A reference specimen, a marking specimen, and a method for marking vibration fatigue limit tests.

Abstract

This invention belongs to the field of aero-engine component testing, specifically relating to a reference specimen, a marking specimen, and a method for marking vibration fatigue limit tests. The reference specimen for marking vibration fatigue limit tests is an integrated structure comprising: a clamping section, a narrow waist section, and a counterweight section connected sequentially; wherein the clamping section is used to connect to a vibration test bench; the narrow waist section and the counterweight section are in a cantilever state during the test; the counterweight section has counterweight holes for connecting counterweight structures of different weights. The counterweight section of this invention, by providing counterweight holes, allows a single specimen to have multiple counterweights to accommodate vibration benches of different frequencies, offering advantages such as reduced testing costs and increased testing efficiency.

Description

Technical Field

[0001] This invention belongs to the field of aero-engine component testing, specifically relating to a reference specimen, a marking specimen, and a method for marking vibration fatigue limit testing. Background Technology

[0002] Typically, aircraft engine components are marked with unique serial numbers for traceability. These serial numbers are generated by leaving permanent marks on the surface of the components using mechanical, pneumatic, laser, or electrochemical methods, known as marking. Marking can cause defects on the material surface and lead to stress concentration. In particular, the high temperature generated by laser marking can cause a remelted layer to form on the material surface, greatly reducing the material's fatigue resistance.

[0003] Aero-engine rotor components such as gears and bladed disks are subjected to large alternating vibration loads. If there is a certain vibration stress at the marking location, it may lead to high-cycle fatigue failure of the components. Such failure modes have already occurred in aero-engines. Therefore, it is necessary to conduct research on the impact of markings on the fatigue performance of materials and provide a reference for the setting of markings on aero-engine rotor components.

[0004] Chinese Patent Publication No. CN119560073A discloses a method for designing rapid vibration fatigue test specimens. The method designs a reference specimen for vibration fatigue testing. The reference specimen includes a clamping section, a narrow waist section, and a counterweight section. By adjusting the structural dimensions of the counterweight section and the narrow waist section, the maximum point of the first-order bending vibration stress of the specimen is made to fall at the narrow neck of the narrow waist section, which is the vibration fatigue initiation crack position. During the test, the specimen is fixed on the vibration table by the clamping section.

[0005] This application uses a dynamic similarity method to enlarge or reduce the reference specimen, and designs a vibration fatigue specimen that matches the size of existing parts. The counterweight section is enlarged or reduced proportionally. That is, the counterweight of the counterweight section of the reference specimen in this application can only be changed by setting different reference specimens. This not only increases the manufacturing cost, but also reduces the test efficiency.

[0006] In view of this, the present invention is hereby proposed. Summary of the Invention

[0007] In order to solve the technical problems existing in the prior art, the present invention provides a specimen and method for marking vibration fatigue limit test.

[0008] This invention includes the following technical solutions: The first aspect of this invention provides a reference specimen for marking vibration fatigue limit tests, the reference specimen being an integral structure comprising: The clamping section, the narrow waist section, and the counterweight section are connected in sequence; The clamping section is used to connect to the vibration test bench; the narrow waist section and the counterweight section are in a cantilever state during the test; the counterweight section has a counterweight hole, which is used to connect counterweight structures of different weights.

[0009] Furthermore, the counterweight hole is a threaded hole.

[0010] A second aspect of the present invention provides a marking specimen for marking vibration fatigue limit test, which is prepared based on the above-mentioned reference specimen and includes a marking area provided on the narrow waist section, wherein at least one mark is processed in the marking area.

[0011] Furthermore, the marked area represents the maximum stress of the first-order bending vibration mode of the reference specimen. The area covered by 90% or more of the stress.

[0012] A third aspect of the present invention provides a method for determining the marking area of ​​a sample, comprising the following steps: Obtain the reference sample described above; Finite element analysis was performed on the reference specimen to obtain the stress distribution of the first-order bending vibration mode of the reference specimen; The maximum stress of the first-order bending vibration mode The area covered by 90% or more of the stress is defined as the marking area.

[0013] A fourth aspect of the present invention provides a method for preparing a stamped sample, comprising the following steps: The marking area is determined according to the method described above; The marking is designed and processed within the marking area to obtain the marking sample.

[0014] The fifth aspect of this invention provides a method for marking vibration fatigue limit test, comprising the following steps: Obtain the marking sample described above; The clamping section of the marked specimen is installed on the vibration test bench; Start the vibration test bench and conduct a vibration fatigue test on the marked specimen at its first-order bending vibration frequency; Record the stress level at which the marked specimens fail due to fatigue to evaluate the vibration fatigue performance of the markings.

[0015] The sixth aspect of this invention provides a method for evaluating a marking method, comprising the following steps: Multiple labeled samples were prepared using different labeling types and / or different labeling processes; Fatigue limit tests were performed on multiple marked specimens according to the method described above. Compare the test results to evaluate the impact of different marking types and / or different marking processes on vibration fatigue performance.

[0016] Furthermore, the marking process includes at least one of laser power, scanning speed, and pulse frequency.

[0017] Furthermore, the marking method includes mechanical marking, pneumatic marking, laser marking, or laser-enhanced marking.

[0018] By adopting the above technical solution, the present invention has the following advantages: 1. The counterweight section of the sample of the present invention can be equipped with counterweight holes to enable a single sample to have multiple counterweights, so as to meet the use of different frequency excitation tables, which has the advantages of reducing test costs and improving test efficiency.

[0019] 2. With the present invention, different counterweights on the sample only change the frequency of the sample and have no effect on the vibration stress distribution. Therefore, there is no need to select the marking area during the test, which improves the test efficiency.

[0020] 3. In this invention, the marking is set at the maximum stress of the first-order bending vibration mode. The area covered by 90% or more of the stress ensures that cracking occurs at the marked location during the fatigue limit test, thus guaranteeing the success rate of the test.

[0021] 4. The evaluation method of the present invention evaluates different marking types and different marking processes to select appropriate marking types and marking processes for aero-engine components, thereby avoiding high-cycle fatigue failure of aero-engine components.

[0022] 5. This invention is simple in design, has a short cycle time, and is highly efficient, which has a positive promoting effect on the application of marking technology in rotating machinery such as aero engines.

[0023] 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

[0024] 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.

[0025] Figure 1This is a schematic diagram of the structure of a reference specimen for marking vibration fatigue limit test in an embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of a marking specimen for marking vibration fatigue limit test in an embodiment of the present invention; Figure 3 This is a schematic diagram of the marking position of a marking specimen used for marking vibration fatigue limit test in an embodiment of the present invention. Figure 4 This is a stress cloud diagram of a reference specimen used for marking vibration fatigue limit tests in an embodiment of the present invention. Figure 5 This is a schematic diagram of the marking area of ​​a reference specimen used for marking vibration fatigue limit test in an embodiment of the present invention. Figure 6 This is a schematic diagram of a patch for marking a specimen for a vibration fatigue limit test, as described in an embodiment of the present invention. In the figure, 10-clamping section, 20-narrow waist section, 30-counterweight section, 31-counterweight hole, 40-marking area, 50-strain gauge, 60-marking. Detailed Implementation

[0026] The following description provides many different embodiments or examples for implementing various features of the invention. The elements and arrangements described in the specific examples below are only for concise expression of the invention and are merely examples, not intended to limit the invention.

[0027] 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.

[0028] Different excitation tables have different excitation frequencies, and the reference specimen with the same counterweight cannot meet the needs of different excitation tables. The reference specimen that needs to be excited by the excitation table at 3000 Hz cannot meet the needs of the excitation table below 3000 Hz. In the existing technology, different reference specimens are used to adapt to the use of different excitation tables. This method requires the manufacture of a sufficient number of reference specimens to meet the test requirements, resulting in high test costs and low test efficiency.

[0029] The first aspect of this embodiment provides a reference specimen for marking vibration fatigue limit tests, combined with... Figure 1 As shown, the reference specimen is an integral structure, comprising: The clamping section 10, the narrow waist section 20, and the counterweight section 30 are connected in sequence; The clamping section 10 is used to connect to the vibration test bench; the narrow waist section 20 and the counterweight section 30 are in a cantilever state during the test; the counterweight section 30 has a counterweight hole 31, which is used to connect counterweight structures of different weights.

[0030] The aforementioned reference specimen can be used with different excitation tables and meet various test requirements simply by changing the weight of the counterweight structure; it has the advantages of reducing costs and improving test efficiency.

[0031] In this embodiment, the reference specimen can be cut from scrapped parts or manufactured using a blank; the upper and lower surfaces of the narrow waist section 20 and the clamping section 10 both use the same arc transition, which can avoid stress concentration in the clamping section 10, leading to fatigue test failure; the upper and lower surfaces of the narrow waist section 20 and the counterweight section 30 both use the same arc transition; the narrow waist section 20 of the reference specimen has a symmetrical structure in the upper and lower (two planes) and left and right (two arc segments), and the edges of the narrow waist section 20 are rounded to remove the influence of stress concentration.

[0032] In some embodiments, the counterweight hole 31 is a threaded hole. Since the counterweight hole 31 is a threaded hole, the corresponding counterweight structure can be screws of different weights. By replacing screws of different weights, different counterweights can be achieved, thereby adjusting the frequency of the sample to meet different testing requirements.

[0033] The second aspect of this embodiment provides a marking specimen for marking vibration fatigue limit testing, which is prepared based on the aforementioned reference specimen, combined with... Figure 2 As shown, it includes a marking area 40 provided on the narrow waist section 20, and at least one marking 60 is processed in the marking area 40.

[0034] Furthermore, the marking area 40 represents the maximum stress of the first-order bending vibration mode of the reference specimen. The area covered by 90% or more of the stress.

[0035] For example, combined Figure 3 As shown, a 1-shaped mark 60 is designed. The mark 60 is located within the marking area 40. The distance between the mark 60 and the front of the clamping section 10 is L, and it is centered (the width of the clamping section 10 is B, and the center of the mark 60 is located at B / 2). The height H of the mark 60 is set according to the sample size.

[0036] The third aspect of this embodiment provides a method for determining the marking area of ​​a sample, including the following steps: Get Figure 1 The reference sample mentioned above; Finite element analysis was performed on the reference specimen to obtain the stress distribution of the first-order bending vibration mode; combined with Figure 4 As shown, according to the finite element analysis, the stress gradient of the reference specimen is uniform, and the stress gradient direction is a plane that increases from front to back and then decreases; the maximum stress of the first-order bending vibration mode of the reference specimen is... Maximum vibration modal stress Located at the edge of the plane of the narrow waist section 20, it is the location of vibration fatigue crack initiation of the reference specimen. There is no stress concentration phenomenon in the narrow waist section 20, which greatly improves the success rate of the test. Combination Figure 5 As shown, the maximum stress of the first-order bending vibration mode is... The area covered by 90% or more of the stress is defined as the marking area 40.

[0037] The fourth aspect of this embodiment provides a method for preparing a stamped sample, including the following steps: The marking area 40 is determined according to the method described above; A mark 60 is designed and processed within the mark area 40 to obtain a mark sample; for example, the mark sample may be as follows: Figure 2 The structure shown.

[0038] In this embodiment, there are no restrictions on the process and type of processing mark 60. All mark types and processes in the prior art should be within the scope of protection of this invention. For example, the mark type can be mechanical mark, pneumatic mark, laser mark, or laser-enhanced mark; the mark process can be at least one of laser power, scanning speed, and pulse frequency.

[0039] The fifth aspect of this embodiment provides a method for marking vibration fatigue limit test, including the following steps: Obtain the marking sample described above; The clamping section 10 of the marked sample is installed on the vibration test bench; Start the vibration test bench and conduct a vibration fatigue test on the marked specimen at its first-order bending vibration frequency; Record the stress level at which the marked specimen fails due to fatigue in order to evaluate the vibration fatigue performance of the marked 60, i.e., obtain the fatigue limit.

[0040] For example, the stress level is obtained as According to stress level and sensitivity The analysis yields the fatigue limit, specifically: Fatigue limit = / .in: ; To mark the first-order modal stress at the patch point of the specimen, The maximum stress in the first-order bending vibration mode at the marked location.

[0041] For example, in the Mark 60 vibration fatigue limit test, the structure used to obtain stress can be a strain gauge 50, combined with... Figure 6 As shown in the figure, the bonding position of strain gauge 50 is indicated.

[0042] The sixth aspect of this embodiment provides a method for evaluating a marking method, including the following steps: Multiple labeled samples were prepared using different labeling types and / or different labeling processes; Fatigue limit tests were performed on multiple marked specimens according to the method described above. Compare the test results to evaluate the impact of different marking types and / or different marking processes on vibration fatigue performance.

[0043] Based on the fatigue limit results of different marking types, the influence of marking on the fatigue limit can be obtained, thereby distinguishing the application scenarios of marking.

[0044] Furthermore, the marking process includes at least one of laser power, scanning speed, and pulse frequency.

[0045] Furthermore, the marking method includes mechanical marking, pneumatic marking, laser marking, or laser-enhanced marking.

[0046] All terms used in this invention (including technical or scientific terms) have the same meaning as understood by one of ordinary skill in the art to which this invention pertains, unless otherwise specifically defined. It should also be understood that terms defined in general dictionaries should be interpreted as having meanings consistent with their meanings in the context of the relevant art, and not as idealized or highly formalized, unless expressly defined herein.

[0047] 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 reference specimen for marking vibration fatigue limit tests, characterized in that, The reference specimen is an integral structure, comprising: The clamping section (10), the narrow waist section (20), and the counterweight section (30) are connected in sequence. The clamping section (10) is used to connect to the vibration test bench; the waist section (20) and the counterweight section (30) are in a cantilever state during the test; the counterweight section (30) has a counterweight hole (31), which is used to connect counterweight structures of different weights.

2. The reference specimen for marking vibration fatigue limit test according to claim 1, characterized in that, The counterweight hole is a threaded hole.

3. A marking specimen for marking vibration fatigue limit tests, characterized in that, The reference specimen is prepared based on any one of claims 1-2, including a marking area (40) provided on the narrow waist section (20), wherein at least one marking is processed in the marking area (40).

4. A marking specimen for marking vibration fatigue limit test according to claim 3, characterized in that, The marked area (40) represents the maximum stress of the first-order bending vibration mode of the reference specimen. The area covered by 90% or more of the stress.

5. A method for determining the marking area of ​​a sample, characterized in that, Includes the following steps: Obtain the reference specimen as described in any one of claims 1-2; Finite element analysis was performed on the reference specimen to obtain the stress distribution of the first-order bending vibration mode of the reference specimen; The maximum stress of the first-order bending vibration mode The area covered by 90% or more of the stress is defined as the marking area (40).

6. A method for preparing a stamped sample, characterized in that, Includes the following steps: The marking area (40) is determined by the method according to claim 5; The marking is designed and processed in the marking area (40) to obtain the marking sample.

7. A method for marking fatigue limit test, characterized in that, Includes the following steps: Obtain the marking sample as described in any one of claims 3-4; The clamping section (10) of the marked specimen is installed on the vibration test bench; Start the vibration test bench and conduct a vibration fatigue test on the marked specimen at its first-order bending vibration frequency; Record the stress level at which the marked specimens fail due to fatigue to evaluate the vibration fatigue performance of the markings.

8. An evaluation method for a marking method, characterized in that, Includes the following steps: Multiple labeled samples were prepared using different labeling types and / or different labeling processes; The fatigue limit test was performed on multiple marked specimens according to the method described in claim 7. Compare the test results to evaluate the impact of different marking types and / or different marking processes on vibration fatigue performance.

9. The evaluation method for a marking method according to claim 8, characterized in that, The marking process includes at least one of laser power, scanning speed, and pulse frequency.

10. The evaluation method for a marking method according to claim 8, characterized in that, The marking methods include mechanical marking, pneumatic marking, laser marking, or laser-enhanced marking.

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