Rotor blade root fatigue characteristic test device and system

Abstract

The utility model discloses a fatigue characteristic test device and system for a root section of a rotor blade, belongs to the technical field of structural strength design, and is used for solving the technical problem that the fatigue characteristic test device is poor in system stability and safety when the centrifugal force load is relatively large. The utility model relates to a rotor blade root fatigue characteristic test device which comprises a centrifugal force loading mechanism, a swing force loading mechanism and an assembly test bench. The positions of the centrifugal force loading mechanism and the swing force loading mechanism on the assembly test bench can be adjusted; the centrifugal force loading mechanism comprises a centrifugal force actuator and a lever, and the lever can amplify the force applied by the centrifugal force actuator and then apply the amplified force to the test piece. The rotor blade root section fatigue characteristic test device and system are safe and stable, and the loading capacity requirement of the device is remarkably reduced.

Description

Technical Field

[0001] This utility model belongs to the field of rotor blade structural strength design technology, and relates to a test device and system for fatigue characteristics of rotor blade root section. Background Technology

[0002] The root section of composite blades is complex to manufacture, and the blades are critical fatigue components of helicopter rotor systems. According to the fatigue section of helicopter strength specifications, fatigue characteristic tests are required on the blade root section. These tests require the simultaneous application of two mutually perpendicular dynamic and static loads to the test specimen—centrifugal force and flapping-whipping load. Therefore, the testing setup needs one actuator to apply centrifugal force and another actuator to apply the combined flapping-whipping force, with the applied centrifugal load needing to be significantly greater than the flapping and whipping loads, even reaching 20 times. However, existing fatigue characteristic testing equipment, due to its structural characteristics, suffers from compromised system stability and safety when subjected to large centrifugal loads. Utility Model Content

[0003] Based on the above analysis, this utility model aims to provide a test device and system for the fatigue characteristics of rotor blade root sections, in order to solve the technical problem of poor system stability and safety of existing rotor blade root section fatigue characteristic test devices when the centrifugal load is large.

[0004] The purpose of this utility model is mainly achieved through the following technical solutions.

[0005] In a first aspect, this utility model provides a test device for fatigue characteristics of rotor blade root section, including a centrifugal force loading mechanism, a swing force loading mechanism, and an assembly test bench; the centrifugal force loading mechanism is used to apply centrifugal force to the test piece, and the centrifugal force loading mechanism includes a centrifugal force actuator and a lever, the lever being able to amplify the force applied by the centrifugal force actuator and apply it to the test piece; the swing force loading mechanism is used to apply a swing vibration resultant force to the test piece.

[0006] Furthermore, the lever moves in a direction perpendicular to the horizontal plane, thereby applying a vertical centrifugal force to the vertically arranged test specimen.

[0007] Furthermore, the swing force loading mechanism includes a swing force actuator, which is arranged horizontally.

[0008] Furthermore, the swing force loading mechanism also includes a horizontal limiting component, which is used to limit the horizontal displacement of the swing force actuator.

[0009] Furthermore, the horizontal limiting component includes a roller assembly, which includes a roller. The roller makes rolling contact with the side wall of the swing force actuator, and the plane of rotation is perpendicular to the direction of the force and displacement output by the swing force actuator. The two sets of roller assemblies make rolling contact with the side walls of the swing force actuator respectively.

[0010] Furthermore, the swing force loading mechanism also includes a counterweight assembly, which is used to balance the weight of the swing force actuator.

[0011] Furthermore, the counterweight assembly includes a counterweight bracket and a counterweight block. A fixed pulley structure is installed on the counterweight bracket, and the counterweight block is connected to the swing force actuator through the fixed pulley structure.

[0012] Furthermore, the weight of the counterweight can be adjusted to balance the gravity of the swing force actuator.

[0013] Furthermore, the positions of the centrifugal force loading mechanism and the pendulum force loading mechanism on the assembly test bench can be adjusted.

[0014] Another aspect of this utility model provides a rotor blade root section fatigue characteristic testing system, including sensors, strain gauges, a control system, and the rotor blade root section fatigue characteristic testing device as described in any one of the first aspects of this utility model.

[0015] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0016] 1. The fatigue characteristic testing device of this utility model, by setting a lever on the centrifugal force loading mechanism, can amplify the load of the centrifugal force actuator and apply it to the test piece through the lever. Thus, a large load centrifugal force loading test can be achieved without a centrifugal force actuator with high loading capacity, and the loading capacity requirement of the device is significantly reduced.

[0017] 2. The fatigue characteristic testing device of this utility model simplifies the overall structure of the device by adjusting the centrifugal force loading mechanism and the pendulum force loading mechanism on the assembly test table, making it easy to disassemble and assemble, reducing costs, and improving the flexibility of the device layout.

[0018] 3. The fatigue characteristic testing device of this utility model, by setting a horizontal limiting component in the swing force loading mechanism, can limit the horizontal swing of the swing force actuator, ensure that the force applied to the test piece passes through the 1 / 4 chord of the blade, so that the force line of the swing force actuator in the horizontal direction remains consistent, thus meeting the test requirements.

[0019] 4. The fatigue characteristic testing device of this utility model can balance the weight of the swing force actuator by setting a counterweight component in the swing force loading mechanism, so as to prevent an initial force from being applied to the test piece.

[0020] In this invention, the above-described technical solutions can be combined with each other to achieve more preferred combinations. Other features and advantages of this invention will be set forth in the following description, and some advantages may become apparent from the description or be learned by practicing the invention. The objectives and other advantages of this invention can be realized and obtained through the embodiments described and the accompanying drawings, which are particularly pointed out. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the overall structure of the fatigue characteristic testing device according to Embodiment 1 of this utility model;

[0022] Figure 2 This is a schematic diagram of the centrifugal force loading mechanism in Embodiment 1 of this utility model;

[0023] Figure 3 This is a schematic diagram of the swing force loading mechanism in Embodiment 1 of this utility model;

[0024] Figure 4 This is a partial structural diagram of the horizontal limiting component of Embodiment 1 of this utility model.

[0025] Figure label:

[0026] 1-Centrifugal force loading mechanism; 11-Centrifugal force actuator; 12-Lever; 13-Lever column; 14-Pull plate; 15-Centrifugal force loading ear; 16-Tightening screw sleeve assembly; 17-Wire rope; 18-Spherical bearing; 2-Swing force loading mechanism; 21-Swing force actuator; 22-Actuator mounting column; 23-Counterweight assembly; 231-Counterweight bracket; 232-Counterweight block; 24-Horizontal limit assembly; 241-Horizontal limit bracket; 242-Roller assembly; 25-Swing force loading ear; 3-Assembly test bench; 31-Assembly section; 4-Blade test piece; 41-First clamping fixture; 42-Second clamping fixture. Detailed Implementation

[0027] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which constitute a part of the present invention and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.

[0028] Example 1

[0029] This embodiment provides a fatigue characteristic testing device for the root section of a rotor blade, used for fatigue characteristic testing of the root section of a helicopter rotor blade. Figure 1As shown, the assembly includes a centrifugal force loading mechanism 1, a swing force loading mechanism 2, and an assembly test bench 3. The positions of the centrifugal force loading mechanism 1 and the swing force loading mechanism 2 on the assembly test bench 3 are adjustable. The centrifugal force loading mechanism 1 is used to apply centrifugal force to the test piece 4. The centrifugal force loading mechanism 1 includes a centrifugal force actuator 11 and a lever 12. The lever 12 can amplify the force applied by the centrifugal force actuator 11 and apply it to the test piece 4. The swing force loading mechanism 2 is used to apply a swinging and oscillating resultant force to the test piece 4.

[0030] The rotor blade root section fatigue characteristic testing device of this embodiment ensures the stability and safety of the system when the centrifugal load is large. It has a simple structure, low cost, is easy to disassemble and assemble, and can be used in flexible locations.

[0031] like Figure 1 As shown, for example, the assembly test bench 3 can be a cast iron platform, and the centrifugal force loading mechanism 1 and the pendulum force loading mechanism 2 are fixed to the assembly test bench 3 by bolts. The test piece 4 is a test part of the blade root section, with one end fixed to the assembly test bench 3. The test piece 4 can be arranged vertically, horizontally, or in other directions. Preferably, this embodiment takes the vertical arrangement of the test piece 4 as an example for explanation. The bottom end of the test piece 4 is fixed to the assembly test bench 3 by the first clamping fixture 41, and the loading end of the test piece 4 is located at the upper end and is equipped with the second clamping fixture 42.

[0032] For example, the first clamping fixture 41 includes a first clamping fixture base and a first fixture fixture; the first clamping fixture base is fixedly connected to the assembly test bench 3 by bolts, one end of the first fixture fixture is fixed to the first clamping fixture base, and the other end is fixedly connected to the bottom end of the test piece 4 by multiple pins or bolts; multiple bolt holes are evenly arranged along the circumference of the first clamping fixture base, and by using bolts to fix it to the assembly test bench 3 through different bolt holes, the installation angle of the blade of the test piece 4 in the horizontal direction can be changed. For example, the second clamping fixture 42 includes two clamping pieces, which are respectively attached to both sides of the loading end of the test piece 4, and are fixedly connected to the centrifugal force loading mechanism 1 and the pendulum force loading mechanism 2 by multiple bolts.

[0033] For example, such as Figure 1 and Figure 2 As shown, the centrifugal actuator 11 can be an electric cylinder actuator used to cause the centrifugal loading mechanism 1 to generate a force application action. The centrifugal actuator 11 is arranged vertically upwards, and its bottom is fixed to the assembly test bench 3 by bolts. The upper end of the centrifugal actuator 11 is the drive end, which outputs a vertical force. The drive end of the centrifugal actuator 11 is connected to the power end of the lever 12 to apply a vertically downward pulling force to the power end of the lever 12. Preferably, the drive end of the centrifugal actuator 11 and the power end of the lever 12 are connected by a steel wire rope 17 and a spherical bearing 18 to accommodate the flexible rotation of the lever 12.

[0034] The centrifugal loading mechanism 1 also includes a lever column 13, a pull plate 14, and a centrifugal loading ear 15.

[0035] like Figure 2 As shown, lever column 13 supports lever 12. Lever column 13 is arranged vertically, with its bottom fixed to the assembly test bench 3 by bolts, and its upper end rotatably connected to the fulcrum of lever 12 so that the motion plane of lever 12 is perpendicular to the horizontal plane. The height of lever column 13 matches the height and stroke of centrifugal actuator 11 to ensure that the initial position of lever 12 can be arranged in a horizontal position.

[0036] like Figure 2 As shown, the pull plate 14 is arranged vertically, and its two ends are connected to the load end of the lever 12 and the centrifugal force loading ear 15 respectively through the tightening screw assembly 16. Preferably, the pull plate 14 can be multi-sectioned to allow for adjustment according to the length of different experimental pieces 4. The tightening screw assembly 16 at both ends of the pull plate 14 not only facilitates quick and easy assembly and disassembly but also allows for fine-tuning of the length according to different experimental pieces 4 to ensure that the lever 12 is initially in a horizontal position.

[0037] like Figure 2 As shown, the centrifugal force loading lug 15 is fixedly connected to the second clamping fixture 42 at the loading end of the test piece 4, so that the load end of the lever 12 can apply centrifugal force to the loading end of the test piece 4. Since the motion plane of the lever 12 in this embodiment is perpendicular to the horizontal plane and the test piece 4 is arranged vertically, the centrifugal force applied to the test piece 4 is in the vertical direction, which makes the fatigue characteristic testing device safer and more stable when applying large loads.

[0038] Preferred, such as Figure 2 As shown, the length of the power arm of lever 12 is more than three times the length of the resistance arm, so that the load of centrifugal actuator 11 can be amplified more than three times through lever 12. Thus, a large load centrifugal force loading test can be achieved without a centrifugal actuator 11 with a high loading capacity, and the loading capacity requirement of the device is significantly reduced.

[0039] The swing force loading mechanism 2 includes a swing force actuator 21, an actuator mounting column 22, a counterweight assembly 23, a horizontal limiting assembly 24, and a swing force loading ear 25.

[0040] For example, such as Figure 3 As shown, the swing force actuator 21 is an electric cylinder actuator used to make the swing force loading mechanism 2 generate a force application action; the swing force actuator 21 is arranged horizontally, and the driving end of the swing force actuator 21 is fixedly connected to the second clamping fixture 42 of the loading end of the test piece 4 through the swing force loading ear 25, and the mounting end of the swing force actuator 21 is connected to the actuator mounting column 22.

[0041] For example, considering that the blade of the test piece 4 has an installation angle in the horizontal direction relative to the moving direction of the pendulum force actuator 21, the pendulum force loading lug 25 includes a pair of double-eared bolt seats, with the double ears of the pair of double-eared bolt seats arranged vertically to clamp the loading end of the test piece 4. The pair of double-eared bolt seats are fixed to a connecting plate, which is connected to the driving end of the pendulum force actuator 21. In one embodiment, the distance between the double-eared bolt seats is adjusted by an oblong hole provided on the connecting plate to clamp the loading end of the test piece 4. In one embodiment, the connecting plate is hinged to the driving end of the pendulum force actuator 21, with the hinge axis in the vertical direction.

[0042] like Figure 3 As shown, the actuator mounting column 22 is vertically arranged and fixed to the assembly test bench 3 by bolts.

[0043] Preferred, such as Figure 2 As shown, the mounting end of the swing force actuator 21 is hinged to the actuator mounting column 22, so that the mounting end of the swing force actuator 21 can rotate in the horizontal direction to prevent an initial horizontal force from being applied to the test piece 4.

[0044] like Figure 3 As shown, the counterweight assembly 23 is used to balance the weight of the swing force actuator 21. The counterweight assembly 23 includes a counterweight bracket 231 and a counterweight block 232. A fixed pulley structure is installed on the upper part of the counterweight bracket 231. The fixed pulley structure includes a steel wire rope and at least one fixed pulley. The two ends of the steel wire rope are connected to the counterweight block 232 and the swing force actuator 21, respectively. By adjusting the weight of the counterweight block 232, the weight of the swing force actuator 21 can be balanced to prevent an initial force from being applied to the test piece 4.

[0045] like Figure 3 and Figure 4 As shown, the horizontal limiting component 24 is used to limit the horizontal displacement of the swing force actuator 21. The horizontal limiting component 24 includes a horizontal limiting bracket 241 and a roller assembly 242. Two sets of roller assemblies 242 are mounted on the horizontal limiting bracket 241 and are symmetrically arranged on both sides of the swing force actuator 21. Each set of roller assemblies 242 includes at least two rollers, and the shortest line connecting the axles of the rollers in each set of roller assemblies 242 is in the vertical direction.

[0046] The roller makes rolling contact with the side wall of the swing force actuator 21, and the plane of rotation of the roller is perpendicular to the direction of the force and displacement output by the swing force actuator 21. The horizontal limiting assembly 24, by setting two sets of roller assemblies 242, can limit the swing force actuator 21 from oscillating in the horizontal direction, ensuring that the force applied to the test piece 4 passes through the 1 / 4 chord of the blade, so that the force line of the swing force actuator 21 remains consistent in the horizontal direction, thereby meeting the test requirements.

[0047] When using the fatigue characteristic testing device of this embodiment, the test piece 4 is first fixed on the assembly test table 3 using the first clamping fixture 41, and the blade angle can be adjusted by adjusting the position of the mounting holes of the first clamping fixture 41. Then, the centrifugal force loading ear 16 and the swing force loading ear 25 are connected to the first clamping fixture to connect the loading end of the test piece 4 to the centrifugal force loading mechanism 1 and the swing force loading mechanism 2, respectively. During the test, the centrifugal force actuator 11 is first controlled to apply a constant centrifugal force to the test piece 4, and then the swing force actuator 21 is controlled to apply a periodic swing force to the test piece 4 to achieve the effect of fatigue characteristic testing on the test piece 4.

[0048] A preferred embodiment of this solution is as follows: Figure 1 As shown, the assembly test bench 3 has multiple assembly parts 31 in different positions, so that the components in the centrifugal force loading mechanism 1 and the pendulum force loading mechanism 2 can not only be disassembled and assembled with bolts, but also have their installation positions adjusted. The assembly operation is simple, and the test environment can be quickly set up by 2-3 people. For example, the assembly part 31 is an assembly slot or bolt hole.

[0049] Example 2

[0050] This embodiment provides a rotor blade root section fatigue characteristic testing system, including the rotor blade root section fatigue characteristic testing device, sensor, strain gauge and control system of Embodiment 1.

[0051] The control system is electrically connected to the centrifugal force actuator 11 and the swing force actuator 21, and is used to control the centrifugal force actuator 11 and the swing force actuator 21 to generate force action according to the preset test steps; the sensors are two force sensors electrically connected to the control system, which are respectively arranged at the drive end of the centrifugal force actuator 11 and the swing force actuator 21, and are used to feed back the force data of the centrifugal force actuator 11 and the swing force actuator 21 to the control system; the strain gauge is used to measure the test load.

[0052] The sensor, strain gauge, and control system in this embodiment are existing technologies and are not within the scope of technical improvements of this utility model, so they will not be described in detail here.

[0053] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present utility model should be included within the protection scope of the present utility model.

Claims

1. A rotor blade root segment fatigue property test apparatus characterized by, The device comprises a centrifugal force loading mechanism (1), a flapping force loading mechanism (2) and an assembly test bench (3). The centrifugal force loading mechanism (1) is used to apply a centrifugal force to the test piece (4), and comprises a centrifugal force actuator (11) and a lever (12), which can amplify the force applied by the centrifugal force actuator (11) and apply it to the test piece (4). The flapping force loading mechanism (2) is used to apply a flapping force to the test piece (4).

2. The rotor blade root section fatigue characteristics test apparatus according to claim 1, characterized by, The lever (12) moves in a direction perpendicular to the horizontal plane, thereby applying a vertical centrifugal force to the vertically arranged test piece (4).

3. The rotor blade root segment fatigue characteristics test apparatus according to claim 1, characterized by, The flapping force loading mechanism (2) comprises a flapping force actuator (21), which is horizontally arranged.

4. The rotor blade root segment fatigue characteristics test apparatus according to claim 3, characterized by, The flapping force loading mechanism (2) further comprises a horizontal limiting assembly (24), which is used to limit the horizontal displacement of the flapping force actuator (21).

5. The rotor blade root segment fatigue characteristics test apparatus according to claim 4, characterized by, The horizontal limiting assembly (24) comprises a roller assembly (242), which comprises rollers that are in rolling contact with the side wall surface of the flapping force actuator (21) and whose rotation plane is perpendicular to the direction of the force and displacement output by the flapping force actuator (21); two sets of the roller assembly (242) are arranged on the two sides of the flapping force actuator (21) respectively, each set of the roller assembly (242) comprises at least two rollers, and the shortest connecting line of the wheel shafts of the rollers in each set of the roller assembly (242) is in the vertical direction.

6. The rotor blade root segment fatigue characteristics test apparatus according to claim 3, characterized by, The flapping force loading mechanism (2) further comprises a counterweight assembly (23), which is used to balance the gravity of the flapping force actuator (21).

7. The rotor blade root segment fatigue characteristics test apparatus according to claim 6, characterized by, The counterweight assembly (23) comprises a counterweight support (231) and a counterweight block (232), the counterweight support (231) is provided with a fixed pulley structure, and the counterweight block (232) is connected to the flapping force actuator (21) through the fixed pulley structure.

8. The rotor blade root segment fatigue characteristics test apparatus according to claim 7, characterized by, The weight of the counterweight block (232) can be adjusted to balance the gravity of the flapping force actuator (21).

9. The rotor blade root segment fatigue property test apparatus according to any one of claims 1 to 8, characterized by, The positions of the centrifugal force loading mechanism (1) and the flapping force loading mechanism (2) on the assembly test bench (3) can be adjusted.

10. A rotor blade root segment fatigue property test system characterized by, The device comprises a sensor, a strain gauge, a control system and the rotor blade root segment fatigue characteristic test device according to any one of claims 1 to 9.

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