Evaluation method for dynamic strength of typical vibration area of nickel-based single crystal turbine blade

Abstract

The invention discloses a nickel-based single crystal turbine blade typical vibration area dynamic intensity evaluation method, which comprises the following steps: analyzing typical vibration area characteristics and a principal stress direction according to a vibration characteristic simulation result, and designing typical characteristics and crystal orientation of a simulation piece; performing a high-cycle fatigue test and a tensile test on the simulation part to obtain high-cycle fatigue strength and tensile strength, and drawing a fatigue limit model considering stress concentration; testing again to obtain high-cycle fatigue strength, and drawing a three-point equal-life model considering stress concentration; the turbine blade is subjected to a core dynamic test to obtain dynamic stress, static stress is obtained according to a vibration characteristic analog simulation result, a straight line perpendicular to the abscissa is made through a static stress numerical point, and the high-cycle fatigue strength corresponding to the intersection point of the straight line and the three-point equal-life model is the vibration fatigue limit; the ratio of the dynamic stress to the vibration fatigue limit is the dynamic strength. The method considers the main stress direction and the stress concentration problem, and the evaluation result is accurate.

Description

Technical Field

[0001] The present invention belongs to the technical field of performance evaluation of aero-engine turbine blades, and in particular relates to a method for evaluating the dynamic strength of a typical vibration region of a nickel-based single-crystal turbine blade. Background Art

[0002] In the field of aerospace, engines are known as the "crown of modern industry," and turbine blades are called "the most beautiful pearl in the crown." Turbine blades made of nickel-based single-crystal high-temperature alloys, in particular, have become an indispensable key component in aircraft engines because of their excellent fatigue resistance and creep resistance in high-temperature environments.

[0003] Dynamic strength assessment of core aircraft engine components is a key technology for ensuring safe and reliable operation. It directly impacts the structural integrity, extended service life, improved efficiency and performance, reduced maintenance costs, and enhanced safety of aircraft engines. Dynamic strength assessment of turbine blades is particularly crucial, not only as a foundation for ensuring safe component operation but also as a key to driving overall engine performance improvements and technological innovation.

[0004] Existing methods for evaluating the dynamic strength of nickel-based single-crystal turbine blades are typically based on simple empirical rules. However, these methods often lack accuracy when dealing with the anisotropy of single crystals due to discrepancies between observed and inferred indicators. Principal stress orientation and stress concentration issues are particularly prominent in typical vibration zones of single-crystal turbine blades, such as the film holes at the leading edge, the blade basin, the blade back, and the trailing edge window. Existing technical approaches fail to fully consider these two issues, instead relying solely on conventional methods to measure the fatigue limit and tensile strength of smooth test pieces. This leads to inaccurate dynamic strength assessments of these stress-concentrated areas, yet accurate dynamic strength assessments of these areas are crucial for ensuring component safety.

[0005] Given that turbine blades frequently experience vibration-induced cracks and fractures in actual applications, it is particularly urgent to provide a more accurate dynamic strength assessment for the typical vibration area of turbine blades. Therefore, it is urgent to develop a method for assessing the dynamic strength of nickel-based single-crystal turbine blades in typical vibration areas to ensure the safe and reliable operation of aircraft engine turbine blades.

[0006] The invention patent application with publication number CN116757017A discloses a fatigue strength assessment method, storage medium, and equipment for a single-crystal blade with a special-shaped air film hole. This assessment method establishes a geometric model of a single-crystal blade with a special-shaped air film hole, imports it into finite element simulation software, adds the elastic anisotropic material properties of the simulation, and uses the critical plane method coupled with the critical distance theory to obtain the equivalent stress at the hole edge at the stress concentration area, and establishes a hole edge equivalent stress-vibration displacement amplitude relationship. A high-temperature vibration fatigue test is performed on the single-crystal blade with a special-shaped air film hole simulation to obtain the hole edge vibration displacement amplitude and hole edge equivalent stress without considering local plastic deformation. Crystal plasticity is loaded into the finite element simulation software to obtain the fatigue strength assessment results of the single-crystal blade with a special-shaped air film hole. Although this technical solution can achieve the fatigue strength assessment of the single-crystal blade with a special-shaped air film hole, the two issues of principal stress direction and stress concentration are not considered during the assessment process, resulting in inaccurate assessment results. Summary of the Invention

[0007] To solve the problems existing in the prior art, the present invention provides a method for evaluating the dynamic strength of a typical vibration region of a nickel-based single crystal turbine blade. The evaluation method comprises the following steps in order:

[0008] Step 1: Use finite element simulation software to establish a turbine blade model with a typical vibration area, and simulate the vibration characteristics of the turbine blade model to obtain vibration characteristics simulation results; based on the obtained vibration characteristics simulation results, analyze the deformation mode under each order of vibration mode, and determine the order of vibration mode under which the typical deformation mode is located. Subsequently, evaluate the dynamic strength of the typical vibration area of the turbine blade under this order of vibration mode;

[0009] Step 2: Based on the obtained vibration characteristics simulation results, analyze the typical vibration area characteristics and principal stress directions of the turbine blade under this order vibration mode, and design the typical characteristics and crystal orientation of the simulation part based on the typical vibration area characteristics and principal stress directions;

[0010] Step 3: Prepare several simulated parts with the designed typical features and crystal orientations for subsequent experiments;

[0011] Step 4: Perform a high-cycle fatigue test on the simulated part using a fatigue testing machine to obtain the high-cycle fatigue strength. Simultaneously, perform a tensile test on the simulated part using a tensile testing machine to obtain the tensile strength. Draw a fatigue limit model that takes stress concentration into account in a coordinate system where the abscissa is the tensile strength and the ordinate is the high-cycle fatigue strength. Connect the two numerical points of the obtained high-cycle fatigue strength and tensile strength.

[0012] Step 5: Use the fatigue testing machine to perform a high-cycle fatigue test on the simulated component again to obtain another high-cycle fatigue strength; with the origin as the rotation point, rotate the original coordinate system clockwise by a certain angle to form a new coordinate system, and plot the other high-cycle fatigue strength on the ordinate of the new coordinate system; draw a three-point equal life model that takes stress concentration into account in the original coordinate system, that is, connect the three numerical points of high-cycle fatigue strength in the original coordinate system, tensile strength in the original coordinate system, and high-cycle fatigue strength in the new coordinate system;

[0013] Step 6: Based on the obtained vibration characteristic simulation results, prepare a turbine blade with a typical vibration area, and use a core maneuvering test device to perform a core maneuvering test on the turbine blade to obtain dynamic stress. At the same time, based on the obtained vibration characteristic simulation results, obtain static stress; plot the dynamic stress and static stress on the ordinate and abscissa of the original coordinate system respectively, and draw a straight line perpendicular to the abscissa through the numerical point of the static stress. The straight line intersects with the three-point equal life model, and the high-cycle fatigue strength corresponding to the intersection point is the vibration fatigue limit; the ratio of the dynamic stress to the vibration fatigue limit is used as the dynamic strength of the typical vibration area of the turbine blade;

[0014] Step 7: Evaluate the safety of the turbine blades based on the dynamic strength value. If the dynamic strength value is greater than 1.67, it means that the turbine blades with typical vibration areas are unsafe and need to be redesigned or the material selected. If the dynamic strength value is less than or equal to 1.67, it means that the turbine blades with typical vibration areas are safe and can be used normally.

[0015] Preferably, in step 1, the finite element simulation software includes any one or more of Abaqus, Ansys, MSC.Marc, and iSight.

[0016] In any of the above schemes, preferably, in step one, the typical vibration area of the turbine blade includes any one or more of the air film holes at the leading edge, the air film holes at the blade basin, the air film holes at the blade back, and the tail window at the trailing edge.

[0017] In any of the above solutions, preferably, in step one, the typical deformation modes are bending deformation and torsional deformation, the bending deformation is in a first-order vibration mode, and the torsional deformation is in a third-order vibration mode.

[0018] In any of the above schemes, it is preferred that in step 2, under the first-order vibration mode, the principal stress direction of the turbine blade is a vertical direction perpendicular to the horizontal plane, that is, the crystal orientation of the simulation component is

[001] direction; under the third-order vibration mode, the principal stress direction of the turbine blade is an inclined direction at a certain angle to the horizontal plane, that is, the crystal orientation of the simulation component is

[011] direction.

[0019] In any of the above schemes, preferably, in step 2, a typical feature of the simulation part is that a structure identical to or similar to the air film hole and / or the rear window is provided on the simulation part.

[0020] In any of the above schemes, preferably, in step 4, when performing the high cycle fatigue test and the tensile test, the strain gauge is attached to the typical characteristic position of the simulation part, and the attachment direction of the strain gauge is consistent with the crystal orientation; the tension-compression ratio of the high cycle fatigue test is -1, and the number of cycles is 2×10 7 , the tension-compression ratio of the tensile test is 1.

[0021] In any of the above schemes, preferably, in step 5, when performing the high-cycle fatigue test, the strain gauge is attached to the typical characteristic position of the simulation component, and the attachment direction of the strain gauge is consistent with the crystal orientation; the tension-compression ratio of the high-cycle fatigue test is 0.01, and the number of cycles is 2×10 7 times; adjust the rotation angle of the new coordinate according to the tension-compression ratio of the high-cycle fatigue test, and control the rotation angle within 20-70 degrees.

[0022] In any of the above solutions, it is preferred that the three-point equal life model drawn in step five is more preferred than the fatigue limit model drawn in step four, and the vibration fatigue limit of the simulation component is determined according to the three-point equal life model.

[0023] Traditional methods for evaluating blade dynamic strength often use standard parts for testing and plotting Goodman curves. Working parts are not designed based on the typical vibration ranges of different vibration modes in single-crystal turbine blades. This results in fatigue limits lower than the Goodman curves that consider Kt, resulting in a certain deviation from actual performance. In a three-point equal life model established after considering Kt, the Goodman curves that consider Kt are further optimized, resulting in a more reasonable evaluation model for specimen design and significant progress in dynamic stress assessment.

[0024] This paper evaluates the dynamic strength of nickel-based single-crystal turbine blades under actual operating conditions, analyzing in detail the main deformation modes and stress concentration areas of the turbine blades under different vibration modes. In the first-order vibration mode analysis, the turbine blades primarily deform in bending, with stresses concentrated in areas such as the film holes at the leading edge and the tail window at the trailing edge, which are considered typical vibration regions. In the third-order vibration mode analysis, the turbine blades primarily deform in torsion, with stresses concentrated in areas such as the film holes at the blade base and the blade back, which are also considered typical vibration regions.

[0025] Based on the above analysis, the present invention proposes a more accurate dynamic strength assessment method. This method requires appropriate assessment based on the actual operating conditions and principal stress directions of single-crystal turbine blades. Specifically, the safety of turbine blades is assessed based on the dynamic strength value. If the dynamic strength value is greater than 1.67, the turbine blade with a typical vibration region is unsafe and requires structural redesign or material selection. If the dynamic strength value is less than or equal to 1.67, the turbine blade with a typical vibration region is safe and can be used normally. This method can more accurately assess and ensure the dynamic strength of single-crystal turbine blades under various operating conditions, thereby improving the safety and reliability of the entire aircraft engine system.

[0026] The method for evaluating the dynamic strength of a typical vibration region of a nickel-based single crystal turbine blade according to the present invention has the following beneficial effects:

[0027] (1) The evaluation method of the present invention can better evaluate the dynamic strength of the typical vibration area of a single-crystal turbine blade with crystal anisotropy characteristics, forming a dynamic strength evaluation method that conforms to the actual vibration conditions of the single-crystal turbine blade under service conditions, greatly improving the accuracy of the design and evaluation links, making up for the shortcomings of the design method, saving the time and economic costs of repeated experiments, and providing strong support for improving the safety and reliability of aircraft engines.

[0028] (2) The present invention is different from the previous standard test piece design. Instead, it takes into account the anisotropic characteristics of single crystals and innovatively proposes to design simulation parts based on the principal stress direction and stress gradient in the vibration area.

[0029] (3) Different from the traditional method of measuring stress state by attaching strain gauges in the

[001] direction, the present invention highlights the design of strain gauge attachment scheme based on key vibration modes and vibration principal stress directions.

[0030] (4) The present invention changes the method of directly measuring the tensile strength and fatigue limit of the standard parts, and instead obtains the fatigue limit and tensile strength by performing a Kt (stress concentration factor) test on the parts with typical vibration characteristics.

[0031] (5) The present invention establishes a three-point equal-life dynamic strength assessment model for typical stress concentration locations of single-crystal turbine blades taking into account the direction of dynamic stress, and establishes three-point equal-life models for the first-order and third-order vibration modes respectively through the test results of simulated parts.

[0032] (6) The present invention takes into account the anisotropy of single crystal materials and the directional characteristics of principal stress, and can more accurately evaluate the dynamic strength of single crystal turbine blades under different working conditions, especially the evaluation of first-order and third-order vibration modes, thereby ensuring the safe and reliable operation of aircraft engine turbine blades, while also promoting the improvement of the overall performance of aircraft engines and technological innovation. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 A flow chart of a preferred embodiment of a method for evaluating the dynamic strength of a typical vibration region of a nickel-based single crystal turbine blade according to the present invention;

[0034] Figure 2 for Figure 1 The placement position and placement method of the strain gauge in the first-order vibration mode in the embodiment shown;

[0035] Figure 3 for Figure 1 The patching position and patching method of the strain gauge in the third-order vibration mode in the embodiment shown;

[0036] Figure 4 for Figure 1 The illustrated embodiment shows a comparison diagram of a three-point equal life model taking stress concentration into account, a fatigue limit model taking stress concentration into account, and a fatigue limit model not taking stress concentration into account. DETAILED DESCRIPTION

[0037] In order to further understand the content of the present invention, the present invention will be described in detail below with reference to specific embodiments.

[0038] like Figure 1 As shown, according to a preferred embodiment of the method for evaluating the dynamic strength of a typical vibration region of a nickel-based single crystal turbine blade of the present invention, the evaluation method includes the following steps in order:

[0039] Step 1: Use finite element simulation software to establish a turbine blade model with a typical vibration area, and simulate the vibration characteristics of the turbine blade model to obtain vibration characteristics simulation results; based on the obtained vibration characteristics simulation results, analyze the deformation mode under each order of vibration mode, and determine the order of vibration mode under which the typical deformation mode is located. Subsequently, evaluate the dynamic strength of the typical vibration area of the turbine blade under this order of vibration mode;

[0040] Step 2: Based on the obtained vibration characteristics simulation results, analyze the typical vibration area characteristics and principal stress directions of the turbine blade under this order vibration mode, and design the typical characteristics and crystal orientation of the simulation part based on the typical vibration area characteristics and principal stress directions;

[0041] Step 3: Prepare several simulated parts with the designed typical features and crystal orientations for subsequent experiments;

[0042] Step 4: Perform a high-cycle fatigue test on the simulated part using a fatigue testing machine to obtain the high-cycle fatigue strength. Simultaneously, perform a tensile test on the simulated part using a tensile testing machine to obtain the tensile strength. Draw a fatigue limit model that takes stress concentration into account in a coordinate system where the abscissa is the tensile strength and the ordinate is the high-cycle fatigue strength. Connect the two numerical points of the obtained high-cycle fatigue strength and tensile strength.

[0043] Step 5: Use the fatigue testing machine to perform a high-cycle fatigue test on the simulated component again to obtain another high-cycle fatigue strength; with the origin as the rotation point, rotate the original coordinate system clockwise by a certain angle to form a new coordinate system, and plot the other high-cycle fatigue strength on the ordinate of the new coordinate system; draw a three-point equal life model that takes stress concentration into account in the original coordinate system, that is, connect the three numerical points of high-cycle fatigue strength in the original coordinate system, tensile strength in the original coordinate system, and high-cycle fatigue strength in the new coordinate system;

[0044] Step 6: Based on the obtained vibration characteristic simulation results, prepare a turbine blade with a typical vibration area, and use a core maneuvering test device to perform a core maneuvering test on the turbine blade to obtain dynamic stress. At the same time, based on the obtained vibration characteristic simulation results, obtain static stress; plot the dynamic stress and static stress on the ordinate and abscissa of the original coordinate system respectively, and draw a straight line perpendicular to the abscissa through the numerical point of the static stress. The straight line intersects with the three-point equal life model, and the high-cycle fatigue strength corresponding to the intersection point is the vibration fatigue limit; the ratio of the dynamic stress to the vibration fatigue limit is used as the dynamic strength of the typical vibration area of the turbine blade;

[0045] Step 7: Evaluate the safety of the turbine blades based on the dynamic strength value. If the dynamic strength value is greater than 1.67, it means that the turbine blades with typical vibration areas are unsafe and need to be redesigned or the material selected. If the dynamic strength value is less than or equal to 1.67, it means that the turbine blades with typical vibration areas are safe and can be used normally.

[0046] In step 1, the finite element simulation software is Abaqus. The typical vibration areas of the turbine blade include the film holes on the leading edge, the film holes on the blade basin, the film holes on the blade back, and the tail window on the trailing edge. The typical deformation modes are bending and torsional deformation, with the bending deformation occurring in the first-order vibration mode and the torsional deformation occurring in the third-order vibration mode.

[0047] In step 2, in the first-order vibration mode, the principal stress direction of the turbine blade is vertical, perpendicular to the horizontal plane, meaning the crystal orientation of the simulated component is

[001] . In the third-order vibration mode, the principal stress direction of the turbine blade is inclined at a 45-degree angle to the horizontal plane, meaning the crystal orientation of the simulated component is

[011] . A typical feature of the simulated component is that it is provided with a structure identical to or similar to the air film holes and the rear window.

[0048] In step 4, when performing high cycle fatigue test and tensile test, the strain gauge is attached to the typical characteristic position of the simulation part, and the patch direction of the strain gauge is the same as the crystal orientation. The patch position and patch method of the strain gauge under the first-order vibration mode are as follows: Figure 2 As shown, the patch position and patch method of the strain gauge under the third-order vibration mode are as follows Figure 3 As shown in the figure, the tension-compression ratio of the high cycle fatigue test is -1, and the number of cycles is 2×10 7 The tension-compression ratio of the tensile test is 1.

[0049] In step 5, when performing the high-cycle fatigue test, the strain gauge is attached to the typical characteristic part of the simulation part, and the direction of the strain gauge is consistent with the crystal orientation; the tension-compression ratio of the high-cycle fatigue test is 0.01, and the number of cycles is 2×10 7 times; adjust the rotation angle of the new coordinate according to the tension-compression ratio of the high-cycle fatigue test. The rotation angle of this embodiment is 35 degrees.

[0050] The three-point equal life model drawn in step five is more preferred than the fatigue limit model drawn in step four, and the vibration fatigue limit of the simulation component is determined according to the three-point equal life model.

[0051] In the traditional method of evaluating the dynamic strength of blades, standard parts are often used for testing and drawing Goodman curves. The working parts are not designed according to the typical vibration areas of different vibration modes of single-crystal turbine blades. The fatigue limit is lower than the Goodman curve considering Kt (stress concentration), and there is a certain deviation from the actual performance. In the three-point equal life model established after considering Kt (stress concentration), the Goodman curve considering Kt (stress concentration) is optimized again, so that there is a more reasonable evaluation mode when designing the specimen, and there has been great progress in the evaluation of dynamic stress. The comparison diagram of the three-point equal life model considering stress concentration, the fatigue limit model considering stress concentration, and the fatigue limit model without considering stress concentration is shown below. Figure 4 As shown, the intersection data of the model's ordinate high cycle fatigue strength and the abscissa tensile strength and tension-compression ratio lines are obtained from the Kt test.

[0052] This example evaluates the dynamic strength of nickel-based single-crystal turbine blades under actual operating conditions, analyzing in detail the main deformation modes and stress concentration areas of the turbine blades under different vibration modes. In the first-order vibration mode analysis, the turbine blades primarily deform by bending, with stresses primarily concentrated in areas such as the film holes at the leading edge and the tail window at the trailing edge, which are considered typical vibration areas. In the third-order vibration mode analysis, the turbine blades primarily deform by torsional deformation, with stresses primarily concentrated in areas such as the film holes at the blade base and the blade back, which are also considered typical vibration areas.

[0053] Based on the above analysis, this embodiment proposes a more accurate dynamic strength assessment method. This method requires appropriate assessment based on the actual operating conditions and principal stress directions of single-crystal turbine blades. Specifically, the safety of turbine blades is assessed based on the dynamic strength value. If the dynamic strength value is greater than 1.67, the turbine blade with a typical vibration region is unsafe and requires structural redesign or material selection. If the dynamic strength value is less than or equal to 1.67, the turbine blade with a typical vibration region is safe and can be used normally. This method can more accurately assess and ensure the dynamic strength of single-crystal turbine blades under various operating conditions, thereby improving the safety and reliability of the entire aircraft engine system.

[0054] The method for evaluating the dynamic strength of a typical vibration region of a nickel-based single-crystal turbine blade in this embodiment has the following beneficial effects: (1) It can better evaluate the dynamic strength of a typical vibration region of a single-crystal turbine blade with crystal anisotropy characteristics, forming a dynamic strength evaluation method that conforms to the actual vibration conditions of a single-crystal turbine blade under service conditions, greatly improving the accuracy of the design and evaluation process, and providing strong support for improving the safety and reliability of aircraft engines. (2) Unlike the previous standard test piece design, it takes into account the characteristics of single-crystal crystal anisotropy and innovatively proposes to design a simulation piece based on the principal stress direction and stress gradient of the vibration region. (3) Unlike the traditional

[001] direction strain gauge measurement of stress state, it highlights the design of strain gauges based on key vibration modes and vibration principal stress directions. (4) Instead of directly measuring the tensile strength and fatigue limit of standard parts, the fatigue limit and tensile strength are obtained by performing Kt tests on parts with typical vibration characteristics. (5) A three-point equal-life dynamic strength assessment model for typical stress concentration locations of single-crystal turbine blades, taking into account the direction of dynamic stress, was established. Three-point equal-life models for the first-order and third-order vibration modes were established using simulated component test results. (6) By taking into account the anisotropy of single-crystal materials and the directional characteristics of principal stresses, the dynamic strength of single-crystal turbine blades can be more accurately assessed under different operating conditions, especially for the first-order and third-order vibration modes, thereby ensuring the safe and reliable operation of aircraft engine turbine blades.

[0055] Special Note: The technical solution of this invention involves numerous parameters, and the synergistic effects between these parameters must be comprehensively considered to achieve the beneficial effects and significant improvements of this invention. Furthermore, the value ranges of each parameter in the technical solution were obtained through extensive testing. The inventors have recorded extensive experimental data for each parameter and their combinations. Due to space limitations, the specific experimental data will not be disclosed here.

[0056] Those skilled in the art will readily appreciate that the present invention's method for evaluating the dynamic strength of a nickel-based single-crystal turbine blade in a typical vibration region comprises any combination of the components described in the Summary and Detailed Description sections of the present invention specification, as well as the components illustrated in the accompanying drawings. Due to space limitations and for the sake of clarity, not all of the various solutions resulting from these combinations are described. Any modifications, equivalent substitutions, and improvements within the spirit and principles of the present invention are intended to be included within the scope of protection of the present invention.

Claims

1. A method for evaluating the dynamic strength of a typical vibration region of a nickel-based single crystal turbine blade, characterized by: The evaluation method comprises the following steps in order: Step 1: Use finite element simulation software to establish a turbine blade model with a typical vibration area, and simulate the vibration characteristics of the turbine blade model to obtain vibration characteristics simulation results; based on the obtained vibration characteristics simulation results, analyze the deformation mode under each order of vibration mode, and determine the order of vibration mode under which the typical deformation mode is located. Subsequently, evaluate the dynamic strength of the typical vibration area of the turbine blade under this order of vibration mode; Step 2: Based on the obtained vibration characteristics simulation results, analyze the typical vibration area characteristics and principal stress directions of the turbine blade under this order vibration mode, and design the typical characteristics and crystal orientation of the simulation part based on the typical vibration area characteristics and principal stress directions; Step 3: Prepare several simulated parts with the designed typical features and crystal orientations for subsequent experiments; Step 4: Use a fatigue testing machine to perform a high-cycle fatigue test on the simulated part to obtain the high-cycle fatigue strength, and use a tensile testing machine to perform a tensile test on the simulated part to obtain the tensile strength; Draw a fatigue limit model taking stress concentration into account in a coordinate system where the horizontal axis is tensile strength and the vertical axis is high cycle fatigue strength, that is, connect the two numerical points of high cycle fatigue strength and tensile strength; Step 5: Use the fatigue testing machine to perform a high-cycle fatigue test on the simulated component again to obtain another high-cycle fatigue strength; with the origin as the rotation point, rotate the original coordinate system clockwise by a certain angle to form a new coordinate system, and plot the other high-cycle fatigue strength on the ordinate of the new coordinate system; draw a three-point equal life model that takes stress concentration into account in the original coordinate system, that is, connect the three numerical points of high-cycle fatigue strength in the original coordinate system, tensile strength in the original coordinate system, and high-cycle fatigue strength in the new coordinate system; Step 6: Based on the obtained vibration characteristics simulation results, a turbine blade with a typical vibration area is prepared, and a core maneuvering test is performed on the turbine blade using a core maneuvering test device to obtain dynamic stress. At the same time, static stress is obtained based on the obtained vibration characteristics simulation results. The dynamic stress and static stress are plotted on the ordinate and abscissa of the original coordinate system, respectively. A straight line perpendicular to the abscissa is drawn through the numerical point of the static stress. This straight line intersects with the three-point equal life model. The high-cycle fatigue strength corresponding to the intersection point is the vibration fatigue limit. The ratio of the dynamic stress to the vibration fatigue limit is used as the dynamic strength of the typical vibration area of the turbine blade. Step 7: Evaluate the safety of the turbine blade based on the dynamic strength value. If the dynamic strength value is greater than 1.67, it means that the turbine blade with a typical vibration area is unsafe and needs to be redesigned or the material selected. If the value of the dynamic strength is less than or equal to 1.67, it means that the turbine blade with a typical vibration area is safe and can be used normally.

2. The method for evaluating the dynamic strength of a typical vibration region of a nickel-based single crystal turbine blade according to claim 1, characterized in that: In step 1, the finite element simulation software includes any one or more of Abaqus, Ansys, MSC.Marc, and iSight.

3. The method for evaluating the dynamic strength of a typical vibration region of a nickel-based single crystal turbine blade according to claim 2, characterized in that: In step 1, the typical vibration area of the turbine blade includes any one or more of the film holes at the leading edge, the film holes at the blade basin, the film holes at the blade back, and the tail window at the trailing edge.

4. The method for evaluating the dynamic strength of a typical vibration region of a nickel-based single crystal turbine blade according to claim 3, characterized in that: In step 1, the typical deformation modes are bending deformation and torsional deformation, the bending deformation is in the first-order vibration mode, and the torsional deformation is in the third-order vibration mode.

5. The method for evaluating the dynamic strength of a typical vibration region of a nickel-based single crystal turbine blade according to claim 4, characterized in that: In step 2, under the first-order vibration mode, the principal stress direction of the turbine blade is a vertical direction perpendicular to the horizontal plane, that is, the crystal orientation of the simulation component is [001] direction; under the third-order vibration mode, the principal stress direction of the turbine blade is an inclined direction at a certain angle to the horizontal plane, that is, the crystal orientation of the simulation component is [011] direction.

6. The method for evaluating the dynamic strength of a typical vibration region of a nickel-based single crystal turbine blade according to claim 5, characterized in that: In step 2, a typical feature of the simulation part is that a structure identical to or similar to the air film hole and / or the rear window is provided on the simulation part.

7. The method for evaluating the dynamic strength of a typical vibration region of a nickel-based single crystal turbine blade according to claim 6, characterized in that: In step 4, when performing high-cycle fatigue and tensile tests, the strain gauges were attached to the typical characteristic parts of the simulated component, and the direction of the strain gauges was consistent with the crystal orientation. The tension-compression ratio of the high-cycle fatigue test was -1, and the number of cycles was 2×10 7 The tension-compression ratio of the tensile test is 1.

8. The method for evaluating the dynamic strength of a typical vibration region of a nickel-based single crystal turbine blade according to claim 7, characterized in that: In step 5, when performing the high-cycle fatigue test, the strain gauge is attached to the typical characteristic part of the simulation part, and the direction of the strain gauge is consistent with the crystal orientation; the tension-compression ratio of the high-cycle fatigue test is 0.01, and the number of cycles is 2×10 7 times; adjust the rotation angle of the new coordinate according to the tension-compression ratio of the high-cycle fatigue test, and control the rotation angle within 20-70 degrees.

9. The method for evaluating the dynamic strength of a typical vibration region of a nickel-based single crystal turbine blade according to claim 8, characterized in that: The three-point equal life model drawn in step five is more preferred than the fatigue limit model drawn in step four, and the vibration fatigue limit of the simulation component is determined according to the three-point equal life model.

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