Multi-working-condition corrugated pipe dynamic characteristic testing device

Abstract

The invention relates to the technical field of multi-working-condition corrugated pipe dynamic characteristic testing, in particular to a multi-working-condition corrugated pipe dynamic characteristic testing device which is used for testing a corrugated pipe under a composite working condition through excitation of a vibration exciter or a force hammer and measuring vibration acceleration parameters of three-axis acceleration sensors at the two ends of the corrugated pipe. The vibration isolation performance parameters of the corrugated pipe under the composite working condition can be accurately obtained after calculation, the testing precision is higher, a vibration exciter or a force hammer is selected for excitation according to the size of the mass caliber of the corrugated pipe, the influence of the additional mass and rigidity of the vibration exciter on the measuring precision can be avoided, the environment can be simulated, and the method is closer to the real service condition. By loading different working conditions and composite working conditions such as high temperature, pressure load, axial or transverse displacement and the like, the actual working condition of the corrugated pipe is truly simulated, and the vibration isolation performance parameters of the corrugated pipe can be accurately obtained.

Description

Technical Field

[0001] The invention relates to the technical field of multi-working-condition bellows dynamic characteristics testing, in particular to a multi-working-condition bellows dynamic characteristics testing device. Background Art

[0002] As a flexible thin-walled connector, bellows are mainly used to compensate for displacement and suppress vibration transmission in piping systems. 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. The unique thin-walled structure is also prone to damage. It is increasingly important to accurately predict their vibration characteristics to avoid resonance. However, these parameters are not fixed, and their values ​​are highly dependent on the actual working conditions of the bellows. The same bellows installed in different working conditions will have different vibration isolation performance parameters. Therefore, it is meaningful to conduct vibration isolation performance tests on bellows only if multiple working conditions are considered.

[0003] At present, the vibration isolation performance test of bellows is usually carried out under a single working condition, without considering the influence of pressure, displacement and high temperature environment inside the pipe on the vibration isolation performance of the bellows, and it is impossible to simulate complex working conditions.

[0004] Conventional exciter-sensor systems (e.g., spring-mass simulators) can only simulate single-directional vibrations and are unable to reproduce multi-directional displacements (e.g., simultaneous axial tension and transverse shear in ship piping systems). In the test, pressure, temperature and vibration need to be loaded independently, but under actual working conditions, the interaction between the three is significant.

[0005] Current standard tests are usually conducted under static or single dynamic loads, ignoring the coupling effects of three key working conditions: 1. The pressure inside the pipe and the pressure load will change the stiffness of the bellows. For example, under high pressure, the stress concentration in the trough of the bellows will lead to local hardening, and the measured stiffness will deviate, affecting the accuracy of the vibration isolation performance parameters.

[0006] 2. Axial / lateral displacement: When compensating for large displacement, the bellows undergoes plastic deformation, and its damping characteristics decay nonlinearly, with the vibration level difference shifting by 3~7dB.

[0007] 3. High temperature environment. For example, when the temperature of 1Cr18Ni9Ti material is above 700℃, the Young's modulus will drop significantly and the resonant frequency will drift by more than 10%. However, existing tests lack the ability to simulate thermal-mechanical coupling.

[0008] 4. Sensitivity to boundary conditions: Under fixed-free and fixed-fixed constraints, the bellows transmission force differs by 3 times, and the vibration isolation performance differs significantly.

[0009] The current test method cannot truly simulate the multi-working environment of the bellows, and cannot accurately obtain the vibration isolation performance parameters of the bellows under multiple working conditions.

[0010] Therefore, in view of the shortcomings of the existing technology, it is necessary to provide a multi-working condition bellows dynamic characteristics test device to solve the shortcomings of the existing technology. Summary of the Invention

[0011] The purpose of the present invention is to avoid the shortcomings of the prior art and provide a multi-working condition bellows dynamic characteristics test device. The multi-working condition bellows dynamic characteristics test device tests the bellows under composite working conditions through an exciter or a hammer to excite the bellows, measures the vibration acceleration parameters of the three-axis acceleration sensors at both ends of the bellows, and can accurately obtain the vibration isolation performance parameters of the bellows under composite working conditions after calculation. The test accuracy is higher. The exciter or hammer is selected for excitation according to the mass and caliber of the bellows, which can avoid the influence of the additional mass and stiffness of the exciter on the measurement accuracy. It can also simulate the environment and be closer to the actual service conditions. By loading different working conditions and composite working conditions such as high temperature, pressure load, axial or lateral displacement, the actual working conditions of the bellows are truly simulated, and the vibration isolation performance parameters of the bellows can be accurately obtained.

[0012] The above-mentioned purpose of the present invention is achieved through the following technical means.

[0013] Provided is a multi-working condition bellows dynamic characteristics test device, comprising a force hammer, a flat base and a radial displacement base, a guide rail being provided next to the flat base, the guide rail extending to the top of the flat base, lifting cylinders being installed at the four corners of the upper surface of the flat base, an axial positioning plate being installed on each of the four lifting cylinders, an axial actuator being fixedly installed on the axial positioning plate, an upper flange being fixedly installed on the output end of the axial actuator, a fixed platform being installed on the flat base, a connecting rod being fixedly installed on the top end of the connecting rod, a bellows body being installed on a flange between the upper and lower flanges, and a vibration exciter being installed on the bottom of the connecting rod below the fixed platform; A mobile high-temperature furnace is slidably installed on the guide rail, and a movable sealing door is hingedly installed on the side of the mobile high-temperature furnace. The top and bottom of the mobile high-temperature furnace are provided with cutting grooves that cooperate with the output end of the axial actuator and the connecting rod. The cutting groove extends 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 insulation positioning grooves. The internal bolts of the insulation positioning groove are installed with insulation cover plates, and the insulation cover plates are movably covered on the outside of the cutting groove. A radial displacement mechanism is installed 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.

[0014] Specifically, the radial displacement mechanism includes an articulated seat fixedly mounted on the radial displacement base, an articulated shaft is articulatedly mounted on the articulated seat, a radial actuator is fixedly mounted on the end of the articulated shaft away from the articulated seat, and the output end of the radial actuator moves through the mobile high-temperature furnace and is connected to the side of the upper flange.

[0015] Specifically, a high-temperature resistant air 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 air pipe, and a water pump is installed on the high-temperature resistant water pipe. The high-temperature resistant air 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 air pipe and the high-temperature resistant water pipe are movably passed through the bottom of the mobile high-temperature furnace.

[0016] Specifically, a hammer force sensor is installed inside the hammer, and three-axis acceleration sensors are installed at both ends of the bellows body near the upper flange and the lower flange. The three-axis acceleration sensor and the hammer force sensor are electrically connected to the signal acquisition instrument, and the signal acquisition instrument is electrically connected to the computer.

[0017] Specifically, a vertical auxiliary positioning frame is also installed on the radial displacement base, a lifting block is movably sleeved on the vertical auxiliary positioning frame, and the radial actuator movably passes through the lifting block.

[0018] Specifically, 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.

[0019] The present invention tests the bellows under composite working conditions through an exciter or a hammer to excite the bellows, measures the vibration acceleration parameters of the three-axis acceleration sensors at both ends of the bellows, and can accurately obtain the vibration isolation performance parameters of the bellows under composite working conditions after calculation. The test accuracy is higher, and the exciter or hammer is selected for excitation according to the mass and caliber of the bellows, which can avoid the influence of the additional mass and stiffness of the exciter on the measurement accuracy, and can also simulate the environment, which is closer to the actual service condition. By loading different working conditions and composite working conditions such as high temperature, pressure load, axial or lateral displacement, the actual working condition of the bellows is truly simulated, and the vibration isolation performance parameters of the bellows can be accurately obtained. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The present invention is further described with reference to the accompanying drawings, but the contents in the accompanying drawings do not constitute any limitation to the present invention.

[0021] Figure 1 This is a three-dimensional structure diagram of a multi-condition bellows dynamic characteristics test device of the present invention. Figure 1 .

[0022] Figure 2 This is a three-dimensional structure diagram of a multi-condition bellows dynamic characteristics test device of the present invention. Figure 2 .

[0023] Figure 3 It is a side sectional view of a multi-operating-condition bellows dynamic characteristics testing device of the present invention.

[0024] Figure 4 The present invention provides a schematic diagram of the connections of a signal acquisition instrument, a computer, a hammer force sensor, and a triaxial acceleration sensor in a multi-working-condition bellows dynamic characteristics test device.

[0025] Figure 5 It is a schematic diagram of the three-dimensional structure of a mobile high-temperature furnace of a multi-working-condition bellows dynamic characteristics test device of the present invention.

[0026] Figure 6 It is a schematic diagram of the three-dimensional structure of a mobile high-temperature furnace in Example 2 of a multi-working condition bellows dynamic characteristics test device of the present invention.

[0027] from Figures 1 to 6 Including: 1. Hammer; 2. Flat base; 3. Radial displacement base; 4. Guide rails; 5. Lifting cylinder; 6. Axial positioning plate; 7. Axial actuator; 8. Upper flange; 9. Fixed platform; 10. Connecting rod; 11. Lower flange; 12. Bellows body; 13. Vibrator; 14. Mobile high-temperature furnace; 15. Movable sealing door; 16. Cut into groove; 17. Insulation positioning groove; 18. Insulation cover; 19. Articulated seat; 20. Articulated shaft; 21. Radial actuator; 22. High temperature resistant air pipe; 23. High temperature resistant water pipes; 24. Air pump; 25. Water pump; 26. Three-axis acceleration sensor; 27. Signal acquisition instrument; 28. Computer; 29. Vertical auxiliary positioning frame; 30. Lifting block; 31. Axial force sensor; 32. Axial servo valve; 33. Radial force sensor; 34. Radial servo valve; 35. Liquid nitrogen cold tank; 36. Refrigerant pipe. DETAILED DESCRIPTION

[0028] The present invention is further described with reference to the following examples.

[0029] Example 1: like Figure 1-5 As shown, a multi-working condition bellows dynamic characteristics test 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, and the guide rail 4 extends to the top of 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 also installed on the four lifting cylinders 5. An axial positioning plate 6 is fixedly installed on the axial positioning plate 6. An upper flange 8 is fixedly installed on 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 on the top of the connecting rod 10. A bellows body 12 is installed on the flange between the upper flange 8 and the lower flange 11. An exciter 13 is installed on the bottom of the connecting rod 10 below the fixed platform 9.

[0030] A mobile high-temperature furnace 14 is slidably mounted on the guide rail 4, and a movable sealing door 15 is hingedly mounted on the side of the mobile high-temperature furnace 14. The top and bottom of the mobile high-temperature furnace 14 are provided with an incision groove 16 that movably cooperates with the output end of the axial actuator 7 and the connecting rod 10. The incision groove 16 extends 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 insulation positioning grooves 17. The internal bolts of the insulation positioning groove 17 are installed with an insulation cover 18, and the insulation cover 18 movably covers the outside of the incision groove 16. A radial displacement mechanism is installed on the radial displacement base 3, and the radial displacement mechanism movably passes through the mobile high-temperature furnace 14 and is connected to the side of the upper flange 8.

[0031] The moving direction of the mobile high-temperature furnace 14 is perpendicular to the output direction of the radial displacement mechanism, and it moves and outputs on both sides of the bellows body 12 respectively. The output of the lifting cylinder 5 can adjust the height of the axial positioning plate 6 and then roughly adjust the height of the axial actuator 7. Then, the axial actuator 7 is started according to the parameters such as the length of the bellows to achieve precise adjustment of the displacement of the axial upper flange 8. The lower flange 11 is fixed by the connecting rod 10 and the fixed platform 9, and then the bellows body 12 is positioned. The vibrator 13 excites 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 mobile high-temperature furnace 14 is slid so that the output end of the axial actuator 7 and the connecting rod 10 are movably engaged with the inside of the cut-in groove 16. At this time, the bellows body 12 enters the inner center of the mobile high-temperature furnace 14, and the movable sealing door 15 is closed. The thermal insulation cover 18 is then bolted to prevent heat dissipation, and the mobile high-temperature furnace 14 can be started to simulate the heating condition. At the same time, the radial displacement mechanism also moves through the mobile high-temperature furnace 14, and the radial displacement condition of the bellows body 12 inside the mobile high-temperature furnace 14 can be simulated.

[0032] The radial displacement mechanism includes an articulated seat 19 fixedly mounted on the radial displacement base 3, an articulated shaft 20 is articulatedly mounted on the articulated seat 19, and a radial actuator 21 is fixedly mounted on the end of the articulated shaft 20 away from the articulated 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.

[0033] The radial displacement mechanism generates the force required for the radial working condition 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 output end of the other end is connected to the flange 8 to simulate the radial displacement working condition of the bellows body 12.

[0034] A high-temperature resistant air 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 air pipe 22, and a water pump 25 is installed on the high-temperature resistant water pipe 23. The high-temperature resistant air pipe 22 is connected to the external ventilation equipment through the air pump 24, and the high-temperature resistant water pipe 23 is connected to the external water tank through the water pump 25. The high-temperature resistant air pipe 22 and the high-temperature resistant water pipe 23 are movably passed through the bottom of the mobile high-temperature furnace 14.

[0035] The bottom of the lower flange 11 can realize the working condition of the bellows body 12 under air pressure or water pressure state through the high-temperature resistant air pipe 22 and the high-temperature resistant water pipe 23, and gas or water can be introduced into the interior of the bellows body 12. The high-temperature resistant air pipe 22 and the high-temperature resistant water pipe 23 are also movable through the mobile high-temperature furnace 14, which can be simulated simultaneously with the high-temperature conditions, or can be simulated separately.

[0036] A hammer force sensor is installed inside the hammer 1, and a three-axis acceleration sensor 26 is installed at both ends of the bellows body 12 near the upper flange 8 and the lower flange 11. The three-axis acceleration sensor 26 and the hammer force sensor are electrically connected to the signal acquisition device 27, and the signal acquisition device 27 is electrically connected to the computer 28.

[0037] In order to avoid the influence of the additional mass and stiffness of the exciter 13 on the measurement accuracy, the bellows body 12 with a smaller volume can be excited by the hammer 1. The exciter 13 is removed and the hammer 1 is used for excitation. The simulated loading process of different working conditions remains unchanged. In the specific test, the model of the hammer 1 is PCB086C04, with a measurement range of 250KN and a sensitivity of 2.34Pc / N. The triaxial accelerometer 26 adopts a range of 10e4 m / s2, and the model of the charge amplifier is GSTYE5852B, with voltage / IEPE input, impedance >100Ω, noise <5μV, and accuracy ±1%. The signal acquisition instrument 27 adopts 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 model adopts LMS Test.Lab 18, which can perform the functions required for control and various data analysis.

[0038] The acceleration at both ends of the bellows body 12 is obtained by the three-axis acceleration sensor 26, and 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 formula: 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, that is, the vibration acceleration at the end connected to the exciter 13. The vibration level difference of the bellows body 12 at different excitation frequencies of the exciter 13 can be obtained by calculation, and the vibration isolation performance of the bellows body 12 can be judged based on the calculated vibration level difference.

[0039] 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 movably passes through the lifting block 30 .

[0040] The vertical auxiliary positioning frame 29 and the lifting block 30 can serve as the third fulcrum of the radial actuator 21 to prevent the radial displacement mechanism from being too long and affecting the safety of the working condition simulation. At the same time, the movably installed lifting block 30 and the articulated shaft 20 can realize the coordination of the bellows body 12 of different heights, so that the radial actuator 21 can output radial displacement at an angle.

[0041] 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 .

[0042] The axial actuator 7 adopts Instron8874, with an axial load capacity of +25kN and an actuator stroke of 100mm.

[0043] The axial force sensor 31 adopts STB-3000kg, with a working excitation voltage of 15V, a sensitivity of 2.000mv / v, an input impedance of 1050Ω, and an input impedance of 1000Ω.

[0044] The radial actuator 21 is MTS 244, with a rated force of 1000N and a stroke of 250mm.

[0045] The radial force sensor 33 adopts STB-3000kg, with a working excitation voltage of 15V, a sensitivity of 2.000mv / v, an input impedance of 1050Ω, and an input impedance of 1000Ω.

[0046] The triaxial accelerometer 26 has a range of 10e4 m / s2, a charge amplifier model of GSTYE5852B, voltage / IEPE input, impedance >100Ω, noise <5μV, and accuracy ±1%.

[0047] The high temperature furnace adopts GW-1000 model, the heating element material is φ1.5 iron-chromium-aluminum resistance wire, the working temperature is 200~1000℃, the temperature measuring element is K-type thermocouple, the temperature measurement sensitivity is 0.1℃, the temperature measurement accuracy is 0.2%, the working voltage is 380V, and the maximum power when heating is 5KW.

[0048] The peak value of the sinusoidal force of the exciter 13 is 650N, the effective frequency range is 2-5000N, the rated current is 18A, and the main resonance frequency is 3000Hz.

[0049] Air pump 24 power 3W-2.4 / 40, intake pressure 0.1034mpa (standard atmospheric pressure), exhaust volume 2.4m3 / min.

[0050] The present invention uses an exciter 13 or a hammer 1 to excite the bellows under complex working conditions, measures the vibration acceleration parameters of the three-axis acceleration sensors 26 at both ends of the bellows, and can accurately obtain the vibration isolation performance parameters of the bellows under complex working conditions after calculation. The test accuracy is higher. The exciter 13 or hammer 1 is selected for excitation according to the mass and caliber of the bellows, which can avoid the influence of the additional mass and stiffness of the exciter 13 on the measurement accuracy. It can also simulate the environment and be closer to the actual service conditions. By loading different working conditions and complex working conditions such as high temperature, pressure load, axial or lateral displacement, the actual working conditions of the bellows are truly simulated, and the vibration isolation performance parameters of the bellows can be accurately obtained.

[0051] Example 2: like Figure 6As shown, other schemes of this embodiment remain unchanged. On the basis of Example 1, a low-temperature working condition simulation technology is added. By fixing a liquid nitrogen cooling tank 35 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 started, and the refrigerant is passed into the inside of the mobile high-temperature furnace 14 to cool the surrounding environment of the bellows body 12 and simulate a low-temperature working condition.

[0052] 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 the technical solutions of the present invention may be modified or replaced by equivalents without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A multi-condition bellows dynamic characteristics test device, characterized by: It includes a force hammer, a flat base and a radial displacement base, a guide rail is further provided next to the flat base, the guide rail extends to the top of the flat base, lifting cylinders are installed at the four corners of the upper surface of the flat base, and an axial positioning plate is installed on the four lifting cylinders at the same time, an axial actuator is fixedly installed on the axial positioning plate, an upper flange is fixedly installed on 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 on the top end of the connecting rod, a bellows body is installed on the flange between the upper flange and the lower flange, and an exciter is installed on the bottom of the connecting rod below the fixed platform; A mobile high-temperature furnace is slidably mounted on the guide rail, and a movable sealing door is hingedly mounted on 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 groove extends 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 insulation positioning grooves, and the internal bolts of the insulation positioning grooves are installed with insulation cover plates, and the insulation cover plates movably cover the outside of the cutting grooves. A radial displacement mechanism is installed on the radial displacement base, and the radial displacement mechanism movably passes through the mobile high-temperature furnace and is connected to the side of the upper flange.

2. The multi-operating-condition bellows dynamic characteristics test device according to claim 1, characterized in that: The radial displacement mechanism includes an articulated seat fixedly mounted on the radial displacement base, an articulated shaft articulatedly mounted on the articulated seat, a radial actuator fixedly mounted on one end of the articulated shaft away from the articulated seat, and an output end of the radial actuator moves through the mobile high-temperature furnace and is connected to the side of the upper flange.

3. The multi-operating-condition bellows dynamic characteristics test device according to claim 2, characterized in that: A high-temperature resistant air 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 air pipe, and a water pump is installed on the high-temperature resistant water pipe. The high-temperature resistant air 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 air pipe and the high-temperature resistant water pipe movably pass through the bottom of the mobile high-temperature furnace.

4. The multi-operating-condition bellows dynamic characteristics test device according to claim 3, characterized in that: A hammer force sensor is installed inside the hammer, and three-axis acceleration sensors are installed on both ends of the bellows body close to the upper flange and the lower flange. The three-axis acceleration sensor and the hammer force sensor are electrically connected to a signal acquisition instrument, and the signal acquisition instrument is electrically connected to a computer.

5. The multi-operating-condition bellows dynamic characteristics test device according to claim 4, characterized in that: A vertical auxiliary positioning frame is also installed on the radial displacement base. A lifting block is movably sleeved on the vertical auxiliary positioning frame, and the radial actuator movably passes through the lifting block.

6. The multi-operating-condition bellows dynamic characteristics test device according to claim 5, 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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