Aero-engine blade vulnerable region division method, system and device and storage medium

Abstract

The invention provides an aero-engine blade vulnerable region division method, system and device and a storage medium, and the method comprises the steps: firstly building numerical models for various real aero-engine blades, carrying out the modal analysis through finite element analysis software, comparing the sizes of the front edge cross sections in the first three-order modals, selecting the numerical model with the thin cross section, and carrying out the modal analysis through the finite element analysis software; and marking as a dangerous numerical model, selecting a dangerous mode of the dangerous numerical model according to a dynamic stress test result, and taking the corresponding maximum stress point position in the dangerous mode as the vulnerable area of the corresponding real blade. According to the division method, the easily damaged weak part of the blade can be found out before the foreign object damage experiment is carried out, good operability and good interpretability are achieved, and the experiment cost can be greatly reduced while the experiment process is accelerated.

Description

Technical Field

[0001] The present invention relates to the technical field of aircraft engine blades, and in particular to a method, system, device and storage medium for dividing a vulnerable area of ​​an aircraft engine blade. Background Art

[0002] During flight, the engine often encounters foreign objects hitting or entering the engine, causing foreign object damage. Foreign object damage may come from various external objects such as birds, hail, debris, dust, etc., which may damage the engine's blades, turbines, turbine blades and other key components, causing engine performance to decline or even fail. Foreign object damage is one of the important hidden dangers to aircraft safety. High-speed aircraft engines often inhale various hard objects. Once these foreign objects enter the engine, their relative speed with the compressor blades can be as high as 100m / s to 350m / s, causing serious impact damage, especially to the first few stages of compressor blades and the leading edges of the blades. In the prior art, the damage caused by hard objects such as metal, sand and gravel hitting the engine is called "foreign object damage" (FOD for short).

[0003] Foreign object damage has a very serious impact on the engine, which may cause blade deformation, cracks, or even breakage. Once a blade breaks, it will fly off and cause serious damage to other blades or the casing. Since the location where the foreign object hits the leading edge of the blade is random, if we only use the control variable method to explore the effects of different foreign objects, different impact locations, and different impact angles on the fatigue limit of the blade, it will take a lot of time and money. If the weak areas on the blade that are most affected by impact damage can be marked before the experiment, it will greatly speed up the experiment and save resources. Summary of the invention

[0004] Purpose of the invention: The first purpose of the present invention is to provide a method for dividing vulnerable areas of aircraft engine blades which is easy to operate and has good interpretability. The second purpose is to provide a system, device and storage medium corresponding to the above-mentioned method for dividing vulnerable areas of aircraft engine blades.

[0005] Technical solution: A method for dividing the vulnerable area of ​​an aircraft engine blade includes the following steps:

[0006] (1) Establish several numerical models of real blades to be tested, give test conditions, and calculate the corresponding blade modes of each numerical model;

[0007] (2) Extract the natural frequencies and stress distributions of the first ten modes of each numerical model from the calculation results of the blade modes, and record the leading edge maximum stress point position and leading edge cross-sectional dimension data of each order of each numerical model;

[0008] (3) According to the leading edge section size data under the first three modes of each numerical model, the numerical models whose leading edge section size data is less than or equal to the set value are screened out and marked as dangerous numerical models;

[0009] (4) Based on the dynamic stress measurement data of the real blade corresponding to the dangerous numerical model, the corresponding order with dynamic stress greater than or equal to the dangerous threshold is screened out. The maximum stress point on the leading edge of the dangerous numerical model blade corresponding to the order is the vulnerable area of ​​the real blade corresponding to the dangerous numerical model.

[0010] Specifically, in step (1), a numerical model of the real blade to be tested is established and imported into the finite element analysis software, the material parameters of each numerical model are set, the mesh type, boundary conditions and blade speed are given, and the modes of each blade are calculated.

[0011] Specifically, the material parameters include density, elastic modulus, and Poisson's ratio.

[0012] Specifically, in step (3), the front cross-section size data is the front cross-section radius value.

[0013] Specifically, in step (4), the dangerous threshold of dynamic stress is 50 MPa.

[0014] The present invention also provides a system for dividing vulnerable areas of aircraft engine blades, comprising:

[0015] Modal calculation module: used to establish numerical models of several real blades to be tested, given test conditions, and calculate the corresponding blade modes of each numerical model;

[0016] Data extraction and recording module: used to extract the natural frequency and stress distribution of the first ten modes of each numerical model from the calculation results of the blade mode, and record the leading edge maximum stress point position and leading edge section size data of each order of each numerical model;

[0017] Dangerous blade screening module: used to screen out numerical models whose leading edge section size data is less than or equal to a set value according to the leading edge section size data under the first three modes of each numerical model, and mark them as dangerous numerical models;

[0018] Vulnerable area marking module: It is used to screen out the corresponding orders whose dynamic stress is greater than or equal to the dangerous threshold value according to the dynamic stress measurement data of the real blade corresponding to the dangerous numerical model. The maximum stress point on the leading edge of the dangerous numerical model blade corresponding to the order is the vulnerable area of ​​the real blade corresponding to the dangerous numerical model.

[0019] Specifically, the modal calculation module includes: establishing a numerical model of the real blade to be tested, importing it into the finite element analysis software, setting the material parameters of each numerical model, giving the grid type, boundary conditions and blade speed, and calculating each blade mode.

[0020] Specifically, in the dangerous blade screening module, the front section size data is the front section radius value.

[0021] The present invention also provides a device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps of the above-mentioned method for dividing the vulnerable area of ​​the aircraft engine blade are implemented.

[0022] The present invention also provides a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the steps of the above-mentioned method for dividing the vulnerable area of ​​the aircraft engine blade are implemented.

[0023] Beneficial effect: Compared with the prior art, the significant effect of the present invention is: the present invention performs modal analysis on the numerical models of various real blades, compares the leading edge cross-sectional dimensions under the first three modes, selects the blades with thinner blade profiles as dangerous blades, and selects the dangerous modes of the dangerous blades according to the dynamic stress test results. The corresponding maximum stress point position under the dangerous mode is the vulnerable area of ​​the blade. This method can find out the weak parts of the blade that are easily damaged before conducting the foreign object damage experiment. It has good operability and good interpretability. While speeding up the experimental process, it can greatly reduce the cost of the experiment. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a flow chart of the method for dividing the vulnerable area of ​​an aero-engine blade according to the present invention.

[0025] Figure 2 It is a cross-sectional dimension diagram of the first-stage leading edge of each blade of the present invention.

[0026] Figure 3 It is a cross-sectional dimension diagram of the second-order leading edge of each blade of the present invention.

[0027] Figure 4 It is a dimensional diagram of the 3rd-order leading edge section of each blade of the present invention. DETAILED DESCRIPTION

[0028] The present invention is further described in detail below with reference to the accompanying drawings.

[0029] See also Figure 1 As shown, the present invention discloses a method for dividing the vulnerable area of ​​an aero-engine blade, comprising the following steps:

[0030] (1) Use UG or other engineering modeling software to establish numerical models of various real aircraft engine blades, and import them into workbench or other finite element analysis software. Set the material parameters such as density, elastic modulus, Poisson's ratio, etc. of the corresponding numerical model of each blade, and set the mesh type, boundary conditions and rotation speed. After the settings are completed, calculate the modes of each blade.

[0031] (2) The natural frequencies and stress distributions of the first ten modes of the numerical model of each blade are extracted from the calculation results of the blade modes, and the leading edge maximum stress point position and leading edge cross-sectional size data of each order of each numerical model are recorded.

[0032] In this embodiment, five different types of aircraft engine blades are selected as examples for testing.

[0033] Please refer to Table 1 below, which records the natural frequencies of the first ten modes of each blade.

[0034] Table 1

[0035]

[0036] (3) According to the leading edge section size data under the first three modes of each numerical model, the numerical model whose leading edge section size data is smaller than the set value is selected and marked as a dangerous numerical model.

[0037] See also Figure 2-4 As shown, the leading edge section dimension diagrams of the above five blades under the 1st to 3rd order modes are respectively taken. Taking the leading edge section radius as the reference value and comprehensively considering the 1st to 3rd order modal data, blade No. 8111 has the smallest leading edge section radius. Therefore, in the above working conditions, blade No. 8111 is more susceptible to stress and is more easily injured by foreign objects than other blades. Therefore, in this embodiment, the numerical model corresponding to blade No. 8111 is a dangerous numerical model. In practical applications, the numerical threshold of the leading edge section radius can also be set according to expert experience to screen out dangerous blades with a leading edge section radius less than or equal to the threshold.

[0038] (4) Perform dynamic stress tests on the real blades corresponding to the dangerous numerical model or directly obtain dynamic stress measurement data from the blade manufacturer. Based on the dynamic stress measurement data of blade No. 8111, select the corresponding order with dynamic stress greater than or equal to the dangerous threshold. The maximum stress point at the leading edge of the numerical model corresponding to this order is the vulnerable area of ​​the real blade corresponding to the dangerous numerical model. Table 2 below is the dynamic stress measurement data table of blade No. 8111.

[0039] Table 2

[0040]

[0041] In this embodiment, dynamic stress exceeding 50Mpa is regarded as a dangerous threshold. According to the dynamic stress measurement data, the dynamic stress at 243Hz of strain gauge No. 2, 956Hz of strain gauge No. 1, and 3753Hz of strain gauge No. 3 all exceed 50Mpa, corresponding to the natural frequencies of the 1st, 3rd, and 10th modes of blade No. 8111, respectively. Therefore, the maximum stress points at the leading edge of the blade corresponding to the 1st, 3rd, and 10th orders are designated as vulnerable areas.

[0042] The present invention also discloses a system for dividing vulnerable areas of aircraft engine blades corresponding to the above division method, comprising:

[0043] Modal calculation module: used to establish the numerical model of the real blade to be tested, import it into the finite element analysis software, set the material parameters of each numerical model, give the grid type, boundary conditions and blade speed, and calculate the modes of each blade.

[0044] Data extraction and recording module: used to extract the natural frequency and stress distribution of the first ten modes of each numerical model from the calculation results of the blade mode, and record the leading edge maximum stress point position and leading edge section size data of each order of each numerical model.

[0045] Dangerous blade screening module: It is used to screen out numerical models whose leading edge section radius values ​​are less than or equal to the set value based on the leading edge section size data under the first three modes of each numerical model, and mark them as dangerous numerical models.

[0046] Vulnerable area marking module: It is used to screen out the corresponding orders whose dynamic stress is greater than or equal to the dangerous threshold value according to the dynamic stress measurement data of the real blade corresponding to the dangerous numerical model. The maximum stress point on the leading edge of the dangerous numerical model blade corresponding to the order is the vulnerable area of ​​the real blade corresponding to the dangerous numerical model.

[0047] The present invention also provides a device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps of the above-mentioned method for dividing the vulnerable area of ​​the aircraft engine blade are implemented.

[0048] The present invention also provides a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the steps of the above-mentioned method for dividing the vulnerable area of ​​the aircraft engine blade are implemented.

Claims

1. A method for dividing vulnerable areas of aircraft engine blades, characterized in that: The following steps are involved: (1) Establish several numerical models of real blades to be tested, give test conditions, and calculate the corresponding blade modes of each numerical model; (2) Extract the natural frequencies and stress distributions of the first ten modes of each numerical model from the calculation results of the blade modes, and record the leading edge maximum stress point position and leading edge cross-sectional dimension data of each order of each numerical model; (3) According to the leading edge section size data under the first three modes of each numerical model, the numerical models whose leading edge section size data is less than or equal to the set value are screened out and marked as dangerous numerical models; (4) Based on the dynamic stress measurement data of the real blade corresponding to the dangerous numerical model, the corresponding order with dynamic stress greater than or equal to the dangerous threshold is screened out. The maximum stress point on the leading edge of the dangerous numerical model blade corresponding to the order is the vulnerable area of ​​the real blade corresponding to the dangerous numerical model.

2. The method for dividing the vulnerable area of ​​an aircraft engine blade according to claim 1, characterized in that: In step (1), a numerical model of the real blade to be tested is established and imported into the finite element analysis software, the material parameters of each numerical model are set, the mesh type, boundary conditions and blade speed are given, and the modes of each blade are calculated.

3. The method for dividing the vulnerable area of ​​an aircraft engine blade according to claim 2, characterized in that: The material parameters include density, elastic modulus, and Poisson's ratio.

4. The method for dividing the vulnerable area of ​​an aircraft engine blade according to claim 1, characterized in that: In step (3), the front cross-section dimension data is the front cross-section radius value.

5. The method for dividing the vulnerable area of ​​an aircraft engine blade according to claim 1, characterized in that: In step (4), the dangerous threshold of dynamic stress is 50 MPa.

6. A system for dividing vulnerable areas of aircraft engine blades, characterized in that: include: Modal calculation module: used to establish numerical models of several real blades to be tested, given test conditions, and calculate the corresponding blade modes of each numerical model; Data extraction and recording module: used to extract the natural frequency and stress distribution of the first ten modes of each numerical model from the calculation results of the blade mode, and record the leading edge maximum stress point position and leading edge section size data of each order of each numerical model; Dangerous blade screening module: used to screen out numerical models whose leading edge section size data is less than or equal to a set value according to the leading edge section size data under the first three modes of each numerical model, and mark them as dangerous numerical models; Vulnerable area marking module: It is used to screen out the corresponding orders whose dynamic stress is greater than or equal to the dangerous threshold value according to the dynamic stress measurement data of the real blade corresponding to the dangerous numerical model. The maximum stress point on the leading edge of the dangerous numerical model blade corresponding to the order is the vulnerable area of ​​the real blade corresponding to the dangerous numerical model.

7. The aircraft engine blade vulnerable area division system according to claim 6, characterized in that: The modal calculation module includes: establishing a numerical model of the real blade to be tested, importing it into the finite element analysis software, setting the material parameters of each numerical model, giving the grid type, boundary conditions and blade speed, and calculating each blade mode.

8. The aircraft engine blade vulnerable area division system according to claim 6, characterized in that: In the dangerous blade screening module, the front section size data is the front section radius value.

9. A device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 5 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 5 are implemented.

Images