Test device and test method for damping of wear of a damped wind turbine blade

Abstract

The present invention relates to a test apparatus for the wear of damped platform fan blades, applicable to vibration wear tests of a group of blades with damped platform structures. The blades have protrusions on the other side corresponding to the damped platform structures. The apparatus includes: a vibration device for generating excitation force; a clamping assembly, partially mounted on the vibration table of the vibration device, for fixing one end of the blade and mounting the other end of the blade in a vertically movable manner, enabling the damped platform structures on the blades to vibrate and wear against each other in contact; and a controller, communicatively connected to the vibration device, controlling the vibration device to generate different excitation forces in a frequency-varying manner, thus improving the efficiency of testing and detection.

Description

Technical Field

[0001] This invention belongs to the technical field of aircraft blade testing equipment, and particularly relates to a testing device and method for testing the wear of a fan blade damping table with a damping table. Background Technology

[0002] The low-pressure stage I blades of a certain type of engine are blades with damping platforms. This design aims to reduce blade vibration during engine operation and improve blade lifespan. After prolonged engine operation, the damping platforms on the blades experience varying degrees of wear. To reduce wear and maintain structural strength, a special material is typically infiltrated into the contact area between the damping platforms of the two blades, forming an infiltrated layer of a certain thickness. To verify the wear resistance of the treated blades, vibration wear tests are required. Traditionally, tests are conducted using a fixed frequency and a fixed excitation force. However, a single frequency cannot accurately reflect the actual operating conditions of the blades, leading to a higher probability of defective products and low testing efficiency. Summary of the Invention

[0003] In view of this, the test device for wear of fan blade damping table with damping table provided by the present invention solves the technical problem of low detection efficiency of blades by traditional methods.

[0004] A test apparatus for damping wear of fan blades with damping platform is provided, suitable for vibration wear testing of a group of blades with damping platform structures. The other side of the blade has a protrusion at a corresponding position to the damping platform structure, including...

[0005] Vibration equipment is used to generate excitation force;

[0006] The clamping assembly is partially mounted on the vibration table of the vibration equipment to fix one end of the blade and to install the other end of the blade in a way that allows relative movement in the vertical direction, so as to achieve mutual vibration and wear between the damping table structures on the blade in a contact manner.

[0007] The controller is connected in communication with the vibration equipment and controls the vibration equipment to generate different excitation forces in a frequency conversion manner.

[0008] Beneficial effects

[0009] Currently, there is no domestic testing method for damping table wear using a vibration table. The test method proposed in this patent uses a vibration table to conduct variable frequency random vibration. The vibration table provides a vibration source to simulate the vibration of an engine during operation. At the same time, a fixture is designed to fix the test blades, so that the working surfaces of the damping tables of the two blades are in contact with each other. Upper and lower support sliders are added to adjust the tightness of the contact surfaces. The vibration table outputs a random vibration with superimposed wide and narrow bands, which drives the two blades to vibrate randomly at the same time, causing the contact surfaces of the damping tables of the two blades to rub against each other. This makes the vibration wear on the test instrument the same as the wear mechanism during actual operation, effectively verifying the wear resistance of the blade damping table and providing data support for the repair and process optimization of the damping table working surface. Attached Figure Description

[0010] To more clearly illustrate the technical solutions of the embodiments of this disclosure, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0011] Figure 1 This is a schematic diagram of the structure of the present invention;

[0012] Figure 2 This is a schematic diagram of the system of the present invention;

[0013] Figure 3 This is a schematic diagram of the vibrational spectrum, where,

[0014] 1. Controller; 2. Base; 21. Mounting block; 22. First groove; 23. Second groove; 24. First baffle; 25. Second baffle; 26. Arc-shaped surface; 3. Base plate; 4. Flat plate; 5. Support frame; 51. First support plate; 52. Second support plate; 53. First compression spring; 54. Second compression spring; 55. First moving block; 56. Second moving block; 6. Damping platform structure; 7. Protrusion; 8. Lifting ring. Detailed Implementation

[0015] The embodiments of this disclosure will now be described in detail with reference to the accompanying drawings.

[0016] The following specific examples illustrate the implementation of this disclosure. Those skilled in the art can easily understand other advantages and effects of this disclosure from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of this disclosure, and not all of them. This disclosure can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this disclosure. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. Based on the embodiments in this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.

[0017] It should be noted that various aspects of embodiments within the scope of the appended claims are described below. It will be apparent that the aspects described herein can be embodied in a wide variety of forms, and any particular structure and / or function described herein is merely illustrative. Based on this disclosure, those skilled in the art will understand that one aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number of aspects set forth herein can be used to implement the device and / or practice the method. Additionally, this device and / or method can be implemented using other structures and / or functionalities besides one or more of the aspects set forth herein.

[0018] It should also be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of this disclosure. The drawings only show the components related to this disclosure and are not drawn according to the number, shape and size of the components in actual implementation. In actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0019] Furthermore, specific details are provided in the following description to facilitate a thorough understanding of the examples. However, those skilled in the art will understand that these aspects can be practiced without these specific details.

[0020] like Figures 1 to 3 The test apparatus for damping wear of fan blades with damping platform shown is suitable for vibration wear testing of a group of blades with damping platform structure 6, typically two blades. The other side of the blade has a protrusion 7 at a corresponding position to the damping platform structure 6, including...

[0021] Vibration equipment is used to generate excitation force. Generally, it vibrates for a standard duration according to design specifications. After vibration, the performance of the blades is tested to see if it meets the standards. The excitation force is related to the frequency density value (PSD).

[0022] The clamping assembly is partially mounted on the vibration table of the vibration equipment to fix one end of the blade and to mount the other end of the blade in a vertically movable manner, so as to achieve mutual vibration and wear between the damping table structures 6 on the blade in a contact manner. Specifically, the clamping assembly includes a movable clamping component and a base 2. The base 2 is mounted on the vibration table and a mounting block 21 is detachably mounted on the base 2. For example, it can be installed using a bolt assembly, as follows:

[0023] 1) Structure of mounting block 21

[0024] The mounting block 21 has a first groove 22 and a second groove 23 spaced apart on its side facing the movable clamping assembly. The included angle between the axes of the first groove 22 and the second groove 23 is an acute angle, for example, 5°-10°, and both are inclined and their shapes are adapted to the side dimensions of one end of the blade. A first adjustment assembly is fixedly installed at one end of each of the first groove 22 and the second groove 23. The first adjustment assembly is used to adjust the position of the blade in the groove in a first direction. A second adjustment assembly is rotatably installed at the other end of each of the first groove 22 and the second groove 23. The second adjustment assembly is used to adjust the position of the blade in the groove in a second direction. The first direction and the second direction are opposite in that the blade position is adjusted along the direction of the groove, and the adjustment directions are opposite. The first adjustment assembly includes a first baffle 24 and a bolt assembly respectively installed on the left side of the first groove 22 and the second groove 23. The two first baffles 24 are respectively installed at the left side openings of the first groove 22 and the second groove 23. The bolt assembly passes through the first groove 22 and the second groove 23 respectively. Therefore, rotating the bolt assembly can adjust the position within the first groove 22 and the second groove 23.

[0025] The second adjustment assembly includes a second baffle 25 and a bolt assembly. The second baffle 25 is installed on the right side of the first groove 22 and the second groove 23 by means of a pin or a rotating shaft, and the bolt assembly passes through the first groove 22 and the second groove 23 respectively. Rotating the corresponding bolt assembly can adjust the position of the blade. Therefore, by adjusting the position of the two blades through the first adjustment assembly and the second adjustment assembly, it is ensured that the damping platform structure 6 on the two blades can contact each other to meet the test requirements of contact friction.

[0026] Furthermore, the mounting block 21 is provided with an arc-shaped surface 26, on which the first groove 22 and the second groove 23 are both located. The arc-shaped surface 26 increases the contact area between the first groove 22 and the second groove 23 and the blade, providing a stable clamping force. The angles between the first groove 22 and the second groove 23 and the horizontal plane are both acute angles. The vertical height of one end of the first groove 22 and the second groove 23 is greater than the vertical height of the other end, and the lengths of the first groove 22 and the second groove 23 are both greater than the width of one end of the blade, facilitating the alignment of the damping platform structures 6 on the two blades. The first moving block 55 and the second moving block 56 described above are both triangular in structure, with their respective inclined surfaces contacting the corresponding protrusions 7 in a surface-to-surface manner. Under the action of two compression springs, force is transmitted, ensuring that the damping platform structures 6 of the two blades can periodically rub against each other, achieving the overall vibration friction test.

[0027] 2) The movable clamping assembly provides movable support for the blades by allowing them to move relatively vertically. The movable clamping assembly includes a base plate 3 located near the vibrating device. A support frame 5 is positioned on the base plate 3 corresponding to the mounting block 21. The support frame 5 has a first support plate 51 and a second support plate 52 spaced apart vertically. Specifically…

[0028] The bottom end of the support frame 5 is mounted on the base plate 3 in a movable or fixed manner via the flat plate 4 to improve the stability of the support frame 5. The movable manner can be achieved by means of sliding grooves and slide rails to ensure that the position of the support frame 5 on the base plate 3 can be adjusted.

[0029] Both the first support plate 51 and the second support plate 52 are arranged in a U-shape. The first support plate 51 is installed at the top of the support frame 5, and the second support plate 52 is located near the bottom of the support frame 5 with its bottom surface in contact with the top surface of the plate 4. The plate 4 supports the second support plate 52. Specifically,

[0030] The first support plate 51 is close to one end of the mounting block 21, and a third groove is provided at the position corresponding to the damping platform structure 6 on the blade. A first compression spring 53 is installed in the third groove. A first moving block 55 is installed at the free end of the first compression spring 53. The first moving block 55 presses down on the protrusion 7 on a blade in a surface contact manner. The maximum cross-sectional area of ​​the first moving block 55 is adapted to the cross-sectional area of ​​the third groove. Under the action of the vibration equipment, the first moving block 55 can reciprocate in the vertical direction.

[0031] The second support plate 52 is close to one end of the mounting block 21, and a fourth groove is provided at the position corresponding to the damping platform structure 6 on the blade. A second compression spring 54 is installed in the fourth groove. A second moving block 56 is installed at the free end of the second compression spring 54. The second moving block 56 supports the protrusion 7 on another blade in a surface contact manner. The maximum cross-sectional area of ​​the second moving block 56 is adapted to the cross-sectional area of ​​the fourth groove. Under the action of the vibration equipment, the second moving block 56 can reciprocate in the vertical direction.

[0032] The vibration equipment is started and outputs excitation force in a variable frequency manner. Under the combined action of the first moving block 55 and the second moving block 56, the damping platform structure 6 on the two blades periodically contacts and rubs in the vertical direction to realize the vibration wear test of the two blades. Preferably, the top surface of the mounting block 21 and the top surface of the bottom plate 3 are both equipped with lifting rings 8 to facilitate the movement and hoisting of the whole equipment.

[0033] Furthermore, the free ends of the two blades are limited by damping platform limiters to ensure better vertical friction effect of their respective damping platform structures 6.

[0034] Secondly, a test method is provided, using the aforementioned controller 1, which is communicatively connected to the vibration equipment, to control the vibration equipment to generate different excitation forces in a frequency conversion manner. Preferably, the vibration equipment is controlled to generate different excitation forces in a frequency conversion manner. Specifically...

[0035] The bending mode, torsional mode, double bending mode and compound bending-torsional mode corresponding to the signals of different standard blades can be obtained and determined based on the frequency tests of bending and rotation.

[0036] The first, second, third, and fourth vibration frequencies corresponding to each standard blade are determined based on the bending mode, torsional mode, double bending mode, and combined bending-torsional mode, which is the maximum frequency.

[0037] Determine the first, second, third, and fourth order vibration frequencies corresponding to the current blade. Based on these frequencies, determine the first, second, third, and fourth order vibration bands. Narrow bands refer to the amplitude deviation of the blade, similar to a tolerance range, typically ±5%. Determine the vibration spectrum of the current blade. The first, second, third, and fourth order vibration bands should all fall within the vibration spectrum range; generally, the vibration spectrum is selected as 1Hz-1000Hz.

[0038] Vibration frequencies are randomly assigned within the vibration spectrum, according to military or national standards, and vibration tests are conducted according to preset rules. The vibration spectrum includes low-power spectral density, first-order vibration narrowband, second-order vibration narrowband, third-order vibration narrowband, and fourth-order vibration narrowband. The excitation forces corresponding to the first-order, second-order, third-order, and fourth-order vibration narrowbands are all the same, for example, the excitation force corresponding to 1 PSD. The excitation forces corresponding to the frequencies at the low-power spectral density are also the same, for example, the excitation force corresponding to 0.03 PSD. The initial vibration frequency is preferably 1 Hz. Vibration tests are conducted according to preset rules.

[0039] At least one vibration frequency is allocated within each of the first-order, second-order, third-order, and fourth-order vibration narrowbands, where,

[0040] If the random frequency is the third vibration frequency corresponding to the third-order vibration narrow band, the vibration test shall be conducted for the longest duration.

[0041] If the random frequency is the fourth vibration frequency corresponding to the fourth-order vibration narrow band, the vibration test shall be conducted for the second longest duration.

[0042] If the random frequency is the second vibration frequency corresponding to the second-order vibration narrow band, then the vibration test is conducted for the third longest duration.

[0043] If the random frequency is the first vibration frequency corresponding to the first-order vibration narrow band, the vibration test is conducted with the third longest duration.

[0044] If the random frequency is within the low power spectral density range, the vibration test is conducted with the fourth longest duration.

[0045] The first longest duration is longer than the second longest duration, the second longest duration is longer than the third longest duration, and the third longest duration is longer than the fourth longest duration. The first, second, third, and fourth longest durations are determined by different coefficients allocated according to the total vibration duration of the current blade. For example, the first longest duration is 30 minutes, the fourth longest duration is less than 2 minutes, and the second and third longest durations are generally 10 minutes to 25 minutes. The total vibration duration is determined according to the specifications.

[0046] This method uses resonant vibration modes for vibration simulation experiments, unlike traditional methods that use a fixed frequency for a fixed duration. This invention is the first to provide vibration simulation using fourth-order vibration frequencies, which better reflects the wear conditions of blades under actual working environments.

[0047] The above description is merely a specific embodiment of this disclosure, but the scope of protection of this disclosure is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this disclosure should be included within the scope of protection of this disclosure. Therefore, the scope of protection of this disclosure should be determined by the scope of the claims.

Claims

1. A test apparatus for the wear of damping table on fan blades, suitable for vibration wear tests of a group of blades with damping table structures, wherein the other side of the blade has a protrusion at a corresponding position to the damping table structure, characterized in that, include, Vibration equipment is used to generate excitation force; The clamping assembly is partially mounted on the vibration table of the vibration equipment to fix one end of the blade and to install the other end of the blade in a way that allows relative movement in the vertical direction, so as to achieve mutual vibration and wear between the damping table structures on the blade in a contact manner. The controller is connected in communication with the vibration equipment and controls the vibration equipment to generate different excitation forces in a frequency conversion manner. The clamping assembly includes a movable clamping component and a base. The base is mounted on the vibration table, and a mounting block is detachably mounted on the base. The mounting block has a first groove and a second groove spaced apart on the side facing the movable clamping assembly. The included angle between the axes of the first groove and the second groove is an acute angle, and they are set in an inclined manner and their shapes are adapted to the side dimensions of one end of the blade. A first adjustment component is fixedly installed at one end of both the first groove and the second groove. The first adjustment component is used to adjust the position of the blade in the groove in the first direction. A second adjustment component is rotatably mounted at the other end of the first and second grooves. The second adjustment component is used to adjust the position of the blade in the groove in a second direction. The first and second directions are opposite to the directions in which the blade position is adjusted. The movable clamping assembly provides movable support for the blade in a manner in which the blade can move relative to it in the vertical direction.

2. The experimental apparatus according to claim 1, characterized in that, The mounting block has an arc-shaped surface, and both the first groove and the second groove are located on the arc-shaped surface.

3. The experimental apparatus according to claim 2, characterized in that, The angles between the first groove and the second groove and the horizontal plane are both acute angles, and the height of one end of the first groove and the second groove in the vertical direction is greater than the height of the other end in the vertical direction.

4. The experimental apparatus according to claim 3, characterized in that, The lengths of both the first and second grooves are greater than the width of one end of the blade.

5. The test apparatus according to claim 4, characterized in that, The movable clamping assembly includes a base plate adjacent to the vibrating device, a support frame disposed on the base plate at a position corresponding to the mounting block, and a first support plate and a second support plate spaced apart in the vertical direction on the support frame. The bottom end of the support frame is movably mounted on the base plate via a flat plate to improve the stability of the support frame. Both the first support plate and the second support plate are configured with a U-shaped structure. The first support plate is installed at the top of the support frame, and the second support plate is disposed near the bottom of the support frame with its bottom surface in contact with the top surface of the flat plate. The second support plate is supported by the flat plate. The first support plate is adjacent to one end of the mounting block and has a third groove at a position corresponding to the damping platform structure on the blade. A first compression spring is installed in the third groove, and a first moving block is installed at the free end of the first compression spring. The first moving block presses down on the protrusion on the blade in a surface contact manner. The maximum cross-sectional area of ​​the first moving block is adapted to the cross-sectional area of ​​the third groove. Under the action of the vibration equipment, the first moving block can reciprocate in the vertical direction. The second support plate is adjacent to one end of the mounting block and has a fourth groove at a position corresponding to the damping platform structure on the blade. A second compression spring is installed in the fourth groove, and a second moving block is installed at the free end of the second compression spring. The second moving block supports the protrusion on another blade in a surface contact manner. The maximum cross-sectional area of ​​the second moving block is adapted to the cross-sectional area of ​​the fourth groove. Under the action of the vibration equipment, the second moving block can reciprocate in the vertical direction. The vibration equipment is started and outputs excitation force in a variable frequency manner. Under the combined action of the first and second moving blocks, the damping platform structures on the two blades periodically contact and rub against each other in the vertical direction, thereby realizing the vibration wear test of the two blades.

6. The experimental apparatus according to claim 5, characterized in that, Lifting rings are installed on the top surface of the mounting block and the top surface of the base plate.

7. A test method, characterized in that, Using the test apparatus as described in any one of claims 1 to 6, wherein controlling the vibration device to generate different excitation forces in a frequency-varying manner includes: Obtain the bending vibration mode, torsional vibration mode, double bending vibration mode and combined bending-torsional vibration mode corresponding to the signals of different standard blade models; The first, second, third, and fourth vibration frequencies corresponding to each standard blade are determined based on the bending mode, torsional mode, double bending mode, and combined bending-torsional mode. Determine the first, second, third, and fourth vibration frequencies corresponding to the current blade. Based on the first-order, second-order, third-order, and fourth-order vibration frequencies corresponding to the current blade, determine the first-order vibration narrowband, second-order vibration narrowband, third-order vibration narrowband, and fourth-order vibration narrowband, and determine the vibration spectrum of the current blade. The first-order vibration narrowband, second-order vibration narrowband, third-order vibration narrowband, and fourth-order vibration narrowband are all within the range of the vibration spectrum. Vibration frequencies are randomly assigned within the range of the vibration spectrum, and vibration tests are conducted according to preset rules.

8. The test method according to claim 7, characterized in that, The vibration spectrum includes a low-power spectral density, a first-order vibration narrowband, a second-order vibration narrowband, a third-order vibration narrowband, and a fourth-order vibration narrowband. The excitation forces corresponding to the first-order, second-order, third-order, and fourth-order vibration narrowbands are all the same. The excitation forces corresponding to the frequencies under the low-power spectral density are all the same. Vibration tests are conducted according to preset rules, including: At least one vibration frequency is allocated within each of the first-order, second-order, third-order, and fourth-order vibration narrowbands, wherein... If the random frequency is the third vibration frequency corresponding to the third-order vibration narrow band, the vibration test shall be conducted for the longest duration. If the random frequency is the fourth vibration frequency corresponding to the fourth-order vibration narrow band, the vibration test shall be conducted for the second longest duration. If the random frequency is the second vibration frequency corresponding to the second-order vibration narrow band, then the vibration test is conducted for the third longest duration. If the random frequency is the first vibration frequency corresponding to the first-order vibration narrow band, the vibration test is carried out by allocating the third longest duration. If the random frequency is within the low power spectral density range, the vibration test is conducted with the fourth longest duration. The first longest duration is greater than the second longest duration, the second longest duration is greater than the third longest duration, and the third longest duration is greater than the fourth longest duration. The first longest duration, the second longest duration, the third longest duration, and the fourth longest duration are determined by different coefficients allocated according to the total vibration duration of the current blade.

9. The test method according to claim 8, characterized in that, The first longest duration is 30 minutes, and the fourth longest duration is less than 2 minutes.

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