Thin plate vibration characteristic and fatigue test tooling suitable for spin test device

Abstract

The application belongs to the field of aero-engine fatigue test and is a thin support plate vibration characteristic and fatigue test tool suitable for a spin vane tester, comprising a thin support plate, a clamping device and a load applying device; the clamping device comprises a base, a fixed frame, a chuck and a circular fixing block; a test platform is arranged below the base, and the base and the test platform are respectively provided with mutually vertically arranged inverted T-shaped grooves; the chuck is connected in the rectangular mounting groove and comprises an upper chuck and a lower chuck, the lower chuck and the bottom of the rectangular mounting groove are provided with at least one set of shims; through the mutual cooperation of the base, the fixed frame, the shims and the chuck, the test requirements of multi-dimensional and complex excitation (X, Y, Z and theta directions) of the thin support plate matched with the spin vane tester are met, and the freedom of the test is effectively improved.

Description

Technical Field

[0001] The present application belongs to the field of aircraft engine fatigue testing, and in particular relates to a thin support plate vibration characteristic and fatigue testing tool suitable for a rotary flute tester. Background Art

[0002] Thin struts are important imported components for aircraft engines. As aircraft engines evolve toward higher loads and lighter weight, the harsh operating environment places higher demands on these struts in the air intake casing. High-cycle fatigue is particularly common in thin struts, as they are aerodynamically excited by the fan rotor blades, causing high-frequency vibrations in the thin wall. Cracks in these struts are a common occurrence. These cracks can severely reduce engine life and impact flight safety. Therefore, conducting laboratory vibration and fatigue tests on thin struts to obtain test data is crucial to verify the effectiveness of the strut strength design and improvement measures.

[0003] Vibration fatigue testing of thin support plates often requires simulating their actual operating conditions, such as the aerodynamic loads they experience and the weld configuration to the air intake casing. Currently, vibration characteristics and fatigue testing of thin support plates are typically conducted on electromagnetic vibration tables. Due to frequency response limitations, these tables can only meet low-frequency testing requirements (1-3 kHz) and are unable to handle high-frequency excitation (3-8 kHz). Currently, the thin support plate testing fixtures used in conjunction with electromagnetic vibration tables are primarily compression-type. These fixtures apply a clamping force to the fixture via bolts, securing the thin support plate.

[0004] The existing technical solutions have the following disadvantages:

[0005] 1) Vibration characteristics and fatigue testing place high demands on the connection stiffness between the thin support plate and the fixture. Currently, the clamping fixture is single-end fixed, meaning that at one end of the thin support plate, a clamping force is applied by tightening two to three bolts on the fixture to achieve clamping of the thin support plate. This type of clamping fixture generates local static stress due to rigid clamping, causing varying degrees of damage to the thin support plate and easily leading to abnormal fracture positions. Furthermore, the clamping fixture lacks end-face loading capabilities and is inconsistent with the overall welding method of the thin support plate and the air intake casing. Therefore, it cannot simulate the actual holding method of the thin support plate, resulting in the thin support plate failing to meet the required vibration load during vibration fatigue testing.

[0006] 2) The clamping fixture lacks a positioning system, making it impossible to precisely control the clamping position of the thin support plate. Different clamping positions can significantly affect test results. Furthermore, the clamping fixture's clamping method is relatively simple. Once the thin support plate is clamped, its position cannot be freely adjusted to meet test requirements. Therefore, the electromagnetic vibration table cannot satisfy the requirement for excitation at any position of the thin support plate.

[0007] 3) The existing clamping tooling is not universal. For different types of thin support plates, test tooling of different lengths and sizes needs to be designed, resulting in huge economic cost waste. At the same time, the design and processing time of the clamping tooling are long, which seriously affects the test efficiency.

[0008] Therefore, how to ensure that the thin support plate has high clamping freedom and strong versatility is a problem that needs to be solved. Summary of the Invention

[0009] The purpose of this application is to provide a thin support plate vibration characteristics and fatigue test tool suitable for a rotary flute tester, so as to solve the problem that the thin support plate clamping form in the prior art is single and non-universal.

[0010] The technical solution of the present application is: a thin support plate vibration characteristics and fatigue test fixture suitable for a whistle tester, comprising a thin support plate, a clamping device and a load applying device, wherein the thin support plate is connected to the clamping device, and the load applying device can apply different loads to the end of the thin support plate; the clamping device comprises a base, a fixing frame, a chuck and a circular fixing block, the fixing frame, the chuck and the circular fixing block are each provided in two groups and are respectively provided at the two ends of the thin support plate, a test platform is provided below the base and mutually perpendicular inverted T-shaped grooves are respectively provided on the base and the test platform, and T-shaped grooves are provided between the fixing frame and the base, and between the base and the test platform. The bolts are connected; a rectangular mounting groove is provided in the fixing frame, the clamp is connected in the rectangular mounting groove and the clamp includes an upper clamp and a lower clamp, the upper clamp and the lower clamp cooperate to form an outer rectangular and inner circular structure, the circular fixing block is arranged in a circular inner cavity formed between the upper clamp and the lower clamp, and the circular fixing block is coaxially rotated with the upper clamp and the lower clamp, and the load applying device is against the outer wall surface of the circular fixing block; at least one group of pads is provided between the lower clamp and the bottom of the rectangular mounting groove, and multiple groups of pads are arranged up and down and the thickness of different pads is the same or different, and the total thickness of the two rows of pads arranged at both ends of the corresponding thin support plate is the same.

[0011] Preferably, the load applying device includes a plane frame and an annular top plate provided at one end of the thin support plate, and a circular frame, a pressure plate, a strain dynamometer and an adapter provided at the other end of the thin support plate; the plane frame and the circular frame are both bolted to the fixing frame, the annular top plate is coaxially arranged with the circular fixing block and the annular top plate is abutted against the outer wall of the circular fixing block, and the plane frame and the annular top plate are connected with the clamping bolt at the axis; the adapter is coaxially connected to the circular fixing block, one end of the strain dynamometer is connected to the adapter and the other end is connected to the pressure plate, the circular frame is located on the outside of the pressure plate, and a clamping bolt is also connected between the circular frame and the pressure plate, and rotating the clamping bolt can adjust the clamping force between the annular top plate or the adapter and the circular fixing block.

[0012] Preferably, the middle part of one of the clamping bolts is threadedly connected to the plane frame, and the end is rotatably connected to the annular top clamping plate; one end of the pressure plate is provided with a circular protrusion inserted into the strain dynamometer, and the other end is provided with a circular groove; the middle part of the other clamping bolt is threadedly connected to the circular frame, and the other end is rotatably connected to the circular groove.

[0013] Preferably, one end of the thin support plate is connected to the inner ring front section by electron beam welding, the inner ring front section and the lower end of the thin support plate are connected to the circular fixing block at this end by argon arc welding, and the other end of the thin support plate is connected to another group of circular fixing blocks by argon arc welding.

[0014] Preferably, the two groups of circular fixing blocks are both double-layer structures, and the double-layer circular fixing blocks are detachably connected.

[0015] Preferably, a positioning hole is provided on the upper chuck, and a positioning bolt is threadedly connected to the fixing frame at a position corresponding to the position above the upper chuck. A ball head is provided at the end of the positioning bolt, and the positioning hole is a spherical concave structure. The ball head at the bottom of the positioning bolt is inserted into the positioning hole; pin holes are provided at corresponding positions of the upper chuck and the lower chuck, and a positioning pin is inserted into the pin hole.

[0016] Preferably, a positioning groove is provided at the bottom of the rectangular mounting groove, a positioning protrusion is provided at the position of the lower chuck corresponding to the positioning groove, a protrusion is provided at the bottom of the pad and a groove is provided at the top, the protrusion on the pad can be snap-fitted with the positioning groove or the groove on the pad, and the groove on the pad can also be snap-fitted with the positioning protrusion.

[0017] The present application discloses a tool for testing the vibration characteristics and fatigue of a thin support plate of a rotary flute tester, comprising a thin support plate, a clamping device and a load applying device; the clamping device comprises a base, a fixing frame, a chuck and a circular fixing block; a test platform is provided below the base and the base and the test platform are respectively provided with inverted T-shaped grooves arranged perpendicular to each other; the chuck is connected to the rectangular mounting groove and the chuck comprises an upper chuck and a lower chuck, the chuck is connected to the rectangular mounting groove and the chuck comprises an upper chuck and a lower chuck, and at least one set of pads is provided between the lower chuck and the bottom of the rectangular mounting groove; through the mutual cooperation of the base, the fixing frame, the pads and the chuck, the test requirements of the thin support plate and the rotary flute tester for carrying out multi-dimensional and complex excitation (X, Y, Z, θ directions) are met, and the degree of freedom of the test is effectively improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions provided by this application, the following is a brief introduction to the accompanying drawings. Obviously, the accompanying drawings described below are only some embodiments of this application.

[0019] Figure 1 This is a schematic diagram of the cross-sectional structure of the rotary flute tester of this application;

[0020] Figure 2 This is a schematic diagram of the overall structure of this application;

[0021] Figure 3 This is a schematic diagram of the connection structure between the tooling and the whistle tester for this application;

[0022] Figure 4 This is a schematic diagram of the connection structure between the circular fixing block and the thin support plate of this application;

[0023] Figure 5 This is a schematic diagram of the fixed frame structure of this application;

[0024] Figure 6 This is a schematic diagram of the cross-sectional structure of the chuck of this application;

[0025] Figure 7 This is a schematic diagram of the pad structure with various thicknesses for this application.

[0026] 1. Base; 2. Fixing frame; 3. Plane frame; 4. Annular top plate; 5. Upper chuck; 6. Spacer block; 7. Reciprocating frame; 8. Pressure plate; 9. Strain gauge; 10. Adapter; 11. Clamping bolt; 12. Lower chuck; 13. Front section of inner ring; 14. Positioning bolt; 15. Pin hole; 16. Thin support plate; 17. Positioning groove; 18. Circular fixing block; 19. Test platform. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solutions and advantages of the implementation of this application clearer, the technical solutions in the embodiments of this application will be described in more detail below in conjunction with the drawings in the embodiments of this application.

[0028] A thin support plate vibration characteristics and fatigue test fixture suitable for a rotary flute tester. The thin support plate 16 high frequency vibration characteristics and fatigue test is carried out on the rotary flute tester. The working principle diagram is shown in the figure below. Figure 1 As shown, the whistle tester primarily consists of a rotating disc, a stationary disc, a bearing housing, a floating bearing, a fixed bearing, a retaining ring, a bushing, and a shaft. The perforated rotating disc cuts through the high-pressure airflow, generating an alternating load that excites the specimen into periodic vibration. The test fixture designed in this invention, combined with the whistle exciter, conducts high-frequency vibration and fatigue testing of thin support plates 16, effectively determining their high-order natural frequencies, relative stress distribution, and fatigue limit.

[0029] like Figure 2 As shown, the apparatus comprises a thin support plate 16, a clamping device and a load applying device. The thin support plate 16 is connected to the clamping device, and the load applying device can apply different loads to the ends of the thin support plate 16.

[0030] The clamping device includes a base 1, a fixing frame 2, a chuck and a circular fixing block 18. The fixing frame 2, the chuck and the circular fixing block 18 are each provided in two groups and are respectively provided at the two ends of the thin support plate 16. Figure 3 A test platform 19 is provided under the base 1 and inverted T-shaped grooves arranged perpendicular to each other are respectively provided on the base 1 and the test platform 19. The fixing frame 2 and the base 1, and the base 1 and the test platform 19 are connected by T-shaped bolts.

[0031] A rectangular mounting groove is provided in the fixing frame 2, and the chuck is connected to the rectangular mounting groove and the chuck includes an upper chuck 5 and a lower chuck 12. The upper chuck 5 and the lower chuck 12 cooperate to form an outer rectangular and inner circular structure. The circular fixing block 18 is provided in the circular inner cavity formed between the upper chuck 5 and the lower chuck 12, and the circular fixing block 18 is coaxially rotated with the upper chuck 5 and the lower chuck 12, and the load applying device is against the outer wall surface of the circular fixing block 18; at least one group of pads 6 is provided between the lower chuck 12 and the bottom of the rectangular mounting groove, and multiple groups of pads 6 are arranged up and down and the thickness of different pads 6 is the same or different, and the total thickness of the two rows of pads 6 arranged at both ends of the corresponding thin support plate 16 is the same.

[0032] By providing inverted T-shaped slots in the X and Y directions on the base 1 and test platform 19, respectively, and employing multiple sets of balancing cableways connected to the fixed frame 2, the fixed frame 2 can be driven to move freely within the X and Y travel range of the inverted T-shaped slots, thereby easily changing the position of the thin support plate 16 and achieving excitation of different positions of the thin support plate 16. This solves the problem of the single clamping fixture mechanism that can only meet the unidirectional excitation requirements of the thin support plate 16. The base 1 is connected to the test platform 19 and the fixed frame 22 respectively via T-bolts through six bolt holes and cableways, ensuring sufficient connection rigidity.

[0033] The fixing frame 2 adopts a three-dimensional design, and by matching the spacers 6 of different thicknesses, it realizes the excitation of different support plate heights (Z direction) of the thin support plate 16. The fixing frame 2 is connected to the base 1 through the two bolt holes on the left and right by T-bolts.

[0034] High-precision scale lines (0 to 360 degrees) are designed on the inner surface of the chuck. By rotating the required rotation angle in the chuck, the different rotation angles (θ) of the thin support plate 16 can be adjusted in real time and accurately according to the test requirements, thereby achieving precise and stable control of any position and any angle of the thin support plate 16, and then the circular fixing block 18 can be tightened and fixed through the load application device.

[0035] In summary, through the mutual cooperation of the base 1, the fixed frame 2, the pad 6, and the chuck, the test requirements of the thin support plate 16 with the rotary flute tester for multi-dimensional and complex excitation (X, Y, Z, θ directions) are met, which effectively improves the degree of freedom of the test and greatly improves the work efficiency. It can be used with the rotary flute tester to carry out vibration characteristics and fatigue tests of the thin support plate 16, obtain its high-order natural frequency, relative stress distribution and fatigue limit results, and simulate the real stress situation of the thin support plate 16 after being subjected to aerodynamic load.

[0036] The split design offers a compact structure and coordinated functionality, making it easy to disassemble and reposition, making operation quick and easy. Processing ensures coaxiality with the thin support plate 16, ensuring the uniformity and stability of the device. Bolt tightening and positioning of each component of the test fixture ensures the overall structural rigidity and test accuracy.

[0037] Preferably, the load applying device includes a plane frame 3 and an annular top plate 4 provided at one end of the thin support plate 16, and a circular frame 7, a pressure plate 8, a strain dynamometer 9 and an adapter 10 provided at the other end of the thin support plate 16; the plane frame 3 and the circular frame 7 are both bolted to the fixing frame 2, the annular top plate 4 is coaxially arranged with the circular fixing block 18 and the annular top plate 4 is against the outer wall of the circular fixing block 18, and the plane frame 3 and the annular top plate 4 are connected with the clamping bolt 11 at the axis; the adapter 10 is coaxially connected to the circular fixing block 18, one end of the strain dynamometer 9 is connected to the adapter 10 and the other end is connected to the pressure plate 8, the circular frame 7 is located on the outside of the pressure plate 8, and a clamping bolt 11 is also connected between the circular frame 7 and the pressure plate 8. Rotating the clamping bolt 11 can adjust the clamping force between the annular top plate 4 or the adapter 10 and the circular fixing block 18.

[0038] The plane frame 3 and the circular frame 7 are both connected to the fixed frame 2 by 6 tightening screws. By rotating the clamping bolt 11 near one end of the adapter 10 in the forward or reverse direction, the degree of compression between the adapter 10 and the circular fixing block 18 can be controlled, thereby applying a pre-tightening force to the thin support plate 16. The magnitude of the pre-tightening force can be observed in real time by the stress dynamometer. By the bolting of each part, sufficient connection stiffness is guaranteed. The direction of the arrow in the figure is the direction of pre-tightening force application.

[0039] Preferably, a clamping bolt 11 is threadedly connected to the planar frame 3 at its center and rotatably connected to the annular clamping plate 4 at its distal end. One end of the pressure plate 8 is provided with a circular projection that inserts into the strain gauge 9, and the other end defines a circular groove. Another clamping bolt 11 is threadedly connected to the circular frame 7 at its center and rotatably engaged within the circular groove at its other end. The strain gauge 9 employs a design in which one end is retained and the other end generates a preload force through the screwing of the clamping bolt 11. This effectively measures the vibration characteristics of the thin support plate 16 and the varying degrees of radial load during fatigue testing.

[0040] Preferably, if Figure 4 ①, one end of the thin support plate 16 is connected to the inner ring front section 13 by electron beam welding, as shown Figure 4 In steps ② and ③, the inner ring front section 13 and the lower end of the thin support plate 16 are connected to the circular fixing block 18 at that end using argon arc welding. The other end of the thin support plate 16 is also connected to another set of circular fixing blocks 18 using argon arc welding. Without damaging the structure of the thin support plate 16, the thin support plate 16 is welded integrally to the intake casing, ensuring a rigid connection between the thin support plate 16 and the fixing blocks. Furthermore, the two welded circular fixing blocks have the same diameter and are aligned horizontally, ensuring concentricity between the front and rear ends of the thin support plate 16.

[0041] Preferably, both sets of circular fixing blocks 18 are double-layered, and the double-layer circular fixing blocks 18 are detachably connected, such as by bolts. To accommodate thin support plates 16 of different models and sizes, only the inner circular fixing blocks 18 need to be re-welded, effectively improving versatility and eliminating the need to redesign a complete set of tooling. This saves significant manpower, material resources, and time, and improves work efficiency.

[0042] Combine Figure 6 Preferably, a positioning hole is formed in the upper chuck 5, and a positioning bolt 14 is threadedly connected to the fixed frame 2 at a position corresponding to the position above the upper chuck 5. The end of the positioning bolt 14 has a ball head, and the positioning hole is a spherical concave structure. The ball head at the bottom of the positioning bolt 14 is inserted into the positioning hole. Pin holes 15 are formed at corresponding positions on the upper chuck 5 and the lower chuck 12, and a positioning pin is inserted into the pin hole 15. Considering that the tightening of the positioning bolt 14 will apply torque to the chuck and the spacer 6, a ball hinge is designed between the positioning bolt 14 and the upper chuck 5 to ensure the relative position between the upper and lower chucks, while achieving precise positioning of the chuck and the thin support plate 16.

[0043] like Figure 5-7 Preferably, a positioning groove 17 is defined at the bottom of the rectangular mounting slot, and a positioning bump is defined at the position of the lower chuck 12 corresponding to the positioning groove 17. The spacer 6 has a bump at the bottom and a groove at the top. The bump on the spacer 6 can engage with the positioning groove 17 or the groove on the spacer 6, and the groove on the spacer 6 can also engage with the positioning bump. The arrangement of the bump and groove restricts the relative position of the lower chuck 12, the fixed frame 2, and the spacer 6, preventing rotation when the bolts are tightened, and achieving precise positioning of the fixed frame 2 and the chuck.

[0044] The above are only specific embodiments of the present application, but the scope of protection of this application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A tool for testing the vibration characteristics and fatigue of thin support plates of a rotary flute tester, characterized by: The invention comprises a thin support plate (16), a clamping device and a load applying device, wherein the thin support plate (16) is connected to the clamping device, and the load applying device can apply different loads to the end of the thin support plate (16); the clamping device comprises a base (1), a fixing frame (2), a clamping head and a circular fixing block (18), and the fixing frame (2), the clamping head and the circular fixing block (18) are each provided in two groups and are respectively provided at the two ends of the thin support plate (16); a test platform (19) is provided below the base (1), and the base (1) and the test platform (19) are respectively provided with inverted T-shaped grooves arranged perpendicular to each other; the fixing frame (2) and the base (1), and the base (1) and the test platform (19) are both connected by T-shaped bolts; a rectangular mounting hole is provided in the fixing frame (2) The mounting groove is provided, wherein the chuck is connected to the rectangular mounting groove and the chuck includes an upper chuck (5) and a lower chuck (12), the upper chuck (5) and the lower chuck (12) cooperate to form an outer rectangular and inner circular structure, the circular fixing block (18) is provided in the circular inner cavity formed between the upper chuck (5) and the lower chuck (12), and the circular fixing block (18) is coaxially rotated with the upper chuck (5) and the lower chuck (12), and the load applying device is against the outer wall surface of the circular fixing block (18); at least one group of pads (6) is provided between the lower chuck (12) and the bottom of the rectangular mounting groove, multiple groups of pads (6) are provided up and down, and the thickness of different pads (6) is the same or different, and the total thickness of the two rows of pads (6) provided at both ends of the corresponding thin support plate (16) is the same; One end of the thin support plate (16) is connected to the inner ring front section (13) by electron beam welding, the inner ring front section (13) and the lower end of the thin support plate (16) are connected to the circular fixing block (18) at the end by argon arc welding, and the other end of the thin support plate (16) is connected to another group of circular fixing blocks (18) by argon arc welding.

2. The thin support plate vibration characteristics and fatigue testing tool for a rotary flute tester according to claim 1, characterized in that: The load applying device comprises a plane frame (3) and an annular top plate (4) provided at one end of the thin support plate (16), and a circular frame (7), a pressure plate (8), a strain gauge (9) and an adapter (10) provided at the other end of the thin support plate (16); the plane frame (3) and the circular frame (7) are both bolted to the fixed frame (2), the annular top plate (4) is coaxially arranged with the circular fixed block (18), and the annular top plate (4) and the outer wall of the circular fixed block (18) are against each other, and the plane frame (3) and the annular top plate are (4) is connected with a clamping bolt (11); the adapter (10) is coaxially connected to the circular fixed block (18); one end of the strain gauge (9) is connected to the adapter (10) and the other end is connected to the pressure plate (8); the circular frame (7) is located outside the pressure plate (8); a clamping bolt (11) is also connected between the circular frame (7) and the pressure plate (8); rotating the clamping bolt (11) can adjust the clamping force between the annular top plate (4) or the adapter (10) and the circular fixed block (18).

3. The thin support plate vibration characteristics and fatigue testing tool for a rotary flute tester according to claim 2, characterized in that: The middle part of one of the clamping bolts (11) is threadedly connected to the plane frame (3), and the end is rotatably connected to the annular top plate (4); one end of the pressure plate (8) is provided with a circular protrusion inserted into the strain gauge (9), and the other end is provided with a circular groove; the middle part of the other clamping bolt (11) is threadedly connected to the circular frame (7), and the other end is rotatably connected to the circular groove.

4. The thin support plate vibration characteristics and fatigue testing tool for a rotary flute tester according to claim 1, characterized in that: The two groups of circular fixing blocks (18) are both double-layer structures, and the double-layer circular fixing blocks (18) are detachably connected.

5. The thin support plate vibration characteristics and fatigue testing tool for a rotary flute tester according to claim 1, characterized in that: A positioning hole is provided on the upper clamp (5), and a positioning bolt (14) is threadedly connected to the fixing frame (2) at a position corresponding to the upper portion of the upper clamp (5). A ball head is provided at the end of the positioning bolt (14), and the positioning hole is a spherical concave structure. The ball head at the bottom of the positioning bolt (14) is inserted into the positioning hole; pin holes (15) are provided at corresponding positions of the upper clamp (5) and the lower clamp (12), and a positioning pin is inserted into the pin hole (15).

6. The thin support plate vibration characteristics and fatigue testing tool for a rotary flute tester according to claim 1, characterized in that: A positioning groove (17) is provided at the bottom of the rectangular mounting groove, a positioning protrusion is provided at a position of the lower clamp (12) corresponding to the positioning groove (17), a protrusion is provided at the bottom of the pad (6) and a groove is provided at the top, the protrusion on the pad (6) can be snap-fitted with the positioning groove (17) or the groove on the pad (6), and the groove on the pad (6) can also be snap-fitted with the positioning protrusion.

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