Load-adjustable bolt connection vibration failure experiment device and testing method thereof

Abstract

The application provides a load-adjustable bolt connection vibration failure experiment device.The device comprises a fixed base, an adjustable base, a vibration test device, a transmission device, a vibration excitation device and a data acquisition and analysis device; the fixed base is a casting, one end of which is provided with a linear T-shaped groove, and the other end is provided with a threaded hole; the adjustable base is also a casting, the bottom of which is provided with a limiting block, the periphery of which is provided with through holes, and the upper part of which is provided with a circular arc T-shaped groove and a positioning shaft.The load-adjustable bolt connection vibration failure experiment device has the advantages of simple structure, high ease of use and adjustability, can be used for bolt loosening failure and fatigue failure experiment testing under different vibration conditions, provides a reliable experiment platform for bolt vibration loosening and vibration fatigue testing research, and has important value for the research of bolt connection vibration failure dynamics reliability and the like.In addition, the application further provides a test method of the load-adjustable bolt connection vibration failure experiment device.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of mechanical engineering design and equipment testing technology, and particularly relates to a load-adjustable bolt connection vibration failure experiment device and a testing method thereof. BACKGROUND

[0002] Bolt connection is widely used in aerospace, rail transportation, mechanical equipment, civil engineering and other fields due to its simple structure, convenient installation and removal, and high connection tightness. Therefore, the reliability of bolt connection is crucial for the safe operation of various mechanical equipment. However, with the progress of modern science and technology, machinery is developing towards high speed, high temperature and high pressure, and vibration is involved in every aspect of mechanical operation. For bolt connection structures used on power machinery, the connecting parts must withstand the continuous action of vibration load, making the bolt connection structure prone to loosening failure, even fatigue fracture and other problems. Especially, when the bolt connection structure is subjected to the coupling action of two or more different directions of external load (such as axial vibration, lateral vibration, torsional vibration, bending vibration load, etc.), bolt loosening failure is more likely to occur.

[0003] In order to explore the loosening failure problem of bolt connection, a large number of experimental studies have been carried out, but most of the current bolt vibration failure experiment devices have fixed and single load direction, and the load type provided is displacement load, which cannot change the direction of vibration excitation load according to actual requirements and cannot realize the conversion of force load and displacement load, which has great limitations. SUMMARY

[0004] Based on this, the present application provides a load-adjustable bolt connection vibration failure experiment device and a testing method thereof. In order to study the loosening failure and fatigue failure problems of bolt connection structure under different vibration conditions, and to provide a reliable experiment device for the reliability research and dynamics design of bolt connection, which has important application value for the reliability research and fastener vibration failure analysis of bolt connection.

[0005] In a first aspect, the present application provides a load-adjustable bolt connection vibration failure experiment device, comprising a fixed base, an adjustable base, a vibration test device, a transmission device, a vibration excitation device and a data acquisition and analysis device; the fixed base is a casting, one end of which is provided with a linear T-shaped groove, and the other end is provided with a threaded hole; the adjustable base is a casting, the bottom of which is provided with a limiting block, the periphery of which is provided with a through hole, and the upper part of which is provided with a circular arc T-shaped groove and a positioning shaft; the vibration test device comprises a test table, a vibration plate, a first pressure sensor, a special clamp and a laser displacement sensor; the test table is provided with a positioning hole and a through hole at the bottom, one end of the test table is provided with the laser displacement sensor, the test table is provided with a limiting step and three bolt holes of different sizes, the surface of the bolt hole is provided with the first pressure sensor, and the first pressure sensor is connected and assembled with the special clamp; the vibration plate is provided with three bolt holes which are the same as the test table; the transmission device comprises a first joint, a second joint, a transmission spring, a push rod, a connecting spring, a second pressure sensor, a linear bearing, a connecting bearing seat, a third joint and a connecting rod; the first joint is connected and assembled with the vibration plate, the second joint is connected and assembled with the first joint, the transmission spring is connected and assembled with the second joint and the push rod, the connecting spring is connected and assembled with the push rod and the second pressure sensor, the connecting bearing seat is connected and assembled with the second pressure sensor, the linear bearing and the adjustable base, the third joint is connected and assembled with the push rod and the connecting rod; the vibration excitation device comprises an adjustable output shaft hub and a speed regulating motor; the adjustable output shaft hub is connected and assembled with the output shaft of the speed regulating motor; the data acquisition and analysis device is electrically connected with the first pressure sensor, the second pressure sensor and the laser displacement sensor respectively.

[0006] Further, the limiting block is connected with the T-shaped groove.

[0007] Further, eight through holes are formed in the adjustable base for connecting and fixing the fixed base through eight high-strength bolts.

[0008] Further, the positioning shaft of the adjustable base is located at the center of the circular arc T-shaped groove.

[0009] Further, the positioning hole of the test table is concentrically assembled with the positioning shaft, the test table can rotate around the positioning shaft by 0°~90°, and the test table is connected and fixed with the adjustable base through six high-strength bolts.

[0010] Further, the test table is provided with a limiting step, and the test table and the vibrating plate are provided with bolt holes of different sizes corresponding to test bolts of different specifications, and the test bolts of different specifications are matched with different special fixtures; the laser displacement sensor is installed at one end of the test table and used for monitoring the vibration displacement of the vibrating plate.

[0011] Further, the adjustable output shaft center wheel is composed of a base wheel with a sliding groove, a centering sliding block, positioning bolts and distance adjusting bolts; the centering sliding block is connected and assembled with the base wheel with the sliding groove through the two positioning bolts and the two distance adjusting bolts.

[0012] Further, the centering sliding block is provided with an output shaft, the output shaft is connected with the connecting rod through a bearing for motion transmission, and is fastened and assembled through bolts, the position of the output shaft is adjusted, the stroke size of the push rod is changed, and then the size of the output force or the output displacement amplitude is changed.

[0013] Further, the speed regulating motor is fastened and assembled with the fixed base through four high-strength bolts

[0014] In the second aspect, the application provides a test method of the load-adjustable bolt connection vibration failure experiment device, and the test method comprises the following steps:

[0015] (1) the bolt to be tested is installed on the test table through the special fixture, the nut is tightened, and whether a gasket is selected is determined, a torque wrench is used to control the tightening torque or a constant torque wrench is directly used to control the size of the pre-tightening force;

[0016] (2) the position of the output shaft center of the adjustable output shaft center wheel is adjusted, the size of the desired output displacement or force is set, the adjustable base is adjusted to the corresponding position, and then the eight high-strength fastening bolts are tightened to fix the adjustable base;

[0017] (3) the size of the angle between the test table and the vibration direction is adjusted according to the experimental requirements, so that vibration failure experiments of different vibration load types are performed;

[0018] (4) the power supply is turned on, the data acquisition system is turned on, the values of the second pressure sensor and the laser displacement sensor are cleared, and the output parameters of the speed regulating motor are set;

[0019] (5) the initial experimental parameters are recorded, and the motor power switch is pressed to start the test;

[0020] (6) the real-time response data of each sensor are recorded, the states of the test bolt are monitored in real time, and the time of bolt loosening failure or fatigue failure is recorded;

[0021] (7) processing various data recorded by the data acquisition system, the bolt connection vibration failure loosening curve and fatigue curve diagram can be drawn, and the influence law of different parameters on vibration failure is analyzed;

[0022] (8) by replacing test bolts of different specifications or changing the bolt connection mode, more rich and extensive experimental research can be carried out.

[0023] Compared with the prior art, the advantages of the load-adjustable bolt connection vibration failure experimental device and the test method thereof are as follows: the bolt connection vibration loosening and vibration fatigue failure problems can be reliably tested, a simple and easy-to-use operation test method is provided, the device has the characteristics of simple structure, easy adjustment, high reliability and the like, can provide experimental reference for bolt connection vibration failure research and dynamics design, and has important value for the research of bolt vibration loosening and bolt vibration fatigue failure. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 Fig. 1 is a structural schematic view of the load-adjustable bolt connection vibration failure experimental device of the present application;

[0025] Figure 2 Fig. 2 is a schematic view of the load-adjustable bolt connection vibration failure experimental device test table perpendicular to the vibration direction state shown in Fig. 1; Figure 1

[0026] Figure 3 Fig. 3 is a schematic view of the load-adjustable bolt connection vibration failure experimental device test table and the vibration direction at an arbitrary angle state shown in Fig. 1; Figure 1

[0027] Figure 4 Fig. 4 is a front view of the vibration test device and part of the transmission device of the load-adjustable bolt connection vibration failure experimental device shown in Fig. 1; Figure 1

[0028] Figure 5 Fig. 5 is a structural schematic view of the vibration excitation device of the load-adjustable bolt connection vibration failure experimental device shown in Fig. 1; Figure 1

[0029] Figure 6 Fig. 6 is a clamping force-vibration number loosening curve diagram of the test bolt of the load-adjustable bolt connection vibration failure experimental device shown in Fig. 1 under different vibration displacement amplitudes; Figure 1

[0030] ​​​​​In the figure: 1-fixed base, 2-adjustable base, 3-test bench, 4-vibration plate, 5-first pressure sensor, 6-special fixture, 7-laser displacement sensor, 8-first joint, 9-second joint, 10-transmission spring, 11-push rod, 12-connection spring, 13-second pressure sensor, 14-connection bearing seat, 15-linear bearing, 16-third joint, 17-connecting rod, 18-bearing, 19-adjustable output shaft wheel, 20-speed regulating motor, 21-distance adjusting bolt, 22-high-strength fastening bolt, 23-test bolt, 24-adjusting center sliding block, 25-positioning bolt. Embodiment

[0031] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. The described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0032] Please refer to Figures 1-6 The present application provides a load-adjustable bolt connection vibration failure experiment device, a load-adjustable bolt connection vibration failure experiment device, comprising a fixed base 1, an adjustable base 2, a vibration test device, a transmission device, a vibration excitation device and a data acquisition and analysis device.

[0033] The fixed base 1 has a T-shaped groove, the adjustable base 2 is a casting, the bottom has a limiting block for cooperating with the T-shaped groove, the periphery has a through hole, and the upper part has a circular arc T-shaped groove and a positioning shaft, the adjustable base 2 is connected and fixed with the fixed base 1 through the T-shaped groove by the high-strength fastening bolt 22.

[0034] The vibration test device comprises a test bench 3, a vibration plate 4, a first pressure sensor 5, a special fixture 6 and a laser displacement sensor 7; the test bench 3 has a positioning hole and a through hole at the bottom, one end of the test bench 3 is provided with the laser displacement sensor, the test bench 3 cooperates with the positioning shaft of the adjustable base 2 and is connected and fixed through the circular arc T-shaped groove by the high-strength fastening bolt 22; the test bench 3 has a limiting step and three bolt holes of different sizes are opened, the hole surface is provided with the first pressure sensor 5; the special fixture 6 is connected with the first pressure sensor 5; one end of the test bench 3 is provided with the laser displacement sensor 7; the vibration plate 4 is connected with the test bench 3 through the test bolt 23, and the vibration plate 4 has three bolt holes opened thereon which are the same as the test bench 3;

[0035] The transmission device comprises a first joint 8, a second joint 9, a transmission spring 10, a push rod 11, a connecting spring 12, a second pressure sensor 13, a linear bearing 14, a connecting bearing seat 15, a third joint 16 and a connecting rod 17; the first joint 8 is connected and assembled with the vibrating plate 4, and the second joint 9 is connected with the first joint 8; the transmission spring 10 is connected with the second joint 9 and the push rod 11; the connecting spring 12 is connected with the push rod 11 and the second pressure sensor 13; the connecting bearing seat 15 is connected and assembled with the second pressure sensor 13, the linear bearing 14 and the adjustable base 2; the third joint 16 is connected with the push rod 11 and the connecting rod 17.

[0036] The vibration excitation device comprises an adjustable output shaft center wheel 19 and a speed regulating motor 20, wherein the adjustable output shaft center wheel is connected and assembled with the output shaft of the speed regulating motor; the connecting rod 17 is connected with a self-aligning sliding block 24 through a bearing 18; the self-aligning sliding block 24 is connected with the adjustable output shaft center wheel 19 through a positioning bolt 25 and a distance adjusting bolt 21.

[0037] The data acquisition and analysis device is electrically connected with the first pressure sensor 5, the second pressure sensor 13 and the laser displacement sensor 7 respectively; the fixed base 1 and the adjustable base 2 are casted and processed, and the rest of the parts are quenched and tempered steel except the sensors, so as to ensure the rigidity of the experimental device; all the connecting and fastening bolts of the experimental device except the test bolt 23 are high-strength bolts, so as to ensure the connecting strength of each part.

[0038] The adjustable base limiting block is matched with the fixed base T-shaped groove, so that the two can slide in the fixed direction. The adjustable base is provided with eight through holes, which can be connected and fixed with the fixed base through eight high-strength bolts. The center of the positioning shaft of the adjustable base is located at the center of the circular arc T-shaped groove. The test table positioning hole is concentrically assembled with the positioning shaft, and the test table can rotate around the positioning shaft by 0°~90°. The test table can be connected and fixed with the adjustable base through six high-strength bolts. The test table is provided with a limiting step, so that the vibration direction of the vibrating plate remains unchanged. The test table and the vibrating plate are provided with bolt holes of different sizes, which correspond to test bolts of different specifications, and the test bolts of different specifications are matched with special clamps of different specifications. The laser displacement sensor is installed at one end of the test table to monitor the vibration displacement of the vibrating plate.

[0039] The adjustable output shaft center wheel is composed of a base wheel with a sliding groove, a self-aligning sliding block, a positioning bolt and a distance adjusting bolt. The self-aligning sliding block is connected and assembled with the base wheel with a sliding groove through two positioning bolts and two distance adjusting bolts.

[0040] The output shaft is reserved on the aligning sliding block, the output shaft and the connecting rod transmit the movement through the bearing and are fastened and assembled through the bolt, the position of the output shaft is adjusted, the stroke size of the push rod is changed, and the size of the output force or output displacement amplitude is changed.

[0041] The speed regulating motor is fastened and assembled with the fixed base through four high-strength bolts.

[0042] In addition, the application provides a test method of the load-adjustable bolt connection vibration failure experiment device, including the following steps:

[0043] (1) the test bolt 23 is installed on the test table 3 through the special fixture 6, the nut is tightened, the tightening torque can be controlled by the torque wrench or the size of the pre-tightening force is directly controlled by the constant torque wrench;

[0044] (2) the distance adjusting bolt 21 is adjusted, the position of the output shaft of the adjustable output shaft hub 19 is changed, the size of the desired output displacement or force is set (the transmission spring 10 is locked, and the vibration plate is subjected to the cyclic displacement load; otherwise, it is the cyclic force load), the adjustable base 2 is adjusted to the corresponding position, and the high-strength fastening bolt 22 is tightened after the adjustment is completed to fix the adjustable base 2;

[0045] (3) the angle between the test table 3 and the vibration direction can be adjusted according to the experimental requirements (for the test bolt, 0° is transverse vibration, 90° is axial vibration, and between the two is coupled vibration of transverse and axial directions), so that loose experiments of different angles and types are carried out;

[0046] (4) the power supply is turned on, the data acquisition system is opened, the values of the second pressure sensor 13 and the laser displacement sensor 7 are cleared, and the output parameters of the speed regulating motor 20 are set (different speeds or frequencies are set to meet different output requirements);

[0047] (5) the initial experimental parameters are recorded, and the motor power switch is pressed to start the test;

[0048] (6) the real-time response data of each sensor are recorded, the states of the test bolt 23 are monitored in real time, and the time of bolt loosening failure or fatigue failure is recorded;

[0049] (7) the data recorded by the data acquisition system are processed, the loosening curve and the fatigue curve of the bolt connection vibration failure are drawn, and the influence law of different parameters on the vibration failure is analyzed, as shown in the drawing; Figure 5

[0050] (8) different specifications of test bolts or bolt connection modes are changed, and more rich and extensive experimental researches can be carried out.

[0051] ​Compared with the prior art, the load-adjustable bolt connection vibration failure experiment device and the test method thereof have the advantages that the vibration loosening and vibration fatigue failure of the bolt connection can be reliably tested, a simple and easy-to-use operation test mode is provided, the device has the characteristics of simple structure, easy adjustment, high reliability and the like, and can provide an experimental reference for vibration failure research and dynamics design of the bolt connection, and has important value for research on bolt vibration loosening and bolt vibration fatigue failure.

[0052] Finally, it should be noted that: the above only for the preferred embodiments of the present application, not limited to the present application, although in the foregoing detailed description of the present application with reference to the foregoing embodiments, for those skilled in the art, it still can be modified, or part of the technical features of the equivalent replacement, within the spirit and principles of the present application, any modification, equivalent replacement, improvement, etc., should be included within the scope of the present application.

Claims

1. A load-adjustable bolt connection vibration failure test apparatus, characterized in that, The system includes a fixed base, an adjustable base, a vibration testing device, a transmission device, a vibration excitation device, and a data acquisition and analysis device. The fixed base is a casting with a straight T-slot at one end and a threaded hole at the other. The adjustable base is a casting with a limit block at the bottom, through holes around the perimeter, and an arc-shaped T-slot and a positioning shaft at the top. The vibration testing device includes a test platform, a vibration plate, a first pressure sensor, a special fixture, and a laser displacement sensor. The test platform has positioning holes and through holes at its bottom, and the laser displacement sensor is located at one end of the test platform. The test platform has a limit step and three bolt holes of different sizes. The first pressure sensor is located on the surface of the bolt holes and is connected to the special fixture. The vibration plate has three bolt holes identical to those on the test platform. The transmission device includes... The system comprises a first connector, a second connector, a transmission spring, a push rod, a connecting spring, a second pressure sensor, a linear bearing, a connecting bearing seat, a third connector, and a connecting rod. The first connector is connected to the vibrating plate, the second connector is connected to the first connector, the transmission spring is connected to the second connector and the push rod, the connecting spring is connected to the push rod and the second pressure sensor, the connecting bearing seat is connected to the second pressure sensor, the linear bearing, and the adjustable base, and the third connector is connected to the push rod and the connecting rod. The vibration excitation device includes an adjustable output shaft wheel and a speed-regulating motor. The adjustable output shaft wheel is connected to the output shaft of the speed-regulating motor. The data acquisition and analysis device is electrically connected to the first pressure sensor, the second pressure sensor, and the laser displacement sensor, respectively.

2. The load-adjustable bolt connection vibration failure test device according to claim 1, characterized in that, The limiting block is connected to the T-slot in a mating manner.

3. The load-adjustable bolt connection vibration failure test device according to claim 2, characterized in that, The adjustable base has eight through holes for connecting and fixing to the fixed base using eight high-strength bolts.

4. The load-adjustable bolt connection vibration failure test device according to claim 3, characterized in that, The center of the adjustable base positioning shaft is located at the center of the arc-shaped T-slot.

5. The load-adjustable bolt connection vibration failure test device according to claim 4, characterized in that, The positioning hole of the test platform is concentrically assembled with the positioning shaft, and the test platform can rotate 0° to 90° around the positioning shaft; the test platform and the adjustable base are connected and fixed by six high-strength bolts.

6. The load-adjustable bolt connection vibration failure test device according to claim 5, characterized in that, The test platform has a limiting step, and the test platform and the vibration plate have bolt holes of different sizes that correspond to test bolts of different specifications. Different specifications of test bolts are equipped with different special fixtures. The laser displacement sensor is installed at one end of the test platform to monitor the vibration displacement of the vibration plate.

7. The load-adjustable bolt connection vibration failure test device according to claim 6, characterized in that, The adjustable output shaft wheel consists of a base wheel with a groove, a self-aligning slider, a positioning bolt, and an adjusting bolt; the self-aligning slider and the base wheel with the groove are connected and assembled by two positioning bolts and two adjusting bolts.

8. The load-adjustable bolt connection vibration failure test apparatus according to claim 7, characterized in that, The self-aligning slider has an output shaft. The output shaft and the connecting rod transmit motion through bearings and are fastened together with bolts. By adjusting the position of the output shaft, the stroke of the push rod is changed, thereby changing the magnitude of the output force or output displacement.

9. The load-adjustable bolt connection vibration failure test device according to claim 8, characterized in that, The speed-regulating motor is fastened to the fixed base by four high-strength bolts.

10. A test method for a load-adjustable bolt connection vibration failure test apparatus as described in any one of claims 1-9, characterized in that, Includes the following steps: (1) Install the bolt to be tested on the test bench using a special fixture, tighten the nut, and choose whether to add a washer. Use a torque wrench to control the tightening torque or use a constant torque wrench to control the preload. (2) Adjust the position of the output shaft of the adjustable output shaft wheel, set the desired output displacement or force, adjust the adjustable base to the corresponding position, and tighten the eight high-strength fastening bolts to fix the adjustable base after adjustment; (3) The angle between the test bench and the vibration direction can be adjusted according to the experimental requirements to conduct vibration failure experiments with different vibration load types. (4) Connect the power supply, turn on the data acquisition system, clear the values ​​of the second pressure sensor and the laser displacement sensor to zero, and set the output parameters of the speed-regulating motor; (5) Record all initial experimental parameters and press the motor power switch to start the test; (6) Record the real-time response data of each sensor, monitor the various states of the test bolts in real time, and record the time of bolt loosening failure or fatigue failure; (7) Process the data recorded by the data acquisition system, and draw the loosening curve and fatigue curve of the vibration failure of bolt connection, and analyze the influence of different parameters on vibration failure; (8) By changing the test bolts of different specifications or changing the bolt connection method, more extensive and richer experimental research can be carried out.

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