Composite material bending moment loading device and method

Abstract

The invention provides a composite material bending moment loading device which comprises a first test piece clamping assembly, one end of a composite material test piece is connected with the first test piece clamping assembly, a bolt of the first test piece clamping assembly is loosened, and the composite material test piece rotates in the axial direction; the other end of the composite material test piece is connected with the second test piece clamping assembly, a bolt of the second test piece clamping assembly is loosened, and the composite material test piece rotates in the axial direction; meanwhile, the invention further provides a composite material bending moment loading method. The extension beam is adopted to replace a cantilever beam structure, and the problems that a test piece is long, the swing bending moment section is a non-zero section, and the stroke of a swing loading actuator is large, so that the test loading frequency is small are solved.

Description

Technical Field

[0001] The present application belongs to the technical field of fatigue testing, and specifically relates to a composite material bending moment loading device and method. Background Art

[0002] In the fatigue test of helicopter rotor system, the application of flapping bending moment is essential. At present, flapping bending moment loading is mostly carried out in the form of simply supported beams. For the test of long test pieces and the test section load of non-blade pin hole section (hereinafter referred to as 0 section), if the same load level is reached, the stroke of the actuator for simply supported beam flapping loading is large, resulting in a small test loading frequency, which seriously affects the test progress.

[0003] The invention provides a novel composite material bending moment loading device, which solves the problem that the test loading frequency is small due to the long test piece, the swing bending moment section is non-zero, and the swing loading actuator stroke is large. Summary of the invention

[0004] Purpose of the invention: To provide a composite material bending moment loading device and method, which solves the problem that when the test piece is long, the swing bending moment profile is non-zero, and the swing loading actuator stroke is large, resulting in a low test loading frequency.

[0005] In a first aspect, the present application provides a composite material bending moment loading device, the device comprising:

[0006] A first test piece clamping assembly, one end of the composite material test piece is connected to the first test piece clamping assembly, and the bolts of the first test piece clamping assembly are loosened, so that the composite material test piece rotates axially;

[0007] The other end of the composite material test piece is connected to the second test piece clamping assembly. The bolts of the second test piece clamping assembly are loosened, and the composite material test piece rotates axially.

[0008] Preferably, the device further comprises:

[0009] A feedback lever is swung to connect with the first test piece clamping assembly.

[0010] The oscillation feedback rod is connected to the first test piece clamping assembly.

[0011] Preferably, the device further comprises:

[0012] A U-shaped frame connected to the second test piece clamping assembly;

[0013] The swinging and oscillating actuator is connected with the U-shaped frame.

[0014] In a second aspect, the present application also provides a composite material bending moment loading method, the method comprising:

[0015] Step 1: A first test piece clamping assembly is used to clamp one end of the composite material test piece, and a second test piece clamping assembly is used to clamp the other end of the composite material test piece;

[0016] Step 2, one end of the first support joint and the second support joint is fixed to the load-bearing support frame 9, and the other ends of the first support joint and the second support joint are connected to the U-shaped frame through the first pin shaft and the second pin shaft respectively, so that the U-shaped frame can rotate around the first pin shaft and the second pin shaft fixed to the first support joint and the second support joint;

[0017] Step 3, the U-shaped frame is fixed to the second test piece clamping assembly by bolts, a fork ear structure is provided under the U-shaped frame, and the fork ear structure is connected to the flapping vibration actuator through a sixth pin shaft, and the flapping vibration actuator is used to apply motion to drive the rotation of the U-shaped frame to apply the flapping vibration bending moment to the composite material test piece;

[0018] Step 4: The other end of the first test piece clamping assembly is connected to a centrifugal force actuator fixed on the load-bearing support frame through a third pin shaft, and the centrifugal force actuator contracts to apply centrifugal force to the composite material test piece;

[0019] Step 5, a hole is provided in the middle of the first test piece clamping assembly, which is connected to a swing feedback rod fixed on the load-bearing support frame through a fifth pin shaft, and the swing feedback rod can be telescopically adjusted to adjust the angle of the test piece in the horizontal direction, and balance the swing direction force generated by the swing vibration actuator when loading and swinging;

[0020] Step 6: A hole is provided in the middle of the first test piece clamping assembly and is connected to a swing feedback rod fixed on the load-bearing support frame through a thread. The swing feedback rod can be telescopically adjusted to adjust the angle of the test piece in the horizontal direction and balance the swing direction force generated when the swing actuator is loaded with a swing bending moment;

[0021] Preferably, the tightening bolts of the first test piece clamping assembly and the second test piece clamping assembly are loosened, and the composite material test piece is allowed to rotate freely, so as to adjust the ratio between the flapping and shimmying bending moments during loading.

[0022] Preferably, the method further comprises:

[0023] The first test piece clamping assembly and the tightening bolts of the first test piece clamping assembly are tightened, the composite material test piece cannot rotate, and the loading angle is kept unchanged to maintain the ratio between the swinging vibration bending moments.

[0024] Preferably, the method further comprises:

[0025] Step 7: The loading point of the swinging vibration actuator is close to the rotation center of the U-shaped frame around the first pin shaft and the second pin shaft fixed to the first supporting joint and the second supporting joint.

[0026] Preferably, the method further comprises:

[0027] Step 8, the flapping vibration actuator is extended and retracted to drive the U-shaped frame to rotate around the first pin and the second pin, thereby applying the flapping vibration bending moment to the composite material test piece;

[0028] Step 9: Loosen or tighten the bolts of the first test piece clamping assembly and the second test piece clamping assembly to rotate and change and lock the loading angle of the composite test piece, thereby changing the bending moment ratio applied in the swing direction and the swing direction in the monitoring area, so that the swinging and swinging bending moment loaded in the monitoring area of ​​the composite test piece meets the requirements.

[0029] This application has the following technical effects:

[0030] The composite material bending moment loading device provided in the present application has a simple principle and adopts an extended beam to replace the cantilever beam structure, which successfully solves the problems that the test piece is long, the swing bending moment profile is non-zero, and the swing loading actuator has a large stroke, resulting in a low test loading frequency. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a structural schematic diagram of a composite material bending moment loading device provided in an embodiment of the present application;

[0032] Figure 2 It is a structural schematic diagram of another composite material bending moment loading device provided in an embodiment of the present application;

[0033] Wherein: 1 composite material test piece, 2 first test piece clamping assembly, 3 second test piece clamping assembly, 4 U-shaped frame, 5 first pin shaft, 6 second pin shaft, 7 first support joint, 8 second support joint, 9 load-bearing support frame, 10 third pin shaft, 11 centrifugal force actuator, 12 fourth pin shaft, 13 fifth pin shaft, 14 swing feedback rod, 15 swing feedback rod, 16 sixth pin shaft, 17 swing swing actuator. DETAILED DESCRIPTION

[0034] See attached Figure 1 , a composite material bending moment loading device is provided, which is used to implement composite material bending moment loading.

[0035] One end of the composite test piece 1 is connected to the first test piece clamping assembly 2. By loosening the bolts of the first test piece clamping assembly 2, the composite test piece 1 can rotate axially; the other end of the composite test piece 1 is connected to the second test piece clamping assembly 3. By loosening the bolts of the second test piece clamping assembly 3, the composite test piece 1 can rotate axially.

[0036] The other end of the first test piece clamping assembly 2 is fixedly connected to the U-shaped frame 4. The two ears of the U-shaped frame 4 are respectively twisted on the first support joint 7 and the second support joint 8 through the first pin shaft 5 and the second pin shaft 6. The first pin shaft 5 is coaxial with the second pin shaft 6. The first support joint 7 and the second support joint 8 are fixed on the load-bearing support frame 9 by bolts as the main load-bearing structure.

[0037] The other end of the first test piece clamping assembly 2 is connected to the load loading device 11 through the third pin shaft 10, and the other end of the load loading device 11 is connected to the load-bearing support frame 9 through the fourth pin shaft 12. The load loading device 11 (or other force-applying device) applies a load Fc, which is transmitted to the load-bearing support frame 9 through the third pin shaft 10, the first test piece clamping assembly 2, the composite test piece 1, the second test piece clamping assembly 3, the U-shaped frame 4, the pin shaft 5, the second pin shaft 6, the first support joint 7, and the second support joint 8, and the main load-bearing is completed by the load-bearing support frame 9.

[0038] The first test piece clamping assembly 2 extends a rod along the swing direction (Z direction) and is connected to the swing feedback rod 14 via the fifth pin 13, and the other end of the swing feedback rod 14 is fixed to the load-bearing support frame 9; the first test piece clamping assembly 2 extends a rod along the swing direction (Y direction) and is connected to the swing feedback rod 15, and the other end of the swing feedback rod 15 is fixed to the load-bearing support frame 9. The rod extending from the U-shaped frame 4 is connected to the load loading device 17 via the sixth pin 16, and the other end of the load loading device 17 is fixed to the load-bearing support frame 9. The load loading device 17 (or other force-applying device) applies a load to drive the U-shaped frame 4 to rotate around the first pin 5 and the second pin 6, thereby applying the swing bending moment to the composite material test piece 1. Loosening or tightening the bolts of the first test piece clamping assembly 2 and the second test piece clamping assembly 3 can rotate to change and lock the loading angle of the composite test piece 1, thereby changing the bending moment ratio applied in the swing direction and the swing direction in the monitoring area, so that the swinging and swinging bending moment loaded in the monitoring area of ​​the composite test piece 1 meets the requirements.

[0039] It should be noted that:

[0040] 1. The composite material bending moment loading device of the present invention successfully solves the problem that the test piece is long, the swing bending moment section is non-zero, and the swing loading actuator has a large stroke, resulting in a low test loading frequency;

[0041] 2. In the device, the swing feedback rod 14, the shimmy feedback rod 15, the first test piece clamping assembly 2, the composite test piece 1, the second test piece clamping assembly 3, the U-shaped frame 4, the first pin 5, the second pin 6, the first support joint 7, the second support joint 8 are transmitted to the load-bearing support frame 9 to form an outrigger beam structure, which greatly reduces the travel requirement of the load loading device 17, and thus significantly improves the test loading frequency under the same conditions;

[0042] 3. The load loading device 17 in the device applies load to drive the U-shaped frame 4 to rotate around the first pin 5 and the second pin 6, thereby applying the swinging bending moment to the composite test piece 1. Loosening or tightening the bolts of the first test piece clamping assembly 2 and the second test piece clamping assembly 3 can rotate to change and lock the loading angle of the composite test piece 1, thereby changing the bending moment ratio of the swinging direction and the swinging direction applied to the monitoring area. The swinging feedback rod 14 and the swinging feedback rod 15 are set in the first test piece clamping assembly 2 to play a good supporting role and help reduce the deformation of both ends of the test piece.

[0043] The present invention is further described in detail below. Figure 2 , one end of the composite test piece 1 is connected to the first test piece clamping assembly 2. By loosening the bolts of the first test piece clamping assembly 2, the composite test piece 1 can rotate axially; the other end of the composite test piece 1 is connected to the second test piece clamping assembly 3. By loosening the bolts of the second test piece clamping assembly 3, the composite test piece 1 can rotate axially. The other end of the first test piece clamping assembly 2 is fixedly connected to the U-shaped frame 4. The two ears of the U-shaped frame 4 are respectively twisted on the first support joint 7 and the second support joint 8 through the first pin shaft 5 and the second pin shaft 6. The first pin shaft 5 is coaxial with the second pin shaft 6. The first support joint 7 and the second support joint 8 are fixed on the load-bearing support frame 9 by bolts as the main load-bearing structure; the other end of the first test piece clamping assembly 2 is connected to the centrifugal force actuator 11 through the third pin shaft 10. The other end of the centrifugal force actuator 11 is connected to the load-bearing support frame 9 through the fourth pin shaft 12. The centrifugal force is transmitted by a centrifugal actuator (or other force-applying device) through the third pin 10, the first test piece clamping assembly 2, the composite test piece 1, the second test piece clamping assembly 3, the U-shaped frame 4, the first pin 5, the second pin 6, the first support joint 7, and the second support joint 8 to the load-bearing support frame 9, and the main load-bearing is completed by the load-bearing support frame 9.

[0044] The first test piece clamping assembly 2 extends a rod along the swing direction (Z direction) and is connected to the swing feedback rod 14 via the fifth pin 13, and the other end of the swing feedback rod 14 is connected to the load-bearing support frame 9; the first test piece clamping assembly 2 extends a rod along the swing direction (Y direction) and is connected to the swing feedback rod 15, and the other end of the swing feedback rod 15 is connected to the load-bearing support frame 9. The U-shaped frame 4 extends a rod and is connected to the swing loading actuator 17 via the sixth pin 16, and the other end of the swing loading actuator 17 is connected to the load-bearing support frame 9. The swing actuator 17 is extended and retracted to drive the U-shaped frame 4 to rotate around the first pin 5 and the second pin 6, thereby applying the swing bending moment to the composite material test piece 1. Loosening or tightening the bolts of the first test piece clamping assembly 2 and the second test piece clamping assembly 3 can rotate to change and lock the loading angle of the composite test piece 1, thereby changing the bending moment ratio applied in the swing direction and the swing direction in the monitoring area, so that the swinging and swinging bending moment loaded in the monitoring area of ​​the composite test piece 1 meets the requirements.

[0045] In other embodiments of the present application, the process of the loading method is as follows: (refer to Figure 2 )

[0046] Step 1

[0047] The first test piece clamping assembly 2 is used to clamp one end of the composite material test piece 1, and the second test piece clamping assembly 3 is used to clamp the other end of the composite material test piece 1. The tightening bolts of the first test piece clamping assembly 2 and the second test piece clamping assembly 3 are loosened, and the composite material test piece 1 can rotate freely to adjust the ratio between the swinging and swaying bending moments during loading. The tightening bolts of the first test piece clamping assembly 2 and the first test piece clamping assembly 3 are tightened, and the composite material test piece 1 cannot rotate, and the loading angle is kept unchanged to maintain the ratio between the swinging and swaying bending moments;

[0048] Step 2

[0049] One end of the first support joint 7 and the second support joint 8 is fixed on the load-bearing support frame 9, and the other ends of the first support joint 7 and the second support joint 8 are connected to the U-shaped frame 4 through the first pin shaft 5 and the second pin shaft 6 respectively, so that the U-shaped frame 4 can rotate around the first pin shaft 5 and the second pin shaft 6 fixed to the first support joint 7 and the second support joint 8;

[0050] Step 3

[0051] The U-shaped frame 4 is fixed to the second test piece clamping assembly 3 by bolts, and a fork ear structure is provided below the U-shaped frame 4, which is connected to a flapping vibration actuator 17 through a sixth pin shaft 16, and the flapping vibration actuator 17 is used to apply motion, drive the rotation of the U-shaped frame 4, and thus apply a flapping vibration bending moment to the composite material test piece 1;

[0052] Step 4

[0053] The other end of the first test piece clamping assembly 2 is connected to a centrifugal force actuator 11 fixed on the load-bearing support frame 9 through a third pin shaft 10, and the centrifugal force actuator 11 contracts to apply centrifugal force to the composite material test piece 1;

[0054] Step 5

[0055] The first test piece clamping assembly 2 has a hole in the middle thereof, which is connected to a swinging feedback rod 14 fixed on the load-bearing support frame 9 through a fifth pin shaft 13. The swinging feedback rod 14 can be telescopically adjusted to adjust the angle of the test piece in the horizontal direction, and balance the swinging direction force generated by the swinging vibration actuator 17 when loading and swinging;

[0056] Step 6

[0057] The first test piece clamping assembly 2 has a hole in the middle thereof, which is connected to a swing feedback rod 15 fixed on the load-bearing support frame 9 through a thread, and the swing feedback rod 14 can be telescopically adjusted to adjust the angle of the test piece in the horizontal direction, and balance the swing direction force generated when the swing actuator 17 is loaded with the swing bending moment;

[0058] Step 7

[0059] Since the loading point of the swinging vibration actuator 17 is close to the rotation center of the U-shaped frame 4 around the first and second pins 5 and 6 fixed to the first supporting joints 7 and the second supporting joints 8, the loading displacement is greatly reduced and the test loading frequency is significantly improved.

Claims

1. A composite material bending moment loading device, characterized in that: The device comprises: A first test piece clamping assembly, one end of the composite material test piece is connected to the first test piece clamping assembly, and the bolts of the first test piece clamping assembly are loosened, so that the composite material test piece rotates axially; The other end of the composite material test piece is connected to the second test piece clamping assembly. The bolts of the second test piece clamping assembly are loosened, and the composite material test piece rotates axially.

2. The device according to claim 1, characterized in that The device also includes: A feedback lever is swung to connect with the first test piece clamping assembly. The oscillation feedback rod is connected to the first test piece clamping assembly.

3. The device according to claim 2, characterized in that The device also includes: A U-shaped frame connected to the second test piece clamping assembly; The swinging and oscillating actuator is connected with the U-shaped frame.

4. A composite material bending moment loading method, characterized in that: The method comprises: Step 1: A first test piece clamping assembly is used to clamp one end of the composite material test piece, and a second test piece clamping assembly is used to clamp the other end of the composite material test piece; Step 2, one end of the first support joint and the second support joint is fixed to the load-bearing support frame 9, and the other ends of the first support joint and the second support joint are connected to the U-shaped frame through the first pin shaft and the second pin shaft respectively, so that the U-shaped frame can rotate around the first pin shaft and the second pin shaft fixed to the first support joint and the second support joint; Step 3, the U-shaped frame is fixed to the second test piece clamping assembly by bolts, a fork ear structure is provided under the U-shaped frame, and the fork ear structure is connected to the flapping vibration actuator through a sixth pin shaft, and the flapping vibration actuator is used to apply motion to drive the rotation of the U-shaped frame to apply the flapping vibration bending moment to the composite material test piece; Step 4: The other end of the first test piece clamping assembly is connected to a centrifugal force actuator fixed on the load-bearing support frame through a third pin shaft, and the centrifugal force actuator contracts to apply centrifugal force to the composite material test piece; Step 5, a hole is provided in the middle of the first test piece clamping assembly, which is connected to a swing feedback rod fixed on the load-bearing support frame through a fifth pin shaft, and the swing feedback rod can be telescopically adjusted to adjust the angle of the test piece in the horizontal direction, and balance the swing direction force generated by the swing vibration actuator when loading and swinging; Step 6: There is a hole in the middle of the first test piece clamping assembly which is connected to the swing feedback rod fixed on the load-bearing support frame through a thread. The swing feedback rod can be telescopically adjusted to adjust the angle of the test piece in the horizontal direction and balance the swing direction force generated when the swing actuator is loaded with the swing bending moment.

5. The method according to claim 4, characterized in that The tightening bolts of the first test piece clamping assembly and the second test piece clamping assembly are loosened, and the composite material test piece is rotated freely to adjust the ratio between the swinging bending moments during loading.

6. The method according to claim 5, characterized in that The method further comprises: The first test piece clamping assembly and the tightening bolts of the first test piece clamping assembly are tightened, the composite material test piece cannot rotate, and the loading angle is kept unchanged to maintain the ratio between the swinging vibration bending moments.

7. The method according to claim 6, characterized in that The method further comprises: Step 7: The loading point of the swinging vibration actuator is close to the rotation center of the U-shaped frame around the first pin shaft and the second pin shaft fixed to the first supporting joint and the second supporting joint.

8. The method according to claim 7, characterized in that The method further comprises: Step 8, the flapping vibration actuator is extended and retracted to drive the U-shaped frame to rotate around the first pin and the second pin, thereby applying the flapping vibration bending moment to the composite material test piece; Step 9: Loosen or tighten the bolts of the first test piece clamping assembly and the second test piece clamping assembly to rotate and change and lock the loading angle of the composite test piece, thereby changing the bending moment ratio applied in the swing direction and the swing direction in the monitoring area, so that the swinging and swinging bending moment loaded in the monitoring area of ​​the composite test piece meets the requirements.

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