Aero-engine composite material blade vibration fatigue test clamp and use method thereof

Abstract

The invention relates to an aero-engine composite material blade vibration fatigue test clamp and a use method thereof. The device comprises a basic platform used for being connected with a vibration test bench; the positioning plate is detachably connected to the foundation platform; the connecting block is mounted on the positioning plate; the fixed clamping end is connected with the connecting block, and the other end of the fixed clamping end is provided with a profiling clamping curved surface complementary with the contour of the tenon of the detected blade; the sliding clamping end is arranged opposite to the fixed clamping end; the guide plate is connected with the sliding clamping end; the driving screw rod is in threaded fit with the foundation platform and is matched with the guide plate to drive the guide plate to drive the sliding clamping end to move relative to the fixed clamping end, so that the blade tenon is clamped or loosened; and the two ends of the guide rod are connected with the basic platform and the positioning plate correspondingly, and the guide rod penetrates through the guide hole of the guide plate so as to guide movement of the guide plate. The problems that a traditional universal clamp is poor in flexibility, high in replacement and maintenance cost, insufficient in connection rigidity, low in simulation precision and the like are solved.

Description

Technical Field

[0001] This invention belongs to the field of aero-engine testing technology, specifically relating to a vibration fatigue testing fixture for aero-engine composite material blades and its usage method. Background Technology

[0002] As a crucial component of aero-engines, blades' reliability directly impacts the engine's thrust, efficiency, fuel consumption, and service life, and is directly related to the aircraft's safety performance. Composite material blades, with their advantages of high specific stiffness, high specific strength, corrosion resistance, and high design flexibility, are used in high bypass ratio engines.

[0003] However, aero-engines operate in harsh environments with high pressure and high speed. The blades bear enormous centrifugal loads and are subjected to complex and uneven excitations, such as stall flutter and wake excitation, which can induce high-frequency, alternating, and severe vibrations. Studies have shown that high-frequency vibration is a significant cause of high-cycle fatigue in blades and is a major failure mode, directly threatening engine reliability and flight safety. Therefore, vibration fatigue testing simulating blade operating conditions is crucial to ensure long-term, high-reliability operation throughout the entire lifespan of the blades.

[0004] Currently, general-purpose fixtures applicable to standard test pieces often use two regular parallel planes as clamping surfaces. However, for some blades with special tenon structures, the clamping end of the fixture has a weak fit with the tenon contour, resulting in an insufficient contact area between the test piece and the clamping surface of the fixture, unstable clamping, and even excessive clamping force may generate assembly stress, leading to damage to the tenon structure.

[0005] Furthermore, many clamping ends cannot replicate the complex contact state and load distribution between the blade tenon and the wheel mortise. This shortcoming can easily lead to insufficient stiffness in the connection between the clamping end and the blade, resulting in energy loss during transmission or causing non-ideal local vibrations between the blade and the clamp. Local vibrations consume and disperse the energy input to the testing equipment, causing the energy that should be applied to excite blade vibration to be wasted in non-ideal locations and generating a large amount of heat.

[0006] Therefore, the general-purpose vibration fatigue testing fixture has shortcomings such as insufficient stiffness in the connection between the fixture and the blade and poor contact surface fit, which leads to low efficiency and reduced accuracy of vibration fatigue testing. Summary of the Invention

[0007] Therefore, this invention provides a vibration fatigue test fixture for composite material blades of aero-engines and its usage method, which overcomes the problems of poor flexibility, high replacement and maintenance costs, insufficient connection stiffness, and low simulation accuracy of traditional general-purpose fixtures.

[0008] To solve the above-mentioned technical problems, the present invention provides a vibration fatigue testing fixture for composite material blades of aero-engines and its method of use, comprising: A base platform for connecting to a vibration test bench; A positioning plate is detachably connected to the base platform; The connecting block is installed on the positioning plate; The fixed clamping end is connected to the connecting block, and the other end is provided with a contoured clamping surface that is complementary to the contour of the tenon of the blade being tested. A sliding clamping end is disposed opposite to the fixed clamping end; wherein, both the fixed clamping end and the sliding clamping end are provided with a contoured clamping surface that matches and contacts the tenon contour of the blade being tested; The guide plate is connected to the sliding clamping end; A drive screw engages with the base platform and with the guide plate to drive the guide plate to move the sliding clamping end relative to the fixed clamping end, thereby clamping or releasing the tenon of the blade being tested. The guide rod has its two ends connected to the base platform and the positioning plate respectively, and passes through the guide hole of the guide plate to guide the movement of the guide plate.

[0009] In one embodiment of the present invention, the base platform is an L-shaped integrated structure, including a first long side plate and a first short side plate that are perpendicularly connected to each other. The first long side plate is provided with a guide rail structure for connecting to a vibration test bench. The center of the first short side plate is provided with a first threaded hole for installing the drive screw. The other end of the first long side plate opposite to the first short side plate is provided with a plurality of second threaded holes for installing the positioning plate.

[0010] In one embodiment of the present invention, the positioning plate is a T-shaped integrated structure, including a second short side plate and a second long side plate. The second short side plate is connected to the base platform, and the second long side plate is provided with connection holes suitable for installing the connecting block.

[0011] In one embodiment of the present invention, the connecting block is a cuboid structure, and its two opposite surfaces are provided with a plurality of third threaded holes for connecting to the positioning plate and the fixed clamping end, respectively.

[0012] In one embodiment of the present invention, each of the fixed clamping end and the sliding clamping end is provided with a connecting ear on its side, and the connecting ear is provided with a through hole. In the clamping state, the fixed clamping end and the sliding clamping end are locked together by fasteners passing through the through holes.

[0013] In one embodiment of the present invention, the guide plate includes a flat plate that slides with the guide rod, and the flat plate is provided with a guide hole; The front of the flat plate is provided with a boss structure, and the sliding clamping end is connected to the boss structure; A blind hole cylinder is provided on the back of the plate. One end of the drive screw extends into the blind hole cylinder and is clearance-fitted with it to transmit axial thrust.

[0014] In one embodiment of the present invention, the drive screw includes a threaded section and a smooth shaft section along the axial direction. The threaded section and the threaded hole on the base platform form a helical transmission pair, and the smooth shaft section cooperates with the guide plate to output axial thrust.

[0015] In one embodiment of the invention, a handle is mounted on the end of the drive screw.

[0016] In one embodiment of the present invention, there are four guide rods, which pass through corresponding mounting holes on the base platform, the guide plate and the positioning plate, respectively, and both ends of the guide rods are threaded and locked in place by nuts.

[0017] This invention also provides a method for using a vibration fatigue testing fixture for composite material blades of aero-engines, characterized in that the method includes: S1. Align the guide rail at the bottom of the long side plate of the foundation platform with the mounting groove on the vibration table, push it into place, and fasten it to the vibration table with bolts. S2. Attach the optional connecting block to the center of the second long side plate of the positioning plate, and use bolts to fasten the connecting block to the positioning plate. Then align the assembly plane of the fixed clamping end with the connecting block and connect it with bolts to complete the pre-assembly of the fixed unit assembly. S3. Lift up the assembled fixing unit assembly so that the threaded holes on both sides of the second short side plate of the positioning plate are precisely aligned with the threaded hole array on the first long side plate of the base platform. Use bolts to fix the assembly to the base platform. S4. Fit the sliding clamping end assembly face with the boss structure of the guide plate, and use bolts to connect the sliding clamping end and the guide plate; S5. Pass the four guide rods through the assembly holes of the short side plate of the base platform, the four corners of the guide plate, and the four corners of the positioning plate from the outside in sequence, and ensure that the fixed clamping end and the sliding clamping end can be face to face and hug each other. Then install washers and nuts at both ends of the guide rods to ensure that the guide rods are firmly connected to the base platform and there is no relative displacement. S6. Screw the drive screw into the threaded hole in the center of the base platform, and insert its front optical shaft into the blind hole cylindrical cavity on the back of the guide plate. When the drive screw drives the sliding clamping end and the fixed clamping end to fully engage and clamp the tenon of the blade under test, use a bolt to pass through the connecting ear on the outside of the clamping end to fix the two clamping ends together.

[0018] The technical solution of the present invention has the following advantages compared with the prior art: This invention discloses a vibration fatigue testing fixture for aero-engine composite blades and its usage method. By employing a contoured clamping end design and connection mechanism, it ensures that the contact surface of the blade tenon is a high-fidelity, full-size contoured surface. This fixture solution systematically overcomes the shortcomings of insufficient connection stiffness while ensuring the authenticity of the test data. Through a modular, detachable clamping design, the connection stiffness between the blade and the fixture is improved, suppressing local vibrations during the test, thereby enhancing the accuracy and reliability of the test data.

[0019] Aero-engine blades are subjected to high-speed airflow scouring and high-frequency, alternating, severe vibrations induced by complex and non-uniform flow fields over long periods. High-frequency vibration is a major cause of high-cycle fatigue in blades, directly threatening engine reliability and flight safety. In the field of blade vibration fatigue damage testing, the irregular shape of the clamping end of general-purpose fixtures leads to poor connection stiffness between the fixture and the blade, often introducing localized vibrations during vibration testing, causing non-ideal damage to the tenon and affecting the accuracy and safety of the test. This invention adopts a series-modular structural design of an L-shaped base platform, a T-shaped positioning plate, connecting blocks, and contoured clamping ends, greatly improving the versatility and applicability of the fixture. For the same type of blade, only a few types of clamping ends and connecting blocks need to be manufactured to achieve a universal combination of fixture and blade, significantly reducing manufacturing costs. The high-fidelity contoured clamping end used in this invention ensures surface contact between the fixture and the tenon, avoiding stress concentration defects and localized vibrations caused by insufficient contact area, thereby improving the testing accuracy and reliability of blade vibration fatigue tests.

[0020] Furthermore, by employing an integrated center of gravity adjustment mechanism, the connecting blocks are innovatively designed as counterweights for the fixture system. By selecting connecting blocks of different sizes, the fore-and-aft position of the clamping end in space can be precisely adjusted, thereby achieving active adjustment of the center of gravity of the entire fixture-sample system. This design integrates the center of gravity balancing function into the fixture structure, eliminating the need for additional counterweights, effectively removing equipment safety hazards caused by center of gravity deviation, and avoiding the resulting decrease in testing accuracy.

[0021] This invention designs a sliding clamping mechanism driven by a drive screw and guided by guide rods. The drive screw only bears torque and transmits axial thrust through the cooperation between its end and the guide plate; while the rigid frame composed of four high-precision guide rods independently undertakes the functions of guidance and bending moment resistance, ensuring that the sliding clamping end can maintain extremely high motion accuracy and stability when subjected to vibration loads, effectively preventing jamming and loosening during the clamping process. Attached Figure Description

[0022] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0023] Figure 1 This is a schematic diagram of the overall structure of the first side of the vibration fatigue test fixture for composite material blades of aero-engines according to the present invention.

[0024] Figure 2 This is a schematic diagram of the overall structure of the second side of the vibration fatigue test fixture for composite material blades of aero-engines according to the present invention.

[0025] Figure 3 This is a schematic diagram of the overall structure of the third side of the vibration fatigue test fixture for composite material blades of aero-engines according to the present invention.

[0026] Figure 4 This is a cross-sectional structural schematic diagram of the vibration fatigue test fixture for composite material blades of aero-engines according to the present invention.

[0027] Figure 5 This is a schematic diagram of the assembly structure of the vibration fatigue test fixture for composite material blades of aero-engines and the blade under test.

[0028] Figure 6 This is a schematic diagram of the structure of the guide plate of the present invention.

[0029] Figure 7 This is a schematic diagram of the structure of the fixed clamping end or the sliding clamping end of the present invention.

[0030] Explanation of reference numerals in the instruction manual: 1. Basic platform; 11. First long side plate; 12. First short side plate; 13. Guide rail structure; 2. Positioning plate; 21. Second short side plate; 22. Second long side plate; 3. Connecting block; 4. Fixed clamping end; 41. Contour clamping curved surface; 42. Connecting lug; 421. Through hole; 5. Sliding clamping end; 6. Guide plate; 61. Flat plate; 611. Guide hole; 62. Boss structure; 63. Blind hole cylinder; 7. Screw; 71. Handle; 8. Guide rod; 81. Nut; 9. The blade being tested. Detailed Implementation

[0031] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention.

[0032] In this invention, when directions (up, down, left, right, front, and back) are described, it is only for the convenience of describing the technical solution of this invention, and does not indicate or imply that the technical features referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this invention.

[0033] In this invention, "several" means one or more, "multiple" means two or more, "greater than," "less than," "exceeding," etc., are understood to exclude the stated number; "above," "below," "within," etc., are understood to include the stated number. In the description of this invention, the terms "first" and "second" are used only to distinguish technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0034] In this invention, unless otherwise explicitly defined, the terms "setting," "installing," and "connecting" should be interpreted broadly. For example, they can refer to a direct connection or an indirect connection through an intermediate medium; a fixed connection, a detachable connection, or an integrally formed connection; a mechanical connection, an electrical connection, or a connection capable of mutual communication; or the internal connection of two components or the interaction between two components. Those skilled in the art can reasonably determine the specific meaning of the above terms in this invention based on the specific content of the technical solution.

[0035] Reference Figures 1 to 5 As shown, the present invention provides a vibration fatigue testing fixture for composite material blades of aero-engines and its method of use, comprising: Basic platform 1 is used for connection to the vibration test bench; Positioning plate 2 is detachably connected to the base platform 1; Connecting block 3 is installed on the positioning plate 2; The fixed clamping end 4 is connected to the connecting block 3, and the other end is provided with a contoured clamping surface 41 that is complementary to the tenon contour of the blade 9 being tested; The sliding clamping end 5 is disposed opposite to the fixed clamping end 4; wherein, both the fixed clamping end 4 and the sliding clamping end 5 are provided with a contoured clamping surface 41 that matches and contacts the tenon contour of the blade 9 being tested; Guide plate 6 is connected to the sliding clamping end 5; The drive screw 7 is threadedly engaged with the base platform 1 and with the guide plate 6 to drive the guide plate 6 to move the sliding clamping end 5 relative to the fixed clamping end 4, so as to clamp or loosen the tenon of the tested blade 9. The guide rod 8 has its two ends connected to the base platform 1 and the positioning plate 2 respectively, and passes through the guide hole 611 of the guide plate 6 to guide the movement of the guide plate 6.

[0036] In one embodiment, refer to Figure 2 As shown, the base platform 1 is an L-shaped integrated structure, including a first long side plate 11 and a first short side plate 12 that are perpendicularly connected to each other. The first long side plate 11 is provided with a guide rail structure 13 for connecting with the vibration test bench. Specifically, a parallel guide rail is machined on each side of the first long side plate 11 and connected to the vibration test bench by bolts. The first short side plate 12 has a first threaded hole in the center for installing the drive screw 7. The other end of the first long side plate 11 opposite to the first short side plate 12 has a plurality of second threaded holes for installing the positioning plate 2.

[0037] In one embodiment, refer to Figure 2 As shown, the positioning plate 2 is a T-shaped integrated structure, including a second short side plate 21 and a second long side plate 22. The second short side plate 21 is connected to the base platform 1, and the second long side plate 22 is provided with connection holes suitable for installing the connecting block 3.

[0038] In one embodiment, the connecting block 3 is a cuboid structure, with several third threaded holes on its two opposite surfaces for connecting to the positioning plate 2 and the fixed clamping end 4, respectively. By selecting connecting blocks 3 of different thicknesses and materials, the front-to-back position of the clamping end in space can be adjusted, thereby achieving balance of the center of gravity of the entire fixture system, effectively preventing deviation of the center of gravity, and ensuring experimental accuracy and safety.

[0039] In one embodiment, refer to Figure 7 As shown, the fixed clamping end 4 and the sliding clamping end 5 are each provided with a connecting ear 42 on their side. The connecting ear 42 is provided with a through hole 421. In the clamping state, the fixed clamping end 4 and the sliding clamping end 5 are locked together by fasteners passing through the through hole 421.

[0040] It should be noted that the fixed clamping end 4 is a specific contoured structure. One end is an assembly plane, which is fixedly connected to the connecting block 3 by bolts. The other end is contoured according to the contour of the tenon of the blade 9 being tested, forming a complementary contoured clamping surface 41. The contoured clamping surface 41 design ensures a high degree of contact between the clamping end and the tenon surface, thereby avoiding local vibrations caused by loose connections during vibration, and ensuring the accuracy and reliability of the test.

[0041] The sliding clamping end 5 has the same structure as the fixed clamping end 4, and is used to engage the tenon from the other side of the blade. Both are ultimately locked in place by fasteners such as bolts passing through the connecting lug 42 to secure the blade. The difference between the fixed clamping end 4 and the sliding clamping end 5 is that the end of the sliding clamping end 5 facing away from the tenon is connected to the guide plate 6.

[0042] In one embodiment, refer to Figure 6 As shown, the guide plate 6 includes a flat plate 61 that slides with the guide rod 8, and the flat plate 61 is provided with a guide hole 611; the front of the flat plate 61 is provided with a boss structure 62, and the sliding clamping end 5 is connected to the boss structure 62; the back of the flat plate 61 is provided with a blind hole cylinder 63, and one end of the drive screw 7 extends into the blind hole cylinder 63 and is clearance-fitted with it to transmit axial thrust.

[0043] By controlling the rotation of the drive screw 7, the entire guide plate 6 and the sliding clamping end 5 are driven to move axially along the guide rod 8, thereby realizing the clamping and releasing actions.

[0044] In one embodiment, the drive screw 7 includes a threaded section and a smooth shaft section along the axial direction. The threaded section forms a helical transmission pair with the threaded hole on the base platform 1, and the smooth shaft section is in clearance fit with the inner cavity of the blind hole cylinder 63 on the back side, transmitting only axial thrust. A handle 71 is installed at the other end, which is operated by the experimenter to rotate the drive screw 7.

[0045] In one embodiment, there are four guide rods 8, and the total length of the guide rods 8 is greater than the hole distance between the corresponding mounting holes on the base platform 1 and the guide plate 6. The four guide rods 8 pass through the corresponding mounting holes on the base platform 1, the guide plate 6 and the positioning plate 2, respectively. The two ends of the guide rods 8 are threaded and locked by nuts 81, thereby reliably fixing the guide rods 8 on the base platform 1 and providing a rigid frame for precise guidance of the sliding clamping end 5.

[0046] This embodiment also provides a method for using a vibration fatigue testing fixture for composite material blades of aero-engines, characterized in that the method includes: S1. Align the guide rail at the bottom of the long side plate of the foundation platform 1 with the mounting groove on the vibration table, push it into place, and fasten it to the vibration table with bolts. S2. Attach the optional connecting block 3 to the center of the second long side plate 22 of the positioning plate 2, and use bolts to fasten the connecting block 3 to the positioning plate 2. Then align the assembly plane of the fixing clamping end 4 with the connecting block 3 and connect it with bolts to complete the pre-assembly of the fixing unit assembly. S3. Lift up the assembled fixing unit assembly so that the threaded holes on both sides of the second short side plate 21 of the positioning plate 2 are precisely aligned with the threaded hole array on the first long side plate 11 of the base platform 1, and use bolts to fix the assembly to the base platform 1. S4. Fit the end face of the sliding clamping end 5 with the boss structure 62 of the guide plate 6, and use bolts to connect the sliding clamping end 5 and the guide plate 6. S5. Pass the four guide rods 8 through the assembly holes of the short side plate of the base platform 1, the four corners of the guide plate 6, and the four corners of the positioning plate 2 from the outside in sequence, and ensure that the fixed clamping end 4 and the sliding clamping end 5 can be face to face and hug each other. Then install washers and nuts 81 at both ends of the guide rods 8 to ensure that the guide rods 8 are firmly connected to the base platform 1 and there is no relative displacement. S6. Screw the drive screw 7 into the threaded hole in the center of the base platform 1, and insert its front optical shaft into the inner cavity of the blind hole cylinder 63 on the back of the guide plate 6. When the drive screw 7 drives the sliding clamping end 5 and the fixed clamping end 4 to fully engage and clamp the tenon of the tested blade 9, use a bolt to pass through the connecting ear 42 on the outside of the clamping end to fix the two clamping ends together.

[0047] Finally, it should be noted that the above specific embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to examples, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A vibration fatigue testing fixture for composite material blades of aero-engines, characterized in that, include: The base platform (1) is used to connect to the vibration test bench; The positioning plate (2) is detachably connected to the base platform (1); Connecting block (3) is installed on the positioning plate (2); The fixed clamping end (4) is connected to the connecting block (3), and the other end is provided with a contoured clamping surface (41) that is complementary to the tenon contour of the blade (9) being tested. The sliding clamping end (5) is arranged opposite to the fixed clamping end (4); wherein, both the fixed clamping end (4) and the sliding clamping end (5) are provided with a contoured clamping surface (41) that matches and contacts the tenon contour of the blade (9) being tested. The guide plate (6) is connected to the sliding clamping end (5); The drive screw (7) is threaded into the base platform (1) and into the guide plate (6) to drive the guide plate (6) to move the sliding clamping end (5) relative to the fixed clamping end (4) so ​​as to clamp or loosen the tenon of the blade (9) being tested. The guide rod (8) is connected at both ends to the base platform (1) and the positioning plate (2) respectively, and passes through the guide hole (611) of the guide plate (6) to guide the movement of the guide plate (6).

2. The vibration fatigue test fixture for composite material blades of aero-engines according to claim 1, characterized in that, The base platform (1) is an L-shaped integrated structure, including a first long side plate (11) and a first short side plate (12) that are perpendicularly connected to each other. The first long side plate (11) is provided with a guide rail structure (13) for connecting with the vibration test bench. The first short side plate (12) has a first threaded hole in the center for installing the drive screw (7). The other end of the first long side plate (11) opposite to the first short side plate (12) is provided with a number of second threaded holes for installing the positioning plate (2).

3. The vibration fatigue test fixture for composite material blades of aero-engines according to claim 1, characterized in that, The positioning plate (2) is a T-shaped integrated structure, including a second short side plate (21) and a second long side plate (22). The second short side plate (21) is connected to the base platform (1), and the second long side plate (22) is provided with connection holes suitable for installing the connecting block (3).

4. The vibration fatigue test fixture for composite material blades of aero-engines according to claim 1, characterized in that, The connecting block (3) is a cuboid structure, and its two opposite surfaces are provided with several third threaded holes for connecting to the positioning plate (2) and the fixed clamping end (4).

5. The vibration fatigue test fixture for composite material blades of aero-engines according to claim 1, characterized in that, The fixed clamping end (4) and the sliding clamping end (5) are each provided with a connecting ear (42) on their respective sides. The connecting ear (42) is provided with a through hole (421). In the clamping state, the fixed clamping end (4) and the sliding clamping end (5) are locked together by fasteners passing through the through hole (421).

6. The vibration fatigue test fixture for composite material blades of aero-engines according to claim 1, characterized in that, The guide plate (6) includes a flat plate (61) that slides with the guide rod (8), and the flat plate (61) is provided with a guide hole (611). The flat plate (61) has a boss structure (62) on its front side, and the sliding clamping end (5) is connected to the boss structure (62). The back of the plate (61) is provided with a blind hole cylinder (63), and one end of the drive screw (7) extends into the blind hole cylinder (63) and is clearance-fitted with it to transmit axial thrust.

7. The vibration fatigue test fixture for composite material blades of aero-engines according to claim 1, characterized in that, The drive screw (7) includes a threaded section and a smooth shaft section along the axial direction. The threaded section and the threaded hole on the base platform (1) form a helical transmission pair. The smooth shaft section cooperates with the guide plate (6) to output axial thrust.

8. The vibration fatigue test fixture for composite material blades of aero-engines according to claim 1, characterized in that, A handle (71) is mounted on the end of the drive screw (7).

9. A vibration fatigue testing fixture for composite material blades of aero-engines according to claim 1, characterized in that, The number of guide rods (8) is four. The four guide rods (8) pass through the corresponding mounting holes on the base platform (1), the guide plate (6) and the positioning plate (2), respectively. Both ends of the guide rods (8) are threaded and locked and fixed by nuts (81).

10. A method of using the vibration fatigue testing fixture for aero-engine composite material blades according to any one of claims 1-9, characterized in that, The method includes: S1. Align the guide rail at the bottom of the long side plate of the base platform (1) with the mounting groove on the vibration table, push it into place, and use bolts to fasten it to the vibration table. S2. Attach the selected connecting block (3) to the center of the second long side plate (22) of the positioning plate (2), and use bolts to fasten the connecting block (3) to the positioning plate (2). Then align the assembly plane of the fixed clamping end (4) with the connecting block (3) and connect it with bolts to complete the pre-assembly of the fixed unit assembly. S3. Lift up the assembled fixing unit assembly so that the threaded holes on both sides of the second short side plate (21) of the positioning plate (2) are precisely aligned with the threaded hole array on the first long side plate (11) of the base platform (1), and use bolts to fix the assembly to the base platform (1). S4. Fit the end face of the sliding clamping end (5) with the boss structure (62) of the guide plate (6), and use bolts to connect the sliding clamping end (5) and the guide plate (6). S5. Pass the four guide rods (8) through the assembly holes of the short side plate of the base platform (1), the four corners of the guide plate (6), and the four corners of the positioning plate (2) from the outside in sequence, and ensure that the fixed clamping end (4) and the sliding clamping end (5) are face to face and hug each other. Then install washers and nuts (81) at both ends of the guide rods (8) to ensure that the guide rods (8) are firmly connected to the base platform (1) and there is no relative displacement. S6. Screw the drive screw (7) into the threaded hole in the center of the base platform (1) and insert its front optical shaft into the inner cavity of the blind hole cylinder (63) on the back of the guide plate (6). When the drive screw (7) drives the sliding clamping end (5) and the fixed clamping end (4) to fully hug and clamp the tenon of the blade (9) to be tested, use a bolt to pass through the connecting ear (42) on the outside of the clamping end to fix the two clamping ends together.

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