CN-122021168-A - Gas turbine compressor blade service life assessment method based on high-cycle fatigue characteristics

Abstract

The invention provides a service life assessment method of a gas turbine compressor blade based on high-cycle fatigue characteristics, which aims to solve the problem that a fatigue test under simple simulation and laboratory conditions cannot be effectively combined to meet the service life assessment of a core component of the gas turbine blade. According to the method, the strength condition and the vibration condition of the blade are determined through finite element analysis, then the attenuation rule of stable fatigue strength of the blade is obtained through actually measuring vibration stress and the fatigue limit values of the blade in different use time periods, and the service life of the gas turbine compressor blade is comprehensively estimated by taking high Zhou Zhendong fatigue reserve as a standard. The invention is not only limited to the compressor of the ship gas turbine, but also is suitable for effectively evaluating the service life of the movable vane of the compressor of the industrial gas turbine and the aeroengine, and can provide a fatigue reliability design direction for a newly developed model.

Inventors

• ZHANG LIANG
• YU HAITAO
• SUN YONG
• ZHAO JIAFENG
• YU JINGLEI
• JIN PENG
• HONG QINGSONG

Assignees

• 中国船舶集团有限公司第七〇三研究所

Dates

Publication Date

20260512

Application Date

20260202

Claims (8)

1. 1. The service life assessment method of the gas turbine compressor blade based on the high cycle fatigue characteristics is characterized by comprising the following steps of: s1, determining the static strength condition of a target blade, and carrying out finite element calculation analysis on the strength of the blade based on the boundary condition of blade installation to obtain the stress strain of the blade; S2, determining the vibration condition of a target blade, carrying out blade vibration characteristic analysis by considering the blade installation boundary, and determining a campbell diagram of the blade, wherein aerodynamic load, temperature load and centrifugal force load are considered in dynamic vibration calculation, and the maximum vibration stress point of the low-order mode blade is determined; S3, measuring the vibration condition of each blade in a non-contact mode, simultaneously measuring the vibration condition of each blade in the working process of the unit, and obtaining the vibration stress value of the maximum vibration stress point through conversion; S4, acquiring the fatigue limit of the long blade when not in use, and determining the use time section of the extraction blade based on the actual operation use condition of the blade, wherein the use time section is not less than 2 nearly identical time sections; s5, determining the fatigue strength of the gas turbine compressor in the working state through a Goldman asymmetric cycle fatigue curve; S6, determining the fatigue strength attenuation law of the blade in different life periods, comparing the fatigue test results, and determining the attenuation law of different time periods relative to the fatigue strength of the newly manufactured blade; s7, when the fatigue strength reserve is attenuated to 1, the vibration fatigue life of the blade is ended.
2. 2. The method for evaluating the service life of a gas turbine compressor blade based on high cycle fatigue characteristics according to claim 1, wherein the static strength condition in S1 includes considering aerodynamic load, temperature load, centrifugal force load of the blade.
3. 3. The method for evaluating the service life of a gas turbine compressor blade based on high cycle fatigue characteristics according to claim 1, wherein the step S3 of measuring the vibration condition of each blade in a non-contact manner is specifically to obtain the vibration condition of all blades at one level and evaluate the vibration condition by responding to the maximum blade result.
4. 4. The method for evaluating the service life of a gas turbine compressor blade based on high cycle fatigue characteristics according to claim 1, wherein the at least 2 nearly identical time periods in S4 are specifically a multiple of the running time of a selected test object for performing a blade fatigue test.
5. 5. The method for evaluating the service life of a gas turbine compressor blade based on high cycle fatigue characteristics according to claim 1, wherein the determining of the fatigue strength decay law of the blade in different service life periods in S6 is specifically to compare fatigue test results and determine the decay law of the blade in different time periods and 1 st service life period relative to the fatigue strength of the new blade.
6. 6. The method for evaluating the service life of a gas turbine compressor blade based on high cycle fatigue characteristics according to claim 5, wherein the fatigue strength decay law is obtained by the following formula: wherein: Logarithmic fatigue life for New blade The corresponding stress value; Is a constant calculated from the test results; n=0, 1,2,3. Work H trailing blade, work 2H trailing blade.
7. 7. The method for evaluating the service life of a gas turbine compressor blade based on high cycle fatigue characteristics according to claim 1, wherein the step S7 is characterized in that when the fatigue strength reserve is attenuated to 1, the vibration fatigue life of the blade is terminated, and when the ratio of the fatigue strength converted by the Goldman curve to the maximum value of the measured vibration stress is 1, the vibration fatigue life of the blade is considered to be terminated.
8. 8. The method for evaluating the service life of a gas turbine compressor blade based on high cycle fatigue characteristics according to claim 7, wherein the fatigue strength reserve is calculated as follows: wherein: is a vibration stress allowable value obtained by a Goldman curve; maximum value of working vibration stress of the blade.

Description

Gas turbine compressor blade service life assessment method based on high-cycle fatigue characteristics Technical Field The invention belongs to the technical field of structural reliability of gas turbines, and particularly relates to a service life assessment method of a gas turbine compressor blade based on high-cycle fatigue characteristics. Background The compressor blade is positioned at the forefront position in the gas turbine engine, and is one of the core parts of the gas turbine which are most sensitive to the influence of the external environment of the unit, have high damage frequency and have various fault modes. Therefore, it is important to be able to perform an effective life assessment of the compressor blades, whether for maintenance of the used units or for new machine development. The compressor blade is one of key components in the gas turbine, and has extremely complex working environment, severe stress state, long-term bearing of high-speed airflow impact and periodical centrifugal stress and pneumatic load. Under such high stress alternating conditions, microcracks are easily generated inside the blade material and gradually spread, eventually leading to fatigue failure. The fatigue performance of the compressor blade is directly related to the operation safety and service life of the gas turbine, so how to effectively obtain the service life of the compressor blade under the typical use condition of the gas turbine is a key technology which is highly needed. The service life research of the rotor blade of the air compressor has great technical difficulty and wide involved range, and the material performance and the processing technology of the blade are required to be considered in the service life research, and the vibration response characteristics of the blade caused by the running environment of the blade are required to be considered. The working environment of the compressor rotor blade is required to be capable of bearing very severe loads and mechanical responses generated by the very severe loads, and is also required to be capable of directly withstanding the influence of high-speed airflow scouring and even surface erosion, so that the actual service life of the compressor blade cannot be obtained under laboratory conditions, and great difficulty exists in directly utilizing classical fatigue theory and damage theory. Disclosure of Invention The invention aims to provide a service life assessment method of a gas turbine compressor blade based on high-cycle fatigue characteristics, which solves the problem that a fatigue test under simple simulation and laboratory conditions cannot be effectively combined to meet the service life assessment of a core component of the gas turbine blade. A service life assessment method of a gas turbine compressor blade based on high cycle fatigue characteristics comprises the following steps: s1, determining the static strength condition of a target blade, and carrying out finite element calculation analysis on the strength of the blade based on the boundary condition of blade installation to obtain the stress strain of the blade; S2, determining the vibration condition of a target blade, carrying out blade vibration characteristic analysis by considering the blade installation boundary, and determining a campbell diagram of the blade, wherein aerodynamic load, temperature load and centrifugal force load are considered in dynamic vibration calculation, and the maximum vibration stress point of the low-order mode blade is determined; S3, measuring the vibration condition of each blade in a non-contact mode, simultaneously measuring the vibration condition of each blade in the working process of the unit, and obtaining the vibration stress value of the maximum vibration stress point through conversion; S4, acquiring the fatigue limit of the long blade when not in use, and determining the use time section of the extraction blade based on the actual operation use condition of the blade, wherein the use time section is not less than 2 nearly identical time sections; s5, determining the fatigue strength of the gas turbine compressor in the working state through a Goldman asymmetric cycle fatigue curve; S6, determining the fatigue strength attenuation law of the blade in different life periods, comparing the fatigue test results, and determining the attenuation law of different time periods relative to the fatigue strength of the newly manufactured blade; s7, when the fatigue strength reserve is attenuated to 1, the vibration fatigue life of the blade is ended. Further, the static strength condition in S1 includes considering aerodynamic load, temperature load, and centrifugal force load of the blade. Further, in the step S3, the vibration condition of each blade is measured in a non-contact mode, specifically, the vibration condition of all the blades at one level is obtained, and the vibration condition is evaluated by responding to the maximum