Aircraft structure fatigue single-machine tracking analysis method and system

Abstract

The invention belongs to the field of structural health monitoring, and particularly relates to an aircraft structural fatigue single-machine tracking analysis method and system, and the method comprises the steps: taking flight parameter preprocessing data as the input of single-machine tracking data, and building a whole-aircraft finite element model; obtaining a stress / strain result of the structural fatigue key area according to a full-aircraft finite element model; according to the stress / strain result of the structural fatigue key area, crack initiation life prediction / crack propagation life prediction is carried out by adopting a corresponding life calculation method, and a life prediction result of each structural fatigue key part is obtained; and combining the life prediction result of the structural fatigue key part with the weight evaluation under actual use condition statistics, and determining damage and life management parameters. By establishing the relationship between flight parameter-load and load-stress, single-machine tracking analysis can be carried out on the fatigue part of the aircraft structure more dynamically and flexibly.

Description

Technical Field

[0001] The present application belongs to the field of structural health monitoring, and in particular, relates to a single-machine tracking and analysis method and system for aircraft structural fatigue. Background Art

[0002] The current single-aircraft tracking design is specifically a single-target tracking flight in a multi-aircraft formation detection mission. It conducts analysis and research in the areas of drone swarm formation construction, trajectory planning and control, and collaborative positioning and tracking, but has not conducted single-aircraft tracking research in the field of structural health monitoring.

[0003] At present, when predicting the fatigue life of aircraft, a single model is generally designed for prediction, and there is a lack of diversity in model selection. Secondly, the original data are basically obtained by combining static tests with fatigue tests.

[0004] Therefore, how to conduct more flexible single-aircraft tracking based on aircraft structural fatigue is a problem that needs to be solved. Summary of the invention

[0005] The purpose of this application is to provide a single-machine tracking and analysis method and system for aircraft structure fatigue, so as to solve the problem that the existing aircraft fatigue life prediction is relatively single.

[0006] The technical solution of the present application is: a single-machine tracking analysis method for aircraft structure fatigue, comprising:

[0007] Based on the existing service data, durability test data and stress analysis data, the key areas where aircraft structural fatigue occurs are identified, and appropriate control points are selected in the key areas of structural fatigue. Sensors are set at the control points, and the sensor data at the control points are collected and recorded regularly. The sensor data is combined with load-related parameters to obtain flight parameter preprocessing data.

[0008] The flight parameter pre-processing data is used as the input of the single-aircraft tracking data, and the load and stress on the aircraft are used as the output. The appropriate data processing method is selected to establish the finite element model of the whole aircraft. Based on the finite element model of the whole aircraft, the conversion equations of "flight parameter-load" and "load-stress" are constructed, and then the stress / strain results of the key areas of structural fatigue are obtained through the conversion equations of "flight parameter-load" and "load-stress".

[0009] According to the stress / strain results in the key fatigue areas of the structure, the corresponding life calculation method is used to carry out crack initiation life prediction / crack propagation life prediction, and the life prediction results of each key fatigue part of the structure are obtained;

[0010] Combine the life prediction results of key parts of structural fatigue with the severity evaluation under actual usage statistics to determine the damage and life management parameters. Use the damage and life management parameters to analyze and evaluate the aircraft structure life and provide users with usage and maintenance recommendations.

[0011] Preferably, the load related parameters include a load factor and a load coefficient.

[0012] Preferably, the method for identifying critical areas of structural fatigue is: statistically analyzing the locations of components where structural fatigue occurs in existing service data, durability test data, and stress analysis data, and sorting them according to the number of occurrences of structural fatigue, and selecting a certain number of component locations with the largest number of structural fatigue occurrences as critical areas of structural fatigue.

[0013] Preferably, the sensor includes a load sensor and a stress strain sensor.

[0014] Preferably, the data processing methods include: principal component analysis, multivariate linear regression and neural network.

[0015] Preferably, the life calculation method includes a stress-life curve calculation method and a strain-life curve calculation method.

[0016] Preferably, the analysis and evaluation of the aircraft structure life is specifically as follows: evaluating whether the conditions of the design service life have changed; if there are changes, performing differentiated life analysis and evaluation on the fleet aircraft according to the changes, optimizing the allocation of training tasks for the fleet aircraft, and revising the structural integrity control plan for the in-service fleet.

[0017] As a specific implementation, a single-machine tracking and analysis system for aircraft structure fatigue includes a tracking location determination module, a conversion equation construction module, a damage life prediction module, and a mission difference prediction module;

[0018] The tracking location determination module can identify the critical areas where structural fatigue occurs in the aircraft based on the existing service data, durability test data and stress analysis data, select appropriate control points in the critical areas of structural fatigue, set sensors at the control points, regularly collect and record sensor data at the control points, and combine the sensor data with load-related parameters to obtain flight parameter preprocessing data;

[0019] The conversion equation construction module can use the flight parameter pre-processing data as the input of the single-aircraft tracking data, and the load and stress on the aircraft as the output, select the appropriate data processing method, and establish the finite element model of the whole aircraft; based on the finite element model of the whole aircraft, the "flight parameter-load" and "load-stress" conversion equations are constructed, and then the stress / strain results of the key areas of structural fatigue are obtained through the "flight parameter-load" and "load-stress" conversion equations;

[0020] The damage life prediction module can carry out crack initiation life prediction / crack propagation life prediction based on the stress / strain results in the key fatigue areas of the structure and adopt the corresponding life calculation method to obtain the life prediction results of each key fatigue part of the structure;

[0021] The mission difference prediction module can combine the life prediction results of key parts of structural fatigue with the severity evaluation under actual usage statistics, determine the damage and life management parameters, analyze and evaluate the aircraft structure life through the damage and life management parameters, and provide users with usage and maintenance recommendations.

[0022] Preferably, the load related parameters include a load factor and a load coefficient.

[0023] Preferably, the method for identifying critical areas of structural fatigue is: statistically analyzing the locations of components where structural fatigue occurs in existing service data, durability test data, and stress analysis data, and sorting them according to the number of occurrences of structural fatigue, and selecting a certain number of component locations with the largest number of structural fatigue occurrences as critical areas of structural fatigue.

[0024] Preferably, the sensor includes a load sensor and a stress strain sensor.

[0025] Preferably, the data processing methods include: principal component analysis, multivariate linear regression and neural network.

[0026] Preferably, the life calculation method includes a stress-life curve calculation method and a strain-life curve calculation method.

[0027] Preferably, the analysis and evaluation of the aircraft structure life is specifically as follows: evaluating whether the conditions of the design service life have changed; if there are changes, performing differentiated life analysis and evaluation on the fleet aircraft according to the changes, optimizing the allocation of training tasks for the fleet aircraft, and revising the structural integrity control plan for the in-service fleet.

[0028] The aircraft structural fatigue single-machine tracking analysis method and system of the present application adopts a combination of qualitative and quantitative methods to carry out predictions on usage mission differences. When the aircraft's training and use intensity is lower than the design usage, the maintenance interval can be extended; when the aircraft's training and use conditions are more serious than the design conditions, the risk can be reduced through single-machine tracking. By establishing the relationship between flight parameters-load and "load-stress", single-machine tracking and analysis of aircraft structural fatigue parts can be performed more dynamically and flexibly. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solution provided by the present application, the following is a brief introduction to the accompanying drawings. Obviously, the accompanying drawings described below are only some embodiments of the present application.

[0030] Figure 1 This is a schematic diagram of the overall process of this application;

[0031] Figure 2 Schematic diagram of the potential benefits of single-machine tracking of aircraft structural fatigue for this application. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] A single-machine tracking analysis method for aircraft structure fatigue, such as Figure 1 , including the following steps:

[0034] Step S100, tracking part selection and parameter determination:

[0035] Based on the existing service data, durability test data and stress analysis data, the key areas of aircraft structural fatigue are identified, and appropriate control points are selected in the key areas of structural fatigue. Sensors are set at the control points, and the sensor data at the control points are regularly collected and recorded. The sensor data is combined with load-related parameters to obtain flight parameter preprocessing data. Load-related parameters include load factors and load coefficients.

[0036] Preferably, the method for identifying critical areas of structural fatigue is: statistically analyzing the locations of components where structural fatigue occurs in existing service data, durability test data, and stress analysis data, and sorting them according to the number of occurrences of structural fatigue, and selecting a certain number of component locations with the largest number of structural fatigue occurrences as critical areas of structural fatigue.

[0037] Preferably, the sensor includes a load sensor, a stress strain sensor, and the like.

[0038] By analyzing and comparing the characteristics of fatigue single-machine tracking parameters of various types of aircraft, we summarize and establish the selection method of fatigue single-machine tracking parameters, and combined with the improvement of fatigue single-machine tracking technology such as sensor technology, we give a qualitative analysis of the range of parameter selection and clarify the trend of the industry.

[0039] Step S200, constructing load / stress conversion equation:

[0040] The flight parameter preprocessing data is used as the input of single-aircraft tracking data, and the loads and stresses on the aircraft are used as output. An appropriate data processing method is selected to establish a finite element model of the entire aircraft. The data processing methods include principal component analysis, multivariate linear regression, neural network and other methods. Based on the finite element model of the entire aircraft, the "flight parameter-load" and "load-stress" conversion equations are constructed, and then the stress / strain results of the key areas of structural fatigue are obtained through the "flight parameter-load" and "load-stress" conversion equations.

[0041] Guided by the construction methods of "flight parameters-load" and "load-stress", a load prediction process for aircraft structure is summarized and proposed, so that during the use of the aircraft, the relationship between a certain aircraft state parameter combination and the load / stress of key parts can be quickly obtained, which plays a key role in the fatigue single-machine tracking of aircraft damage accumulation, life consumption, etc.

[0042] The relationship between input parameters and load and strain is obtained through multivariate linear regression or neural network, and damage and life prediction results based on measured data are given. Compared with traditional engineering calculation methods, it has stronger dynamics, flexibility and higher accuracy.

[0043] Step S300, using damage analysis and life prediction:

[0044] According to the stress / strain results in the key areas of structural fatigue, the corresponding life calculation method is used to carry out crack initiation life prediction / crack propagation life prediction, and the life prediction results of each key part of structural fatigue are obtained.

[0045] Preferably, the life calculation method includes a stress-life curve calculation method, a strain-life curve calculation method, etc. The stress-life curve calculation method and the strain-life curve calculation method are both existing methods and will not be described in detail.

[0046] Step S400, using task difference prediction:

[0047] Combine the life prediction results of key parts of structural fatigue with the severity evaluation under actual usage statistics to determine the damage and life management parameters. Use the damage and life management parameters to analyze and evaluate the aircraft structure life and provide users with usage and maintenance recommendations.

[0048] Preferably, the analysis and evaluation of the aircraft structure life is specifically as follows: evaluating whether the conditions (mission composition) of the design service life have changed; if there are changes, performing differentiated life analysis and evaluation on the fleet aircraft according to the changes, optimizing the allocation of training tasks for the fleet aircraft, and revising the structural integrity control plan for the in-service fleet.

[0049] The advantages of fatigue single-machine tracking are that it can extend the maintenance interval of key fatigue parts and reduce risks: when the aircraft's training and use intensity is lower than the design use condition, the maintenance interval can be extended; when the aircraft's training and use condition is more serious than the design condition, the risk can be reduced through single-machine tracking, such as Figure 2 .

[0050] In summary, this application uses a combination of qualitative and quantitative methods to carry out mission difference prediction. When the aircraft's training and use intensity is lower than the design usage, the maintenance interval can be extended; when the aircraft's training and use is more serious than the design, the risk can be reduced through single-machine tracking. By establishing the relationship between flight parameters-load and "load-stress", single-machine tracking analysis of aircraft structural fatigue parts can be performed more dynamically and flexibly.

[0051] As a specific implementation, it also includes a single-machine tracking and analysis system for aircraft structure fatigue, which specifically includes a tracking location determination module, a conversion equation construction module, a damage life prediction module and a mission difference prediction module.

[0052] The tracking location determination module can identify the critical areas where structural fatigue occurs in the aircraft based on the existing service data, durability test data and stress analysis data, select appropriate control points in the critical areas of structural fatigue, set sensors at the control points, regularly collect and record sensor data at the control points, and combine the sensor data with load-related parameters to obtain flight parameter preprocessing data;

[0053] The conversion equation construction module can use the flight parameter pre-processing data as the input of the single-aircraft tracking data, and the load and stress on the aircraft as the output, select the appropriate data processing method, and establish the finite element model of the whole aircraft; based on the finite element model of the whole aircraft, the "flight parameter-load" and "load-stress" conversion equations are constructed, and then the stress / strain results of the key areas of structural fatigue are obtained through the "flight parameter-load" and "load-stress" conversion equations;

[0054] The damage life prediction module can carry out crack initiation life prediction / crack propagation life prediction based on the stress / strain results in the key fatigue areas of the structure and adopt the corresponding life calculation method to obtain the life prediction results of each key fatigue part of the structure;

[0055] The mission difference prediction module can combine the life prediction results of key parts of structural fatigue with the severity evaluation under actual usage statistics, determine the damage and life management parameters, analyze and evaluate the aircraft structure life through the damage and life management parameters, and provide users with usage and maintenance recommendations.

[0056] Preferably, the load related parameters include a load factor and a load coefficient.

[0057] Preferably, the method for identifying critical areas of structural fatigue is: statistically analyzing the locations of components where structural fatigue occurs in existing service data, durability test data, and stress analysis data, and sorting them according to the number of occurrences of structural fatigue, and selecting a certain number of component locations with the largest number of structural fatigue occurrences as critical areas of structural fatigue.

[0058] Preferably, the sensor includes a load sensor and a stress strain sensor.

[0059] Preferably, the data processing methods include: principal component analysis, multivariate linear regression and neural network.

[0060] Preferably, the life calculation method includes a stress-life curve calculation method and a strain-life curve calculation method.

[0061] Preferably, the analysis and evaluation of the aircraft structure life is specifically as follows: evaluating whether the conditions of the design service life have changed; if there are changes, performing differentiated life analysis and evaluation on the fleet aircraft according to the changes, optimizing the allocation of training tasks for the fleet aircraft, and revising the structural integrity control plan for the in-service fleet.

[0062] Finally, it should be noted that: the drawings of the embodiments disclosed in the present invention only involve structures related to the embodiments disclosed in the present invention, and other structures can refer to the general design. In the absence of conflict, the same embodiment and different embodiments of the present invention can be combined with each other;

[0063] Finally: The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A single-machine tracking analysis method for aircraft structure fatigue, characterized in that: include: Based on the existing service data, durability test data and stress analysis data, the key areas where aircraft structural fatigue occurs are identified, and appropriate control points are selected in the key areas of structural fatigue. Sensors are set at the control points, and the sensor data at the control points are collected and recorded regularly. The sensor data is combined with load-related parameters to obtain flight parameter preprocessing data. The flight parameter pre-processing data is used as the input of the single-aircraft tracking data, and the load and stress on the aircraft are used as the output. The appropriate data processing method is selected to establish the finite element model of the whole aircraft. Based on the finite element model of the whole aircraft, the conversion equations of "flight parameter-load" and "load-stress" are constructed, and then the stress / strain results of the key areas of structural fatigue are obtained through the conversion equations of "flight parameter-load" and "load-stress". According to the stress / strain results in the key fatigue areas of the structure, the corresponding life calculation method is used to carry out crack initiation life prediction / crack propagation life prediction, and the life prediction results of each key fatigue part of the structure are obtained; Combine the life prediction results of key parts of structural fatigue with the severity evaluation under actual usage statistics to determine the damage and life management parameters. Use the damage and life management parameters to analyze and evaluate the aircraft structure life and provide users with usage and maintenance recommendations.

2. The single-machine tracking analysis method for aircraft structure fatigue according to claim 1, characterized in that: Load-related parameters include load factor and load coefficient.

3. The single-machine tracking analysis method for aircraft structure fatigue according to claim 1, characterized in that: The method for identifying critical areas of structural fatigue is to conduct statistical analysis on the locations of components where structural fatigue occurs in the existing service data, durability test data, and stress analysis data, and sort them according to the number of occurrences of structural fatigue, and select a certain number of component locations with the largest number of structural fatigue occurrences as critical areas of structural fatigue.

4. The single-machine tracking analysis method for aircraft structure fatigue according to claim 1, characterized in that: Sensors include load sensors and stress strain sensors.

5. The single-machine tracking analysis method for aircraft structure fatigue according to claim 1, characterized in that: Data processing methods include: principal component analysis, multiple linear regression and neural network.

6. The single-machine tracking analysis method for aircraft structure fatigue according to claim 1, characterized in that: The life calculation methods include stress-life curve calculation method and strain-life curve calculation method.

7. The single-machine tracking analysis method for aircraft structure fatigue according to claim 1, characterized in that: The specific analysis and evaluation of the aircraft structure life is as follows: evaluating whether there are any changes in the conditions of the design service life. If there are changes, conducting differentiated life analysis and evaluation of the fleet aircraft based on the changes, optimizing the allocation of fleet aircraft training tasks, and revising the structural integrity control plan of the in-service fleet.

8. A single-machine tracking and analysis system for aircraft structure fatigue, using the method described in any one of claims 1 to 7, characterized in that: It includes tracking part determination module, conversion equation construction module, damage life prediction module and task difference prediction module; The tracking location determination module can identify the critical areas where structural fatigue occurs in the aircraft based on the existing service data, durability test data and stress analysis data, select appropriate control points in the critical areas of structural fatigue, set sensors at the control points, regularly collect and record sensor data at the control points, and combine the sensor data with load-related parameters to obtain flight parameter preprocessing data; The conversion equation construction module can use the flight parameter pre-processing data as the input of the single-aircraft tracking data, and the load and stress on the aircraft as the output, select the appropriate data processing method, and establish the finite element model of the whole aircraft; based on the finite element model of the whole aircraft, the "flight parameter-load" and "load-stress" conversion equations are constructed, and then the stress / strain results of the key areas of structural fatigue are obtained through the "flight parameter-load" and "load-stress" conversion equations; The damage life prediction module can carry out crack initiation life prediction / crack propagation life prediction based on the stress / strain results in the key fatigue areas of the structure and adopt the corresponding life calculation method to obtain the life prediction results of each key fatigue part of the structure; The mission difference prediction module can combine the life prediction results of key parts of structural fatigue with the severity evaluation under actual usage statistics, determine the damage and life management parameters, analyze and evaluate the aircraft structure life through the damage and life management parameters, and provide users with usage and maintenance recommendations.

9. The aircraft structure fatigue single-machine tracking and analysis system according to claim 8, characterized in that: Load-related parameters include load factor and load coefficient.

10. The aircraft structure fatigue single-machine tracking and analysis system according to claim 8, characterized in that: The method for identifying critical areas of structural fatigue is to conduct statistical analysis on the locations of components where structural fatigue occurs in the existing service data, durability test data, and stress analysis data, and sort them according to the number of occurrences of structural fatigue, and select a certain number of component locations with the largest number of structural fatigue occurrences as critical areas of structural fatigue.

11. The aircraft structure fatigue single-machine tracking and analysis system according to claim 8, characterized in that: Sensors include load sensors and stress strain sensors.

12. The aircraft structure fatigue single-machine tracking and analysis system according to claim 8, characterized in that: Data processing methods include: principal component analysis, multiple linear regression and neural network.

13. The aircraft structure fatigue single-machine tracking and analysis system according to claim 8, characterized in that: The life calculation methods include stress-life curve calculation method and strain-life curve calculation method.

14. The aircraft structure fatigue single-machine tracking and analysis system according to claim 8, characterized in that: The specific analysis and evaluation of the aircraft structure life is as follows: evaluating whether there are any changes in the conditions of the design service life. If there are changes, conducting differentiated life analysis and evaluation of the fleet aircraft based on the changes, optimizing the allocation of fleet aircraft training tasks, and revising the structural integrity control plan of the in-service fleet.

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