Axial-torsional thermo-mechanical fatigue-creep life prediction method and system

Abstract

The present application relates to the technical field of mechanical fatigue life prediction, in particular to an axial-torsional thermal mechanical fatigue-creep life prediction method and system, which uses a creep-induced grain cracking effect coefficient to determine the specific conditions under which the creep damage is activated under the condition of axial-torsional thermal mechanical loading; at the same time, a temperature effect coefficient is introduced to describe the influence of temperature on the fatigue-creep damage; a time effect coefficient is also used to depict the effect of time on the fatigue-creep damage. The present application is based on the axial-torsional thermal mechanical fatigue-creep damage mechanism, that is, the model is constructed from the fundamental factors affecting the fatigue-creep damage, thereby effectively improving the accuracy of life prediction; the fatigue-creep damage model is constructed with the help of mature fatigue damage model, which maximally reduces the number of required material constants and greatly facilitates engineering application.

Description

Technical Field

[0001] This invention relates to the field of mechanical fatigue life prediction technology, specifically to a method and system for predicting axial-torsional thermomechanical fatigue-creep life. Background Technology

[0002] Key components of aero-engines are often subjected to combined thermal and mechanical loads during service. Mechanical loads primarily encompass axial and torsional loads. The combined effect of these two loads can induce axial-torsional thermomechanical fatigue-creep at critical critical locations of the components. The presence of axial-torsional loads makes the thermomechanical cyclic deformation behavior and fatigue damage mechanisms more complex than those under uniaxial loads. Therefore, axial-torsional thermomechanical fatigue-creep has become a key limiting factor for the failure life of engineering components under high-temperature environments. To assess the structural integrity of these high-temperature components, developing robust and practical life prediction methods under axial-torsional thermomechanical loads is particularly necessary and crucial.

[0003] For materials where creep damage is dominant under thermomechanical fatigue loading, the mechanical strain-life curve under in-phase thermomechanical fatigue (IP-TMF) loading is lower than that under out-of-phase (OP) loading. This is because intergranular cracking induced by creep damage makes IP-TMF more severe. Currently, the main method for assessing creep damage is to establish a creep damage model. However, this method requires the introduction of a large number of material constants to evaluate creep damage, and these material constants often need to be determined using creep test data, which presents many inconveniences in practical engineering applications. Furthermore, if creep damage is assessed separately and then accumulated with fatigue damage, it may be difficult to fully consider the interaction between creep and fatigue damage, which is also detrimental to engineering applications. Therefore, there is an urgent need to develop a simple axial-torsional thermomechanical fatigue-creep life prediction method that is easy to apply in engineering. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the purpose of this invention is to provide a method and system for predicting axial-torsional thermomechanical fatigue-creep life.

[0005] The technical solution adopted by this invention to solve its technical problem is:

[0006] A method for predicting axial-torsional thermomechanical fatigue-creep life includes the following steps:

[0007] S1. Obtain the strain tensor components and stress tensor components of the material under axial-torsional thermomechanical loading process;

[0008] S2. Using the obtained strain tensor components and stress tensor components, based on the critical surface method, determine the critical surface that makes the maximum shear strain range reach the global maximum value, and obtain the maximum shear strain range, normal strain range between the maximum shear strain reversal points and the normal average stress on the critical surface.

[0009] S3. Obtain the creep-induced intergranular cracking effect coefficient, temperature effect coefficient, and time effect coefficient;

[0010] S4. Calculate the axial-torsional thermomechanical fatigue-creep life using the following expression. :

[0011] ;

[0012] in, Indicates the range of maximum shear strain on the critical surface; This represents the normal strain range between the maximum shear strain reversal points on the critical surface; This represents the normal mean stress on the critical surface; Indicates Young's modulus; Indicates the fatigue strength coefficient; Indicates the fatigue strength index; Indicates the fatigue plasticity coefficient; Indicates the fatigue plasticity index; Representing Macaulay brackets, the expression is: Positive values ​​in parentheses are equal to the value itself, and negative values ​​are equal to 0. Indicates the creep-induced intergranular cracking effect coefficient; Indicates the temperature effect coefficient; This represents the time effect coefficient.

[0013] As a preferred embodiment, a further technical solution of the present invention is:

[0014] Preferably, the creep-induced intergranular cracking effect coefficient is obtained by the following expression:

[0015] ;

[0016] in, The equivalent temperature represents the temperature process during the axial-torsional thermomechanical loading process. Indicates the melting temperature of the material; This indicates the von Mises equivalent stress; Indicates the tensile strength of the material; Indicates axial stress; It is a fatigue material constant, obtained through axial-torsional thermomechanical fatigue testing.

[0017] Preferably, the temperature effect coefficient is obtained by the following expression:

[0018] ;

[0019] in, Represents the hyperbolic tangent function; This represents the material constants that express the temperature effect; It represents the equivalent temperature of the temperature process during the axial-torsional thermomechanical load process.

[0020] Preferably, the equivalent temperature of the temperature history during the axial-torsional thermomechanical load history is obtained by the following expression. :

[0021] ;

[0022] in, express Temperature at any moment; This represents the count variable for temperature load data points; Indicates the first The time corresponding to each data point; This indicates the number of temperature load data points; This indicates the critical temperature.

[0023] Preferably, the time effect coefficient is obtained using the following expression:

[0024] ;

[0025] in, Indicates the cycle period; This represents the material constant that expresses the effect of time.

[0026] Preferably, the process of obtaining the strain tensor components and stress tensor components of the material under axial-torsional thermomechanical loading in S1 specifically includes:

[0027] Establish a finite element model of the component to be analyzed;

[0028] The axial-torsional thermomechanical load history is applied, which includes time-varying mechanical load boundary conditions and temperature field boundary conditions.

[0029] Using elastoplastic finite element analysis, the strain tensor components at each time point of the critical material point in the component during the complete cyclic loading cycle were calculated. and stress tensor components .

[0030] Preferably, in step S2, the critical surface that causes the maximum shear strain range to reach its global maximum value is determined based on the critical surface method using the obtained strain tensor components and stress tensor components. The process of obtaining the maximum shear strain range on the critical surface, the normal strain path between the maximum shear strain reversal points, and the normal mean stress specifically includes:

[0031] Step 1: For each candidate plane, perform the following procedure:

[0032] Based on strain tensor components Calculate the shear strain at each moment on the candidate plane. and normal strain ;

[0033] Based on stress tensor components Calculate the normal stress on the candidate plane at each moment. ;

[0034] Within one cycle, determine the range of shear strain on the candidate plane. This refers to the difference between the maximum and minimum shear strain within the cycle, and records the range of maximum in-plane shear strain reached by the candidate plane within the cycle. ;

[0035] In the shear strain-time history, two inflection points are identified that allow the maximum shear strain range in the candidate plane to be reached, and the normal strain range between the two inflection points is calculated. ;

[0036] Calculate the normal stress of the candidate plane over one cycle. The average value is used to obtain the normal mean stress. .

[0037] This invention also discloses an axial-torsional thermomechanical fatigue-creep life prediction system, which applies the above-mentioned axial-torsional thermomechanical fatigue-creep life prediction method, specifically including:

[0038] The component acquisition module is used to acquire the strain tensor components and stress tensor components of the material under axial-torsional thermomechanical loading processes.

[0039] The critical surface determination module is used to determine the critical surface that makes the maximum shear strain range reach the global maximum value based on the critical surface method using the obtained strain tensor components and stress tensor components, and to obtain the maximum shear strain range, normal strain range between the maximum shear strain reversal points and the normal average stress on the critical surface.

[0040] The coefficient acquisition module is used to acquire the creep-induced intergranular cracking effect coefficient, temperature effect coefficient, and time effect coefficient.

[0041] The life calculation module is used to calculate the axial-torsional thermomechanical fatigue-creep life using the following expression. :

[0042] ;

[0043] in, Indicates the range of maximum shear strain on the critical surface; This represents the normal strain range between the maximum shear strain reversal points on the critical surface; This represents the normal mean stress on the critical surface; Indicates Young's modulus; Indicates the fatigue strength coefficient; Indicates the fatigue strength index; Indicates the fatigue plasticity coefficient; Indicates the fatigue plasticity index; Representing Macaulay brackets, the expression is: Positive values ​​in parentheses are equal to the value itself, and negative values ​​are equal to 0. Indicates the creep-induced intergranular cracking effect coefficient; Indicates the temperature effect coefficient; This represents the time effect coefficient.

[0044] This invention also discloses an electronic device, characterized in that it includes a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other through the communication bus;

[0045] Memory is used to store processor-executable instructions;

[0046] The processor, when executing instructions stored in memory, implements the aforementioned axial-torsional thermomechanical fatigue-creep life prediction method.

[0047] The present invention, which adopts the above technical solution, has the following prominent features compared with the prior art:

[0048] This invention utilizes a creep-induced intergranular cracking effect coefficient to determine the specific conditions under which creep damage is activated under axial-torsional thermomechanical loading. Simultaneously, a temperature effect coefficient is introduced to describe the influence of temperature on the amount of fatigue-creep damage. Furthermore, a time effect coefficient is employed to characterize the effect of time on the amount of fatigue-creep damage. This invention is based on the axial-torsional thermomechanical fatigue-creep damage mechanism, constructing a model by addressing the fundamental factors affecting the amount of fatigue-creep damage, thereby effectively improving the accuracy of life prediction. By leveraging a mature fatigue damage model to construct the fatigue-creep damage model, the number of required material constants is minimized, greatly facilitating engineering applications. Attached Figure Description

[0049] Figure 1 This is a schematic flowchart of the axial-torsional thermomechanical fatigue-creep life prediction method in an embodiment of the present invention;

[0050] Figure 2 This is a schematic diagram comparing the predicted and tested lifespans of the nickel-based superalloy GH4169 in this embodiment of the invention;

[0051] Figure 3 This is a schematic diagram of the axial-torsional thermomechanical fatigue-creep life prediction system in an embodiment of the present invention;

[0052] Figure 4 This is a schematic diagram of an electronic device in an embodiment of the present invention. Detailed Implementation

[0053] The present invention will be further illustrated below with reference to specific embodiments. The purpose of this illustration is solely to provide a better understanding of the invention. Therefore, the examples given do not limit the scope of protection of the present invention.

[0054] like Figure 1 As shown in the figure, this embodiment presents a method for predicting axial-torsional thermomechanical fatigue-creep life, including the following steps:

[0055] S1. Obtain the strain tensor components and stress tensor components of the material under axial-torsional thermomechanical loading process;

[0056] S2. Using the obtained strain tensor components and stress tensor components, based on the critical surface method, determine the critical surface that makes the maximum shear strain range reach the global maximum value, and obtain the maximum shear strain range, normal strain range between the maximum shear strain reversal points and the normal average stress on the critical surface.

[0057] S3. Obtain the creep-induced intergranular cracking effect coefficient, temperature effect coefficient, and time effect coefficient;

[0058] S4. Calculate the axial-torsional thermomechanical fatigue-creep life using the following expression. :

[0059] ;

[0060] in, Indicates the range of maximum shear strain on the critical surface; This represents the normal strain range between the maximum shear strain reversal points on the critical surface; This represents the normal mean stress on the critical surface; Indicates Young's modulus; Indicates the fatigue strength coefficient; Indicates the fatigue strength index; Indicates the fatigue plasticity coefficient; Indicates the fatigue plasticity index; Representing Macaulay brackets, the expression is: Positive values ​​in parentheses are equal to the value itself, and negative values ​​are equal to 0. Indicates the creep-induced intergranular cracking effect coefficient; Indicates the temperature effect coefficient; This represents the time effect coefficient.

[0061] During implementation, the required material fatigue constant , , , The constants can be obtained through standard methods of uniaxial strain-controlled fatigue testing (such as referring to ASTM E606). For example, symmetrical cyclic fatigue tests can be performed on standard material specimens at different strain amplitudes. The number of cycles at failure of each specimen can be recorded. After separating the elastic strain amplitude and the plastic strain amplitude, the elastic strain amplitude-life curve and the plastic strain amplitude-life curve can be fitted in a double logarithmic coordinate system, respectively, to obtain the above four constants.

[0062] The creep-induced intergranular cracking effect coefficient, used to determine whether creep damage is activated and whether intergranular cracking will occur under axial-torsional thermomechanical loading conditions, is obtained by the following expression:

[0063] ;

[0064] in, The equivalent temperature represents the temperature process during the axial-torsional thermomechanical loading process. Indicates the melting temperature of the material; This indicates the von Mises equivalent stress; Indicates the tensile strength of the material; Indicates axial stress; This is a fatigue material constant, obtained through axial-torsional thermomechanical fatigue testing. That is, creep-induced intergranular cracking only occurs significantly when temperature, stress, and tensile stress conditions are simultaneously met; in this case, increasing the damage parameter (…) Otherwise, this effect is not considered. .

[0065] The temperature effect coefficient, which describes the influence of temperature on the amount of fatigue-creep damage, is obtained through the following expression:

[0066] ;

[0067] in, Represents the hyperbolic tangent function; This represents the material constants that express the temperature effect; This represents the equivalent temperature during the temperature process in the axial-torsional thermomechanical loading process. That is, the higher the temperature, the better. The higher the value, the amplified the fatigue-creep damage; conversely, the lower the temperature, the greater the fatigue-creep damage. The smaller the value, the smaller the damage.

[0068] The equivalent temperature of the temperature history in the axial-torsional thermomechanical load history is obtained by the following expression. :

[0069] ;

[0070] in, express Temperature at any moment; This represents the count variable for temperature load data points; Indicates the first The time corresponding to each data point; This indicates the number of temperature load data points; This indicates the critical temperature.

[0071] The time effect coefficient used to describe the influence of cycle time (i.e., load frequency or holding time) on fatigue-creep damage is obtained through the following expression:

[0072] ;

[0073] in, Indicates the cycle period; This represents the material constant that expresses the effect of time.

[0074] The process of obtaining the strain tensor components and stress tensor components of the material under axial-torsional thermomechanical loading in S1 specifically includes:

[0075] Establish a finite element model of the component to be analyzed;

[0076] The axial-torsional thermomechanical load history is applied, which includes time-varying mechanical load boundary conditions and temperature field boundary conditions.

[0077] Using elastoplastic finite element analysis, the strain tensor components at each time point of the critical material point in the component during the complete cyclic loading cycle were calculated. and stress tensor components .

[0078] S2 utilizes the obtained strain tensor components and stress tensor components based on the critical surface method to determine the critical surface that makes the maximum shear strain range reach its global maximum value. The process of obtaining the maximum shear strain range on the critical surface, the normal strain path between the maximum shear strain reversal points, and the normal mean stress specifically includes:

[0079] Step 1: For each candidate plane, perform the following procedure:

[0080] Based on strain tensor components Calculate the shear strain at each moment on the candidate plane. and normal strain ;

[0081] Based on stress tensor components Calculate the normal stress on the candidate plane at each moment. ;

[0082] Within one cycle, determine the range of shear strain on the candidate plane. This refers to the difference between the maximum and minimum shear strain within the cycle, and records the range of maximum in-plane shear strain reached by the candidate plane within the cycle. ;

[0083] In the shear strain-time history, two inflection points are identified that allow the maximum shear strain range in the candidate plane to be reached, and the normal strain range between the two inflection points is calculated. ;

[0084] Calculate the normal stress of the candidate plane over one cycle. The average value is used to obtain the normal mean stress. .

[0085] The following will further illustrate the present invention using the life prediction process of uniaxial and axial-torsional thermomechanical fatigue of nickel-based superalloy GH4169.

[0086] Table 1 lists the test details and life results of uniaxial and axial-torsional thermomechanical fatigue tests on nickel-based superalloy GH4169, where TIP indicates that the thermal phase angle between the axial strain waveform and the temperature waveform is in phase, and TOP... 90 Indicates a thermal phase angle of 90°, indicating non-in-phase, TOP 180 MIP indicates that the thermal phase angle is 180° out of phase, MIP indicates that the mechanical phase angle between the axial strain waveform and the torsional strain waveform is in phase, and MOP indicates that the mechanical phase angle is 90° out of phase.

[0087] Table 1. Test details and life results of thermomechanical fatigue tests on nickel-based superalloy GH4169.

[0088]

[0089] Fatigue material constants of nickel-based superalloy GH4169 at room temperature: creep-induced intergranular cracking effect coefficient The critical temperature is 2.86. The material constant is 550℃. The material constant is 1150. The value is 0.00115; therefore, the axial-torsional thermomechanical fatigue-creep life is obtained through calculation. Comparison with experimental lifetime results, for example Figure 2 The prediction error shown is within 2 factors, achieving satisfactory prediction results.

[0090] This invention is based on the Shang-Wang model, which performs well under proportional and non-proportional multiaxial fatigue loading at room temperature. It continues the approach of Shang-Wang parameters, and by modifying the equivalent amplitude, considers the effects of creep-induced intergranular cracking, temperature, and time on failure life under axial-torsional thermomechanical loading. Furthermore, this invention can also describe the effects of tensile mean stress and non-proportional additional hardening. The material constants involved in this invention are easy to determine, which facilitates the application and expansion of the proposed method.

[0091] See Figure 3 This invention also discloses an axial-torsional thermomechanical fatigue-creep life prediction system, which applies the above-mentioned axial-torsional thermomechanical fatigue-creep life prediction method, specifically including:

[0092] The component acquisition module is used to acquire the strain tensor components and stress tensor components of the material under axial-torsional thermomechanical loading processes.

[0093] The critical surface determination module is used to determine the critical surface that makes the maximum shear strain range reach the global maximum value based on the critical surface method using the obtained strain tensor components and stress tensor components, and to obtain the maximum shear strain range, normal strain range between the maximum shear strain reversal points and the normal average stress on the critical surface.

[0094] The coefficient acquisition module is used to acquire the creep-induced intergranular cracking effect coefficient, temperature effect coefficient, and time effect coefficient.

[0095] The life calculation module is used to calculate the axial-torsional thermomechanical fatigue-creep life using the following expression. :

[0096] ;

[0097] in, Indicates the range of maximum shear strain on the critical surface; This represents the normal strain range between the maximum shear strain reversal points on the critical surface; This represents the normal mean stress on the critical surface; Indicates Young's modulus; Indicates the fatigue strength coefficient; Indicates the fatigue strength index; Indicates the fatigue plasticity coefficient; Indicates the fatigue plasticity index; Representing Macaulay brackets, the expression is: Positive values ​​in parentheses are equal to the value itself, and negative values ​​are equal to 0. Indicates the creep-induced intergranular cracking effect coefficient; Indicates the temperature effect coefficient; This represents the time effect coefficient.

[0098] In practice, the creep-induced intergranular cracking effect coefficient is obtained through the following expression:

[0099] ;

[0100] in, The equivalent temperature represents the temperature process during the axial-torsional thermomechanical loading process. Indicates the melting temperature of the material; This indicates the von Mises equivalent stress; Indicates the tensile strength of the material; Indicates axial stress; It is a fatigue material constant, obtained through axial-torsional thermomechanical fatigue testing.

[0101] The temperature effect coefficient is obtained through the following expression:

[0102] ;

[0103] in, Represents the hyperbolic tangent function; This represents the material constants that express the temperature effect; It represents the equivalent temperature of the temperature process during the axial-torsional thermomechanical load process.

[0104] The equivalent temperature of the temperature history in the axial-torsional thermomechanical load history is obtained by the following expression. :

[0105] ;

[0106] in, express Temperature at any moment; This represents the count variable for temperature load data points; Indicates the first The time corresponding to each data point; This indicates the number of temperature load data points; This indicates the critical temperature.

[0107] The time effect coefficient is obtained using the following expression:

[0108] ;

[0109] in, Indicates the cycle period; This represents the material constant that expresses the effect of time.

[0110] The component acquisition module is specifically used for:

[0111] Establish a finite element model of the component to be analyzed;

[0112] The axial-torsional thermomechanical load history is applied, which includes time-varying mechanical load boundary conditions and temperature field boundary conditions.

[0113] Using elastoplastic finite element analysis, the strain tensor components at each time point of the critical material point in the component during the complete cyclic loading cycle were calculated. and stress tensor components .

[0114] The critical surface determination module is specifically used for:

[0115] Step 1: For each candidate plane, perform the following procedure:

[0116] Based on strain tensor components Calculate the shear strain at each moment on the candidate plane. and normal strain ;

[0117] Based on stress tensor components Calculate the normal stress on the candidate plane at each moment. ;

[0118] Within one cycle, determine the range of shear strain on the candidate plane. This refers to the difference between the maximum and minimum shear strain within the cycle, and records the range of maximum in-plane shear strain reached by the candidate plane within the cycle. ;

[0119] In the shear strain-time history, two inflection points are identified that allow the maximum shear strain range in the candidate plane to be reached, and the normal strain range between the two inflection points is calculated. ;

[0120] Calculate the normal stress of the candidate plane over one cycle. The average value is used to obtain the normal mean stress. .

[0121] This invention also provides an electronic device, such as... Figure 4As shown, it includes a processor 001, a communication interface 002, a memory 003, and a communication bus 004. The processor 001, communication interface 002, and memory 003 communicate with each other via the communication bus 004.

[0122] Memory 003 is used to store computer programs;

[0123] Processor 001, when executing the program stored in memory 003, implements the above-mentioned axial-torsional thermomechanical fatigue-creep life prediction method, including:

[0124] S1. Obtain the strain tensor components and stress tensor components of the material under axial-torsional thermomechanical loading process;

[0125] S2. Using the obtained strain tensor components and stress tensor components, based on the critical surface method, determine the critical surface that makes the maximum shear strain range reach the global maximum value, and obtain the maximum shear strain range, normal strain range between the maximum shear strain reversal points and the normal average stress on the critical surface.

[0126] S3. Obtain the creep-induced intergranular cracking effect coefficient, temperature effect coefficient, and time effect coefficient;

[0127] S4. Calculate the axial-torsional thermomechanical fatigue-creep life using the following expression. :

[0128] ;

[0129] in, Indicates the range of maximum shear strain on the critical surface; This represents the normal strain range between the maximum shear strain reversal points on the critical surface; This represents the normal mean stress on the critical surface; Indicates Young's modulus; Indicates the fatigue strength coefficient; Indicates the fatigue strength index; Indicates the fatigue plasticity coefficient; Indicates the fatigue plasticity index; Representing Macaulay brackets, the expression is: Positive values ​​in parentheses are equal to the value itself, and negative values ​​are equal to 0. Indicates the creep-induced intergranular cracking effect coefficient; Indicates the temperature effect coefficient; This represents the time effect coefficient.

[0130] The present invention utilizes the creep-induced intergranular cracking effect coefficient to determine the specific conditions under which creep damage is activated under axial-torsional thermomechanical loading. Simultaneously, a temperature effect coefficient is introduced to describe the influence of temperature on the amount of fatigue-creep damage. Furthermore, a time effect coefficient is employed to characterize the effect of time on the amount of fatigue-creep damage. This invention is based on the axial-torsional thermomechanical fatigue-creep damage mechanism, constructing a model by addressing the fundamental factors affecting the amount of fatigue-creep damage, thereby effectively improving the accuracy of life prediction. By leveraging a mature fatigue damage model to construct the fatigue-creep damage model, the number of required material constants is minimized, greatly facilitating engineering applications.

[0131] The communication bus mentioned in the above electronic devices can be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus, etc. This communication bus can be divided into address bus, data bus, control bus, etc. For ease of illustration, only one thick line is used to represent it in the diagram, but this does not mean that there is only one bus or one type of bus.

[0132] The communication interface is used for communication between the aforementioned electronic devices and other devices.

[0133] The memory may include random access memory (RAM) or non-volatile memory (NVM), such as at least one disk storage device. Optionally, the memory may also be at least one storage device located remotely from the aforementioned processor.

[0134] The processors mentioned above can be general-purpose processors, including central processing units (CPUs), network processors (NPs), etc.; they can also be digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components.

[0135] In the above embodiments, implementation can be achieved, in whole or in part, through software, hardware, firmware, or any combination thereof. When implemented in software, it can be implemented, in whole or in part, as a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of the present invention are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium accessible to a computer or a data storage device such as a server or data center that integrates one or more available media. The available medium can be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., solid-state disk (SSD)).

[0136] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0137] The various embodiments in this specification are described in a related manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, the device and electronic device embodiments are basically similar to the method embodiments, so the descriptions are relatively simple; relevant parts can be referred to the descriptions of the method embodiments.

[0138] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are included within the scope of protection of the present invention.

Claims

1. A method for predicting axial-torsional thermomechanical fatigue-creep life, characterized in that, Includes the following steps: S1. Obtain the strain tensor components and stress tensor components of the material under axial-torsional thermomechanical loading process; S2. Using the obtained strain tensor components and stress tensor components, based on the critical surface method, determine the critical surface that makes the maximum shear strain range reach the global maximum value, and obtain the maximum shear strain range, normal strain range between the maximum shear strain reversal points and the normal average stress on the critical surface. S3. Obtain the creep-induced intergranular cracking effect coefficient, temperature effect coefficient, and time effect coefficient; S4. Calculate the axial-torsional thermomechanical fatigue-creep life using the following expression. : ； in, Indicates the range of maximum shear strain on the critical surface; This represents the normal strain range between the maximum shear strain reversal points on the critical surface; This represents the normal mean stress on the critical surface; Indicates Young's modulus; Indicates the fatigue strength coefficient; Indicates the fatigue strength index; Indicates the fatigue plasticity coefficient; Indicates the fatigue plasticity index; Representing Macaulay brackets, the expression is: Positive values ​​in parentheses are equal to the value itself, and negative values ​​are equal to 0. Indicates the creep-induced intergranular cracking effect coefficient; Indicates the temperature effect coefficient; This represents the time effect coefficient.

2. The axial-torsional thermomechanical fatigue-creep life prediction method according to claim 1, characterized in that, The creep-induced intergranular cracking effect coefficient is obtained through the following expression: ； in, The equivalent temperature represents the temperature process during the axial-torsional thermomechanical loading process. Indicates the melting temperature of the material; This indicates the von Mises equivalent stress; Indicates the tensile strength of the material; Indicates axial stress; It is a fatigue material constant, obtained through axial-torsional thermomechanical fatigue testing.

3. The axial-torsional thermomechanical fatigue-creep life prediction method according to claim 2, characterized in that, The temperature effect coefficient is obtained through the following expression: ； in, Represents the hyperbolic tangent function; This represents the material constants that express the temperature effect; It represents the equivalent temperature of the temperature process during the axial-torsional thermomechanical load process.

4. The axial-torsional thermomechanical fatigue-creep life prediction method according to claim 3, characterized in that, The equivalent temperature of the temperature history in the axial-torsional thermomechanical load history is obtained by the following expression. : ； in, express Temperature at any moment; This represents the count variable for temperature load data points; Indicates the first The time corresponding to each data point; This indicates the number of temperature load data points; This indicates the critical temperature.

5. The method for predicting axial-torsional thermomechanical fatigue-creep life according to claim 1, characterized in that, The time effect coefficient is obtained using the following expression: ； in, Indicates the cycle period; This represents the material constant that expresses the effect of time.

6. The axial-torsional thermomechanical fatigue-creep life prediction method according to claim 1, characterized in that, The process of obtaining the strain tensor components and stress tensor components of the material under axial-torsional thermomechanical loading in S1 specifically includes: Establish a finite element model of the component to be analyzed; The axial-torsional thermomechanical load history is applied, which includes time-varying mechanical load boundary conditions and temperature field boundary conditions. Using elastoplastic finite element analysis, the strain tensor components at each time point of the critical material point in the component during the complete cyclic loading cycle were calculated. and stress tensor components .

7. The axial-torsional thermomechanical fatigue-creep life prediction method according to claim 1, characterized in that, S2 utilizes the obtained strain tensor components and stress tensor components based on the critical surface method to determine the critical surface that makes the maximum shear strain range reach its global maximum value. The process of obtaining the maximum shear strain range on the critical surface, the normal strain path between the maximum shear strain reversal points, and the normal mean stress specifically includes: Step 1: For each candidate plane, perform the following procedure: Based on strain tensor components Calculate the shear strain at each moment on the candidate plane. and normal strain ; Based on stress tensor components Calculate the normal stress on the candidate plane at each moment. ; Within one cycle, determine the range of shear strain on the candidate plane. This refers to the difference between the maximum and minimum shear strain within the cycle, and records the range of maximum in-plane shear strain reached by the candidate plane within the cycle. ; In the shear strain-time history, two inflection points are identified that allow the maximum shear strain range in the candidate plane to be reached, and the normal strain range between the two inflection points is calculated. ; Calculate the normal stress of the candidate plane over one cycle. The average value is used to obtain the normal mean stress. .

8. An axial-torsional thermomechanical fatigue-creep life prediction system, characterized in that, The method for predicting axial-torsional thermomechanical fatigue-creep life according to any one of claims 1-7 is specifically included as follows: The component acquisition module is used to acquire the strain tensor components and stress tensor components of the material under axial-torsional thermomechanical loading processes. The critical surface determination module is used to determine the critical surface that makes the maximum shear strain range reach the global maximum value based on the critical surface method using the obtained strain tensor components and stress tensor components, and to obtain the maximum shear strain range, normal strain range between the maximum shear strain reversal points and the normal average stress on the critical surface. The coefficient acquisition module is used to acquire the creep-induced intergranular cracking effect coefficient, temperature effect coefficient, and time effect coefficient. The life calculation module is used to calculate the axial-torsional thermomechanical fatigue-creep life using the following expression. : ； in, Indicates the range of maximum shear strain on the critical surface; This represents the normal strain range between the maximum shear strain reversal points on the critical surface; This represents the normal mean stress on the critical surface; Indicates Young's modulus; Indicates the fatigue strength coefficient; Indicates the fatigue strength index; Indicates the fatigue plasticity coefficient; Indicates the fatigue plasticity index; Representing Macaulay brackets, the expression is: Positive values ​​in parentheses are equal to the value itself, and negative values ​​are equal to 0. Indicates the creep-induced intergranular cracking effect coefficient; Indicates the temperature effect coefficient; This represents the time effect coefficient.

9. An electronic device, characterized in that, It includes a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other through the communication bus; Memory is used to store processor-executable instructions; A processor, when executing instructions stored in memory, implements the axial-torsional thermomechanical fatigue-creep life prediction method according to any one of claims 1-7.

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