settings, move the sample to the preset measurement optical path position at specific intervals, and measure the kinematic pair wear surface morphology based on the visual in-situ, and after the test, conduct further offline measurement and analysis of the kinematic pair; when the preset test time is completed, the test is evaluated, and if it meets the expected test, it ends, otherwise, reset and re-test;

[0046] Step S35: After the test, conduct offline wear analysis, including:

[0047] Use a large-range analytical balance to measure the mass of the sample before and after the test, and calculate the wear amount and wear rate;

[0048] The surface roughness change of the wear scar of the sample before and after the test was measured by a contact roughness meter and a metal Rockwell hardness tester;

[0049] The surface hardness HRC of the wear scar of the sample before and after the test is measured by a metal Rockwell hardness tester;

[0050] The surface morphology was measured by white light interferometry and optical microscopy, and the arithmetic mean height R of the surface roughness was extracted. a , skewness S sk and the root mean square deviation S q feature;

[0051] Observe the shape of wear debris through scanning electron microscope and analyze the wear failure form;

[0052] The element distribution and content wt% of the worn surface and profile were analyzed by Raman spectrometer and X-ray energy spectrometer;

[0053] The above measurements all comply with the measurement specifications of taking the average of three measurements and selecting test sites evenly on the surface to be tested;

[0054] The load distribution, temperature distribution and velocity distribution curves of the test process are derived, and the wear coefficient K is solved using the Archard wear model. actual , establish a wear coefficient fitting model that integrates temperature, load and speed factors:

[0055]

[0056] Among them, e1, e2, e3, e4, e5, e6, and e7 are fitting coefficients, T is temperature, F is load, and v is velocity.

[0057] Preferably, step S4 comprises:

[0058] Step S41: Establishing a kinematic pair wear life evaluation index, determining the wear failure criteria that affect the adjustment accuracy, adjustment resistance and movement synchronization of the motion adjustment mechanism as failure friction coefficient and failure wear coefficient based on the kinematic simulation analysis results of the tail nozzle motion adjustment mechanism in step S1, and determining the wear failure form as surface hardness at failure, surface element distribution at failure and wear mark morphology characteristics at failure based on the friction and wear measurement results of the material-level friction and wear test in step S2 and the wear measurement results of the sample-level friction and wear test in step S3;

[0059] Step S42: Explore the factors that affect the wear life of typical kinematic pairs through correlation analysis, and analyze the correlation between the test condition quantity and the test result quantity based on the Pearson correlation coefficient, where the test condition quantity includes the number of cycles N under full force working state full , Number of cycles N under cruise working state cruise , temperature T, load F and speed v, the test results include friction coefficient COF, wear rate δ, surface roughness arithmetic mean height R a , average root mean square deviation S q , surface roughness average skewness S sk , wear surface, element distribution and content wt% of the cross section and surface hardness HRC of the wear scar, and the number of cycles N under full force working state full , Number of cycles N under cruise working state cruise Principal component analysis to identify key influencing factors;

[0060] Step S43: Establish a wear life prediction model for samples suitable for heavy-load and high-temperature working conditions. Based on the principal component analysis results of step S42, the machine learning algorithms kernel ridge regression KRR, support vector regression SVR and extreme gradient boosting decision tree XGBoost are used to construct the principal component analysis results and the number of cycles N under full-load working conditions. full , Number of cycles N under cruise working state cruise The relationship model between them.

[0061] The friction and wear test system for typical motion pairs of aviation tail nozzles under high temperature and heavy load conditions provided by the present invention comprises:

[0062] Module M1: Deconstruction of the tribological system of typical kinematic pairs of aviation tail nozzles, including analysis of tail nozzle motion adjustment mechanism, establishment of kinematic simulation model of tail nozzle motion adjustment mechanism, dynamic simulation of tail nozzle throat area and vector direction adjustment process, and study of loading mode of typical kinematic pairs and their relative motion form characteristics;

[0063] Module M2: Conduct friction and wear tests on typical moving parts of aircraft tail nozzles, including calculating equivalent working conditions of material level tests, carrying out experimental design, processing and preparing pin-disc test pieces for friction and wear tests on typical moving parts of aircraft tail nozzles, and conducting pin-disc tests based on Rtec multifunctional testing machines. After the tests, friction and wear analysis will be carried out.

[0064] Module M3: Conducting friction and wear tests on typical moving parts of aviation tail nozzles at the sample level, including calculating the equivalent working conditions of the sample level test, carrying out experimental design, preparing the actual equipment of the typical moving parts of aviation tail nozzles, carrying out sample level tests based on the friction and wear test system of the typical moving parts of aviation tail nozzles under simulated working conditions, measuring the vibration and strain data of the test parts online during the test, measuring the surface wear morphology in situ, and carrying out offline wear measurement and analysis after the test;

[0065] Module M4: Conduct friction and wear life prediction modeling for typical moving parts of aviation tail nozzles, including establishing moving part wear life evaluation indicators, exploring the factors affecting the wear life of typical moving parts through correlation analysis, and establishing a sample wear life prediction model suitable for heavy-load and high-temperature conditions based on neural network and machine learning algorithms.

[0066] Preferably, in module M1, the kinematic simulation model of the tail nozzle motion adjustment mechanism includes a cam, a roller, an adjustment plate, a tripod and a tail pipe outer ring, and the motion adjustment mechanism includes three types of typical motion pairs, the typical motion pairs include a cam pair between the cam and the roller, a ball pair between the cam and the adjustment plate, and a pin pair between the tripod and the tail pipe outer ring;

[0067] Studying the loading mode and relative motion characteristics of typical kinematic pairs requires quantitative analysis of the working conditions of typical kinematic pairs of aviation tail nozzles and tribological decoupling analysis of the motion adjustment mechanism of aviation tail nozzles.

[0068] The working conditions of typical motion pairs of aviation tail nozzles are quantitatively analyzed, including the following modules:

[0069] Module M11: The gas pressure on the regulating plate of the aviation tail nozzle motion regulating mechanism is converted into the force it receives. The regulating plate is divided into multiple micro-elements, and the force on each micro-element is calculated. The force is perpendicular to the regulating plate. The force calculation formula is as follows:

[0070]

[0071] Module M12: Calculate the sum of the force on the regulating plate of the aviation tail nozzle motion regulating mechanism, which is expressed as the integral sum of the regulating plate area. The calculation formula of the resultant force is:

[0072] F 合 (S) = ∫ΔPdS

[0073] Where ΔS / dS is the area of ​​each microelement; F is the force on each microelement, F 合 is the resultant force on the regulating plate of the aviation tail nozzle movement regulating mechanism; ΔP is the pressure on each unit;

[0074] Module M13: The pressure P on the regulating plate of the aviation tail nozzle motion regulating mechanism is simplified to be equally distributed along the Y axis considering the symmetric characteristics, and the fitting formula along the X axis is established as follows:

[0075] P=Y*(aX 6 +bX 5 +cX 4 +dX 3 +eX 2 +fX+g)

[0076] Among them, a, b, c, d, e, f, g are fitting parameters, Y is the horizontal size of the adjustment piece, and X is the vertical distance from the left end of the adjustment piece;

[0077] Module M14: Simulate and calculate the working temperature of the typical kinematic pair of the aviation tail nozzle motion regulating mechanism. According to the measured ambient temperature of the aviation tail nozzle when it is working, the actual working temperature of the typical kinematic pair of the aviation tail nozzle motion regulating mechanism is obtained through simulation calculation. The heat generated by friction is fitted and calculated using the following formula:

[0078] Q=μF N Se

[0079] Where Q is the heat generated by friction; μ is the friction coefficient; FN is the normal pressure perpendicular to the surface of the object; S is the actual contact area between the two surfaces of the object; e is the effective energy conversion rate between the surfaces;

[0080] Then, the temperature rise of the typical motion pair of the aviation tail nozzle motion adjustment mechanism is calculated based on the heat generated by friction. The formula is:

[0081]

[0082] Among them, Q is the heat generated by friction; m is the mass of the kinematic pair; and c is the specific heat capacity of the kinematic pair matrix material.

[0083] Preferably, the module M2 comprises:

[0084] Module M21: Calculate the equivalent working conditions of the material level test. According to the deconstruction results of the tribological system of the typical kinematic pair of the aviation tail nozzle in module M1, determine the load form, motion trajectory, actual working temperature and contact form of the typical kinematic pair. Take the force F when the force amplitude of the typical kinematic pair is the largest in a motion trajectory. max 、Position (X, Y, Z) max and the actual operating temperature T actual_max As the input condition for stress distribution simulation modeling, static simulation is carried out, and the average pressure of the contact area is calculated based on the VonMises stress result under the setting of Avg:75% as the equivalent contact pressure σ of the pin-disc test. equivalent , based on the Hertz contact theory, the equivalent load F applied to the pin in the material level test is calculated equivalent , calculate the equivalent rotation speed of the test plate in the material grade test rpm equivalent Make the relative linear velocity of the pin-disk equal to the average velocity of a typical kinematic pair in a motion trajectory, and the motion loading time t in the material level test equivalent Keep the same as the sample level test time, the test temperature T in the material level test equivalent The actual working temperature T when the force amplitude of a typical kinematic pair in a motion trajectory is the maximum actual_max Consistency;

[0085] Module M22: Conduct experimental design, based on central composite design, set equivalent load F according to actual working condition simulation requirements equivalent and test temperature T equivalentTwo factors, the response surface analysis method of 2 factors and 5 levels was used to generate the experimental plan, -α is the test equivalent load of the tail nozzle under the cruise working state, α is the test equivalent load of the tail nozzle under the full afterburner working state, -β is the test temperature of the tail nozzle under the cruise working state, β is the test temperature of the tail nozzle under the full afterburner working state, considering the influence of random errors in operation, four tests were carried out on the central point working condition, and two tests were carried out on each of the other working conditions to determine the deviation caused by other irrelevant factors in the test system, and at the same time, the order of the working conditions was disrupted and all tests were randomly carried out, and the average value of the test data under the same working condition was taken;

[0086] Module M23: Processing and preparation of pin-disc test pieces for material level testing. According to the analysis of the kinematic pair contact form in the deconstruction results of the tribological system of the typical kinematic pair of the aviation tail nozzle in module M1, it is divided into point contact, line contact and surface contact. The hemispherical surface, arc surface and plane surface are processed in turn. The base material of the pin and the disk is the typical kinematic pair base material, and the contact surface has the same coating;

[0087] Module M24: Carry out material level pin-disc test. First, set the test accuracy index, adjust the reset of each execution module, and set the test parameters. The test parameters include: test disk rotation speed rpm equivalent 、Motor load F equivalent , proposed loading time t equivalent and test environment temperature T equivalent ; Then the test is carried out according to the setting. The time is judged during the test. If the set test time is reached, the loading motor and pin sample are lifted, and the other components are reset. At the same time, wear information identification and wear amount offline measurement are carried out; finally, the test is evaluated. If it meets the expected test, the test ends, otherwise the test is reset and re-tested;

[0088] Module M25: After the test, friction and wear analysis is carried out, including friction analysis and wear analysis, and wear surface morphology characterization analysis is carried out, the surface roughness of the wear scar is measured, the surface morphology is measured based on white light interferometry to extract periodic features, and the EDS energy spectrum analysis of the adhesive wear debris particles is performed using a scanning electron microscope;

[0089] For friction analysis, the time-varying characteristics of the friction coefficient COF are analyzed, and the average value of the friction coefficient after stabilization is taken to qualitatively analyze the influence of temperature, load and speed on the average friction coefficient. Considering the Stribeck effect, an average friction coefficient prediction model with speed and temperature as prediction variables is established:

[0090] COF=c1+c2rpm+c3T

[0091] Wherein, c1, c2, c3 are fitting coefficients; T is temperature; rpm is speed;

[0092] For wear analysis, the test pin and test plate were weighed again, the wear amount was calculated, the friction coefficient distribution, load distribution, temperature distribution and speed distribution curves of the test process were derived, the wear coefficient K was solved using the Archard wear model, and a wear coefficient fitting model that integrates temperature, load and speed factors was established:

[0093]

[0094] Among them, d1, d2, d3, d4, d5, d6, and d7 are fitting coefficients; T is temperature; F is load; and rpm is speed.

[0095] Preferably, the module M3 includes:

[0096] Module M31: Calculate the equivalent working conditions of the sample-level test. According to the deconstruction results of the tribological system of the typical kinematic pair of the aviation tail nozzle in module M1, determine the load form, motion trajectory, actual working temperature and contact form of the typical kinematic pair. Based on the sample-level friction and wear test device, directly set the test conditions equivalent to the actual working conditions, including the force position of the kinematic pair, the force magnitude, the change law of the direction with the movement, the kinematic pair movement form and the ambient temperature of the kinematic pair;

[0097] Module M32: Conduct experimental design, using the same central combination design as module M22, and set the actual load F actual and the actual temperature T actual Two factors, the response surface analysis method of 2 factors and 5 levels was used to generate the experimental plan, -α is the actual load of the tail nozzle in the cruise working state, α is the actual load of the tail nozzle in the full afterburner working state, -β is the actual temperature of the tail nozzle in the cruise working state, β is the actual temperature of the tail nozzle in the full afterburner working state, considering the influence of random errors in operation, four tests were conducted on the central point working condition, and two tests were conducted on each of the other working conditions to determine the deviation caused by other irrelevant factors in the test system, and at the same time, the order of the working conditions was disrupted and all tests were randomly conducted, and the average value of the test data under the same working condition was taken;

[0098] Module M33: Prepare the test pieces of typical kinematic pairs of actual equipment aviation tail nozzles, carry out visual identification feature marking on the test pieces of typical kinematic pairs of actual equipment aviation tail nozzles, spray ArUco marks on the surfaces of the test pieces of the rotating pair, ball and socket pair, and cam pair, respectively, so that the visual module of the friction and wear test system of the typical kinematic pairs of aviation tail nozzles can track the target during the test, and randomly carve scratches of varying depths on the contour of the test piece to distinguish the test piece with the same metallic luster from the background, so that the friction and wear test system of the typical kinematic pairs of aviation tail nozzles can recognize the contour features during the test;

[0099] Module M34: Carry out sample-level tests. Sample-level tests are carried out based on the friction and wear test system for simulating working conditions of typical kinematic pairs of aviation tail nozzles. First, the test accuracy index is set, each execution module is reset, and the test parameters are set at the same time. The test parameters include: displacement-load relationship, data acquisition frequency, ambient heating temperature, and planned loading time; then, heating is carried out in the temperature-controlled box according to the settings to reach the preset ambient temperature, and then the test is started according to the settings. During the test, the strain of the test piece is measured online based on the built-in high-resolution and high-frame-rate visual module of the test system, and the online vibration characteristic measurement of the motion process of the typical kinematic pair is carried out based on the motion amplification algorithm. At the same time, according to the experimental settings, the sample is moved to the preset measurement optical path position at specific intervals, and the wear surface morphology of the kinematic pair is measured in situ based on vision. After the test, further offline measurement and analysis of the kinematic pair is carried out; when the preset test time is completed, the test is evaluated. If it meets the expected test, it ends, otherwise the reset is performed and the test is repeated;

[0100] Module M35: Offline wear analysis after the test, including:

[0101] Use a large-range analytical balance to measure the mass of the sample before and after the test, and calculate the wear amount and wear rate;

[0102] The surface roughness change of the wear scar of the sample before and after the test was measured by a contact roughness meter and a metal Rockwell hardness tester;

[0103] The surface hardness HRC of the wear scar of the sample before and after the test is measured by a metal Rockwell hardness tester;

[0104] The surface morphology was measured by white light interferometry and optical microscopy, and the arithmetic mean height R of the surface roughness was extracted. a , skewness S sk and the root mean square deviation S q feature;

[0105] Observe the shape of wear debris through scanning electron microscope and analyze the wear failure form;

[0106] The element distribution and content wt% of the worn surface and profile were analyzed by Raman spectrometer and X-ray energy spectrometer;

[0107] The above measurements all comply with the measurement specifications of taking the average of three measurements and selecting test sites evenly on the surface to be tested;

[0108] The load distribution, temperature distribution and velocity distribution curves of the test process are derived, and the wear coefficient K is solved using the Archard wear model. actual , establish a wear coefficient fitting model that integrates temperature, load and speed factors:

[0109]

[0110] Among them, e1, e2, e3, e4, e5, e6, and e7 are fitting coefficients, T is temperature, F is load, and v is velocity.

[0111] Preferably, the module M4 includes:

[0112] Module M41: Establish the wear life evaluation index of the kinematic pair. Based on the kinematic simulation analysis results of the tail nozzle motion adjustment mechanism in module M1, determine that the wear failure criteria that affect the adjustment accuracy, adjustment resistance and motion synchronization of the motion adjustment mechanism are the failure friction coefficient and the failure wear coefficient. Based on the friction and wear measurement results of the material-level friction and wear test of module M2 and the wear measurement results of the sample-level friction and wear test of module M3, determine that the wear failure form is characterized by the surface hardness at failure, the surface element distribution at failure and the wear mark morphology at failure.

[0113] Module M42: Explore the factors that affect the wear life of typical kinematic pairs through correlation analysis, and analyze the correlation between the test condition quantity and the test result quantity based on the Pearson correlation coefficient, where the test condition quantity includes the number of cycles N under full force working state full , Number of cycles N under cruise working state cruise , temperature T, load F and speed v, the test results include friction coefficient COF, wear rate δ, surface roughness arithmetic mean height R a , average root mean square deviation S q , surface roughness average skewness S sk , wear surface, element distribution and content wt% of the cross section and surface hardness HRC of the wear scar, and the number of cycles N under full force working state full , Number of cycles N under cruise working state cruise Principal component analysis to identify key influencing factors;

[0114] Module M43: Establish a wear life prediction model for samples suitable for heavy-load and high-temperature working conditions. Based on the principal component analysis results of module M42, the machine learning algorithms kernel ridge regression KRR, support vector regression SVR and extreme gradient boosting decision tree XGBoost are used to construct the principal component analysis results and the number of cycles N under full-load working conditions. full , Number of cycles N under cruise working state cruise The relationship model between them.

[0115] Compared with the prior art, the present invention has the following beneficial effects:

[0116] (1) The present invention is a typical kinematic pair friction and wear test method based on high temperature and heavy load conditions. By conducting quantitative analysis on the working environment and motion conditions of the kinematic pair, the working conditions of the kinematic pair are fully simulated, making the test results and subsequent optimization indicators more convincing;

[0117] (2) The present invention conducts sample-level friction and wear tests on typical kinematic pairs. By performing tribological decoupling analysis on the motion adjustment mechanism of the aviation tail nozzle, the sample is designed according to the required kinematic pairs. The loading device can provide the required load according to the displacement-load calibration relationship, measure stress and strain in real time, etc., to solve the problem that current testing machines rarely conduct sample-level tests.

[0118] (3) The present invention will establish a kinematic pair wear life evaluation index for friction and wear tests, explore the main factors affecting the wear life of typical kinematic pairs through correlation analysis, and establish a sample wear life prediction model suitable for heavy load and high temperature conditions based on algorithms such as neural networks and machine learning. These evaluation indicators and prediction models can greatly promote the design and improvement of subsequent aviation tail nozzle motion adjustment mechanisms and become an important reference. BRIEF DESCRIPTION OF THE DRAWINGS

[0119] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings:

[0120] Figure 1 It is a schematic diagram of the kinematic simulation model of the tail nozzle motion adjustment mechanism;

[0121] Figure 2 This is a flow chart of the friction and wear test method for typical moving pairs of aviation tail nozzles under high temperature and heavy load conditions;

[0122] Figure 3 This is a flow chart of the test method for the material level of typical motion pairs of aviation tail nozzles;

[0123] Figure 4 This is a schematic diagram of the central composite experimental design method;

[0124] Figure 5 This is a schematic diagram of a material level test pin-on-disc;

[0125] Figure 6 This is a flow chart of the test method for typical moving sub-sample level of aviation tail nozzle;

[0126] Figure 7 This is the stress distribution result in the contact area of ​​a typical kinematic pair. DETAILED DESCRIPTION

[0127] The present invention is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several changes and improvements can also be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0128] Embodiment 1:

[0129] like Figure 2 The present invention provides a method for testing the friction and wear of typical moving pairs of an aviation tail nozzle under high temperature and heavy load conditions, comprising:

[0130] Step S1: Deconstructing the tribological system of typical kinematic pairs of aviation tail nozzles, including analyzing the tail nozzle motion adjustment mechanism, establishing a kinematic simulation model of the tail nozzle motion adjustment mechanism, conducting dynamic simulation of the tail nozzle throat area and vector direction adjustment process, and studying the loading mode of typical kinematic pairs and their relative motion form characteristics;

[0131] Step S2: Conducting a friction and wear test on a typical moving pair material level of an aviation tail nozzle, including calculating the equivalent working conditions of the material level test, carrying out experimental design, processing and preparing a pin-on-disc test piece for a friction and wear test on a typical moving pair material level of an aviation tail nozzle, and conducting a pin-on-disc test based on an Rtec multifunctional testing machine, and conducting a friction and wear analysis after the test;

[0132] Step S3: Conducting a friction and wear test at the sample level of a typical moving pair of an aviation tail nozzle, including calculating the equivalent working conditions of the sample level test, carrying out experimental design, preparing the actual equipment of the typical moving pair test piece of the aviation tail nozzle, carrying out a sample level test based on a friction and wear test system for simulating working conditions of the typical moving pair of the aviation tail nozzle, measuring the vibration and strain data of the sample during the test online, measuring the surface wear morphology in situ, and carrying out offline wear measurement and analysis after the test;

[0133] Step S4: Conduct friction and wear life prediction modeling for typical moving parts of aviation tail nozzles, including establishing moving part wear life evaluation indicators, exploring factors affecting the wear life of typical moving parts through correlation analysis, and establishing a sample wear life prediction model suitable for heavy-load and high-temperature conditions based on neural network and machine learning algorithms.

[0134] In step S1, if Figure 1 The kinematic simulation model of the tail nozzle motion adjustment mechanism includes a cam, a roller, an adjustment plate, a tripod and a tail pipe outer ring. The motion adjustment mechanism includes three types of typical motion pairs, including a cam pair between the cam and the roller, a ball pair between the cam and the adjustment plate, and a pin pair between the tripod and the tail pipe outer ring.

[0135] Studying the loading mode and relative motion characteristics of typical kinematic pairs requires quantitative analysis of the working conditions of typical kinematic pairs of aviation tail nozzles and tribological decoupling analysis of the motion adjustment mechanism of aviation tail nozzles.

[0136] The quantitative analysis of the working conditions of the typical motion pair of the aviation tail nozzle includes the following steps:

[0137] Step S11: convert the gas pressure on the regulating plate of the aviation tail nozzle motion regulating mechanism into the force it receives, divide the regulating plate into multiple micro-elements, and calculate the force on each micro-element. The force is perpendicular to the regulating plate. The calculation formula of the force is as follows:

[0138]

[0139] Step S12: Calculate the sum of the resultant force on the regulating plate of the aviation tail nozzle motion regulating mechanism, which is expressed as the integral sum of the regulating plate area. The calculation formula of the resultant force is:

[0140] F 合 (S) = ∫ΔPdS

[0141] Where ΔS / dS is the area of ​​each microelement; F is the force on each microelement, F 合 is the resultant force on the regulating plate of the aviation tail nozzle movement regulating mechanism; ΔP is the pressure on each unit;

[0142] Step S13: The pressure P on the regulating plate of the aviation tail nozzle motion regulating mechanism is simplified to be equally distributed along the Y axis by considering the symmetric characteristics, and the fitting formula along the X axis is established as follows:

[0143] P=Y*(aX 6 +bX 5 +cX 4 +dX 3 +eX 2 +fX+g)

[0144] Among them, a, b, c, d, e, f, g are fitting parameters, Y is the horizontal size of the adjustment piece, and X is the vertical distance from the left end of the adjustment piece;

[0145] Step S14: Simulate and calculate the working temperature of the typical kinematic pair of the aviation tail nozzle motion regulating mechanism. According to the measured ambient temperature of the aviation tail nozzle when it is working, the actual working temperature of the typical kinematic pair of the aviation tail nozzle motion regulating mechanism is obtained through simulation calculation. The heat generated by friction is fitted and calculated using the following formula:

[0146] Q=μF N Se

[0147] Where Q is the heat generated by friction; μ is the friction coefficient; F N is the normal pressure perpendicular to the surface of the object; S is the actual contact area between the two surfaces of the object; e is the effective energy conversion rate between the surfaces;

[0148] Then, the temperature rise of the typical motion pair of the aviation tail nozzle motion adjustment mechanism is calculated based on the heat generated by friction. The formula is:

[0149]

[0150] Among them, Q is the heat generated by friction; m is the mass of the kinematic pair; and c is the specific heat capacity of the kinematic pair matrix material.

[0151] The step S2 comprises:

[0152] Step S21: Calculate the equivalent working condition of the material level test. According to the deconstruction results of the tribological system of the typical kinematic pair of the aviation tail nozzle in step S1, determine the load form, motion trajectory, actual working temperature and contact form of the typical kinematic pair. Take the force F when the force amplitude of the typical kinematic pair is the largest in a motion trajectory. max 、Position (X, Y, Z) max and the actual operating temperature T actual_max As the input condition for stress distribution simulation modeling, static simulation is carried out, and the average pressure of the contact area is calculated based on the VonMises stress result under the setting of Avg:75% as the equivalent contact pressure σ of the pin-disc test. equivalent The stress distribution results of the typical kinematic contact area are as follows: Figure 7 , based on the Hertz contact theory, the equivalent load F applied to the pin in the material level test is calculated equivalent , calculate the equivalent rotation speed of the test plate in the material grade test rpm equivalent Make the relative linear velocity of the pin-disk equal to the average velocity of a typical kinematic pair in a motion trajectory, and the motion loading time t in the material level test equivalent Keep the same as the sample level test time, the test temperature T in the material level test equivalent The actual working temperature T when the force amplitude of a typical kinematic pair in a motion trajectory is the maximum actual_max Consistency;

[0153] Step S22: Conduct experimental design, based on central composite design, and set equivalent load F according to actual working condition simulation requirements. equivalent and test temperature T equivalent Two factors, the experimental plan was generated using the response surface analysis method of 2 factors and 5 levels, such as Figure 4 As shown, -α is the test equivalent load of the tail nozzle under the cruise working state, α is the test equivalent load of the tail nozzle under the full afterburner working state, -β is the test temperature of the tail nozzle under the cruise working state, β is the test temperature of the tail nozzle under the full afterburner working state. Considering the influence of random errors in operation, four tests are carried out on the central point working condition, and two tests are carried out on each of the other working conditions to determine the deviation caused by other irrelevant factors in the test system. At the same time, all tests are randomly carried out in a disordered order, and the test data of the same working condition are averaged;

[0154] Step S23: Processing and preparing the pin-disc test piece for material level test, according to the analysis of the kinematic pair contact form in the deconstruction result of the typical kinematic pair tribological system of the aviation tail nozzle in step S1, it is divided into point contact, line contact and surface contact, and the hemispherical surface, arc surface and plane surface are processed in turn. Figure 5 As shown, the pin and disc substrate materials are typical kinematic pair substrate materials, and the contact surface has the same coating;

[0155] Step S24: Conduct material level pin-on-disc test. The specific process is as follows: Figure 3 As shown, first set the test accuracy index, adjust the reset of each execution module, and set the test parameters. The test parameters include: test disk rotation speed rpm equivalent 、Motor load F equivalent , proposed loading time t equivalent and test environment temperature T equivalent ; Then the test is carried out according to the setting. The time is judged during the test. If the set test time is reached, the loading motor and pin sample are lifted, and the other components are reset. At the same time, wear information identification and wear amount offline measurement are carried out; finally, the test is evaluated. If it meets the expected test, the test ends, otherwise the test is reset and re-tested;

[0156] Step S25: After the test, friction and wear analysis is carried out, including friction analysis and wear analysis, and wear surface morphology characterization analysis is carried out, the surface roughness of the wear scar is measured, the surface morphology is measured based on white light interferometry to extract periodic features, and the EDS energy spectrum analysis of the adhered wear debris particles is performed using a scanning electron microscope;

[0157] For friction analysis, the time-varying characteristics of the friction coefficient COF are analyzed, and the average value of the friction coefficient after stabilization is taken to qualitatively analyze the influence of temperature, load and speed on the average friction coefficient. Considering the Stribeck effect, an average friction coefficient prediction model with speed and temperature as prediction variables is established:

[0158] COF=c1+c2rpm+c3T

[0159] Wherein, c1, c2, c3 are fitting coefficients; T is temperature; rpm is speed;

[0160] For wear analysis, the test pin and test plate were weighed again, the wear amount was calculated, the friction coefficient distribution, load distribution, temperature distribution and speed distribution curves of the test process were derived, the wear coefficient K was solved using the Archard wear model, and a wear coefficient fitting model that integrates temperature, load and speed factors was established:

[0161]

[0162] Among them, d1, d2, d3, d4, d5, d6, and d7 are fitting coefficients; T is temperature; F is load; and rpm is speed.

[0163] The step S3 comprises:

[0164] Step S31: Calculate the equivalent working condition of the sample-level test, determine the load form, motion trajectory, actual working temperature and contact form of the typical kinematic pair according to the deconstruction results of the tribological system of the typical kinematic pair of the aviation tail nozzle in step S1, and directly set the test conditions equivalent to the actual working conditions based on the sample-level friction and wear test device, including the force position of the kinematic pair, the force magnitude, the change law of the direction with the movement, the kinematic pair movement form and the ambient temperature of the kinematic pair;

[0165] Step S32: Conduct experimental design, using the same central composite design as step S22, and set the actual load F actual and the actual temperature T actual Two factors, the response surface analysis method of 2 factors and 5 levels was used to generate the experimental plan, -α is the actual load of the tail nozzle in the cruise working state, α is the actual load of the tail nozzle in the full afterburner working state, -β is the actual temperature of the tail nozzle in the cruise working state, β is the actual temperature of the tail nozzle in the full afterburner working state, considering the influence of random errors in operation, four tests were conducted on the central point working condition, and two tests were conducted on each of the other working conditions to determine the deviation caused by other irrelevant factors in the test system, and at the same time, the order of the working conditions was disrupted and all tests were randomly conducted, and the average value of the test data under the same working condition was taken;

[0166] Step S33: preparing a typical kinematic pair test piece of an actual equipment aviation tail nozzle, marking the visual recognition features of the typical kinematic pair test piece of an actual equipment aviation tail nozzle, spraying ArUco marks on the surfaces of the rotating pair, ball and socket pair, and cam pair test pieces respectively, so that the visual module of the friction and wear test system for the simulated working condition of the typical kinematic pair of the aviation tail nozzle can track the target during the test, and randomly engraving scratches of varying depths on the contour of the test piece to distinguish the test piece with the same metallic luster from the background, so that the friction and wear test system for the simulated working condition of the typical kinematic pair of the aviation tail nozzle can recognize the contour features during the test;

[0167] Step S34: Carry out sample-level tests, based on the friction and wear test system of typical motion pairs of aviation tail nozzles to simulate working conditions. The specific process is as follows: Figure 6As shown, first, the test accuracy index is set, each execution module is adjusted to reset, and the test parameters are set at the same time. The test parameters include: displacement-load relationship, data acquisition frequency, ambient heating temperature and planned loading time; then, heating is carried out in the temperature-controlled box according to the settings to reach the preset ambient temperature, and then the test is started according to the settings. During the test, the strain of the test piece is measured online based on the built-in high-resolution and high-frame-rate visual module of the test system, and the online vibration characteristic measurement of the typical kinematic pair motion process is carried out based on the motion amplification algorithm. At the same time, according to the experimental settings, the sample is moved to the preset measurement optical path position at specific intervals, and the wear surface morphology of the kinematic pair is measured in situ based on vision. After the test, further offline measurement and analysis of the kinematic pair is carried out; when the preset test time is completed, the test is evaluated. If it meets the expected test, it ends, otherwise the reset is performed and the test is repeated;

[0168] Step S35: After the test, conduct offline wear analysis, including:

[0169] Use a large-range analytical balance to measure the mass of the sample before and after the test, and calculate the wear amount and wear rate;

[0170] The surface roughness change of the wear scar of the sample before and after the test was measured by a contact roughness meter and a metal Rockwell hardness tester;

[0171] The surface hardness HRC of the wear scar of the sample before and after the test is measured by a metal Rockwell hardness tester;

[0172] The surface morphology was measured by white light interferometry and optical microscopy, and the arithmetic mean height R of the surface roughness was extracted. a , skewness S sk and the root mean square deviation S q feature;

[0173] Observe the shape of wear debris through scanning electron microscope and analyze the wear failure form;

[0174] The element distribution and content wt% of the worn surface and profile were analyzed by Raman spectrometer and X-ray energy spectrometer;

[0175] The above measurements all comply with the measurement specifications of taking the average of three measurements and selecting test sites evenly on the surface to be tested;

[0176] The load distribution, temperature distribution and velocity distribution curves of the test process are derived, and the wear coefficient K is solved using the Archard wear model. actual , establish a wear coefficient fitting model that integrates temperature, load and speed factors:

[0177]

[0178] Among them, e1, e2, e3, e4, e5, e6, and e7 are fitting coefficients, T is temperature, F is load, and v is velocity.

[0179] The step S4 comprises:

[0180] Step S41: Establishing a kinematic pair wear life evaluation index, determining the wear failure criteria that affect the adjustment accuracy, adjustment resistance and movement synchronization of the motion adjustment mechanism as failure friction coefficient and failure wear coefficient based on the kinematic simulation analysis results of the tail nozzle motion adjustment mechanism in step S1, and determining the wear failure form as surface hardness at failure, surface element distribution at failure and wear mark morphology characteristics at failure based on the friction and wear measurement results of the material-level friction and wear test in step S2 and the wear measurement results of the sample-level friction and wear test in step S3;

[0181] Step S42: Explore the factors that affect the wear life of typical kinematic pairs through correlation analysis, and analyze the correlation between the test condition quantity and the test result quantity based on the Pearson correlation coefficient, where the test condition quantity includes the number of cycles N under full force working state. full , Number of cycles N under cruise working state cruise , temperature T, load F and speed v, the test results include friction coefficient COF, wear rate δ, surface roughness arithmetic mean height R a , average root mean square deviation S q , surface roughness average skewness S sk , wear surface, element distribution and content wt% of the cross section and surface hardness HRC of the wear scar, and the number of cycles N under full force working state full , Number of cycles N under cruise working state cruise Principal component analysis to identify key influencing factors;

[0182] Step S43: Establish a wear life prediction model for samples suitable for heavy-load and high-temperature working conditions. Based on the principal component analysis results of step S42, the machine learning algorithms kernel ridge regression KRR, support vector regression SVR and extreme gradient boosting decision tree XGBoost are used to construct the principal component analysis results and the number of cycles N under full-load working conditions. full , Number of cycles N under cruise working state cruiseThe correlation model between them. The key parameters of KRR are alpha = 0.3, kernel = 'laplacian', the key parameters of SVR are kernel = 'rbf', tol = 1, C = 10, epsilon = 0.1, and the key parameters of XGBoost are n_estimators = 60, max_depth = 3, and learning_rate = 0.05. In order to achieve better prediction results, in the explanation variable wear rate δ, the contribution rate of KRR is 60%, the contribution rate of SVR is 20%, and the contribution rate of XGBoost is 20%; the explanation variable surface roughness arithmetic mean height R a and the average skewness of the surface roughness S sk Among them, KRR contributes 20%, SVR contributes 60%, XGBoost contributes 20%, and the contribution rates of the remaining explanatory variables KRR, SVR, and XGBoost are 33% each.

[0183] Embodiment 2:

[0184] The present invention also provides a friction and wear testing system for typical moving pairs of aviation tail nozzles under high temperature and heavy load conditions. The friction and wear testing system for typical moving pairs of aviation tail nozzles under high temperature and heavy load conditions can be realized by executing the process steps of the friction and wear testing method for typical moving pairs of aviation tail nozzles under high temperature and heavy load conditions, that is, those skilled in the art can understand the friction and wear testing method for typical moving pairs of aviation tail nozzles under high temperature and heavy load conditions as a preferred implementation of the friction and wear testing system for typical moving pairs of aviation tail nozzles under high temperature and heavy load conditions.

[0185] The present invention provides a friction and wear test system for typical motion pairs of an aviation tail nozzle under high temperature and heavy load conditions, comprising:

[0186] Module M1: Deconstruction of the tribological system of typical kinematic pairs of aviation tail nozzles, including analysis of tail nozzle motion adjustment mechanism, establishment of kinematic simulation model of tail nozzle motion adjustment mechanism, dynamic simulation of tail nozzle throat area and vector direction adjustment process, and study of loading mode of typical kinematic pairs and their relative motion form characteristics;

[0187] Module M2: Conduct friction and wear tests on typical moving parts of aircraft tail nozzles, including calculating equivalent working conditions of material level tests, carrying out experimental design, processing and preparing pin-disc test pieces for friction and wear tests on typical moving parts of aircraft tail nozzles, and conducting pin-disc tests based on Rtec multifunctional testing machines. After the tests, friction and wear analysis will be carried out.

[0188] Module M3: Conducting friction and wear tests on typical moving parts of aviation tail nozzles at the sample level, including calculating the equivalent working conditions of the sample level test, carrying out experimental design, preparing the actual equipment of the typical moving parts of aviation tail nozzles, carrying out sample level tests based on the friction and wear test system of the typical moving parts of aviation tail nozzles under simulated working conditions, measuring the vibration and strain data of the test parts online during the test, measuring the surface wear morphology in situ, and carrying out offline wear measurement and analysis after the test;

[0189] Module M4: Conduct friction and wear life prediction modeling for typical moving parts of aviation tail nozzles, including establishing moving part wear life evaluation indicators, exploring the factors affecting the wear life of typical moving parts through correlation analysis, and establishing a sample wear life prediction model suitable for heavy-load and high-temperature conditions based on neural network and machine learning algorithms.

[0190] In module M1, the kinematic simulation model of the tail nozzle motion adjustment mechanism includes a cam, a roller, an adjustment plate, a tripod and a tail pipe outer ring. The motion adjustment mechanism includes three types of typical motion pairs, including a cam pair between the cam and the roller, a ball pair between the cam and the adjustment plate, and a pin pair between the tripod and the tail pipe outer ring.

[0191] Studying the loading mode and relative motion characteristics of typical kinematic pairs requires quantitative analysis of the working conditions of typical kinematic pairs of aviation tail nozzles and tribological decoupling analysis of the motion adjustment mechanism of aviation tail nozzles.

[0192] The working conditions of typical motion pairs of aviation tail nozzles are quantitatively analyzed, including the following modules:

[0193] Module M11: The gas pressure on the regulating plate of the aviation tail nozzle motion regulating mechanism is converted into the force it receives. The regulating plate is divided into multiple micro-elements, and the force on each micro-element is calculated. The force is perpendicular to the regulating plate. The force calculation formula is as follows:

[0194]

[0195] Module M12: Calculate the sum of the force on the regulating plate of the aviation tail nozzle motion regulating mechanism, which is expressed as the integral sum of the regulating plate area. The calculation formula of the resultant force is:

[0196] F 合 (S) = ∫ΔPdS

[0197] Where ΔS / dS is the area of ​​each microelement; F is the force on each microelement, F 合 is the resultant force on the regulating plate of the aviation tail nozzle movement regulating mechanism; ΔP is the pressure on each unit;

[0198] Module M13: The pressure P on the regulating plate of the aviation tail nozzle motion regulating mechanism is simplified to be equally distributed along the Y axis considering the symmetric characteristics, and the fitting formula along the X axis is established as follows:

[0199] P=Y*(aX 6 +bX 5 +cX 4 +dX 3 +eX 2 +fX+g)

[0200] Among them, a, b, c, d, e, f, g are fitting parameters, Y is the horizontal size of the adjustment piece, and X is the vertical distance from the left end of the adjustment piece;

[0201] Module M14: Simulate and calculate the working temperature of the typical kinematic pair of the aviation tail nozzle motion regulating mechanism. According to the measured ambient temperature of the aviation tail nozzle when it is working, the actual working temperature of the typical kinematic pair of the aviation tail nozzle motion regulating mechanism is obtained through simulation calculation. The heat generated by friction is fitted and calculated using the following formula:

[0202] Q=μF N Se

[0203] Where Q is the heat generated by friction; μ is the friction coefficient; F N is the normal pressure perpendicular to the surface of the object; S is the actual contact area between the two surfaces of the object; e is the effective energy conversion rate between the surfaces;

[0204] Then, the temperature rise of the typical motion pair of the aviation tail nozzle motion adjustment mechanism is calculated based on the heat generated by friction. The formula is:

[0205]

[0206] Among them, Q is the heat generated by friction; m is the mass of the kinematic pair; and c is the specific heat capacity of the kinematic pair matrix material.

[0207] The module M2 comprises:

[0208] Module M21: Calculate the equivalent working conditions of the material level test. According to the deconstruction results of the tribological system of the typical kinematic pair of the aviation tail nozzle in module M1, determine the load form, motion trajectory, actual working temperature and contact form of the typical kinematic pair. Take the force F when the force amplitude of the typical kinematic pair is the largest in a motion trajectory. max 、Position (X, Y, Z) max and the actual operating temperature T actual_max As the input condition for stress distribution simulation modeling, static simulation is carried out, and the average pressure of the contact area is calculated based on the VonMises stress result under the setting of Avg:75% as the equivalent contact pressure σ of the pin-disc test. equivalent, based on the Hertz contact theory, the equivalent load F applied to the pin in the material level test is calculated equivalent , calculate the equivalent rotation speed of the test plate in the material grade test rpm equivalent Make the relative linear velocity of the pin-disk equal to the average velocity of a typical kinematic pair in a motion trajectory, and the motion loading time t in the material level test equivalent Keep the same as the sample level test time, the test temperature T in the material level test equivalent The actual working temperature T when the force amplitude of a typical kinematic pair in a motion trajectory is the maximum actual_max Consistency;

[0209] Module M22: Conduct experimental design, based on central composite design, set equivalent load F according to actual working condition simulation requirements equivalent and test temperature T equivalent Two factors, the response surface analysis method of 2 factors and 5 levels was used to generate the experimental plan, -α is the test equivalent load of the tail nozzle under the cruise working state, α is the test equivalent load of the tail nozzle under the full afterburner working state, -β is the test temperature of the tail nozzle under the cruise working state, β is the test temperature of the tail nozzle under the full afterburner working state, considering the influence of random errors in operation, four tests were carried out on the central point working condition, and two tests were carried out on each of the other working conditions to determine the deviation caused by other irrelevant factors in the test system, and at the same time, the order of the working conditions was disrupted and all tests were randomly carried out, and the average value of the test data under the same working condition was taken;

[0210] Module M23: Processing and preparation of pin-disc test pieces for material level testing. According to the analysis of the kinematic pair contact form in the deconstruction results of the tribological system of the typical kinematic pair of the aviation tail nozzle in module M1, it is divided into point contact, line contact and surface contact. The hemispherical surface, arc surface and plane surface are processed in turn. The base material of the pin and the disk is the typical kinematic pair base material, and the contact surface has the same coating;

[0211] Module M24: Carry out material level pin-disc test. First, set the test accuracy index, adjust the reset of each execution module, and set the test parameters. The test parameters include: test disk rotation speed rpm equivalent 、Motor load F equivalent , proposed loading time t equivalent and test environment temperature T equivalent ; Then the test is carried out according to the setting. The time is judged during the test. If the set test time is reached, the loading motor and pin sample are lifted, and the other components are reset. At the same time, wear information identification and wear amount offline measurement are carried out; finally, the test is evaluated. If it meets the expected test, the test ends, otherwise the test is reset and re-tested;

[0212] Module M25: After the test, friction and wear analysis is carried out, including friction analysis and wear analysis, and wear surface morphology characterization analysis is carried out, the surface roughness of the wear scar is measured, the surface morphology is measured based on white light interferometry to extract periodic features, and the EDS energy spectrum analysis of the adhesive wear debris particles is performed using a scanning electron microscope;

[0213] For friction analysis, the time-varying characteristics of the friction coefficient COF are analyzed, and the average value of the friction coefficient after stabilization is taken to qualitatively analyze the influence of temperature, load and speed on the average friction coefficient. Considering the Stribeck effect, an average friction coefficient prediction model with speed and temperature as prediction variables is established:

[0214] COF=c1+c2rpm+c3T

[0215] Wherein, c1, c2, c3 are fitting coefficients; T is temperature; rpm is speed;

[0216] For wear analysis, the test pin and test plate were weighed again, the wear amount was calculated, the friction coefficient distribution, load distribution, temperature distribution and speed distribution curves of the test process were derived, the wear coefficient K was solved using the Archard wear model, and a wear coefficient fitting model that integrates temperature, load and speed factors was established:

[0217]

[0218] Among them, d1, d2, d3, d4, d5, d6, and d7 are fitting coefficients; T is temperature; F is load; and rpm is speed.

[0219] The module M3 comprises:

[0220] Module M31: Calculate the equivalent working conditions of the sample-level test. According to the deconstruction results of the tribological system of the typical kinematic pair of the aviation tail nozzle in module M1, determine the load form, motion trajectory, actual working temperature and contact form of the typical kinematic pair. Based on the sample-level friction and wear test device, directly set the test conditions equivalent to the actual working conditions, including the force position of the kinematic pair, the force magnitude, the change law of the direction with the movement, the kinematic pair movement form and the ambient temperature of the kinematic pair;

[0221] Module M32: Conduct experimental design, using the same central combination design as module M22, and set the actual load F actual and the actual temperature T actualTwo factors, the response surface analysis method of 2 factors and 5 levels was used to generate the experimental plan, -α is the actual load of the tail nozzle in the cruise working state, α is the actual load of the tail nozzle in the full afterburner working state, -β is the actual temperature of the tail nozzle in the cruise working state, β is the actual temperature of the tail nozzle in the full afterburner working state, considering the influence of random errors in operation, four tests were conducted on the central point working condition, and two tests were conducted on each of the other working conditions to determine the deviation caused by other irrelevant factors in the test system, and at the same time, the order of the working conditions was disrupted and all tests were randomly conducted, and the average value of the test data under the same working condition was taken;

[0222] Module M33: Prepare the test pieces of typical kinematic pairs of actual equipment aviation tail nozzles, carry out visual identification feature marking on the test pieces of typical kinematic pairs of actual equipment aviation tail nozzles, spray ArUco marks on the surfaces of the test pieces of the rotating pair, ball and socket pair, and cam pair, respectively, so that the visual module of the friction and wear test system of the typical kinematic pairs of aviation tail nozzles can track the target during the test, and randomly carve scratches of varying depths on the contour of the test piece to distinguish the test piece with the same metallic luster from the background, so that the friction and wear test system of the typical kinematic pairs of aviation tail nozzles can recognize the contour features during the test;

[0223] Module M34: Carry out sample-level tests. Sample-level tests are carried out based on the friction and wear test system for simulating working conditions of typical kinematic pairs of aviation tail nozzles. First, the test accuracy index is set, each execution module is reset, and the test parameters are set at the same time. The test parameters include: displacement-load relationship, data acquisition frequency, ambient heating temperature, and planned loading time; then, heating is carried out in the temperature-controlled box according to the settings to reach the preset ambient temperature, and then the test is started according to the settings. During the test, the strain of the test piece is measured online based on the built-in high-resolution and high-frame-rate visual module of the test system, and the online vibration characteristic measurement of the motion process of the typical kinematic pair is carried out based on the motion amplification algorithm. At the same time, according to the experimental settings, the sample is moved to the preset measurement optical path position at specific intervals, and the wear surface morphology of the kinematic pair is measured in situ based on vision. After the test, further offline measurement and analysis of the kinematic pair is carried out; when the preset test time is completed, the test is evaluated. If it meets the expected test, it ends, otherwise the reset is performed and the test is repeated;

[0224] Module M35: Offline wear analysis after the test, including:

[0225] Use a large-range analytical balance to measure the mass of the sample before and after the test, and calculate the wear amount and wear rate;

[0226] The surface roughness change of the wear scar of the sample before and after the test was measured by a contact roughness meter and a metal Rockwell hardness tester;

[0227] The surface hardness HRC of the wear scar of the sample before and after the test is measured by a metal Rockwell hardness tester;

[0228] The surface morphology was measured by white light interferometry and optical microscopy, and the arithmetic mean height R of the surface roughness was extracted. a , skewness S sk and the root mean square deviation S q feature;

[0229] Observe the shape of wear debris through scanning electron microscope and analyze the wear failure form;

[0230] The element distribution and content wt% of the worn surface and profile were analyzed by Raman spectrometer and X-ray energy spectrometer;

[0231] The above measurements all comply with the measurement specifications of taking the average of three measurements and selecting test sites evenly on the surface to be tested;

[0232] The load distribution, temperature distribution and velocity distribution curves of the test process are derived, and the wear coefficient K is solved using the Archard wear model. actual , establish a wear coefficient fitting model that integrates temperature, load and speed factors:

[0233]

[0234] Among them, e1, e2, e3, e4, e5, e6, and e7 are fitting coefficients, T is temperature, F is load, and v is velocity.

[0235] The module M4 comprises:

[0236] Module M41: Establish the wear life evaluation index of the kinematic pair. Based on the kinematic simulation analysis results of the tail nozzle motion adjustment mechanism in module M1, determine that the wear failure criteria that affect the adjustment accuracy, adjustment resistance and motion synchronization of the motion adjustment mechanism are the failure friction coefficient and the failure wear coefficient. Based on the friction and wear measurement results of the material-level friction and wear test of module M2 and the wear measurement results of the sample-level friction and wear test of module M3, determine that the wear failure form is characterized by the surface hardness at failure, the surface element distribution at failure and the wear mark morphology at failure.

[0237] Module M42: Explore the factors that affect the wear life of typical kinematic pairs through correlation analysis, and analyze the correlation between the test condition quantity and the test result quantity based on the Pearson correlation coefficient, where the test condition quantity includes the number of cycles N under full force working state full , Number of cycles N under cruise working state cruise , temperature T, load F and speed v, the test results include friction coefficient COF, wear rate δ, surface roughness arithmetic mean height R a , average root mean square deviation S q , surface roughness average skewness S sk, wear surface, element distribution and content wt% of the cross section and surface hardness HRC of the wear scar, and the number of cycles N under full force working state full , Number of cycles N under cruise working state cruise Principal component analysis to identify key influencing factors;

[0238] Module M43: Establish a wear life prediction model for samples suitable for heavy-load and high-temperature working conditions. Based on the principal component analysis results of module M42, the machine learning algorithms kernel ridge regression KRR, support vector regression SVR and extreme gradient boosting decision tree XGBoost are used to construct the principal component analysis results and the number of cycles N under full-load working conditions. full , Number of cycles N under cruise working state cruise The relationship model between them.

[0239] Those skilled in the art know that, in addition to implementing the system, device and its various modules provided by the present invention in a purely computer-readable program code, it is entirely possible to implement the same program in the form of logic gates, switches, application-specific integrated circuits, programmable logic controllers and embedded microcontrollers by logically programming the method steps. Therefore, the system, device and its various modules provided by the present invention can be considered as a hardware component, and the modules included therein for implementing various programs can also be considered as structures within the hardware component; the modules for implementing various functions can also be considered as both software programs for implementing the method and structures within the hardware component.

[0240] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which does not affect the essence of the present invention. In the absence of conflict, the embodiments of the present application and the features in the embodiments can be combined with each other arbitrarily.

Claims

1. A method for testing the friction and wear of typical moving pairs of an aviation tail nozzle under high temperature and heavy load conditions, characterized in that: include: Step S1: Deconstructing the tribological system of typical kinematic pairs of aviation tail nozzles, including analyzing the tail nozzle motion adjustment mechanism, establishing a kinematic simulation model of the tail nozzle motion adjustment mechanism, conducting dynamic simulation of the tail nozzle throat area and vector direction adjustment process, and studying the loading mode of typical kinematic pairs and their relative motion form characteristics; Step S2: Conducting a friction and wear test on a typical moving pair material level of an aviation tail nozzle, including calculating the equivalent working conditions of the material level test, carrying out experimental design, processing and preparing a pin-on-disc test piece for a friction and wear test on a typical moving pair material level of an aviation tail nozzle, and conducting a pin-on-disc test based on an Rtec multifunctional testing machine, and conducting a friction and wear analysis after the test; Step S3: Conducting a friction and wear test at the sample level of a typical moving pair of an aviation tail nozzle, including calculating the equivalent working conditions of the sample level test, carrying out experimental design, preparing the actual equipment of the typical moving pair test piece of the aviation tail nozzle, carrying out a sample level test based on a friction and wear test system for simulating working conditions of the typical moving pair of the aviation tail nozzle, measuring the vibration and strain data of the sample during the test online, measuring the surface wear morphology in situ, and carrying out offline wear measurement and analysis after the test; Step S4: Conduct friction and wear life prediction modeling for typical moving parts of aviation tail nozzles, including establishing moving part wear life evaluation indicators, exploring factors affecting the wear life of typical moving parts through correlation analysis, and establishing a sample wear life prediction model suitable for heavy-load and high-temperature conditions based on neural network and machine learning algorithms.

2. The friction and wear test method for typical kinematic pairs of aviation tail nozzles under high temperature and heavy load conditions according to claim 1 is characterized in that: In step S1, the kinematic simulation model of the tail nozzle motion adjustment mechanism includes a cam, a roller, an adjustment plate, a tripod and a tail pipe outer ring, and the motion adjustment mechanism includes three types of typical motion pairs, including a cam pair between the cam and the roller, a ball pair between the cam and the adjustment plate, and a pin pair between the tripod and the tail pipe outer ring; Studying the loading mode and relative motion characteristics of typical kinematic pairs requires quantitative analysis of the working conditions of typical kinematic pairs of aviation tail nozzles and tribological decoupling analysis of the motion adjustment mechanism of aviation tail nozzles. The quantitative analysis of the working conditions of the typical motion pair of the aviation tail nozzle includes the following steps: Step S11: convert the gas pressure on the regulating plate of the aviation tail nozzle motion regulating mechanism into the force it receives, divide the regulating plate into multiple micro-elements, and calculate the force on each micro-element. The force is perpendicular to the regulating plate. The calculation formula of the force is as follows: Step S12: Calculate the sum of the resultant force on the regulating plate of the aviation tail nozzle motion regulating mechanism, which is expressed as the integral sum of the regulating plate area. The calculation formula of the resultant force is: F 合 (S)=∫ΔPdS Where ΔS / dS is the area of ​​each microelement; F is the force on each microelement, F 合 is the resultant force on the regulating plate of the aviation tail nozzle movement regulating mechanism; ΔP is the pressure on each unit; Step S13: The pressure P on the regulating plate of the aviation tail nozzle motion regulating mechanism is simplified to be equally distributed along the Y axis by considering the symmetric characteristics, and the fitting formula along the X axis is established as follows: P=Y*(aX 6 +bX 5 +cX 4 +dX 3 +eX 2 +fX+g) Among them, a, b, c, d, e, f, g are fitting parameters, Y is the horizontal size of the adjustment piece, and X is the vertical distance from the left end of the adjustment piece; Step S14: Simulate and calculate the working temperature of the typical kinematic pair of the aviation tail nozzle motion regulating mechanism. According to the measured ambient temperature of the aviation tail nozzle when it is working, the actual working temperature of the typical kinematic pair of the aviation tail nozzle motion regulating mechanism is obtained through simulation calculation. The heat generated by friction is fitted and calculated using the following formula: Q=μF N Yes Where Q is the heat generated by friction; μ is the friction coefficient; F N is the normal pressure perpendicular to the surface of the object; S is the actual contact area between the two surfaces of the object; e is the effective energy conversion rate between the surfaces; Then, the temperature rise of the typical motion pair of the aviation tail nozzle motion adjustment mechanism is calculated based on the heat generated by friction. The formula is: Among them, Q is the heat generated by friction; m is the mass of the kinematic pair; and c is the specific heat capacity of the kinematic pair matrix material.

3. The friction and wear test method for typical kinematic pairs of aviation tail nozzles under high temperature and heavy load conditions according to claim 1 is characterized in that: The step S2 comprises: Step S21: Calculate the equivalent working condition of the material level test. According to the deconstruction results of the tribological system of the typical kinematic pair of the aviation tail nozzle in step S1, determine the load form, motion trajectory, actual working temperature and contact form of the typical kinematic pair. Take the force F when the force amplitude of the typical kinematic pair is the largest in a motion trajectory. max 、Position (X, Y, Z) max and the actual operating temperature T actual_max As the input condition for stress distribution simulation modeling, static simulation is carried out, and the average pressure of the contact area is calculated based on the VonMises stress result under the setting of Avg:75% as the equivalent contact pressure σ of the pin-disc test. equivalent , based on the Hertz contact theory, the equivalent load F applied to the pin in the material level test is calculated equivalent , calculate the equivalent rotation speed of the test plate in the material grade test rpm equivalent Make the relative linear velocity of the pin-disk equal to the average velocity of a typical kinematic pair in a motion trajectory, and the motion loading time t in the material level test equivalent Keep the same as the sample level test time, the test temperature T in the material level test equivalent The actual working temperature T when the force amplitude of a typical kinematic pair in a motion trajectory is the maximum actual_max Consistency; Step S22: Conduct experimental design, based on central composite design, and set equivalent load F according to actual working condition simulation requirements. equivalent and test temperature T equivalent Two factors, the response surface analysis method of 2 factors and 5 levels was used to generate the experimental plan, -α is the test equivalent load of the tail nozzle under the cruise working state, α is the test equivalent load of the tail nozzle under the full afterburner working state, -β is the test temperature of the tail nozzle under the cruise working state, β is the test temperature of the tail nozzle under the full afterburner working state, considering the influence of random errors in operation, four tests were carried out on the central point working condition, and two tests were carried out on each of the other working conditions to determine the deviation caused by other irrelevant factors in the test system, and at the same time, the order of the working conditions was disrupted and all tests were randomly carried out, and the average value of the test data under the same working condition was taken; Step S23: Processing and preparing a pin-disc test piece for a material level test, according to the analysis of the kinematic pair contact form in the deconstruction results of the tribological system of a typical kinematic pair of an aviation tail nozzle in step S1, it is divided into point contact, line contact and surface contact, and a hemispherical surface, an arc surface and a plane are processed in sequence. The base material of the pin and the disk is the base material of a typical kinematic pair, and the contact surface has the same coating; Step S24: Carry out material level pin-disc test. First, set the test accuracy index, adjust the reset of each execution module, and set the test parameters. The test parameters include: test disk rotation speed rpm equivalent 、Motor load F equivalent , proposed loading time t equivalent and test environment temperature T equivalent ; Then the test is carried out according to the setting. The time is judged during the test. If the set test time is reached, the loading motor and pin sample are lifted, and the other components are reset. At the same time, wear information identification and wear amount offline measurement are carried out; finally, the test is evaluated. If it meets the expected test, the test ends, otherwise the test is reset and re-tested; Step S25: After the test, friction and wear analysis is carried out, including friction analysis and wear analysis, and wear surface morphology characterization analysis is carried out, the surface roughness of the wear scar is measured, the surface morphology is measured based on white light interferometry to extract periodic features, and the EDS energy spectrum analysis of the adhered wear debris particles is performed using a scanning electron microscope; For friction analysis, the time-varying characteristics of the friction coefficient COF are analyzed, and the average value of the friction coefficient after stabilization is taken to qualitatively analyze the influence of temperature, load and speed on the average friction coefficient. Considering the Stribeck effect, an average friction coefficient prediction model with speed and temperature as prediction variables is established: COF=c1+c2rpm+c 36 T Wherein, c1, c2, c3 are fitting coefficients; T is temperature; rpm is speed; For wear analysis, the test pin and test plate were weighed again, the wear amount was calculated, the friction coefficient distribution, load distribution, temperature distribution and speed distribution curves of the test process were derived, the wear coefficient K was solved using the Archard wear model, and a wear coefficient fitting model that integrates temperature, load and speed factors was established: Among them, d1, d2, d3, d4, d5, d6, and d7 are fitting coefficients; T is temperature; F is load; and rpm is speed.

4. The friction and wear test method for typical kinematic pairs of aviation tail nozzles under high temperature and heavy load conditions according to claim 3 is characterized in that: The step S3 comprises: Step S31: Calculate the equivalent working condition of the sample-level test, determine the load form, motion trajectory, actual working temperature and contact form of the typical kinematic pair according to the deconstruction results of the tribological system of the typical kinematic pair of the aviation tail nozzle in step S1, and directly set the test conditions equivalent to the actual working conditions based on the sample-level friction and wear test device, including the force position of the kinematic pair, the force magnitude, the change law of the direction with the movement, the kinematic pair movement form and the ambient temperature of the kinematic pair; Step S32: Conduct experimental design, using the same central composite design as step S22, and set the actual load F actual and the actual temperature T actual Two factors, the response surface analysis method of 2 factors and 5 levels was used to generate the experimental plan, -α is the actual load of the tail nozzle in the cruise working state, α is the actual load of the tail nozzle in the full afterburner working state, -β is the actual temperature of the tail nozzle in the cruise working state, β is the actual temperature of the tail nozzle in the full afterburner working state, considering the influence of random errors in operation, four tests were conducted on the central point working condition, and two tests were conducted on each of the other working conditions to determine the deviation caused by other irrelevant factors in the test system, and at the same time, the order of the working conditions was disrupted and all tests were randomly conducted, and the average value of the test data under the same working condition was taken; Step S33: preparing a typical kinematic pair test piece of an actual equipment aviation tail nozzle, marking the visual recognition features of the typical kinematic pair test piece of an actual equipment aviation tail nozzle, spraying ArUco marks on the surfaces of the rotating pair, ball and socket pair, and cam pair test pieces respectively, so that the visual module of the friction and wear test system for the simulated working condition of the typical kinematic pair of the aviation tail nozzle can track the target during the test, and randomly engraving scratches of varying depths on the contour of the test piece to distinguish the test piece with the same metallic luster from the background, so that the friction and wear test system for the simulated working condition of the typical kinematic pair of the aviation tail nozzle can recognize the contour features during the test; Step S34: Conducting a sample-level test, based on the friction and wear test system of the typical kinematic pair of the aviation tail nozzle simulating working conditions, conduct a sample-level test, first set the test accuracy index, adjust the reset of each execution module, and set the test parameters at the same time, the test parameters include: displacement load relationship, data acquisition frequency, ambient heating temperature and planned loading time; then carry out heating in the temperature control box according to the setting to reach the preset ambient temperature, and then start the test according to the setting, during the test, based on the built-in high-resolution and high-frame rate visual module of the test system, perform online test piece strain measurement, and based on the motion amplification algorithm, perform online vibration characteristic measurement of the typical kinematic pair motion process, and according to the experimental settings, move the sample to the preset measurement optical path position at specific intervals, and measure the kinematic pair wear surface morphology based on the visual in-situ, and after the test, conduct further offline measurement and analysis of the kinematic pair; when the preset test time is completed, the test is evaluated, and if it meets the expected test, it ends, otherwise, reset and re-test; Step S35: After the test, conduct offline wear analysis, including: Use a large-range analytical balance to measure the mass of the sample before and after the test, and calculate the wear amount and wear rate; The surface roughness change of the wear scar of the sample before and after the test was measured by a contact roughness meter and a metal Rockwell hardness tester; The surface hardness HRC of the wear scar of the sample before and after the test is measured by a metal Rockwell hardness tester; The surface morphology was measured by white light interferometry and optical microscopy, and the arithmetic mean height R of the surface roughness was extracted. a , skewness S sk and the root mean square deviation S q feature; Observe the shape of wear debris through scanning electron microscope and analyze the wear failure form; The element distribution and content wt% of the worn surface and profile were analyzed by Raman spectrometer and X-ray spectrometer; The above measurements all comply with the measurement specifications of taking the average of three measurements and selecting test sites evenly on the surface to be tested; The load distribution, temperature distribution and velocity distribution curves of the test process are derived, and the wear coefficient K is solved using the Archard wear model. actual , establish a wear coefficient fitting model that integrates temperature, load and speed factors: Among them, e1, e2, e3, e4, e5, e6, and e7 are fitting coefficients, T is temperature, F is load, and v is velocity.

5. The friction and wear test method for typical kinematic pairs of aviation tail nozzles under high temperature and heavy load conditions according to claim 1 is characterized in that: The step S4 comprises: Step S41: Establishing a kinematic pair wear life evaluation index, determining the wear failure criteria that affect the adjustment accuracy, adjustment resistance and movement synchronization of the motion adjustment mechanism as failure friction coefficient and failure wear coefficient based on the kinematic simulation analysis results of the tail nozzle motion adjustment mechanism in step S1, and determining the wear failure form as surface hardness at failure, surface element distribution at failure and wear mark morphology characteristics at failure based on the friction and wear measurement results of the material-level friction and wear test in step S2 and the wear measurement results of the sample-level friction and wear test in step S3; Step S42: Explore the factors that affect the wear life of typical kinematic pairs through correlation analysis, and analyze the correlation between the test condition quantity and the test result quantity based on the Pearson correlation coefficient, where the test condition quantity includes the number of cycles N under full force working state full , Number of cycles N under cruise working state cruise , temperature T, load F and speed v, the test results include friction coefficient COF, wear rate δ, surface roughness arithmetic mean height R a , average root mean square deviation S q , surface roughness average skewness S sk , wear surface, element distribution and content wt% of the cross section and surface hardness HRC of the wear scar, and the number of cycles N under full force working state full , Number of cycles N under cruise working state cruise Principal component analysis to identify key influencing factors; Step S43: Establish a wear life prediction model for samples suitable for heavy-load and high-temperature working conditions. Based on the principal component analysis results of step S42, the machine learning algorithms kernel ridge regression KRR, support vector regression SVR and extreme gradient boosting decision tree XGBoost are used to construct the principal component analysis results and the number of cycles N under full-load working conditions. full , Number of cycles N under cruise working state cruise The relationship model between them.

6. A friction and wear test system for typical motion pairs of aviation tail nozzles under high temperature and heavy load conditions, characterized in that: include: Module M1: Deconstruction of the tribological system of typical kinematic pairs of aviation tail nozzles, including analysis of tail nozzle motion adjustment mechanism, establishment of kinematic simulation model of tail nozzle motion adjustment mechanism, dynamic simulation of tail nozzle throat area and vector direction adjustment process, and study of loading mode of typical kinematic pairs and their relative motion form characteristics; Module M2: Conduct friction and wear tests on typical moving parts of aircraft tail nozzles, including calculating equivalent working conditions of material level tests, carrying out experimental design, processing and preparing pin-disc test pieces for friction and wear tests on typical moving parts of aircraft tail nozzles, and conducting pin-disc tests based on Rtec multifunctional testing machines. After the tests, friction and wear analysis will be carried out. Module M3: Conducting friction and wear tests on typical moving parts of aviation tail nozzles at the sample level, including calculating the equivalent working conditions of the sample level test, carrying out experimental design, preparing the actual equipment of the typical moving parts of aviation tail nozzles, carrying out sample level tests based on the friction and wear test system of the typical moving parts of aviation tail nozzles under simulated working conditions, measuring the vibration and strain data of the test parts online during the test, measuring the surface wear morphology in situ, and carrying out offline wear measurement and analysis after the test; Module M4: Conduct friction and wear life prediction modeling for typical moving parts of aviation tail nozzles, including establishing moving part wear life evaluation indicators, exploring the factors affecting the wear life of typical moving parts through correlation analysis, and establishing a sample wear life prediction model suitable for heavy-load and high-temperature conditions based on neural network and machine learning algorithms.

7. The high temperature and heavy load condition aviation tail nozzle typical kinematic pair friction and wear test system according to claim 6 is characterized in that: In module M1, the kinematic simulation model of the tail nozzle motion adjustment mechanism includes a cam, a roller, an adjustment plate, a tripod and a tail pipe outer ring. The motion adjustment mechanism includes three types of typical motion pairs, including a cam pair between the cam and the roller, a ball pair between the cam and the adjustment plate, and a pin pair between the tripod and the tail pipe outer ring. Studying the loading mode and relative motion characteristics of typical kinematic pairs requires quantitative analysis of the working conditions of typical kinematic pairs of aviation tail nozzles and tribological decoupling analysis of the motion adjustment mechanism of aviation tail nozzles. The working conditions of typical motion pairs of aviation tail nozzles are quantitatively analyzed, including the following modules: Module M11: The gas pressure on the regulating plate of the aviation tail nozzle motion regulating mechanism is converted into the force it receives. The regulating plate is divided into multiple micro-elements, and the force on each micro-element is calculated. The force is perpendicular to the regulating plate. The force calculation formula is as follows: Module M12: Calculate the sum of the force on the regulating plate of the aviation tail nozzle motion regulating mechanism, which is expressed as the integral sum of the regulating plate area. The calculation formula of the resultant force is: F 合 (S)=∫APdS Where ΔS / dS is the area of ​​each microelement; F is the force on each microelement, F 合 is the resultant force on the regulating plate of the aviation tail nozzle movement regulating mechanism; ΔP is the pressure on each unit; Module M13: The pressure P on the regulating plate of the aviation tail nozzle motion regulating mechanism is simplified to be equally distributed along the Y axis considering the symmetric characteristics, and the fitting formula along the X axis is established as: P=Y*(aX 6 +bX 5 +cX 4 +dX 3 +eX 2 +fX+g) Among them, a, b, c, d, e, f, g are fitting parameters, Y is the horizontal size of the adjustment piece, and X is the vertical distance from the left end of the adjustment piece; Module M14: Simulate and calculate the working temperature of the typical kinematic pair of the aviation tail nozzle motion regulating mechanism. According to the measured ambient temperature of the aviation tail nozzle when it is working, the actual working temperature of the typical kinematic pair of the aviation tail nozzle motion regulating mechanism is obtained through simulation calculation. The heat generated by friction is fitted and calculated using the following formula: Q=μF N Yes Where Q is the heat generated by friction; μ is the friction coefficient; F N is the normal pressure perpendicular to the surface of the object; S is the actual contact area between the two surfaces of the object; e is the effective energy conversion rate between the surfaces; Then, the temperature rise of the typical motion pair of the aviation tail nozzle motion adjustment mechanism is calculated based on the heat generated by friction. The formula is: Among them, Q is the heat generated by friction; m is the mass of the kinematic pair; and c is the specific heat capacity of the kinematic pair matrix material.

8. The high temperature and heavy load condition aviation tail nozzle typical kinematic pair friction and wear test system according to claim 6, characterized in that: The module M2 comprises: Module M21: Calculate the equivalent working conditions of the material level test. According to the deconstruction results of the tribological system of the typical kinematic pair of the aviation tail nozzle in module M1, determine the load form, motion trajectory, actual working temperature and contact form of the typical kinematic pair. Take the force F when the force amplitude of the typical kinematic pair is the largest in a motion trajectory. max 、Position (X, Y, Z) max and the actual operating temperature T actual _ max As the input condition for stress distribution simulation modeling, static simulation is carried out, and the average pressure of the contact area is calculated based on the VonMises stress result under the setting of Avg:75% as the equivalent contact pressure σ of the pin-disc test. equivalent , based on the Hertz contact theory, the equivalent load F applied to the pin in the material level test is calculated equivalent , calculate the equivalent rotation speed of the test plate in the material grade test rpm eauivalent Make the relative linear velocity of the pin-disk equal to the average velocity of a typical kinematic pair in a motion trajectory, and the motion loading time t in the material level test eauivalent Keep the same as the sample level test time, the test temperature T in the material level test equivalent The actual working temperature T when the force amplitude of a typical kinematic pair in a motion trajectory is the maximum actual_max Consistency; Module M22: Conduct experimental design, based on central composite design, set equivalent load F according to actual working condition simulation requirements equivalent and test temperature T equivalent Two factors, the response surface analysis method of 2 factors and 5 levels was used to generate the experimental plan, -α is the test equivalent load of the tail nozzle under the cruise working state, α is the test equivalent load of the tail nozzle under the full afterburner working state, -β is the test temperature of the tail nozzle under the cruise working state, β is the test temperature of the tail nozzle under the full afterburner working state, considering the influence of random errors in operation, four tests were carried out on the central point working condition, and two tests were carried out on each of the other working conditions to determine the deviation caused by other irrelevant factors in the test system, and at the same time, the order of the working conditions was disrupted and all tests were randomly carried out, and the average value of the test data under the same working condition was taken; Module M23: Processing and preparation of pin-disc test pieces for material level testing. According to the analysis of the kinematic pair contact form in the deconstruction results of the tribological system of the typical kinematic pair of the aviation tail nozzle in module M1, it is divided into point contact, line contact and surface contact. The hemispherical surface, arc surface and plane surface are processed in turn. The base material of the pin and the disk is the typical kinematic pair base material, and the contact surface has the same coating; Module M24: Carry out material level pin-disc test. First, set the test accuracy index, adjust the reset of each execution module, and set the test parameters. The test parameters include: test disk rotation speed rpm eauivalent 、Motor load F equivalent , planned loading time t equivalent and test environment temperature T equivalent ; Then the test is carried out according to the setting. The time is judged during the test. If the set test time is reached, the loading motor and pin sample are lifted, and the other components are reset. At the same time, wear information identification and wear amount offline measurement are carried out; finally, the test is evaluated. If it meets the expected test, the test ends, otherwise the test is reset and re-tested; Module M25: After the test, friction and wear analysis is carried out, including friction analysis and wear analysis, and wear surface morphology characterization analysis is carried out, the surface roughness of the wear scar is measured, the surface morphology is measured based on white light interferometry to extract periodic features, and the EDS energy spectrum analysis of the adhesive wear debris particles is performed using a scanning electron microscope; For friction analysis, the time-varying characteristics of the friction coefficient COF are analyzed, and the average value of the friction coefficient after stabilization is taken to qualitatively analyze the influence of temperature, load and speed on the average friction coefficient. Considering the Stribeck effect, an average friction coefficient prediction model with speed and temperature as prediction variables is established: COF=c1+c2rpm+c3T Wherein, c1, c2, c3 are fitting coefficients; T is temperature; rpm is speed; For wear analysis, the test pin and test plate were weighed again, the wear amount was calculated, the friction coefficient distribution, load distribution, temperature distribution and speed distribution curves of the test process were derived, the wear coefficient K was solved using the Archard wear model, and a wear coefficient fitting model that integrates temperature, load and speed factors was established: Among them, d1, d2, d3, d4, d5, d6, and d7 are fitting coefficients; T is temperature; F is load; and rpm is speed.

9. The high temperature and heavy load condition aviation tail nozzle typical kinematic pair friction and wear test system according to claim 8, characterized in that: The module M3 comprises: Module M31: Calculate the equivalent working conditions of the sample-level test. According to the deconstruction results of the tribological system of the typical kinematic pair of the aviation tail nozzle in module M1, determine the load form, motion trajectory, actual working temperature and contact form of the typical kinematic pair. Based on the sample-level friction and wear test device, directly set the test conditions equivalent to the actual working conditions, including the force position of the kinematic pair, the force magnitude, the change law of the direction with the movement, the kinematic pair movement form and the ambient temperature of the kinematic pair; Module M32: Conduct experimental design, using the same central combination design as module M22, and set the actual load F actual and the actual temperature T actual Two factors, the response surface analysis method of 2 factors and 5 levels was used to generate the experimental plan, -α is the actual load of the tail nozzle in the cruise working state, α is the actual load of the tail nozzle in the full afterburner working state, -β is the actual temperature of the tail nozzle in the cruise working state, β is the actual temperature of the tail nozzle in the full afterburner working state, considering the influence of random errors in operation, four tests were conducted on the central point working condition, and two tests were conducted on each of the other working conditions to determine the deviation caused by other irrelevant factors in the test system, and at the same time, the order of the working conditions was disrupted and all tests were randomly conducted, and the average value of the test data under the same working condition was taken; Module M33: Prepare the test pieces of typical kinematic pairs of actual equipment aviation tail nozzles, carry out visual identification feature marking on the test pieces of typical kinematic pairs of actual equipment aviation tail nozzles, spray ArUco marks on the surfaces of the test pieces of the rotating pair, ball and socket pair, and cam pair, respectively, so that the visual module of the friction and wear test system of the typical kinematic pairs of aviation tail nozzles can track the target during the test, and randomly carve scratches of varying depths on the contour of the test piece to distinguish the test piece with the same metallic luster from the background, so that the friction and wear test system of the typical kinematic pairs of aviation tail nozzles can recognize the contour features during the test; Module M34: Carry out sample-level tests. Sample-level tests are carried out based on the friction and wear test system for simulating working conditions of typical kinematic pairs of aviation tail nozzles. First, the test accuracy index is set, each execution module is reset, and the test parameters are set at the same time. The test parameters include: displacement-load relationship, data acquisition frequency, ambient heating temperature, and planned loading time; then, heating is carried out in the temperature-controlled box according to the settings to reach the preset ambient temperature, and then the test is started according to the settings. During the test, the strain of the test piece is measured online based on the built-in high-resolution and high-frame-rate visual module of the test system, and the online vibration characteristic measurement of the motion process of the typical kinematic pair is carried out based on the motion amplification algorithm. At the same time, according to the experimental settings, the sample is moved to the preset measurement optical path position at specific intervals, and the wear surface morphology of the kinematic pair is measured in situ based on vision. After the test, further offline measurement and analysis of the kinematic pair is carried out; when the preset test time is completed, the test is evaluated. If it meets the expected test, it ends, otherwise the reset is performed and the test is repeated; Module M35: Offline wear analysis after the test, including: Use a large-range analytical balance to measure the mass of the sample before and after the test, and calculate the wear amount and wear rate; The surface roughness change of the wear scar of the sample before and after the test was measured by a contact roughness meter and a metal Rockwell hardness tester; The surface hardness HRC of the wear scar of the sample before and after the test is measured by a metal Rockwell hardness tester; The surface morphology was measured by white light interferometry and optical microscopy, and the arithmetic mean height R of the surface roughness was extracted. a , skewness S sk and the root mean square deviation S q feature; Observe the shape of wear debris through scanning electron microscope and analyze the wear failure form; The element distribution and content wt% of the worn surface and profile were analyzed by Raman spectrometer and X-ray energy spectrometer; The above measurements all comply with the measurement specifications of taking the average of three measurements and selecting test sites evenly on the surface to be tested; The load distribution, temperature distribution and velocity distribution curves of the test process are derived, and the wear coefficient K is solved using the Archard wear model. actual , establish a wear coefficient fitting model that integrates temperature, load and speed factors: Among them, e1, e2, e3, e4, e5, e6, and e7 are fitting coefficients, T is temperature, F is load, and v is velocity.

10. The high temperature and heavy load condition aviation tail nozzle typical kinematic pair friction and wear testing system according to claim 6, characterized in that: The module M4 comprises: Module M41: Establish the wear life evaluation index of the kinematic pair. Based on the kinematic simulation analysis results of the tail nozzle motion adjustment mechanism in module M1, determine that the wear failure criteria that affect the adjustment accuracy, adjustment resistance and motion synchronization of the motion adjustment mechanism are the failure friction coefficient and the failure wear coefficient. Based on the friction and wear measurement results of the material-level friction and wear test of module M2 and the wear measurement results of the sample-level friction and wear test of module M3, determine that the wear failure form is characterized by the surface hardness at failure, the surface element distribution at failure and the wear mark morphology at failure. Module M42: Explore the factors that affect the wear life of typical kinematic pairs through correlation analysis, and analyze the correlation between the test condition quantity and the test result quantity based on the Pearson correlation coefficient, where the test condition quantity includes the number of cycles N under full force working state full , Number of cycles N under cruise working state cruise , temperature T, load F and speed v, the test results include friction coefficient COF, wear rate δ, surface roughness arithmetic mean height R a , average root mean square deviation S q , surface roughness average skewness S sk , wear surface, element distribution and content wt% of the cross section and surface hardness HRC of the wear scar, and the number of cycles N under full force working state full , Number of cycles N under cruise working state cruise Principal component analysis to identify key influencing factors; Module M43: Establish a wear life prediction model for samples suitable for heavy-load and high-temperature working conditions. Based on the principal component analysis results of module M42, the machine learning algorithms kernel ridge regression KRR, support vector regression SVR and extreme gradient boosting decision tree XGBoost are used to construct the principal component analysis results and the number of cycles N under full-load working conditions. full , Number of cycles N under cruise working state cruise The relationship model between them.

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