Part life assessment method and system based on transient load, electronic equipment, and storage medium

Abstract

The present invention discloses a part life assessment method and system based on transient loads, an electronic device, and a storage medium. The method first determines a reference cycle and performs transient stress analysis under the reference cycle history, determines a life assessment condition according to the transient stress analysis result, takes into account transient temperature and pressure loads borne by parts at different times in typical tasks of actual use of aviation gas turbine engines, can accurately reflect the stress distribution caused by thermal load and temperature gradient changes during the working process, obtains a complete temperature and stress history curve, can accurately screen out the maximum low-cycle fatigue damage as the life assessment condition, and then performs a three-dimensional finite element stress analysis according to the transient load corresponding to the life assessment condition, can more accurately obtain the stress and temperature of key parts, and finally solves the low-cycle fatigue life of the parts according to the stress and temperature of the key parts in combination with fatigue performance data, thereby greatly improving the accuracy of low-cycle fatigue life assessment.

Description

Technical Field

[0001] The present invention relates to the technical field of low cycle fatigue life assessment, and in particular, to a method and system for assessing the life of a component based on transient loads, an electronic device, and a computer-readable storage medium. Background Art

[0002] Low cycle fatigue is one of the main reasons for the failure of parts such as the wheel and casing of civil aviation gas turbine engines, and it is also the bottleneck that restricts the life and safety of civil aviation gas turbine engines. The existing life assessment method for aviation gas turbine engine parts generally selects working conditions with high working loads, such as hot weather takeoff, and uses finite element technology to obtain the stress σ of key parts of parts under various loads, and then combines the working temperature T of key parts to perform life assessment based on the fatigue performance data of parts. Specifically, first, according to the structure and load characteristics of the parts, the working conditions for life assessment are determined, which are generally high load conditions such as hot weather takeoff that are often used by the engine; then, according to the load of the parts under the life assessment conditions, such as speed, aerodynamic force, cavity pressure and temperature distribution, a three-dimensional finite element stress analysis is performed to obtain the stress σ and temperature T of key parts such as wheel center, mortise and tenon, eccentric hole and chamfer; finally, according to the stress σ and temperature T of the key parts of the parts, combined with fatigue performance data such as the stress life curve equation of the parts, the low cycle fatigue life Nf under the "0~σ~0" stress cycle is obtained.

[0003] Since the existing method of evaluating the life of parts is to conduct three-dimensional finite element stress analysis based on the steady-state load under typical working conditions, and then carry out life evaluation, it is believed that the loads such as speed and temperature of the parts under typical working conditions are in a stable and unchanged state. For thin-walled parts whose temperature distribution can quickly reach a stable equilibrium, the maximum stress can be obtained more accurately for life evaluation. However, in the actual operation of the engine, from one working condition to another, the response time and change rate of different types of loads borne by most parts such as the wheel often vary greatly, and even the temperature response time and change rate of different parts are inconsistent. This results in the temperature of some parts not yet reaching equilibrium at an instant, and the parts will be in a state of "hot outside and cold inside" or "cold outside and hot inside", and even cause a significant change in the contact state of adjacent parts. If stress analysis is performed based on the steady-state load under typical working conditions, especially the steady-state temperature distribution, the stress analysis results may be low, which in turn leads to poor accuracy of life evaluation. In addition, patent CN115563818A discloses a method for designing the fatigue life of a wheel considering the influence of transient temperature history. It introduces the influence of transient history when analyzing the standard cycle "0-design condition-0", selects the temperature and stress corresponding to the smaller of the steady-state condition life and the transient fatigue life as the design result of the wheel fatigue life in the engine state, and then uses the temperature and stress as the design basis to formulate a test plan with uniform temperature or gradient temperature field. However, this patent solution only considers one standard cycle of "0-design condition-0", and does not consider the reference cycle that can cover the expected use range of the engine. It is difficult to accurately evaluate the low-cycle fatigue life of components in the entire reference cycle. Moreover, when calculating the stress spectrum, it converts the transient stress spectrum to the same temperature and then performs life analysis, which will lead to low stress analysis results, and then lead to poor accuracy of life assessment. Summary of the invention

[0004] The present invention provides a part life assessment method and system based on transient loads, an electronic device, and a computer-readable storage medium, which can accurately screen out the maximum low-cycle fatigue damage as a life assessment condition, so that the stress and temperature of key parts can be obtained more accurately, thereby greatly improving the accuracy of low-cycle fatigue life assessment and ensuring safety.

[0005] According to one aspect of the present invention, a method for evaluating the life of a component based on transient load is provided, comprising the following contents:

[0006] Determine the reference cycle and perform transient stress analysis under the reference cycle history. Determine the life assessment conditions based on the transient stress analysis results. The reference cycle includes starting conditions, slow-running conditions, take-off conditions, cruising conditions, and parking conditions.

[0007] Perform three-dimensional finite element stress analysis based on the transient loads corresponding to the life assessment conditions to obtain the stress and temperature of key parts;

[0008] The low cycle fatigue life of parts is obtained by solving the stress and temperature of key parts in combination with fatigue performance data.

[0009] Furthermore, the process of determining the reference cycle and performing transient stress analysis under the reference cycle history, and determining the life assessment working condition according to the transient stress analysis result includes the following contents:

[0010] Determine the reference cycle based on the typical mission of the engine;

[0011] The speed and pneumatic pressure at the transient time point are obtained by linear interpolation based on the speed and pneumatic pressure at different steady-state conditions in the reference cycle, thereby obtaining the speed and pneumatic pressure at each transient time point in the reference cycle history;

[0012] Define the transient heat transfer boundary function and perform transient heat transfer analysis to obtain the temperature distribution load of the parts at each transient time point in the reference cycle history;

[0013] According to the speed, aerodynamic pressure and temperature distribution load at each transient time point in the reference cycle history, the load boundary conditions are positioned to form an analysis load step, and a two-dimensional finite element transient stress analysis is performed under the reference cycle history to obtain the stress and temperature of the key parts at each transient time point in the reference cycle history;

[0014] According to the stress and temperature of key parts at each transient time point in the reference cycle history, combined with fatigue performance data, the low cycle fatigue life corresponding to the stress cycle at each time point is obtained;

[0015] The transient moment corresponding to the lowest value of low cycle fatigue life is selected as the life assessment condition.

[0016] Furthermore, the boundary function of the heat convection is linearly interpolated according to the boundary parameters under each steady-state condition to obtain the gas temperature, cold air flow, cold air inlet temperature and heat transfer coefficient at the transient time point.

[0017] Furthermore, during the two-dimensional finite element stress transient analysis, the parts with axisymmetric geometry are simulated using two-dimensional axisymmetric units, and the parts with non-axisymmetric geometry are simulated using plane stress units with thickness.

[0018] Furthermore, the moments corresponding to the minimum life values ​​of each key part at each transient time point in the reference cycle history are screened out as life assessment conditions, and the key parts corresponding to the minimum life values ​​are the low-cycle fatigue damage key parts.

[0019] In addition, the present invention also provides a part life assessment system based on transient loads, comprising:

[0020] A life assessment condition determination module is used to determine a reference cycle and perform transient stress analysis under the reference cycle history, and determine the life assessment condition based on the transient stress analysis results;

[0021] The three-dimensional finite element stress analysis module is used to perform three-dimensional finite element stress analysis based on the transient loads corresponding to the life assessment conditions to obtain the stress and temperature of key parts;

[0022] The low cycle fatigue life calculation module is used to obtain the low cycle fatigue life of parts based on the stress and temperature of key parts combined with fatigue performance data.

[0023] Furthermore, the life assessment working condition determination module includes:

[0024] A reference cycle determination unit, used to determine a reference cycle according to a typical task of the engine, wherein the reference cycle includes a plurality of stable operating conditions;

[0025] A linear interpolation unit is used to obtain the speed and pneumatic pressure at the transient time point by linear interpolation based on the speed and pneumatic pressure of different steady-state working conditions in the reference cycle, so as to obtain the speed and pneumatic pressure at each transient time point in the reference cycle history;

[0026] Transient heat transfer analysis unit, used to define transient heat transfer boundary function and perform transient heat transfer analysis to obtain the temperature distribution load of parts at each transient time point in the reference cycle history;

[0027] The two-dimensional finite element stress analysis unit is used to form an analysis load step according to the load boundary conditions of the speed, aerodynamic pressure and temperature distribution load at each transient time point in the reference cycle history, and to perform a two-dimensional finite element transient stress analysis under the reference cycle history to obtain the stress and temperature of the key parts at each transient time point in the reference cycle history;

[0028] The transient low-cycle fatigue life calculation module is used to obtain the low-cycle fatigue life corresponding to the stress cycle at each time point based on the stress and temperature of the key parts at each transient time point in the reference cycle history, combined with the fatigue performance data;

[0029] The life assessment condition selection unit is used to select the transient moment corresponding to the minimum value of the low cycle fatigue life as the life assessment condition.

[0030] In addition, the present invention also provides an electronic device, including a processor and a memory, wherein the memory stores a computer program, and the processor executes the steps of the above method by calling the computer program stored in the memory.

[0031] In addition, the present invention also provides a computer-readable storage medium for storing a computer program for evaluating the life of a part based on transient loads, wherein the computer program executes the steps of the method described above when running on a computer.

[0032] The present invention has the following beneficial effects:

[0033] The transient load-based component life assessment method of the present invention first determines the reference cycle and performs transient stress analysis under the reference cycle history, and determines the life assessment working condition based on the transient stress analysis result. Since the transient stress analysis under the reference cycle history takes into account the transient temperature and pressure loads borne by the component at different times in the actual use of the typical mission of the aviation gas turbine engine, it can accurately reflect the stress distribution caused by the change of thermal load and temperature gradient during the working process, obtain a complete temperature and stress history curve, and accurately capture the key parts of low-cycle fatigue damage and the maximum low-cycle fatigue damage, so that the maximum low-cycle fatigue damage can be accurately screened out as the life assessment working condition. Then, according to the transient load corresponding to the life assessment working condition, a three-dimensional finite element stress analysis is performed to more accurately obtain the stress and temperature of the key parts. Finally, according to the stress and temperature of the key parts, combined with the fatigue performance data, the low-cycle fatigue life of the component is obtained by solving, which greatly improves the accuracy of low-cycle fatigue life assessment, thereby ensuring safety.

[0034] In addition, the transient load-based component life assessment system of the present invention also has the above advantages.

[0035] In addition to the above-described purposes, features and advantages, the present invention has other purposes, features and advantages. The present invention will be further described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The drawings constituting a part of this application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0037] Figure 1 It is a flow chart of a method for evaluating the life of a part based on transient loads according to a preferred embodiment of the present application;

[0038] Figure 2 yes Figure 1 Schematic diagram of the sub-process of step S1;

[0039] Figure 3 is a schematic diagram of a time variation curve of the rotation speed and the pneumatic pressure under a reference cycle in a preferred embodiment of the present application;

[0040] Figure 4It is a schematic diagram of a curve showing the change of metal temperature at a certain point over time under a reference cycle in a preferred embodiment of the present application;

[0041] Figure 5 It is a curve diagram showing the stress change at a certain point on a part over time in a preferred embodiment of the present application;

[0042] Figure 6 It is a schematic diagram of two-dimensional stress distribution of a power turbine disk of an engine in a preferred embodiment of the present application;

[0043] Figure 7 It is a schematic diagram of the three-dimensional stress distribution of a cyclically symmetrical section of a power turbine disk of an engine in a preferred embodiment of the present application;

[0044] Figure 8 It is a schematic diagram of the module structure of a part life assessment system based on transient loads according to another embodiment of the present application. DETAILED DESCRIPTION

[0045] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0046] Reference Figure 1 The preferred embodiment of the present application provides a method for evaluating the life of a component based on transient loads, comprising the following contents:

[0047] Step S1: determining a reference cycle and performing transient stress analysis under the reference cycle history, and determining a life assessment condition according to the transient stress analysis result;

[0048] Step S2: Perform three-dimensional finite element stress analysis according to the transient load corresponding to the life assessment condition to obtain the stress and temperature of key parts;

[0049] Step S3: According to the stress and temperature of the key parts, the low cycle fatigue life of the parts is obtained by combining the fatigue performance data.

[0050] It can be understood that the method for evaluating the life of parts based on transient loads in this embodiment first determines the reference cycle and performs transient stress analysis under the reference cycle history, and determines the life evaluation condition based on the transient stress analysis results. Since the transient stress analysis under the reference cycle history takes into account the transient temperature and pressure loads borne by the parts at different times in the actual use of typical tasks of aviation gas turbine engines, it can accurately reflect the stress distribution caused by the change of thermal load and temperature gradient during the working process, obtain a complete temperature and stress history curve, and accurately capture the key parts of low-cycle fatigue damage and the largest low-cycle fatigue damage, so that the largest low-cycle fatigue damage can be accurately selected as the life evaluation condition. Then, according to the transient load corresponding to the life evaluation condition, a three-dimensional finite element stress analysis is performed to more accurately obtain the stress and temperature of the key parts. Finally, according to the stress and temperature of the key parts, combined with the fatigue performance data, the low-cycle fatigue life of the parts is obtained, which greatly improves the accuracy of low-cycle fatigue life evaluation, thereby ensuring safety.

[0051] It is understandable that Figure 2 As shown, in the step S1, the process of determining the reference cycle and performing transient stress analysis under the reference cycle history, and determining the life assessment condition according to the transient stress analysis result includes the following:

[0052] Step S11: determining a reference cycle according to a typical task of the engine, wherein the reference cycle includes a plurality of stable operating conditions;

[0053] Step S12: performing linear interpolation based on the speed and pneumatic pressure of different steady-state conditions in the reference cycle to obtain the speed and pneumatic pressure at the transient time point, thereby obtaining the speed and pneumatic pressure at each transient time point in the reference cycle history;

[0054] Step S13: defining a transient heat transfer boundary function and performing transient heat transfer analysis to obtain the temperature distribution load of the parts at each transient time point in the reference cycle history;

[0055] Step S14: forming an analysis load step according to the load positioning load boundary conditions of the rotation speed, aerodynamic pressure and temperature distribution at each transient time point in the reference cycle history, performing a two-dimensional finite element transient stress analysis under the reference cycle history, and obtaining the stress and temperature of the key parts at each transient time point in the reference cycle history;

[0056] Step S15: according to the stress and temperature of the key parts at each transient time point in the reference cycle history, combined with the fatigue performance data, a solution is performed to obtain the low cycle fatigue life corresponding to the stress cycle at each time point;

[0057] Step S16: Select the transient moment corresponding to the lowest value of low cycle fatigue life as the life assessment condition.

[0058] Specifically, based on typical tasks during actual use of the engine, a reference cycle that can cover the expected range of use is first determined after simplification, wherein the reference cycle includes typical operating conditions such as starting conditions, idling conditions, take-off conditions, cruising conditions and parking conditions.

[0059] Then, considering that the speed and aerodynamic pressure respond very quickly during the operation of the engine, the speed, aerodynamic force, cavity pressure and other loads at the transient time point can be obtained by linear interpolation according to the steady-state loads such as the slow-running state, take-off state and cruising state, so that the speed and aerodynamic pressure at each transient time point in the reference cycle history can be obtained, that is, the time variation curve of the speed and aerodynamic pressure under the reference cycle, where the schematic diagram of the time variation curve of the speed and aerodynamic pressure under the reference cycle is shown in Figure 3 In addition, the specific linear interpolation process belongs to the prior art and will not be described in detail here.

[0060] Next, considering that the heat transfer of the parts has a lag relative to the reference changes such as the rotation speed and the aerodynamic pressure, the transient heat transfer analysis is performed after defining the transient heat transfer boundary function to obtain the temperature distribution load of the parts at each transient time point in the reference cycle history. The schematic diagram of the metal temperature change curve at a certain point in the reference cycle is shown in Figure 4 As shown. Among them, the boundary function definition of heat conduction belongs to the prior art, the boundary function of thermal radiation is mainly the emissivity, and the emissivity of each material surface is defined as 0.8. The boundary function of thermal convection can be linearly interpolated according to the boundary parameters under each steady-state condition to obtain parameters such as gas temperature, cold air flow, cold air inlet temperature and heat transfer coefficient at the transient moment. In addition, the transient heat transfer analysis process belongs to the prior art, and the transient heat transfer analysis result is to obtain the temperature distribution of the parts at each transient moment of the reference cycle, and then obtain the time variation curve of the temperature of any part on the part.

[0061] Then, according to the speed N at each transient time point in the reference cycle history i 、 Aerodynamic force F i , cavity pressure P i and temperature distribution Temp i The load boundary conditions of the transient loads are defined to form the analysis load step, and the two-dimensional finite element transient stress analysis of the component under the reference cycle history is performed, where the subscript i represents the i-th transient moment, and the aerodynamic force F i It is obtained by converting the pneumatic pressure at that moment. The specific conversion process belongs to the existing technology and will not be repeated here. According to the results of two-dimensional finite element transient stress analysis, the stress σ of key parts such as wheel center, mortise and tenon, eccentric hole and chamfer at each time point in the reference cycle history can be obtained. i and temperature T i , where the curve of stress variation at a certain point on the part over time is as follows Figure 5As shown. In the two-dimensional finite element stress analysis of the component, the parts with axisymmetric geometry such as the wheel disc are simulated by two-dimensional axisymmetric units, and the parts with non-axisymmetric geometry such as the blades and the mortise and tenon grooves are simulated by plane stress units with thickness. After assigning the corresponding material properties, the load step is defined at each transient time point of the reference cycle and the load boundaries such as the speed, temperature distribution, aerodynamic force and cavity pressure under each load step are applied, and then the stress distribution of the parts is obtained by solving. For example, the two-dimensional stress distribution of a certain engine power turbine disc is shown in Figure 6 As shown, the finite element solution uses the Newton-Raphson method for iteration (no more than 25 times), and the force convergence criterion is set to 50 N. The use of component 2D finite element transient stress analysis can understand the temperature and stress changes of parts throughout the entire working history of the engine, and quickly screen out the minimum life moment of key parts, thereby providing accurate loads and boundaries for component 3D finite element stress analysis, reducing calculation scale and design costs.

[0062] Then, according to the stress σ of the key parts at each transient time point in the reference cycle history i and temperature T i , combined with the fatigue performance data such as the stress life curve equation of the parts, to obtain the "0~σ i The low cycle fatigue life corresponding to the stress cycle of 0~0, wherein the specific low cycle fatigue life solution process belongs to the prior art and will not be repeated here.

[0063] Finally, the moments corresponding to the minimum life values ​​of each key part at each transient time point in the reference cycle history are selected as life assessment conditions, and the key parts corresponding to the minimum life values ​​are the key parts of low-cycle fatigue damage.

[0064] It can be understood that the reference cycle of the present invention includes all typical tasks actually used by the engine. Since the transient load is difficult to obtain, it is obtained by linear interpolation of the steady-state load in the reference cycle, and considering the hysteresis effect of the heat transfer of the parts, the transient heat transfer analysis method is used to obtain the transient load of the temperature distribution of the parts, so that the transient loads such as transient temperature and transient pressure borne by the parts at different times in the actual use of the typical tasks of the aviation gas turbine engine can be obtained, which can fully and completely reflect the stress distribution caused by the change of thermal load and temperature gradient in the working process, and obtain a complete temperature and stress history curve, which can accurately capture the key parts of low-cycle fatigue damage and the maximum low-cycle fatigue damage, thereby ensuring the accuracy and reliability of the selection of low-cycle fatigue life assessment working conditions. In addition, only two-dimensional finite element stress analysis is used for the complete history of the reference cycle, which improves the analysis speed and efficiency, while three-dimensional finite element stress analysis is used for the transient load of the life assessment working condition, which ensures the accuracy of the stress analysis. Therefore, by adopting a stress analysis method combining two-dimensional stress analysis of the complete history and three-dimensional stress analysis of key moments, the efficiency and accuracy of the stress analysis are taken into account at the same time.

[0065] It can be understood that in step S2, according to the transient load of the part under the corresponding working condition at the lowest life time, considering the geometric mutation structures such as chamfers and circular holes, the three-dimensional finite element stress analysis of the component is performed, and the stress σ and temperature T of key parts such as the wheel center, mortise and tenon, eccentric hole and chamfer can be accurately obtained. Among them, the three-dimensional finite element stress analysis of the component uses tetrahedrons and hexahedrons and other units to simulate all the geometric features of the part, and after assigning the corresponding material properties, the speed, temperature distribution, aerodynamic force and cavity pressure and other load boundaries under the corresponding working condition at the lowest life time of each key part are applied, and then the stress distribution of the part is obtained by solving. For example, the three-dimensional stress distribution of the cyclic symmetric section of a certain engine power turbine disk is as follows: Figure 7 As shown, similar to the two-dimensional finite element stress analysis, the Newton-Raphson method is used for iterative solution (no more than 25 times), and the force convergence criterion is set to 50N. The three-dimensional finite element stress analysis of components can accurately reflect the geometric characteristics and load-bearing characteristics of non-axisymmetric structures such as mortise and tenon and circular holes, more accurately obtain the stress level of key parts, and improve the accuracy of life assessment. For structures such as eccentric holes and mortise and tenon, two-dimensional finite element analysis cannot accurately reflect structural characteristics and obtain stress, and it is also impossible to guarantee the accuracy of stress analysis and life assessment. The purpose of two-dimensional finite element analysis is to provide a more accurate load boundary for three-dimensional stress analysis.

[0066] It can be understood that in step S3, the low cycle fatigue life Nf can be obtained by solving the stress σ and temperature T of the key parts obtained by three-dimensional finite element stress analysis in combination with fatigue performance data such as the stress life curve equation of the parts. minThe specific solution process belongs to the prior art and will not be described in detail here.

[0067] In addition, if Figure 8 As shown, another embodiment of the present invention further provides a part life assessment system based on transient loads, preferably using the part life assessment method as described above, including:

[0068] A life assessment condition determination module is used to determine a reference cycle and perform transient stress analysis under the reference cycle history, and determine the life assessment condition based on the transient stress analysis results;

[0069] The three-dimensional finite element stress analysis module is used to perform three-dimensional finite element stress analysis based on the transient loads corresponding to the life assessment conditions to obtain the stress and temperature of key parts;

[0070] The low cycle fatigue life calculation module is used to obtain the low cycle fatigue life of parts based on the stress and temperature of key parts combined with fatigue performance data.

[0071] It can be understood that the transient load-based component life assessment system of this embodiment first determines the reference cycle and performs transient stress analysis under the reference cycle history, and determines the life assessment working condition based on the transient stress analysis results. Since the transient stress analysis under the reference cycle history takes into account the transient temperature and pressure loads borne by the components at different times in the actual use of typical tasks of the aviation gas turbine engine, it can accurately reflect the stress distribution caused by the change of thermal load and temperature gradient during the working process, obtain a complete temperature and stress history curve, and accurately capture the key parts of low-cycle fatigue damage and the largest low-cycle fatigue damage, so that the largest low-cycle fatigue damage can be accurately selected as the life assessment working condition. Then, according to the transient load corresponding to the life assessment working condition, a three-dimensional finite element stress analysis is performed to more accurately obtain the stress and temperature of the key parts. Finally, according to the stress and temperature of the key parts, combined with the fatigue performance data, the low-cycle fatigue life of the parts is obtained, which greatly improves the accuracy of low-cycle fatigue life assessment, thereby ensuring safety.

[0072] In addition, the life assessment operating condition determination module includes:

[0073] A reference cycle determination unit, used to determine a reference cycle according to a typical task of the engine, wherein the reference cycle includes a plurality of stable operating conditions;

[0074] A linear interpolation unit is used to obtain the speed and pneumatic pressure at the transient time point by linear interpolation based on the speed and pneumatic pressure of different steady-state working conditions in the reference cycle, so as to obtain the speed and pneumatic pressure at each transient time point in the reference cycle history;

[0075] Transient heat transfer analysis unit, used to define transient heat transfer boundary function and perform transient heat transfer analysis to obtain the temperature distribution load of parts at each transient time point in the reference cycle history;

[0076] The two-dimensional finite element stress analysis unit is used to form an analysis load step according to the load boundary conditions of the speed, aerodynamic pressure and temperature distribution load at each transient time point in the reference cycle history, and to perform a two-dimensional finite element transient stress analysis under the reference cycle history to obtain the stress and temperature of the key parts at each transient time point in the reference cycle history;

[0077] The transient low-cycle fatigue life calculation module is used to obtain the low-cycle fatigue life corresponding to the stress cycle at each time point based on the stress and temperature of the key parts at each transient time point in the reference cycle history, combined with the fatigue performance data;

[0078] The life assessment condition selection unit is used to select the transient moment corresponding to the minimum value of the low cycle fatigue life as the life assessment condition.

[0079] It can be understood that the various modules and units of the system embodiment correspond to the various steps and sub-steps of the above-mentioned method embodiment respectively, so the specific working principles of each module and unit are not repeated here, and the corresponding reference is made to the above-mentioned method embodiment.

[0080] In addition, another embodiment of the present invention further provides an electronic device, including a processor and a memory, wherein the memory stores a computer program, and the processor executes the steps of the above method by calling the computer program stored in the memory.

[0081] In addition, another embodiment of the present invention further provides a computer-readable storage medium for storing a computer program for evaluating the life of a part based on transient loads, wherein the computer program executes the steps of the method described above when running on a computer.

[0082] Common computer-readable storage media include: floppy disks, flexible disks, hard disks, magnetic tapes, any other magnetic media, CD-ROMs, any other optical media, punch cards, paper tapes, any other physical media with patterns of holes, random access memory (RAM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), flash-erasable programmable read-only memory (FLASH-EPROM), any other memory chip or cartridge, or any other medium that can be read by a computer. Instructions can further be transmitted or received by a transmission medium. The term transmission medium may include any tangible or intangible medium that can be used to store, encode or carry instructions for execution by a machine, and includes digital or analog communication signals or intangible media that facilitate communication of the above instructions. Transmission media include coaxial cables, copper wire, and optical fiber, including the wires of a bus used to transmit a computer data signal.

[0083] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present application may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes. The schemes in the embodiments of the present application may be implemented in various computer languages, for example, object-oriented programming language Java and literal scripting language JavaScript, etc.

[0084] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0085] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0086] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0087] Although the preferred embodiments of the present application have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications falling within the scope of the present application.

[0088] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

[0089] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for evaluating the life of a component based on transient loads, characterized in that: Includes the following: Determine the reference cycle and perform transient stress analysis under the reference cycle history. Determine the life assessment conditions based on the transient stress analysis results. The reference cycle includes starting conditions, slow-running conditions, take-off conditions, cruising conditions, and parking conditions. Perform three-dimensional finite element stress analysis based on the transient loads corresponding to the life assessment conditions to obtain the stress and temperature of key parts; The low cycle fatigue life of parts is obtained by solving the stress and temperature of key parts in combination with fatigue performance data; The process of determining the reference cycle and performing transient stress analysis under the reference cycle history, and determining the life assessment working condition according to the transient stress analysis result includes the following contents: Determine the reference cycle based on the typical mission of the engine; The speed and pneumatic pressure at the transient time point are obtained by linear interpolation based on the speed and pneumatic pressure at different steady-state conditions in the reference cycle, thereby obtaining the speed and pneumatic pressure at each transient time point in the reference cycle history; Define the transient heat transfer boundary function and perform transient heat transfer analysis to obtain the temperature distribution load of the parts at each transient time point in the reference cycle history; According to the speed, aerodynamic pressure and temperature distribution load at each transient time point in the reference cycle history, the load boundary conditions are positioned to form an analysis load step, and a two-dimensional finite element transient stress analysis is performed under the reference cycle history to obtain the stress and temperature of the key parts at each transient time point in the reference cycle history; According to the stress and temperature of key parts at each transient time point in the reference cycle history, combined with fatigue performance data, the low cycle fatigue life corresponding to the stress cycle at each time point is obtained; The transient moment corresponding to the lowest value of low cycle fatigue life is selected as the life assessment condition.

2. The method for evaluating the life of a component based on transient loads according to claim 1, characterized in that: The boundary function of heat convection is linearly interpolated according to the boundary parameters under each steady-state condition to obtain the gas temperature, cold air flow, cold air inlet temperature and heat transfer coefficient at the transient time point.

3. The method for evaluating the life of a component based on transient loads according to claim 1, characterized in that: In the process of 2D finite element stress transient analysis, the parts with axisymmetric geometry are simulated by 2D axisymmetric units, and the parts with non-axisymmetric geometry are simulated by plane stress units with thickness.

4. The method for evaluating the life of a component based on transient loads according to claim 1, characterized in that: The moments corresponding to the minimum life values ​​of each key part at each transient time point in the reference cycle history are selected as life assessment conditions, and the key parts corresponding to the minimum life values ​​are the key parts of low-cycle fatigue damage.

5. A system for evaluating the life of a part based on transient loads, using the method for evaluating the life of a part based on transient loads as claimed in any one of claims 1 to 4, characterized in that: include: A life assessment condition determination module is used to determine a reference cycle and perform transient stress analysis under the reference cycle history, and determine the life assessment condition based on the transient stress analysis results; The three-dimensional finite element stress analysis module is used to perform three-dimensional finite element stress analysis based on the transient loads corresponding to the life assessment conditions to obtain the stress and temperature of key parts; Low cycle fatigue life calculation module, used to obtain the low cycle fatigue life of parts based on the stress and temperature of key parts combined with fatigue performance data; The life assessment working condition determination module comprises: A reference cycle determination unit, used to determine a reference cycle according to a typical task of the engine, wherein the reference cycle includes a plurality of stable operating conditions; A linear interpolation unit is used to obtain the speed and pneumatic pressure at the transient time point by linear interpolation based on the speed and pneumatic pressure of different steady-state working conditions in the reference cycle, so as to obtain the speed and pneumatic pressure at each transient time point in the reference cycle history; Transient heat transfer analysis unit, used to define transient heat transfer boundary function and perform transient heat transfer analysis to obtain the temperature distribution load of parts at each transient time point in the reference cycle history; The two-dimensional finite element stress analysis unit is used to form an analysis load step according to the load boundary conditions of the speed, aerodynamic pressure and temperature distribution load at each transient time point in the reference cycle history, and to perform a two-dimensional finite element transient stress analysis under the reference cycle history to obtain the stress and temperature of the key parts at each transient time point in the reference cycle history; The transient low-cycle fatigue life calculation module is used to obtain the low-cycle fatigue life corresponding to the stress cycle at each time point based on the stress and temperature of the key parts at each transient time point in the reference cycle history, combined with the fatigue performance data; The life assessment condition selection unit is used to select the transient moment corresponding to the minimum value of the low cycle fatigue life as the life assessment condition.

6. An electronic device, characterized in that: The method comprises a processor and a memory, wherein a computer program is stored in the memory, and the processor is used to execute the steps of the method according to any one of claims 1 to 4 by calling the computer program stored in the memory.

7. A computer-readable storage medium for storing a computer program for evaluating the life of a component based on transient loads, characterized in that: When the computer program is run on a computer, the steps of the method according to any one of claims 1 to 4 are executed.

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