A Multi-condition Corrugated Pipe Dynamic Characteristic Testing Device

Abstract

This application relates to the field of multi-condition bellows dynamic characteristic testing technology, and in particular to a multi-condition bellows dynamic characteristic testing device. The device excites and tests bellows under combined working conditions using a vibrator or hammer. It measures the vibration acceleration parameters of triaxial accelerometers at both ends of the bellows, and after calculation, accurately obtains the vibration isolation performance parameters of the bellows under combined working conditions, achieving higher testing accuracy. By selecting the vibrator or hammer according to the bellows' mass and diameter, the influence of the vibrator's added mass and stiffness on measurement accuracy can be avoided. Furthermore, it can simulate the environment, more closely resembling real service conditions. By applying different working conditions and combined working conditions such as high temperature, pressure load, axial or lateral displacement, it realistically simulates the actual working conditions of the bellows, accurately obtaining the vibration isolation performance parameters of the bellows.

Description

Technical Field

[0001] This invention relates to the field of multi-condition bellows dynamic characteristic testing technology, and in particular to a multi-condition bellows dynamic characteristic testing device. Background Technology

[0002] As a flexible thin-walled connector, bellows are mainly used in piping systems to compensate for displacement and suppress vibration transmission. The vibration isolation performance parameters of bellows are key indicators for evaluating their vibration reduction effectiveness. Bellows are widely used in mechanical vibration systems, but their design often focuses on static considerations. Their unique thin-walled structure is also prone to damage. Accurately predicting their vibration characteristics to avoid resonance is becoming increasingly important. However, these parameters are not fixed and their values ​​are highly dependent on the actual working conditions of the bellows. The same bellows installed under different working conditions will have different vibration isolation performance parameters. Therefore, it is only meaningful to conduct vibration isolation performance tests on bellows when multiple working conditions are considered.

[0003] Currently, the vibration isolation performance test of bellows is usually conducted under a single working condition, without considering the influence of internal pressure, displacement and high temperature environment on the vibration isolation performance of bellows, and cannot simulate composite working conditions.

[0004] Traditional exciter-sensor systems (such as spring-mass simulation devices) can only simulate vibration in one direction and cannot reproduce multi-directional displacement (such as the simultaneous axial tension and lateral shear in a ship's pipeline system).

[0005] In the experiment, pressure, temperature and vibration need to be applied independently, but under actual working conditions, the interaction between the three is significant.

[0006] Current standard tests are typically conducted under static or single dynamic loads, neglecting the coupling effects of three key operating conditions:

[0007] 1. Internal pressure and pressure load can change the stiffness of the bellows. For example, under high pressure, stress concentration in the troughs of the bellows can lead to local hardening, resulting in deviations in the measured stiffness and affecting the accuracy of vibration isolation performance parameters.

[0008] 2. Axial / lateral displacement: When large displacement occurs, the bellows undergoes plastic deformation, and its damping characteristics decrease nonlinearly, resulting in a vibration level drop of 3~7dB.

[0009] 3. High temperature environment, for example, when the 1Cr18Ni9Ti material is above 700℃, the Young's modulus will decrease significantly and the resonant frequency will drift by more than 10%, but existing experiments lack the ability to simulate thermo-mechanical coupling.

[0010] 4. Sensitivity to boundary conditions: Under fixed-free and fixed-fixed constraints, the force transmitted by the bellows differs by a factor of 3, resulting in significant differences in vibration isolation performance.

[0011] Current testing methods cannot realistically simulate the multi-condition environment of bellows and cannot accurately obtain the vibration isolation performance parameters of bellows under multiple conditions.

[0012] Therefore, it is essential to provide a multi-condition bellows dynamic characteristic testing device to address the shortcomings of existing technologies. Summary of the Invention

[0013] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a multi-condition bellows dynamic characteristic testing device. This device excites and tests the bellows under combined working conditions using a vibrator or a hammer. It measures the vibration acceleration parameters of triaxial accelerometers at both ends of the bellows and calculates them to accurately obtain the vibration isolation performance parameters of the bellows under combined working conditions. The testing accuracy is higher. By selecting the vibrator or hammer according to the size of the bellows' mass and diameter, the influence of the added mass and stiffness of the vibrator on the measurement accuracy can be avoided. It can also simulate the environment, more closely resembling the actual service conditions. By loading different working conditions and combined working conditions such as high temperature, pressure load, axial or lateral displacement, it can realistically simulate the actual working conditions of the bellows and accurately obtain the vibration isolation performance parameters of the bellows.

[0014] The above-mentioned objectives of the present invention are achieved by the following technical means.

[0015] A multi-condition bellows dynamic characteristic testing device is provided, including a hammer, a flat base and a radial displacement base. A guide rail is also provided next to the flat base and extends to the top of the flat base. Lifting cylinders are installed at the four corners of the upper surface of the flat base. An axial positioning plate is installed on each of the four lifting cylinders. An axial actuator is fixedly installed on the axial positioning plate. An upper flange is fixedly installed at the output end of the axial actuator. A fixed platform is also installed on the flat base. A connecting rod is installed on the fixed platform. A lower flange is fixedly installed at the top of the connecting rod. A bellows body is installed between the upper flange and the lower flange. A vibrator is installed at the bottom of the connecting rod below the fixed platform.

[0016] A mobile high-temperature furnace is slidably mounted on a guide rail. A movable sealing door is hinged to the side of the mobile high-temperature furnace. The top and bottom of the mobile high-temperature furnace are provided with cutting grooves that movably cooperate with the output end and connecting rod of the axial actuator. The cutting grooves extend from the movable sealing door to the center of the mobile high-temperature furnace. The top and bottom of the movable sealing door are provided with heat preservation positioning grooves. Heat preservation cover plates are bolted inside the heat preservation positioning grooves and movably cover the outside of the cutting grooves. A radial displacement mechanism is mounted on the radial displacement base. The radial displacement mechanism movably passes through the mobile high-temperature furnace and is connected to the side of the upper flange.

[0017] Specifically, the radial displacement mechanism includes a hinge seat fixedly mounted on a radial displacement base, a hinge shaft hingedly mounted on the hinge seat, a radial actuator fixedly mounted at the end of the hinge shaft away from the hinge seat, and the output end of the radial actuator moving through the mobile high-temperature furnace and connected to the side of the upper flange.

[0018] Specifically, a high-temperature resistant gas pipe and a high-temperature resistant water pipe are movably installed at the bottom of the lower flange. An air pump is installed on the high-temperature resistant gas pipe, and a water pump is installed on the high-temperature resistant water pipe. The high-temperature resistant gas pipe is connected to an external ventilation device through the air pump, and the high-temperature resistant water pipe is connected to an external water tank through the water pump. The high-temperature resistant gas pipe and the high-temperature resistant water pipe movably pass through the bottom of the mobile high-temperature furnace.

[0019] Specifically, a hammer force sensor is installed inside the hammer, and triaxial acceleration sensors are installed at both ends of the bellows body near the upper and lower flanges. The triaxial acceleration sensors and hammer force sensors are electrically connected to a signal acquisition device, which is electrically connected to a computer.

[0020] Specifically, a vertical auxiliary positioning frame is also installed on the radial displacement base, and a lifting block is movably sleeved on the vertical auxiliary positioning frame, through which the radial actuator moves.

[0021] Specifically, the axial actuator is equipped with an axial force sensor and an axial servo valve, while the radial actuator is equipped with a radial force sensor and a radial servo valve.

[0022] This invention uses a vibrator or hammer to excite and test a bellows under combined working conditions. It measures the vibration acceleration parameters of triaxial accelerometers at both ends of the bellows, and after calculation, accurately obtains the vibration isolation performance parameters of the bellows under combined working conditions. The testing accuracy is higher. Selecting the vibrator or hammer based on the bellows' mass and diameter avoids the influence of the vibrator's added mass and stiffness on measurement accuracy. It also simulates the environment, more closely resembling real service conditions. By applying different working conditions, such as high temperature, pressure load, axial or lateral displacement, and combined working conditions, it realistically simulates the actual working conditions of the bellows, accurately obtaining the vibration isolation performance parameters of the bellows. Attached Figure Description

[0023] The invention will be further described with reference to the accompanying drawings, but the contents of the drawings do not constitute any limitation on the invention.

[0024] Figure 1 This is a three-dimensional structural diagram of a multi-condition bellows dynamic characteristic testing device according to the present invention. Figure 1 .

[0025] Figure 2 This is a three-dimensional structural diagram of a multi-condition bellows dynamic characteristic testing device according to the present invention. Figure 2 .

[0026] Figure 3 This is a side cross-sectional view of a multi-condition bellows dynamic characteristic testing device according to the present invention.

[0027] Figure 4 This is a schematic diagram showing the connection of the signal acquisition instrument, computer, hammer force sensor, and triaxial acceleration sensor of the multi-condition bellows dynamic characteristic test device of the present invention.

[0028] Figure 5 This is a three-dimensional structural diagram of a mobile high-temperature furnace for a multi-condition corrugated pipe dynamic characteristic testing device according to the present invention.

[0029] Figure 6 This is a three-dimensional structural diagram of the mobile high-temperature furnace in Embodiment 2 of the multi-condition corrugated pipe dynamic characteristic test device of the present invention.

[0030] from Figures 1 to 6 Including:

[0031] 1. Power hammer;

[0032] 2. Flat base;

[0033] 3. Radial displacement base;

[0034] 4. Guide rail;

[0035] 5. Lifting hydraulic cylinder;

[0036] 6. Axial positioning plate;

[0037] 7. Axial actuator;

[0038] 8. Upper flange;

[0039] 9. Fixed platform;

[0040] 10. Connecting rod;

[0041] 11. Lower flange;

[0042] 12. Corrugated pipe body;

[0043] 13. Vibrator;

[0044] 14. Mobile high-temperature furnace;

[0045] 15. Movable sealed door;

[0046] 16. Cut-in groove;

[0047] 17. Thermal insulation positioning groove;

[0048] 18. Insulated cover plate;

[0049] 19. Hinge mount;

[0050] 20. Hinge shaft;

[0051] 21. Radial actuator;

[0052] 22. High-temperature resistant gas pipe;

[0053] 23. High-temperature resistant water pipes;

[0054] 24. Air pump;

[0055] 25. Water pump;

[0056] 26. Triaxial accelerometer;

[0057] 27. Signal acquisition instrument;

[0058] 28. Computer;

[0059] 29. Vertical auxiliary positioning frame;

[0060] 30. Lifting block;

[0061] 31. Axial force sensor;

[0062] 32. Axial servo valve;

[0063] 33. Radial force sensor;

[0064] 34. Radial servo valve;

[0065] 35. Liquid nitrogen cooling tank;

[0066] 36. Refrigerant pipe. Detailed Implementation

[0067] The present invention will be further described in conjunction with the following embodiments.

[0068] Example 1:

[0069] like Figure 1-5 As shown, a multi-condition bellows dynamic characteristic testing device includes a hammer 1, a flat base 2, and a radial displacement base 3. A guide rail 4 is also provided next to the flat base 2, extending above the flat base 2. Lifting cylinders 5 are installed at the four corners of the upper surface of the flat base 2. An axial positioning plate 6 is installed on each of the four lifting cylinders 5. An axial actuator 7 is fixedly installed on the axial positioning plate 6. An upper flange 8 is fixedly installed at the output end of the axial actuator 7. A fixed platform 9 is also installed on the flat base 2. A connecting rod 10 is installed on the fixed platform 9. A lower flange 11 is fixedly installed at the top of the connecting rod 10. A bellows body 12 is installed between the upper flange 8 and the lower flange 11. A vibrator 13 is installed at the bottom of the connecting rod 10 below the fixed platform 9.

[0070] A mobile high-temperature furnace 14 is slidably mounted on the guide rail 4. A movable sealing door 15 is hinged to the side of the mobile high-temperature furnace 14. The top and bottom of the mobile high-temperature furnace 14 are provided with cutting grooves 16 that are movablely engaged with the output end of the axial actuator 7 and the connecting rod 10. The cutting grooves 16 extend from the movable sealing door 15 to the center of the mobile high-temperature furnace 14. The top and bottom of the movable sealing door 15 are provided with heat preservation positioning grooves 17. A heat preservation cover plate 18 is bolted inside the heat preservation positioning groove 17. The heat preservation cover plate 18 is movablely covered on the outside of the cutting groove 16. A radial displacement mechanism is mounted on the radial displacement base 3. The radial displacement mechanism moves through the mobile high-temperature furnace 14 and is connected to the side of the upper flange 8.

[0071] The moving direction of the mobile high-temperature furnace 14 is perpendicular to the output direction of the radial displacement mechanism. It moves and outputs on both sides of the bellows body 12. The output of the lifting cylinder 5 can adjust the height of the axial positioning plate 6, thereby roughly adjusting the height of the axial actuator 7. Then, based on parameters such as the length of the bellows, the axial actuator 7 is activated to precisely adjust the axial displacement of the upper flange 8. The lower flange 11 is fixed via the connecting rod 10 and the fixed platform 9, thus positioning the bellows body 12. The vibrator 13 vibrates the bellows body 12 from the bottom of the connecting rod 10. The mobile high-temperature furnace 14 can... The bellows body 12 is heated. When it is necessary to simulate the heating condition, the movable sealing door 15 is opened and the movable high-temperature furnace 14 is slid, so that the output end of the axial actuator 7 and the connecting rod 10 are movably engaged inside the cutting groove 16. At this time, the bellows body 12 enters the center of the interior of the movable high-temperature furnace 14. The movable sealing door 15 is closed, and the heat insulation cover plate 18 is bolted to prevent heat dissipation. The movable high-temperature furnace 14 can then be started to simulate the heating condition. At the same time, the radial displacement mechanism also moves through the movable high-temperature furnace 14, which can simulate the radial displacement condition of the bellows body 12 inside the movable high-temperature furnace 14.

[0072] The radial displacement mechanism includes a hinge seat 19 fixedly mounted on the radial displacement base 3. A hinge shaft 20 is hingedly mounted on the hinge seat 19. A radial actuator 21 is fixedly mounted on the end of the hinge shaft 20 away from the hinge seat 19. The output end of the radial actuator 21 moves through the mobile high-temperature furnace 14 and is connected to the side of the upper flange 8.

[0073] The radial displacement mechanism generates the force required for radial operation through the output of the radial actuator 21. One end of the radial actuator 21 is hinged to the hinge seat 19 through the hinge shaft 20, and the other end of the output is connected to the flange 8 to simulate the radial displacement of the bellows body 12.

[0074] A high-temperature resistant gas pipe 22 and a high-temperature resistant water pipe 23 are movably installed at the bottom of the lower flange 11. An air pump 24 is installed on the high-temperature resistant gas pipe 22, and a water pump 25 is installed on the high-temperature resistant water pipe 23. The high-temperature resistant gas pipe 22 is connected to an external ventilation device through the air pump 24, and the high-temperature resistant water pipe 23 is connected to an external water tank through the water pump 25. The high-temperature resistant gas pipe 22 and the high-temperature resistant water pipe 23 movably pass through the bottom of the mobile high-temperature furnace 14.

[0075] The bottom of the lower flange 11 can realize the working condition of the bellows body 12 under air pressure or water pressure through the high-temperature resistant gas pipe 22 and the high-temperature resistant water pipe 23. Gas or water can be introduced into the interior of the bellows body 12. The high-temperature resistant gas pipe 22 and the high-temperature resistant water pipe 23 can also move through the mobile high-temperature furnace 14, and can be simulated simultaneously with the high-temperature working condition, or can be simulated separately.

[0076] The hammer 1 is equipped with a hammer force sensor. The bellows body 12 is equipped with triaxial acceleration sensors 26 at both ends near the upper flange 8 and the lower flange 11. The triaxial acceleration sensors 26 and the hammer force sensors are electrically connected to the signal acquisition device 27. The signal acquisition device 27 is electrically connected to the computer 28.

[0077] To avoid the influence of the added mass and stiffness of the vibrator 13 on the measurement accuracy, the bellows body 12, which has a small volume, can be excited by the hammer 1. The vibrator 13 is removed, and the hammer 1 is used for excitation. The simulated loading process under different working conditions remains unchanged. In the specific test, the hammer 1 is model PCB086C04, with a measurement range of 250KN and a sensitivity of 2.34Pc / N. The triaxial accelerometer 26 has a range of 10e4 m / s2. The charge amplifier is model GSTYE5852B, with voltage / IEPE input, impedance >100Ω, noise <5μV, and accuracy ±1%. The signal acquisition instrument 27 is a multi-channel signal acquisition instrument 27 (Synergy 16V) with 24 channels, each with an independent 64-bit analog-to-digital converter and a bandwidth of 25 MHz. The modal analysis software is model LMS Test.Lab 18, which can perform the functions required for control and various data analysis.

[0078] The acceleration at both ends of the bellows body 12 is obtained by the triaxial accelerometer 26. The vibration isolation performance parameters of the bellows can be obtained by mathematical calculation. The vibration level difference at both ends of the bellows body 12 is calculated using the formulas: D=A1 / A2 and L=20Lg(D). A1 is the vibration acceleration at the output end and A2 is the acceleration at the input end, i.e., the vibration acceleration at the end connected to the exciter 13. The vibration level difference of the bellows body 12 under different excitation frequencies of the exciter 13 can be obtained by calculation. The vibration isolation performance of the bellows body 12 can be judged based on the calculated vibration level difference.

[0079] A vertical auxiliary positioning frame 29 is also installed on the radial displacement base 3. A lifting block 30 is movably sleeved on the vertical auxiliary positioning frame 29, and the radial actuator 21 moves through the lifting block 30.

[0080] The vertical auxiliary positioning frame 29 and the lifting block 30 can serve as the third fulcrum of the radial actuator 21, avoiding the radial displacement mechanism from being too long and affecting the safety of the working condition simulation. At the same time, the movable lifting block 30 and the hinge shaft 20 enable the coordination of the bellows body 12 at different heights, allowing the radial actuator 21 to tilt and output radial displacement.

[0081] An axial force sensor 31 and an axial servo valve 32 are installed on the axial actuator 7, and a radial force sensor 33 and a radial servo valve 34 are installed on the radial actuator 21.

[0082] The axial actuator 7 uses an Instron 8874 with an axial load capacity of +25kN and an actuator stroke of 100mm.

[0083] The axial force sensor 31 uses STB-3000kg, with a working excitation voltage of 15V, a sensitivity of 2.000mv / v, and an input impedance of 1050Ω and 1000Ω.

[0084] The radial actuator 21 uses MTS 244, with a rated force of 1000N and a stroke of 250mm.

[0085] The radial force sensor 33 uses STB-3000kg, with a working excitation voltage of 15V, a sensitivity of 2.000mv / v, and an input impedance of 1050Ω and 1000Ω.

[0086] The triaxial accelerometer 26 has a range of 10e4 m / s², a charge amplifier model GSTYE5852B, voltage / IEPE input, impedance >100Ω, noise <5μV, and accuracy ±1%.

[0087] The high-temperature furnace uses the GW-1000 model, with heating element material of φ1.5 iron-chromium-aluminum resistance wire, working temperature of 200~1000℃, temperature measuring element of K-type thermocouple, temperature measuring sensitivity of 0.1℃, temperature measuring accuracy of 0.2%, working voltage of 380V, and maximum power of 5KW when heating.

[0088] The exciter 13 has a peak sinusoidal force of 650N, an effective frequency range of 2-5000N, a rated current of 18A, and a main resonant frequency of 3000Hz.

[0089] The air pump has a power rating of 3W-2.4 / 40, an intake pressure of 0.1034 MPa (standard atmospheric pressure), and an exhaust volume of 2.4 m³ / min.

[0090] This invention uses a vibrator 13 or a hammer 1 to excite and test a bellows under combined working conditions. It measures the vibration acceleration parameters of the triaxial accelerometers 26 at both ends of the bellows and calculates them to accurately obtain the vibration isolation performance parameters of the bellows under combined working conditions. The test accuracy is higher. By selecting the vibrator 13 or hammer 1 for excitation according to the size of the bellows' mass and diameter, the influence of the additional mass and stiffness of the vibrator 13 on the measurement accuracy can be avoided. It can also simulate the environment and more closely resemble the actual service conditions. By loading different working conditions such as high temperature, pressure load, axial or lateral displacement, and combined working conditions, it can realistically simulate the actual working conditions of the bellows and accurately obtain the vibration isolation performance parameters of the bellows.

[0091] Example 2:

[0092] like Figure 6 As shown, other solutions in this embodiment remain unchanged. Based on embodiment 1, a low-temperature working condition simulation technology is added. A liquid nitrogen cooling tank 35 is fixedly installed on the outside of the mobile high-temperature furnace 14. The liquid nitrogen cooling tank 35 is connected to the inside of the mobile high-temperature furnace 14 through a refrigerant pipe 36. When it is necessary to simulate a low-temperature environment, the switch of the mobile high-temperature furnace 14 is turned off, the valve of the liquid nitrogen cooling tank 35 is turned on, and the refrigerant is introduced into the inside of the mobile high-temperature furnace 14 to cool the surrounding environment of the corrugated pipe body 12 and simulate a low-temperature working condition.

[0093] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A multi-condition bellows dynamic characteristic testing device, characterized in that: The device includes a hammer, a flat base, and a radial displacement base. A guide rail is also provided next to the flat base, extending above the flat base. Lifting cylinders are installed at the four corners of the upper surface of the flat base. An axial positioning plate is installed on each of the four lifting cylinders. An axial actuator is fixedly installed on the axial positioning plate. An upper flange is fixedly installed at the output end of the axial actuator. A fixed platform is also installed on the flat base. A connecting rod is installed on the fixed platform. A lower flange is fixedly installed at the top of the connecting rod. A bellows body is installed between the upper flange and the lower flange. A vibrator is installed at the bottom of the connecting rod below the fixed platform. A mobile high-temperature furnace is slidably mounted on the guide rail. A movable sealing door is hinged to the side of the mobile high-temperature furnace. The top and bottom of the mobile high-temperature furnace are provided with cutting grooves that movably cooperate with the output end of the axial actuator and the connecting rod. The cutting grooves extend from the movable sealing door to the center of the mobile high-temperature furnace. The top and bottom of the movable sealing door are provided with heat preservation positioning grooves. A heat preservation cover plate is bolted inside the heat preservation positioning groove. The heat preservation cover plate movably covers the outside of the cutting groove. A radial displacement mechanism is mounted on the radial displacement base. The radial displacement mechanism movably passes through the mobile high-temperature furnace and is connected to the side of the upper flange. The radial displacement mechanism includes a hinge seat fixedly mounted on the radial displacement base, a hinge shaft hingedly mounted on the hinge seat, a radial actuator fixedly mounted at the end of the hinge shaft away from the hinge seat, and the output end of the radial actuator movably passes through the mobile high-temperature furnace and is connected to the side of the upper flange. A high-temperature resistant gas pipe and a high-temperature resistant water pipe are movably installed at the bottom of the lower flange. An air pump is installed on the high-temperature resistant gas pipe, and a water pump is installed on the high-temperature resistant water pipe. The high-temperature resistant gas pipe is connected to an external ventilation device through the air pump, and the high-temperature resistant water pipe is connected to an external water tank through the water pump. The high-temperature resistant gas pipe and the high-temperature resistant water pipe movably pass through the bottom of the mobile high-temperature furnace. The hammer is equipped with a hammer force sensor inside. A triaxial accelerometer is installed at both ends of the bellows body near the upper and lower flanges. The triaxial accelerometer and the hammer force sensor are electrically connected to a signal acquisition device, which is electrically connected to a computer.

2. The multi-condition bellows dynamic characteristic testing device according to claim 1, characterized in that: A vertical auxiliary positioning frame is also installed on the radial displacement base, and a lifting block is movably sleeved on the vertical auxiliary positioning frame. The radial actuator moves through the lifting block.

3. The multi-condition bellows dynamic characteristic testing device according to claim 2, characterized in that: An axial force sensor and an axial servo valve are installed on the axial actuator, and a radial force sensor and a radial servo valve are installed on the radial actuator.

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