Elastic test device for bending stiffness and fatigue strength of aluminum alloy structural parts

Abstract

An elastic testing device for the bending stiffness and fatigue strength of an aluminum alloy structural part comprises a mechanical force load application unit, a structural part clamping and swinging unit and a swing arm support and guide unit arranged on a base, a set of structural part clamping and swinging units are arranged on both sides of the mechanical force load application unit, and the structural part clamping and swinging units are connected to the swing arm support and guide units. The structural part clamping and swinging units are clamped on both sides of the structural part to assist the structural part in performing three-point bending movement. The present invention ensures the uniqueness and symmetry of the force positions of the structural parts during the load application process, realizes the repeated application and release of mechanical force loads to the force positions of the structural parts, and realizes the elastic testing of the bending stiffness and fatigue strength of the aluminum alloy structural parts by analyzing the mechanical force load value-bending deformation amount of the structural parts, providing basic data support for the elastic deformation stage for the service performance research of the structural parts.

Description

Technical Field

[0001] The invention relates to an elastic testing device for testing the bending rigidity and fatigue strength of an aluminum alloy beam structural part, belonging to the technical field of elastic testing of structural parts. Background Art

[0002] Aluminum alloy aviation structural parts are generally made by milling pre-stretched plates. The structural parts are characterized by large size, thin wall thickness and low stiffness. During the machining process, a large amount of blank material is removed, and the structural parts are coupled by factors such as blank stress, processing stress, mechanical load, and temperature load, resulting in the internal state of the workpiece, such as residual stress and microstructure, becoming complicated. In addition, structural parts generally have deformation tolerance problems caused by processing deformation, which affects the assembly of the workpiece. Post-processing processes such as rolling correction and pressure correction are required for deformation correction, which further increases the complexity of the internal stress and microstructure of the workpiece.

[0003] Changes in the internal state of structural parts affect the stability of the structural parts, and changes in their internal stress and microstructure will affect the overall bending stiffness and fatigue strength of the structural parts. During the service of aviation equipment, aluminum alloy structural parts are subjected to various loads such as mechanical force, temperature and vibration. The service environment is complex and changeable. The bending stiffness and fatigue strength of structural parts are important factors affecting the flight safety and flight life of aviation equipment.

[0004] In order to analyze the service performance of aluminum alloy structural parts more effectively, a high-precision special device is needed to accurately test the bending stiffness and fatigue strength of aluminum alloy structural parts. However, there is no such accurate testing device at present. Summary of the invention

[0005] In view of the shortcomings of the existing technology for testing the bending stiffness and fatigue strength of aluminum alloy beam-type structural parts, the present invention provides an elastic testing device for testing the bending stiffness and fatigue strength of aluminum alloy structural parts with high testing accuracy by combining the movement characteristics of a three-point bending test on a workpiece under a mechanical external load.

[0006] The elastic testing device for the bending stiffness and fatigue strength of aluminum alloy structural parts of the present invention adopts the following technical scheme:

[0007] The elasticity testing device comprises a control unit and a mechanical force load applying unit, a structural member clamping and swinging unit and a swing arm supporting and guiding unit arranged on a base, wherein a set of structural member clamping and swinging units are arranged on both sides of the mechanical force load applying unit, and the structural member clamping and swinging units are connected with the swing arm supporting and guiding units; a power mechanism, a tension and pressure sensor and a displacement sensor are arranged in the mechanical force load applying unit, and an angle sensor is arranged in the structural member clamping and swinging unit; the control unit comprises a host computer and an I / O module, and the host computer is connected to the power mechanism, the tension and pressure sensor, the displacement sensor and the angle sensor through the I / O module.

[0008] The mechanical force load applying unit comprises a push-pull main body and a power mechanism, wherein the push-pull main body is connected to the power mechanism, which is installed on the base, and a push-pull attachment is arranged at the front end of the push-pull main body. The power mechanism adopts a double-acting cylinder, wherein two air nozzles of the double-acting cylinder are connected to two output ends of a three-position five-way solenoid valve, the input end of the three-position five-way solenoid valve is connected to the output end of an electrical proportional valve, the wiring end of the three-position five-way solenoid valve is connected to an I / O module through a relay, the input end of the electrical proportional valve is connected to an air source, and the wiring end of the electrical proportional valve is connected to the I / O module. The push-pull main body is connected to the power mechanism through a floating joint, a tension pressure sensor is connected between the push-pull main body and the power mechanism, the tension pressure sensor is connected to a floating joint, and the floating joint is installed on the power mechanism. The tension pressure sensor is connected to an I / O module through a tension pressure sensor transmitter, and the I / O module is connected to a host computer. The output end of the push-pull main body or the power mechanism is connected to a displacement sensor through a connecting rod, and the displacement sensor is installed on the base.

[0009] The structural member clamps the swing unit, including a swing arm, a front axle and a rear axle. The front end of the swing arm is hinged with a clamping plate through the front axle, and a clamping block is provided on the clamping plate (used to fasten the end of the structural member in the length direction to the clamping plate). The rear end of the swing arm is installed on the rear axle, and the rear axle is installed on the base directly or through an axle seat. An angle sensor is connected between the swing arm and the rear axle.

[0010] The swing arm support guide unit includes a bottom plate, a slide rail, a slide table, a guide seat, a guide piece, a support frame and a roller. The bottom plate is mounted on the base, the bottom plate is mounted with a slide rail, the slide rail is mounted with a slide table, the slide table is mounted with a guide seat, the two sides of the guide seat are respectively hinged with a guide piece, and the other end of the guide piece is hinged with a slider arranged in the structural member clamping swing unit (specifically the swing arm). The slider is composed of a guide frame and a support frame, the support frame is mounted on the guide frame, the guide frame is hinged with the guide piece through a pin shaft, the support frame is connected to a saddle card (fixed by bolts) to form a slide groove connected to the structural member clamping swing unit, and the bottom of the support frame is mounted with a roller, and the bottom end of the roller is in contact with the bottom plate.

[0011] During the test, the two ends of the structural part are clamped on two sets of structural part clamping swing units, and the middle part is connected to the mechanical force load application unit. The middle position of the structural part is repeatedly bent by the load applied by the mechanical force load application unit. The applied load force is monitored by the tension and pressure sensor. The angle sensor measures the swing angle of the structural part clamping swing unit in real time, so that the structural part clamping swing unit can clamp the structural part and perform three-point bending during the operation of the elastic test device. The swing arm support guide unit ensures the consistency of the swing amplitude of the swing arm structure on both sides of the structural part clamping swing unit and plays a role in supporting the swing arm. The signal of the tension and pressure sensor is received and converted and transmitted to the host computer through the I / O module. The I / O module also transmits the structural part bending data measured by the displacement sensor and the angle sensor to the host computer, so that the host computer can process the mechanical force load and bending data applied to the structural part and obtain the bending stiffness and fatigue strength data.

[0012] The present invention ensures the uniqueness and symmetry of the stress position of the structural part during the load application process, realizes the repeated application and release of mechanical force loads on the stress position of the structural part, and realizes the elastic test of the bending stiffness and fatigue strength of the aluminum alloy structural part by analyzing the mechanical force load value-bending deformation of the structural part. The device can meet the needs of bending stiffness and fatigue strength testing of aluminum alloy beam structural parts, and provides basic data support for the elastic deformation stage for the service performance research of the structural parts. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is an overall schematic diagram of the mechanical structure part of the elasticity testing device of the present invention.

[0014] Figure 2 It is a structural schematic diagram of the mechanical force load applying unit in the present invention.

[0015] Figure 3 It is a schematic diagram of the overall structure of the structural member clamping the swing unit in the present invention.

[0016] Figure 4 It is an exploded schematic diagram of the structural member clamping the swing unit in the present invention.

[0017] Figure 5 It is a schematic diagram of the overall structure of the swing arm support guide unit in the present invention.

[0018] Figure 6 It is an exploded schematic diagram of the swing arm support guide unit in the present invention.

[0019] Figure 7 It is a schematic diagram of the control principle of the elasticity testing device of the present invention.

[0020] In the figure: 00. Base, 01. Mechanical force load application unit, 02. Structural member clamping swing unit, 03. Swing arm support guide unit;

[0021] 1. Push-pull attachment; 2. Push-pull body; 3. Pull pressure sensor; 4. Bolt and nut adapter; 5. Floating joint; 6. Cylinder; 7. Stud bolt; 8. Connecting rod; 9. Displacement sensor; 10. Sensor mounting; 11. Cylinder mounting; 12. Bearing end cover;

[0022] 13. Clamp; 14. Structural part; 15. Hard gasket; 16. Clamp; 17. Front axle; 18. Swing arm; 19. Angle sensor; 20. Front bearing; 21. Rear bearing; 22. Rear axle; 23. Bearing cover; 24. Horizontal axle seat;

[0023] 25. Slide stopper; 26. Slide rail; 27. Slide; 28. Guide seat; 29. ​​Guide sheet; 30. Riding card; 31. Guide frame; 32. Slotted pin shaft; 33. Slotted pin shaft; 34. Support frame; 35. Roller; 36. Bottom plate;

[0024] 37. Host computer; 38. Air compressor; 39. Electric proportional valve; 40. Three-position five-way solenoid valve; 41. Pull pressure sensor transmitter; 42. Relay; 43. I / O module. DETAILED DESCRIPTION

[0025] The elastic testing device for the bending stiffness and fatigue strength of aluminum alloy structural parts of the present invention comprises a device arranged on a base 00 (see Figure 1 ) on the mechanical force load applying unit 01, the structural member clamping swing unit 02 and the swing arm supporting guide unit 03. The two sets of structural member clamping swing units 02 are symmetrically arranged relative to the mechanical force load applying unit 01, and the two sets of structural member clamping swing units 02 are connected to the swing arm supporting guide unit 03. During the test, the structural member 14 is clamped on the two sets of structural member clamping swing units 02, and the middle part is connected to the mechanical force load applying unit 01.

[0026] The structure of the mechanical force load applying unit is as follows: Figure 1 and Figure 2As shown, it includes a push-pull body 2, a tension and pressure sensor 3, a floating joint 5 and a cylinder 6. The push-pull body 2 is connected to the tension and pressure sensor 3 through a stud bolt 7, wherein a nut is provided at each end of the stud bolt to ensure the tight installation of the push-pull body 2 and the tension and pressure sensor 3. The front end of the push-pull body 2 is provided with two upper and lower push-pull accessories 1. During the test, the structural member 14 is clamped on the push-pull body 2 through the push-pull accessories 1, and the push-pull accessories 1 are connected to the push-pull body 2 with bolts. The tension and pressure sensor 3 is connected to the floating joint 5 through a bolt and nut adapter 4, and the floating joint 5 is installed on the pull rod (piston rod) of the cylinder 6, and the cylinder 6 is installed on the base 00 through a cylinder mounting member 11. The bolt and nut adapter 4 is also connected to a connecting rod 8, which is connected to a displacement sensor 9 through the connecting rod 8. The displacement sensor 9 is installed on the base 00 through a sensor mounting member 10 and its installation direction is parallel to the slide rail 26.

[0027] The cylinder 6 is a standard double-acting cylinder, and its front and rear air nozzles are respectively connected to the two output ends of the three-position five-way solenoid valve 40 through air pipes. The air dissipation ends of the three-position five-way solenoid valve 40 are each connected to a muffler. The input end of the three-position five-way solenoid valve 40 is connected to the output end of the electric proportional valve 39 through an air pipe. The input end of the electric proportional valve 39 is connected to the air compressor 38 through an air pipe, and the air compressor 38 provides an air source. The telescopic movement of the cylinder rod of the cylinder 6 is controlled by the pressure regulation of the electric proportional valve 39 and the reversing of the three-position five-way solenoid valve 40. The displacement sensor 9 follows the movement of the cylinder 6 through the connecting rod 8, and measures the bending deflection of the structural member 14 in real time, so that the mechanical force load application unit can apply the mechanical force load to the structural member 14.

[0028] The structural member clamping swing unit is divided into two groups, which are symmetrically installed on both sides of the middle line of the front end of the base 00. The structure of each group of structural member clamping swing unit is as follows: Figure 3 and Figure 4 As shown, it includes a swing arm 18, a front axle 17, a rear axle 22, a horizontal axle seat 24 and an angle sensor 19. The front end of the swing arm 18 is connected (hinged) with a clamping plate 16, and the clamping plate 16 is connected to the front end of the swing arm 18 through a front bearing 20 and a front axle 17 (see Figure 4 ), the front axle 17 limits the axial movement of the axle itself through the axle step and the end spring. The clamping plate 16 is provided with two upper and lower clamping blocks 13, one end of the structural member 14 in the length direction is fastened to the clamping plate 16 by two clamping blocks 13 through bolts, the structural member 14 is between the clamping blocks 13 and the clamping plate 16, and the contact surfaces between the clamping blocks 13 and the structural member 14 and between the clamping plate 16 and the structural member 14 are provided with hard gaskets 15 (see Figure 1) for protection. The rear end of the swing arm 18 is mounted with a rear axle 22 through a rear bearing 21, and the rear axle 22 is connected to a horizontal axle seat 24, which is mounted on a base 00. A set of structural parts clamps the rear axle 22 of the swing unit, and the upper and lower ends of the rear bearing 21 are both mounted with bearing end covers 12 for protection. Another set of structural parts clamps the rear axle 22 of the swing unit, and the upper and lower ends of the rear bearing 21 are both mounted with bearing cover 23 for protection. The rear axle 22 is connected to the measuring shaft of the angle sensor 19 through the upper end of the bearing cover (see Figure 4 ). During the operation of the elastic test device, the two ends of the structural member 14 in the length direction are respectively clamped between the clamping blocks 13 and the clamping plates 16 of the two groups of structural member clamping swing units. The middle position of the structural member 14 is repeatedly bent under the action of the applied load. The clamping blocks 13 and the clamping plates 16 are assisted by the front bearing 20, the swing arm 18 and the rear bearing 21 to bend and swing along with the structural member 14. The angle sensor 19 measures the swing angle of the swing arm 18 in real time, so that the structural member clamping swing unit can clamp the structural member 14 and maintain the three-point bending motion state during the operation of the elastic test device.

[0029] The swing arm support guide unit guides the two swing arms 18 in the structural member clamping swing unit. Figure 5 and Figure 6As shown, the swing arm support guide unit includes a bottom plate 36, a slide rail 26, a slide table 27, a guide seat 28, a guide piece 29, a support frame 34 and a roller 35. The bottom plate 36 is fixed to the front end of the base 00 by screws, the slide rail 26 is installed at the center line position of the bottom plate 36 by screws, the slide rail 26 is installed with a slide table 27, both ends of the slide table 27 are provided with a slide table stopper 25 (the slide table stopper 25 can also be fixedly installed on the slide rail 26), the slide table 27 is installed with a guide seat 28, the two sides of the guide seat 28 are respectively connected to a guide piece 29 through a grooved pin shaft 32, the other end of the guide piece 29 is connected to the guide frame 31 through a grooved pin shaft, the guide frame 31 is fixedly installed on the support frame 34 by bolts, and the upper end of the support frame 34 is fixedly installed on the two swing arms 18 in the structural member clamping swing unit by a riding card 30 and bolts. The bottom of the support frame 34 is equipped with a roller 35 through a grooved pin 33, and the bottom end of the roller 35 contacts the bottom plate 36. The ends of the grooved pin 32 and the grooved pin 33 are both equipped with retaining springs to prevent their axial movement. During the operation of the elastic test device, the bottom end of the support frame 34 mounted on the swing arm 18 in cooperation with the riding card 30 contacts the bottom plate 36 through the roller 35. The existence of the roller 35 prevents the swing arm 18 from generating additional friction during the swinging process, and plays a role in supporting the two swing arms 18 without damping. The two swing arms 18 are connected to the slide 27 through the guide frame 31, the guide sheet 29, and the guide seat 28. The slide rail 26 matched with the slide 27 is located on the middle symmetry line of the two swing arms 18, which ensures the consistency of the swing amplitude of the two swing arms 18 during the swinging process and realizes the guiding function of the swing arms 18.

[0030] The present invention installs the slide rail 26 and the cylinder 6 at the front and rear ends of the center line of the base 00. The swing arm 18 is combined with the slide rail and slide table structure to ensure the consistency of the swing amplitude of the swing arms on both sides, and ensure the uniqueness and symmetry of the stress position of the structural parts during the load application process. The use of the pneumatic structure (cylinder 6) realizes the repeated application and release of mechanical force loads to the stress position of the structural parts.

[0031] The control system of the elastic testing device is as follows: Figure 7 As shown, it includes a host computer 37, an I / O module (input and output module) 43, a relay 42 and a tension and pressure sensor transmitter 41. The host computer 37 is connected to the electric proportional valve 39, the displacement sensor 9, the angle sensor 19, the relay 42, and the tension and pressure sensor transmitter 41 through the I / O module 43, the relay 42 is connected to the three-position five-way solenoid valve 40, and the tension and pressure sensor transmitter 41 is connected to the tension and pressure sensor 3 in the mechanical force load application unit.

[0032] The air compressor 38 continuously provides air source power to the three-position five-way solenoid valve 40 through the electrical proportional valve 39. Under the operation of the host computer 37, the I / O module 43 adjusts the air source pressure by controlling the electrical proportional valve 39 to control the load applied value of the cylinder 6 on the structural member 14 in the mechanical force load application unit. The I / O module 43 adjusts the direction of the air source entering the cylinder 6 by controlling the three-position five-way solenoid valve 40 connected by the relay 42 to control the telescopic movement rate and movement time of the cylinder rod of the cylinder 6 in the mechanical force load application unit. The tension and pressure sensor transmitter 41 receives and converts the signal of the tension and pressure sensor 3 in the mechanical force load application unit and transmits it to the host computer 37 through the I / O module 43. The I / O module 43 also transmits the bending data of the structural member 14 measured by the displacement sensor 9 and the angle sensor 19 to the host computer 37, so that the host computer 37 processes the mechanical force load and bending data applied to the structural member 14 and obtains the bending stiffness and fatigue strength data.

[0033] The use of the displacement sensor 9 and the angle sensor 19 realizes the real-time collection of the bending deformation data of the structural member 14. In conjunction with the actual load application value data of the structural member measured by the tension and pressure sensor 3, the upper computer 37 analyzes the mechanical force load value-bending deformation of the structural member, thereby realizing the elastic test of the bending stiffness and fatigue strength of the aluminum alloy structural member 14.

Claims

1. An elastic testing device for the bending stiffness and fatigue strength of aluminum alloy structural parts, characterized by: It includes a control unit and a mechanical force load applying unit, a structural member clamping and swinging unit and a swing arm supporting and guiding unit arranged on a base, a set of structural member clamping and swinging units are arranged on both sides of the mechanical force load applying unit, and the structural member clamping and swinging units are connected to the swing arm supporting and guiding units; the mechanical force load applying unit is provided with a power mechanism, a tension and pressure sensor and a displacement sensor, and the structural member clamping and swinging unit is provided with an angle sensor; the control unit includes a host computer and an I / O module, and the host computer is connected to the power mechanism, the tension and pressure sensor, the displacement sensor and the angle sensor through the I / O module; The structural member clamps the swing unit, including a swing arm, a front axle and a rear axle, the front end of the swing arm is hinged with a clamping plate through the front axle, the clamping plate is provided with a clamping block, the rear end of the swing arm is installed on the rear axle, and the rear axle is directly or through an axle seat installed on the base; an angle sensor is connected between the swing arm and the rear axle; The swing arm supporting guide unit comprises a bottom plate, a slide rail, a slide table, a guide seat, a guide piece, a support frame and a roller. The bottom plate is mounted on the base, the bottom plate is mounted with a slide rail, the slide table is mounted on the slide rail, the guide seat is mounted on the slide table, the two sides of the guide seat are respectively hinged with a guide piece, and the other end of the guide piece is hinged with a slider arranged in the structural member clamping swing unit; the slider is composed of a guide frame and a support frame, the support frame is mounted on the guide frame, the guide frame is hinged with the guide piece through a pin shaft, the support frame is connected with a riding card to form a slide groove connected to the structural member clamping swing unit, and the bottom of the support frame is mounted with a roller, and the bottom end of the roller is in contact with the bottom plate; During the test, the two ends of the structural part are clamped on two groups of structural part clamping and swinging units, and the middle part is connected to the mechanical force load applying unit; the middle position of the structural part is repeatedly bent by the load applied by the mechanical force load applying unit, and the applied load force is monitored by the tension and pressure sensor. The angle sensor measures the swing angle of the structural part clamping and swinging unit in real time, so that the structural part clamping and swinging unit can clamp and perform three-point bending movements on the structural part during the operation of the elastic test device. The swing arm support guide unit ensures the consistency of the swing amplitude of the swing arm structure on both sides of the structural part clamping and swinging unit and plays a role in supporting the swing arm; the signal of the tension and pressure sensor is received and converted and transmitted to the host computer through the I / O module. The I / O module also transmits the structural part bending data measured by the displacement sensor and the angle sensor to the host computer, so that the host computer can process the mechanical force load and bending data applied to the structural part, and obtain the bending stiffness and fatigue strength data.

2. The elastic testing device for bending stiffness and fatigue strength of aluminum alloy structural parts according to claim 1 is characterized in that: The mechanical force load applying unit comprises a push-pull main body and a power mechanism, wherein the push-pull main body is connected with the power mechanism, the power mechanism is installed on the base, and a push-pull attachment is arranged at the front end of the push-pull main body.

3. The elastic testing device for the bending stiffness and fatigue strength of aluminum alloy structural parts according to claim 1 or 2, characterized in that: The power mechanism adopts a double-acting cylinder, the two air nozzles of the double-acting cylinder are connected to the two output ends of the three-position five-way solenoid valve, the input end of the three-position five-way solenoid valve is connected to the output end of the electric proportional valve, the wiring end of the three-position five-way solenoid valve is connected to the I / O module through a relay, the input end of the electric proportional valve is connected to the air source, and the wiring end of the electric proportional valve is connected to the I / O module.

4. The elastic testing device for bending stiffness and fatigue strength of aluminum alloy structural parts according to claim 2 is characterized by: The push-pull main body is connected to the power mechanism through a floating joint, a pulling pressure sensor is connected between the push-pull main body and the power mechanism, the pulling pressure sensor is connected to the floating joint, and the floating joint is installed on the power mechanism.

5. The elastic testing device for the bending stiffness and fatigue strength of aluminum alloy structural parts according to claim 1 or 4, characterized in that: The tension pressure sensor is connected to the I / O module through the tension pressure sensor transmitter, and the I / O module is connected to the host computer.

6. The elastic testing device for the bending stiffness and fatigue strength of aluminum alloy structural parts according to claim 2 is characterized by: The push-pull main body or the output end of the power mechanism is connected to the displacement sensor through a connecting rod, and the displacement sensor is installed on the base.

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