A method and system for fatigue testing of a baffle-equipped turbine assembly

Abstract

The present application belongs to the technical field of engine component fatigue test, and particularly relates to a baffle turbine assembly fatigue test method and system; specifically comprising the following steps: a first stage test is performed on the turbine disc and baffle assembly; a matching locking device is designed according to the structure of the turbine disc and the counterweight blade; the baffle assembly is disassembled, the locking device is installed, and a second stage test is performed on the turbine disc; separation is realized by disassembling the baffle assembly after the first stage test is completed, and the locking device is introduced in the second stage to replace the baffle assembly to fix the counterweight blade, so that the baffle assembly can be effectively prevented from being prematurely invalid due to over-examination.

Description

Technical Field

[0001] This invention belongs to the field of fatigue testing technology for engine components, and specifically relates to a fatigue testing method and system for a turbine assembly with baffles. Background Technology

[0002] The gas turbine rotor is a core load-bearing component of an engine. It typically employs baffles, guide vanes, and other structures to prevent cooling air leakage and guide cooling air into the turbine blades according to the designed flow path. As life-limited components of aero-engines, the gas turbine disk and baffles operate under high temperature, high speed, and high aerodynamic loads for extended periods, enduring cyclic loads during operation. They are prone to failure due to low-cycle fatigue, leading to adverse effects. Therefore, it is usually necessary to verify their low-cycle fatigue life through full-scale component testing. The current industry standard method is the integral component one-time test method: all parts, including the turbine disk, front and rear baffles, connecting bolts, etc., are assembled into a complete rotor. Alternating centrifugal loads are applied at a constant high temperature on a rotating fatigue tester until a preset number of cycles is reached or the component fails.

[0003] Low-cycle fatigue testing of wheel discs is typically conducted on a vertical rotating testing machine. Because component testing machines struggle to simulate the temperature loads of a real engine operating condition, a uniform temperature field is usually used for testing. However, this method cannot fully replicate the non-uniform temperature distribution and thermal stress within an engine. While a uniform temperature field eliminates the thermal stress effects of temperature gradients on the wheel center, it generally requires increasing the test speed to ensure that the stress level at the wheel center is comparable to that of the engine under test conditions. Since the local stress in critical areas of the baffle is not significantly affected by temperature gradients, these areas often exhibit high stress levels and are frequently over-tested.

[0004] Therefore, the existing technical methods have the following inherent defects:

[0005] (1) Over-testing and under-testing coexist: Due to the different materials (such as material A for turbine disk and material B for baffle), structural dimensions and stress concentration coefficients of various rotor components, the damage accumulation rate varies greatly under uniform temperature test conditions. The stress concentration parts of the baffle (such as the stop) will reach the life limit first (over-testing), while the key parts of the turbine disk (such as the eccentric hole) are often far from reaching the test target (under-testing).

[0006] (2) High safety and economic risks: If the test continues to evaluate the turbine disk, the baffle that has passed the evaluation is at risk of breaking, which may lead to catastrophic accidents and scrapping of valuable test parts; if the test is stopped, the evaluation of the core components is insufficient and the test objective is not achieved.

[0007] (3) Data validity may be questionable: If cracks appear in the baffle during the test after the target is achieved, it will affect the interpretation of valid test cycle data and the validity of the test verification.

[0008] To address the aforementioned issues, this application proposes a fatigue testing method for a turbine assembly with baffles. Summary of the Invention

[0009] To address the above problems, this invention proposes a fatigue testing method for a turbine assembly with baffles, specifically including:

[0010] The first phase of testing was conducted on the turbine disk and baffle assembly;

[0011] Based on the structure of the turbine disk and the counterweight blades, a matching locking device is designed;

[0012] The baffle assembly was disassembled and the locking device was installed to conduct the second phase of testing on the turbine disk.

[0013] Furthermore, the turbine disk and baffle assembly underwent a first-stage test, including:

[0014] Identify the test components for the turbine disk and baffle assembly;

[0015] Based on the working data of the turbine disk and baffle assembly under engine conditions, determine the first stage test data of the turbine disk and baffle assembly.

[0016] Assemble and install the turbine disk and baffle assembly;

[0017] The first phase of the test was initiated based on the data from the first phase of the test.

[0018] Furthermore, based on the working data of the turbine disk and baffle assembly under engine conditions, the first-stage test data of the turbine disk and baffle assembly are determined, including:

[0019] Based on the operating temperature of the turbine disk and baffle assembly under engine conditions, determine the first stage test temperature of the turbine disk and baffle assembly.

[0020] Based on the equivalent stress of the turbine disk and baffle assembly under engine conditions, the equivalent stress and upper limit speed of the test under the first stage test conditions are obtained.

[0021] Based on the equivalent stress and the upper limit speed of the test under the first test condition, the stress coefficient of the turbine disk and baffle assembly test parts is determined.

[0022] Based on the stress coefficient of the test parts of the turbine disk and baffle assembly, determine the number of test cycles for the first stage of the turbine disk and baffle assembly.

[0023] Furthermore, based on the structure of the turbine disk and the counterweight blades, a matching locking device is designed, including:

[0024] The middle part of the locking device matches the tenon groove of the turbine disk, the end face of the locking device fits against the counterweight blade, and the two ends of the locking device lock and fix the counterweight blade.

[0025] Furthermore, a second phase of testing was conducted on the turbine disk after installing a locking device, including:

[0026] Based on the working data of the turbine disk test area under engine conditions, determine the second-stage test data of the turbine disk test area;

[0027] Assemble and install the turbine disk and locking device;

[0028] The second phase of the test will be initiated based on the data from the second phase of the test.

[0029] Furthermore, based on the operating data of the turbine disc test component under engine conditions, the second-stage test data for the turbine disc test component is determined, including:

[0030] The second-stage test temperature of the turbine disk is determined based on the operating temperature of the turbine disk test area under engine conditions.

[0031] Based on the equivalent stress of the turbine disk under engine conditions, the equivalent stress and upper limit speed of the test under the second stage test conditions are obtained.

[0032] Based on the equivalent stress and the upper limit speed of the test under the second stage test conditions, the stress coefficient of the turbine disk test part is determined;

[0033] The number of test cycles for the second stage of the turbine disk is determined based on the stress coefficient of the test area.

[0034] Furthermore, after the first phase of testing, the baffle assembly was disassembled for non-destructive testing.

[0035] Then, based on the number of test cycles in the second stage, the stress coefficient and fatigue characteristic index of the turbine disk test part, the number of test cycles of the turbine disk test part in the first stage equivalent test is obtained.

[0036] Based on the number of test cycles and life dispersion factor of the turbine disk test component in the first stage of equivalent test, the first stage tested safe life of the turbine disk test component is obtained.

[0037] Based on the safety life indicators of the turbine disk and baffle and the first stage of the safety life assessment of the turbine disk assessment components, the second stage of the safety life assessment of the turbine disk assessment components is obtained.

[0038] Furthermore, after the second phase of testing, the turbine disk underwent non-destructive testing.

[0039] Furthermore, the turbine disk and locking device are assembled and installed, including:

[0040] The locking device is embedded in the mortise and tenon joint of the turbine disc;

[0041] Install the locking device onto the counterweight blade, and limit and fix the counterweight blade by bending the assembly section on the locking device.

[0042] Furthermore, the width of the middle part of the locking device is greater than the spacing width of the tenon teeth of the turbine disk tenon groove, and the width of the middle part of the locking device is less than the bottom width of the turbine disk tenon groove.

[0043] This invention proposes a fatigue testing system for a turbine assembly with baffles. Based on the aforementioned fatigue testing method for a turbine assembly with baffles, the system includes:

[0044] Phase 1 test module: configured to conduct phase 1 tests on the turbine disk and baffle assembly;

[0045] Locking replacement module: configured to design a matching locking device based on the structure of the turbine disk and the counterweight blades;

[0046] The second-stage test module is configured to disassemble the baffle assembly and install the locking device to conduct the second-stage test on the turbine disk.

[0047] Beneficial effects

[0048] The advantages of this invention over the prior art are as follows:

[0049] 1. This application achieves separation by disassembling the baffle assembly after the first stage of testing and evaluation, and introduces a locking device in the second stage to replace the baffle assembly to fix the counterweight blade, which can effectively prevent the baffle assembly from failing prematurely due to over-testing.

[0050] 2. This application conducts a targeted second-stage test on the turbine disk after the first-stage test of the baffle assembly. This ensures a complete test of the baffle assembly while avoiding insufficient testing of the turbine disk and the problem of accumulated damage to various components deviating from the actual situation.

[0051] 3. This application removes the baffle assembly after it has been tested, thus preventing the baffle assembly from exceeding its lifespan limit undetected, which could lead to failure and the scrapping of the entire set of test pieces worth millions of dollars.

[0052] 4. This application avoids the problem of low testing efficiency caused by conservatively setting test parameters and extending the test cycle in order to protect the weakest component by adopting a two-stage test.

[0053] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention can be realized and obtained by means of the structures pointed out in the description and the drawings. Attached Figure Description

[0054] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0055] Figure 1a A schematic diagram of an installation of a turbine disk and baffle assembly in the prior art is shown.

[0056] Figure 1b This diagram illustrates another installation schematic of the turbine disk and baffle assembly in the prior art.

[0057] Figure 2a A schematic diagram showing the location of the main test parts of the turbine disk in an embodiment of the present invention is shown.

[0058] Figure 2b A schematic diagram showing the location of the main test parts of the baffle assembly in an embodiment of the present invention is shown.

[0059] Figure 3a A partial front view of the turbine disk tenon groove in an embodiment of the present invention is shown.

[0060] Figure 3b A partial structural diagram of the turbine disk tenon groove in an embodiment of the present invention is shown.

[0061] Figure 3c A top view of a portion of the turbine disk tenon groove in an embodiment of the present invention is shown.

[0062] Figure 4a A schematic diagram of a locking device according to an embodiment of the present invention is shown.

[0063] Figure 4b A schematic diagram showing the angle between a locking device and the rotor center axis in an embodiment of the present invention is shown.

[0064] Figure 5 A schematic diagram of another locking device in an embodiment of the present invention is shown.

[0065] Figure 6 A schematic diagram of the installation of the turbine disk, locking device and counterweight blades in an embodiment of the present invention is shown.

[0066] Figure 7 A flowchart of the experimental method in an embodiment of the present invention is shown. Detailed Implementation

[0067] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0068] In existing technical solutions, the commonly used method is a one-time testing method for the entire component, which specifically includes:

[0069] Specimen assembly: Assemble the turbine disk, front and rear baffles, bolts, counterweight blades, etc. into a complete rotor according to the engine's condition.

[0070] Test conditions: Maintain a constant high temperature environment (usually 400℃~650℃) on a rotating fatigue tester.

[0071] Load application: The centrifugal load spectrum is applied in a cycle of "0-maximum speed-0". The test is usually carried out at room temperature or uniform temperature.

[0072] Termination condition: Reaching the predetermined total number of cycles or detecting component failure.

[0073] This method can evaluate multiple components in a single test, but it cannot solve the problem that the damage accumulation rate of each component is different under a uniform temperature field.

[0074] In existing technical solutions, the gas turbine rotor is tested as a whole until the target number of test cycles or fatigue failure occurs. This method has the following main drawbacks:

[0075] 1) Insufficient accuracy of assessment: The uniform temperature field cannot simulate the actual temperature gradient distribution of the engine, and the cumulative damage of each component deviates from the actual situation.

[0076] 2) Safety risks: Weak components (baffles) may exceed their lifespan limit without being detected, and are relatively prone to failure.

[0077] 3) Poor economic efficiency: A complete set of test pieces worth millions may be scrapped due to the premature failure of a low-cost baffle.

[0078] 4) Low data validity: Either the turbine disk assessment is insufficient, or the baffle data is distorted due to over-assessment.

[0079] 5) Low testing efficiency: In order to take care of the weakest part, it is often necessary to set the test parameters conservatively and extend the test cycle.

[0080] This application proposes a phased fatigue testing method for turbine disk assemblies with baffles and a blade locking device. The method assesses the turbine assembly with baffles in two phases: the first phase assesses the overall structure of the turbine disk-baffle (especially the baffle), and the second phase assesses the core component (turbine disk) separately. This method achieves accurate, comprehensive, and safe step-by-step inspection of all key components such as the turbine disk and baffle, ensuring the effectiveness of the life verification of the entire assembly and the economic efficiency of the test.

[0081] This application provides a fatigue testing method for a turbine assembly with baffles, referencing... Figure 7 Specifically, it includes the following steps:

[0082] The first phase of testing was conducted on the turbine disk and baffle assembly;

[0083] Based on the structure of the turbine disk and the counterweight blades, a matching locking device is designed;

[0084] The baffle assembly was disassembled and the locking device was installed to conduct the second phase of testing on the turbine disk.

[0085] The phased fatigue test method based on dynamic separation is as follows: the first stage test terminates when the baffle assembly is just in the test position; the baffle assembly is disassembled and the locking device replaces the baffle assembly to fix and lock the counterweight blade; the second stage test is to test the turbine disk separately and terminates when the turbine disk is cumulatively tested.

[0086] In one embodiment of the present invention, a first-stage test is conducted on the turbine disk and baffle assembly, including:

[0087] Identify the test components for the turbine disk and baffle assembly;

[0088] Based on the working data of the turbine disk and baffle assembly under engine conditions, determine the first stage test data of the turbine disk and baffle assembly.

[0089] Assemble and install the turbine disk and baffle assembly;

[0090] On the component testing machine, the first stage test is started according to the first stage test data.

[0091] Based on the working data of the turbine disc and baffle assembly under engine conditions, the first-stage test data for the turbine disc and baffle assembly are determined, including:

[0092] Based on the operating temperature of the turbine disk and baffle assembly under engine conditions, determine the first stage test temperature of the turbine disk and baffle assembly.

[0093] Based on the equivalent stress of the turbine disk and baffle assembly under engine conditions, the equivalent stress and upper limit speed of the test under the first stage test conditions are obtained.

[0094] Based on the equivalent stress and the upper limit speed of the test under the first test condition, the stress coefficient of the turbine disk and baffle assembly test parts is determined.

[0095] Based on the stress coefficient of the test parts of the turbine disk and baffle assembly, determine the number of test cycles for the first stage of the turbine disk and baffle assembly.

[0096] After the first phase of testing is completed, the baffle assembly will be disassembled for non-destructive testing.

[0097] Then, based on the number of test cycles in the second stage, the stress coefficient and fatigue characteristic index of the turbine disk test part, the number of test cycles of the turbine disk test part in the first stage equivalent test is obtained.

[0098] Based on the number of test cycles and life dispersion factor of the turbine disk test component in the first stage of equivalent test, the first stage tested safe life of the turbine disk test component is obtained.

[0099] Based on the safety life indicators of the turbine disk and baffle and the first stage of the safety life assessment of the turbine disk assessment components, the second stage of the safety life assessment of the turbine disk assessment components is obtained.

[0100] S01: Stress analysis of turbine disk and baffle assembly under working conditions: First, based on typical flight missions of aircraft or helicopters, obtain the speed, temperature load, aerodynamic load, axial preload and other loads borne by the turbine disk and baffle, and carry out three-dimensional stress analysis of engine turbine disk and baffle assembly.

[0101] S02: Determine the main test areas for the first stage of the test: Select several key locations on the turbine disk and baffle (such as the tenon groove, wheel center, eccentric hole, etc. of the turbine disk, for reference). Figure 2a The stop d1 and the vent d4 formed on the baffle assembly; Figure 2b The stop d1 formed on the baffle assembly, the bolt hole d2 and the ventilation groove d3 are used as the test parts for low-cycle fatigue testing.

[0102] S03: Determine the first stage test temperature: Based on the working temperature of the main test parts (wheel center or tenon groove) of the turbine disk and baffle assembly under engine conditions, determine the test temperature T1 for the low cycle fatigue test of the turbine disk and baffle assembly.

[0103] S04: Determine the upper limit speed for the first stage test: Based on the damage equivalence principle, and according to the equivalent stress of the main test parts of the turbine disk (wheel center or tenon groove) under engine conditions. Ensure the stress coefficient at the key test areas The equivalent stress of the turbine disk at the main test parts was obtained under the first stage fatigue test condition, with a value of approximately 1.0. and the upper limit speed of the test The specific calculation method is as follows:

[0104] (1)

[0105] (2)

[0106] In the formula:

[0107] The stress coefficient of the main test component of the wheel is determined under the first stage of the test conditions.

[0108] —Equivalent stress of the main test parts of the turbine disk under the first stage of test conditions, MPa;

[0109] —Equivalent stress of key components of the turbine disk under engine operating conditions, MPa;

[0110] —Ultimate tensile strength of turbine disk material at engine operating temperature, MPa;

[0111] —Ultimate tensile strength of turbine disk material at the first-stage test temperature, MPa;

[0112] —The functional relationship between the equivalent stress of the main test parts of the turbine disk and the test rotation speed at a certain temperature;

[0113] —The upper limit speed (r / min) for the first stage of low-cycle fatigue testing of turbine disk and baffle assembly.

[0114] In this step, the stress coefficient of the main test parts of the turbine disk is calculated separately using formula (1). The equivalent stress that the main test parts of the turbine disk should achieve under the corresponding test conditions. Finally, three-dimensional finite element iterative calculations were used to adjust the upper limit speed of the turbine disk during the calculation. Until the calculated equivalent stress of the main test parts of the roulette wheel is... The corresponding upper limit speed for the test at this time is .

[0115] S05: Determine the stress coefficient for the first stage of testing: based on the equivalent stress of the engine condition baffle test areas (stop, bolt holes, ventilation slots, etc.). Equivalent stress of secondary test parts of the turbine disk (such as eccentric holes) The upper limit rotational speed of the first stage fatigue test was obtained through finite element calculation. Equivalent stress in these parts under these conditions The test parts of the baffle assembly are calculated using the following formula. Stress coefficient of secondary test parts of turbine disk The specific calculation method is as follows:

[0116] (3)

[0117] (4)

[0118] (5)

[0119] (6)

[0120] In the formula:

[0121] —Stress coefficient of secondary test components of the baffle under the first stage test conditions;

[0122] —Equivalent stress of secondary test parts of the baffle assembly under the first stage test conditions, MPa;

[0123] —Equivalent stress of secondary test parts of the baffle under engine operating conditions, MPa;

[0124] —Ultimate tensile strength of the baffle assembly material at engine operating temperature, MPa;

[0125] —Ultimate tensile strength of the baffle material at the first-stage test temperature, MPa;

[0126] —The functional relationship between the equivalent stress of the secondary test parts of the baffle and the test rotation speed at a certain temperature;

[0127] —The upper limit speed of the first-stage turbine disk and baffle rotor assembly low-cycle fatigue test, in r / min;

[0128] —Stress coefficient of secondary test components of the turbine disk under the first stage test conditions;

[0129] —Equivalent stress of secondary test parts of the turbine disk under the first stage test conditions, MPa;

[0130] —Equivalent stress of secondary test components of the turbine disk under engine operating conditions, MPa;

[0131] —Ultimate tensile strength of turbine disk material at engine operating temperature, MPa;

[0132] —Ultimate tensile strength of turbine disk material at the first-stage test temperature, MPa;

[0133] —The functional relationship between the equivalent stress of the secondary test parts of the turbine disk and the test rotation speed at a certain temperature;

[0134] —The upper limit speed of the first-stage turbine disk and baffle rotor assembly low-cycle fatigue test, in r / min;

[0135] S06: Determine the number of test cycles for the first phase: based on the target safe life index of the turbine disk and baffle assembly. Combined with lifetime dispersion coefficient By combining the stress coefficients in formulas (1), (4), and (6), the required number of test cycles for the turbine disk and baffle assembly is determined. and The calculation method is as follows:

[0136] (7)

[0137] (8)

[0138] (9)

[0139] (10)

[0140] In the formula:

[0141] —The number of test cycles required to verify the safe life index of the main test components of the turbine disk;

[0142] —The number of test cycles required to verify the safe life index for secondary test components of the turbine disk;

[0143] —Number of test cycles required to verify the front fender to the safe life index;

[0144] —Safety life index of turbine disk and baffle assembly, times;

[0145] —Number of test cycles (in seconds) for the turbine disk and baffle assembly in the first phase;

[0146] , —Stress coefficients of the secondary test parts of the wheel and the test parts of the baffle under test conditions;

[0147] p—fatigue characteristic index, mainly determined by the fatigue characteristics of the turbine disk material;

[0148] —Lifetime dispersion factor, a constant related to the number of test specimens, for example: when there is 1 test specimen, K=4.

[0149] Generally, since the baffle is in an over-tested state while parts of the turbine disk are in a normal or under-tested state, the baffle assembly will reach the required number of test cycles before the turbine disk. Therefore, the number of cycles in the first phase of the experiment is taken as follows: = .

[0150] S07: Initial assembly and installation of turbine disk and baffle assembly: The turbine disk, baffle assembly, bolts, etc. are then assembled into a complete rotor test piece according to the engine condition. Counterweight blades are installed to simulate the centrifugal force of real blades, and dynamic balancing is performed.

[0151] S08: Perform the first phase test: the temperature of the first phase test. Below, the test upper limit speed is Low-cycle fatigue testing was conducted until... The machine was stopped after one test cycle.

[0152] S09: Disassembly Inspection and Validity Confirmation: Disassemble the baffle assembly and perform non-destructive testing to confirm its integrity, proving that the baffle has passed the safety life index assessment and verification.

[0153] S10: Evaluation of the turbine disk's interim assessment results: Calculate the number of test cycles for each key component of the turbine disk in the first stage of equivalent assessment. The first phase has already assessed the safe lifespan. And the second phase requires continued assessment of safe lifespan. :

[0154] (11)

[0155] (12)

[0156] (13)

[0157] In the formula:

[0158] —Number of test cycles (times) for each test component of the turbine disk in the first stage of equivalent testing;

[0159] —The safe service life of each component of the turbine disk has been assessed in the first phase, [number] times;

[0160] —The second phase requires continued assessment of the safe lifespan of each component of the turbine disk, [number] times.

[0161] This application utilizes the time separation principle of the TRIZ method to separate the contradictory requirements of "requiring the baffle to survive in the early stage of the test" and "requiring the baffle not to restrict the turbine disk assessment in the later stage of the test" by disassembling the baffle assembly after the first stage of the test assessment. In the second stage, a locking device is introduced to replace the baffle assembly to fix the counterweight blades, which can effectively prevent the baffle assembly from failing prematurely due to over-testing.

[0162] In one embodiment of the present invention, a matching locking device is designed based on the structure of the turbine disk and the counterweight blades, comprising:

[0163] The middle part of the locking device matches the tenon groove of the turbine disk, the end face of the locking device fits against the counterweight blade, and the two ends of the locking device lock and fix the counterweight blade.

[0164] The width of the middle part of the locking device is greater than the spacing width of the tenon teeth of the turbine disk tenon groove, and the width of the middle part of the locking device is less than the bottom width of the turbine disk tenon groove.

[0165] Existing turbine disk and baffle assemblies, such as Figure 1a and Figure 1b As shown, the turbine disk and baffle assembly includes a turbine disk and a baffle assembly. The baffle assembly may be a front baffle installed on the front side of the turbine disk, or it may include front and rear baffles installed on the front and rear sides of the turbine disk, respectively. During low-cycle fatigue testing of the component, it can securely lock the counterweight blades, preventing axial movement of the counterweight blades after assembly. A locking device matching the turbine disk and counterweight blades should be designed to solve the technical problem of securing the counterweight blades after the baffle assembly is removed.

[0166] S11: Locking function design of the locking device: The locking device is also a locking plate, which is a plate-like structure. The locking plate includes a flange for embedding in the turbine disk tenon groove, and end pieces for extending out of the assembly section for limiting and fixing. (Reference) Figure 4a and Figure 3a To ensure effective axial and radial fit, the locking plate width It must be greater than the spacing between the tenon and mortise teeth. The bending height of the first and last sections It must be greater than the thickness of the bearing area of ​​the tenon and mortise. (Right now > ).

[0167] S12: Locking plate installation convenience design: The contact surface between the locking plate and the counterweight blade is flat, and the contact surface runs along the length of the turbine disk tenon groove. To ensure convenient locking plate installation, refer to... Figure 4a and Figure 3a , Figure 4a L2 represents the distance between the two ends of the locking device along the axial direction of the rotor center. Figure 3b In the middle, L1 is the length of the turbine disk tenon groove, and the mathematical relationship between the two is as follows: Locking plate width It must be smaller than the width of the bottom of the tenon. (Right now < < To facilitate installation and ensure a locking effect, the middle edge plate and the first and last end faces of the locking plate can also be designed with non-uniform thickness (see reference). Figure 5 Central locking device B, wherein the width at both ends is greater than the width in the middle. (See reference) Figure 4b and Figure 3c Because the orientation of the turbine disk tenon groove is perpendicular to the rotor center axis Angle, therefore the locking plate is also based on angle. To carry out the design.

[0168] S13: Manufacturing and Installation of Locking Plates: To ensure locking effectiveness, locking plates should be manufactured using high-temperature alloy plates to guarantee their lifespan under long-term testing in high-temperature environments. For ease of counterweight blade installation, the first end face of the locking plate should not be bent in the component state, but should be bent during assembly. The first and last end faces, as well as the middle edge plate, should all be bent. Ensure effective fit with the front and rear side walls of the tenon; refer to Figure 6 Where a is the turbine disk tenon groove, b is the locking device, and c is the counterweight blade. The middle part of the locking device b is embedded in the turbine disk tenon groove a. The end face of the counterweight blade c is in contact with the end face of the locking device b. After the two ends of the locking device b are bent, the ends abut against the side wall of the counterweight blade c.

[0169] In one embodiment of the present invention, the second-stage test of the turbine disk by installing a locking device includes:

[0170] Based on the working data of the turbine disk test area under engine conditions, determine the second-stage test data of the turbine disk test area;

[0171] Assemble and install the turbine disk and locking device;

[0172] On the component testing machine, the second stage test was started according to the second stage test data.

[0173] Based on the operating data of the turbine disc test area under engine conditions, the second-stage test data for the turbine disc test area are determined, including:

[0174] The second-stage test temperature of the turbine disk is determined based on the operating temperature of the turbine disk test area under engine conditions.

[0175] Based on the equivalent stress of the turbine disk under engine conditions, the equivalent stress and upper limit speed of the test under the second stage test conditions are obtained.

[0176] Based on the equivalent stress and the upper limit speed of the test under the second stage test conditions, the stress coefficient of the turbine disk test part is determined;

[0177] The number of test cycles for the second stage of the turbine disk is determined based on the stress coefficient of the test area.

[0178] Assemble and install the turbine disk and locking device, including:

[0179] The locking device is embedded in the mortise and tenon joint of the turbine disc;

[0180] Install the locking device onto the counterweight blade, and limit and fix the counterweight blade by bending the assembly section on the locking device.

[0181] After the second phase of testing, the turbine disk underwent non-destructive testing.

[0182] S14: Determine the second-stage test temperature: Based on the operating temperature of the main test parts of the turbine disk (wheel center, tenon groove, or eccentric hole) under engine conditions, determine the test temperature for the low-cycle fatigue test when the turbine disk is tested alone. .

[0183] S15: Determine the upper limit speed for the second stage test: Based on the damage equivalence principle, and according to the equivalent stress of the main test parts of the turbine disk (wheel center or tenon) under engine conditions. Ensure the stress coefficient at the key test areas The value is approximately 1.0. Formula (1) is used to obtain the upper limit speed of the second stage test. .

[0184] S16: Determine the stress coefficient for the second stage of testing: Obtain the upper limit speed of fatigue testing for secondary test parts of the turbine disk (such as the eccentric hole) through finite element calculation. Equivalent stress under certain conditions The stress coefficient of the secondary test part of the turbine disk is calculated by formula (6). .

[0185] S17: Determine the number of test cycles for the second phase: Based on the turbine disk, the second phase of the test needs to further assess the safe life. Combined with lifetime dispersion coefficient Based on the stress coefficient of the turbine disk test area in the second stage, the number of test cycles required for the turbine disk in the second stage is determined. :

[0186] (14)

[0187] (15)

[0188] (16)

[0189] In the formula

[0190] —Number of test cycles (times) for each test component of the turbine disk in the second stage of equivalent testing;

[0191] —The second phase requires continued assessment of the safe lifespan of each component of the turbine disk, [number] times.

[0192] —The stress coefficient of the main test part of the wheel under the second stage test conditions;

[0193] —Number of test cycles (times) for the secondary test components of the turbine disk in the second stage of equivalent testing;

[0194] —Stress coefficient of secondary test parts of the roulette wheel under the second stage test conditions;

[0195] S18: Initial assembly and installation of turbine disk assembly: Install counterweight blades to simulate the centrifugal force of real blades. Use a specially designed counterweight blade locking device to embed into the turbine disk tenon groove and lock it in place, replacing the original baffle's locking effect on the counterweight blades. Perform dynamic balancing adjustments.

[0196] S19: Conduct the second phase test: Temperature during the second phase test Below, the test upper limit speed is Low-cycle fatigue testing was conducted until... The machine was stopped after one test cycle.

[0197] S20: Disassembly Inspection and Effectiveness Assessment: Conduct a comprehensive non-destructive test on the turbine disk to confirm its integrity and prove that the turbine disk has passed the safety life index assessment.

[0198] This application proposes a fatigue testing system for a turbine assembly with baffles. Based on the above-mentioned fatigue testing method for a turbine assembly with baffles, the system includes:

[0199] Phase 1 test module: configured to conduct phase 1 tests on the turbine disk and baffle assembly;

[0200] Locking replacement module: configured to design a matching locking device based on the structure of the turbine disk and the counterweight blades;

[0201] The second-stage test module is configured to disassemble the baffle assembly and install the locking device to conduct the second-stage test on the turbine disk.

[0202] For example, if the safe life index of a turbine disk-baffle assembly is 10,000 cycles, and there is only one test piece (turbine disk and front baffle), then the life dispersion coefficient K=4. In the first stage of the test, the stress coefficients at the tenon and wheel center are 0.985 and 1.045, respectively, and the stress coefficient of the front baffle is 1.119. The number of test cycles required to verify the safe life index is shown in Table 1. The front baffle is the first to reach the required safe life, so the number of test cycles in the first stage is 22,800. The assessment results for each part are shown in Table 2. In the second stage of the test, the stress coefficients at the tenon and wheel center are 1.000 and 1.035, respectively. The tenon is the last part to reach the safe life, so the number of test cycles in the second stage is 18,600. The assessment results for each part are shown in Table 3, and the cumulative assessment results are shown in Table 4. Through the two stages of testing, the turbine disk-baffle assembly has been successfully verified.

[0203] Table 1. Number of test cycles required to verify safe life indicators under the first stage of test conditions.

[0204]

[0205] Table 2. Evaluation results of various parts of the turbine disk and baffle assembly under the first stage of test conditions.

[0206]

[0207] Table 3. Performance evaluation of various parts of the turbine disk under the second-stage test conditions.

[0208]

[0209] Table 4. Cumulative assessment results of various parts of the turbine disk and baffle assembly during the two-stage test.

[0210]

[0211] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A fatigue testing method for a turbine assembly with baffles, characterized in that, Specifically, it includes: The first phase of testing was conducted on the turbine disk and baffle assembly; Based on the structure of the turbine disk and the counterweight blades, a matching locking device is designed; Disassemble the baffle assembly, install the locking device, and conduct the second phase test on the turbine disk; The first phase of testing of the turbine disk and baffle assembly includes: Identify the test components for the turbine disk and baffle assembly; Based on the working data of the turbine disk and baffle assembly under engine conditions, determine the first stage test data of the turbine disk and baffle assembly. Assemble and install the turbine disk and baffle assembly; The first phase of the test will be initiated based on the data from the first phase of the test. Based on the working data of the turbine disc and baffle assembly under engine conditions, the first-stage test data for the turbine disc and baffle assembly are determined, including: Based on the operating temperature of the turbine disk and baffle assembly under engine conditions, determine the first stage test temperature of the turbine disk and baffle assembly. Based on the equivalent stress of the turbine disk and baffle assembly under engine conditions, the equivalent stress and upper limit speed of the test under the first stage test conditions are obtained. Based on the equivalent stress and the upper limit speed of the test under the first test condition, the stress coefficient of the turbine disk and baffle assembly test parts is determined. Based on the stress coefficient of the test parts of the turbine disk and baffle assembly, determine the number of test cycles for the first stage of the turbine disk and baffle assembly. The second phase of testing of the turbine disk involves installing a locking device, including: Based on the working data of the turbine disk test area under engine conditions, determine the second-stage test data of the turbine disk test area; Assemble and install the turbine disk and locking device; The second phase of the test will be initiated based on the data from the second phase of the test. Based on the operating data of the turbine disc test area under engine conditions, the second-stage test data for the turbine disc test area are determined, including: The second-stage test temperature of the turbine disk is determined based on the operating temperature of the turbine disk test area under engine conditions. Based on the equivalent stress of the turbine disk under engine conditions, the equivalent stress and upper limit speed of the test under the second stage test conditions are obtained. Based on the equivalent stress and the upper limit speed of the test under the second stage test conditions, the stress coefficient of the turbine disk test part is determined; The number of test cycles for the second stage of the turbine disk is determined based on the stress coefficient of the test area.

2. The fatigue testing method for a turbine assembly with baffles according to claim 1, characterized in that, Based on the structure of the turbine disk and the counterweight blades, a matching locking device is designed, including: The middle part of the locking device matches the tenon groove of the turbine disk, the end face of the locking device fits against the counterweight blade, and the two ends of the locking device lock and fix the counterweight blade.

3. The fatigue testing method for a turbine assembly with baffles according to claim 1, characterized in that, At the end of the first phase of the experiment, including: First, disassemble the baffle assembly for non-destructive testing; Then, based on the number of test cycles in the second stage, the stress coefficient and fatigue characteristic index of the turbine disk test part, the number of test cycles of the turbine disk test part in the first stage equivalent test is obtained. Based on the number of test cycles and life dispersion factor of the turbine disk test component in the first stage of equivalent test, the first stage tested safe life of the turbine disk test component is obtained. Based on the safety life indicators of the turbine disk and baffle and the first stage of the safety life assessment of the turbine disk assessment components, the second stage of the safety life assessment of the turbine disk assessment components is obtained.

4. The fatigue testing method for a turbine assembly with baffles according to claim 3, characterized in that, At the end of the second phase of the test, including: Perform non-destructive testing on the turbine disk.

5. The fatigue testing method for a turbine assembly with baffles according to claim 2, characterized in that, Assemble and install the turbine disk and locking device, including: The locking device is embedded in the mortise and tenon joint of the turbine disc; Install the locking device onto the counterweight blade, and limit and fix the counterweight blade by bending the assembly section on the locking device.

6. The fatigue testing method for a turbine assembly with baffles according to claim 2, characterized in that, The width of the middle part of the locking device is greater than the spacing width of the tenon teeth of the turbine disk tenon groove, and the width of the middle part of the locking device is less than the bottom width of the turbine disk tenon groove.

7. A fatigue testing system for a turbine assembly with baffles, based on the fatigue testing method for a turbine assembly with baffles according to any one of claims 1-6, characterized in that, The system includes: Phase 1 test module: configured to conduct phase 1 tests on the turbine disk and baffle assembly; Locking replacement module: configured to design a matching locking device based on the structure of the turbine disk and the counterweight blades; The second-stage test module is configured to disassemble the baffle assembly and install the locking device to conduct the second-stage test on the turbine disk.

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