Ultralow-frequency large-displacement simple harmonic vibration test device and displacement vibration test method and calibration method thereof

Abstract

The invention belongs to the technical field of large engineering machinery measurement, and particularly discloses an ultralow-frequency large-displacement simple harmonic vibration test device and a displacement vibration test method and calibration method thereof.The ultralow-frequency large-displacement simple harmonic vibration test device comprises a back plate arranged in the vertical direction, the back plate has the length direction and the width direction, and the width direction of the back plate coincides with the vertical direction; the back plate is slidably provided with a push rod through a linear bearing set. The rolling bearing driven by the motor and the crank plate rolls in the annular guide groove in the guide groove plate, so that the rolling bearing smoothly moves in the annular guide groove, and the rotary motion of the rolling bearing is converted into simple harmonic vibration in the horizontal direction through the annular guide groove; and then the two push rods perform simple harmonic motion under the assistance of the linear bearings, the vibration sensor is used for detecting simple harmonic vibration data of the push rods in the horizontal direction, and the laser distance measuring sensor is used for synchronously obtaining displacement data of simple harmonic vibration in real time, so that the use requirements of the test device are met.

Description

Technical Field

[0001] This invention belongs to the field of measurement technology for large-scale engineering machinery, specifically involving an ultra-low frequency large displacement simple harmonic vibration test device and its displacement vibration testing method and calibration method, to realize the simulation and accurate measurement of ultra-low frequency large displacement vibration signals, aiming to meet the needs of in-depth analysis of vibration characteristics in complex engineering environments. Background Technology

[0002] Currently, the measurement technology for ultra-low frequency vibration (0.002–0.1 Hz) has attracted much attention, mainly due to the need for accurate measurement of the natural frequencies of long-span bridges such as suspension bridges and cable-stayed bridges, as well as large port lifting equipment structures. This measurement range is far below the national low-frequency vibration standard of 0.1 Hz, with a maximum amplitude of 40 mm.

[0003] Common vibration signal generators use mechanical or electromagnetic drive mechanisms to induce periodic simple harmonic vibrations in vibrating components. Since the drive mechanism can accurately control the motion frequency and stroke, the frequency and amplitude of the generated simple harmonic vibrations are determined. The vibration frequencies that the aforementioned vibration signal generators can provide are generally between 1 and 10 Hz, or even higher, which is far from meeting the requirements of the above-mentioned test scenarios.

[0004] Vibration signal generators can typically provide vibration signal amplitude values ​​within a range of 40mm. However, ultra-low frequency signals, due to their low frequency, have a larger amplitude value variation range. Traditional vibration generators cannot meet the requirements of the testing scenario in terms of amplitude value.

[0005] The measurement of ultra-low frequency large displacement simple harmonic vibration is still in the exploratory stage both domestically and internationally. Internationally renowned sensor manufacturers, such as Denmark's BK, the United States' PCB, and the United States' CTC, do not have detailed information on the relevant parameters and test curves of vibration sensors in the ultra-low frequency range. Understanding the measurement characteristics of sensors in the ultra-low frequency range remains a blind spot. Summary of the Invention

[0006] This invention provides an ultra-low frequency large displacement simple harmonic vibration test device and its displacement vibration test method and calibration method, aiming to provide displacement vibration frequency as low as 0.05Hz and maximum amplitude value adjustable to 400mm.

[0007] The technical problem to be solved by this invention is achieved by the following technical solution:

[0008] An ultra-low frequency large displacement simple harmonic vibration test device includes a back plate arranged in a vertical direction. The back plate has a length direction and a width direction, and the width direction of the back plate coincides with the vertical direction. A push rod is slidably mounted on the back plate through a linear bearing assembly. The push rod extends along the length direction of the back plate, and a guide groove plate is installed at one end of the push rod. The guide groove plate has an annular guide groove in the vertical direction.

[0009] A motor is mounted on the back plate. The output end of the motor extends horizontally and is mounted on a crank plate. A rolling bearing is rotatably mounted on the end of the crank plate. The rolling bearing slides in the annular guide groove, making contact with the inner wall of the annular guide groove. The rolling bearing rotates around the free end of the motor with the relative position of the axis of the rolling bearing and the free end of the motor as the radius. With the crank plate connected, the rotational motion of the rolling bearing is transformed into horizontal simple harmonic motion of the rolling bearing in the annular guide groove.

[0010] A vibration sensor is installed at the other end of the push rod to measure the simple harmonic vibration data of the push rod in the horizontal direction;

[0011] A laser rangefinder is mounted on the backplate to acquire displacement data of simple harmonic motion in real time.

[0012] Preferably, there are two push rods, and the two push rods are located on both sides of the crank plate in the vertical direction, and the ends of the two push rods are jointly fixed to the guide groove plate;

[0013] The linear bearing assembly consists of two pairs of linear bearings, both pairs of which are mounted on the back plate. The linear bearing unit in each linear bearing moves in the same direction as the length of the back plate, and each push rod is mounted in the linear bearing unit.

[0014] Preferably, the end of the push rod is provided with a threaded head, the guide plate is sleeved on the push rod, and the threaded head is locked by a nut.

[0015] Preferably, the other ends of the two push rods are jointly mounted on a fixing plate, and a laser reflector is mounted on the fixing plate. The laser reflector corresponds to the emitting end of the laser ranging sensor and is used to acquire displacement data of simple harmonic motion in real time. The vibration sensor is mounted on the laser reflector and is used to measure the simple harmonic motion data of the push rod in the horizontal direction.

[0016] Using the above scheme, the annular guide groove pushes the two sets of push rods to slide. The annular guide groove is closely connected to the two push rods. Each push rod is embedded in two linear bearing units, and the other end is connected to a fixing plate to form a stable and sturdy frame system to prevent structural deformation during the test and ensure that the device is free from stray abnormal vibrations.

[0017] Preferably, the top cross-section of the laser reflector is elongated, the laser reflector extends along its length, and the vibration sensor is mounted on the laser reflector.

[0018] Preferably, a bracket is mounted on the back plate, the laser rangefinder is mounted on the bracket, and the emitting end of the laser rangefinder corresponds to the laser reflector.

[0019] Preferably, the back plate is mounted on the test bench via a vertical bracket.

[0020] Preferably, the crank plate has graduations.

[0021] Preferably, the vibration sensor is a capacitive sensor or a low-frequency piezoelectric sensor, used to accurately capture the simple harmonic vibration data generated by the device.

[0022] A displacement vibration testing method, implemented using the aforementioned apparatus, includes the following steps:

[0023] The vibration sensor is fixed to the mounting plate, and the laser rangefinder is fixed to the bracket. Both the vibration sensor and the laser rangefinder are connected to the displacement vibration testing equipment.

[0024] When the motor is started, the free end of the motor rotates, driving the crank plate to move in a circular motion, which in turn causes the rolling bearing to roll in the annular guide groove. In other words, the circular motion of the free end of the motor is converted into simple harmonic motion of the rolling bearing in the annular guide groove. Adjusting the speed of the motor adjusts the frequency of the simple harmonic motion, and changing the position of the rolling bearing on the crank plate adjusts the displacement amplitude.

[0025] Preferably, the lowest vibration frequency can be as low as 0.05Hz; the amplitude value can be adjusted in the range of 100mm to 400mm.

[0026] The above-described test apparatus is used for calibrating vibration systems with uncalibrated vibration signals.

[0027] Preferably, the calibration is performed according to the following steps:

[0028] The calibrated vibration sensor is fixed on the mounting plate, and the vibration sensor is connected to the displacement vibration test system to be calibrated.

[0029] The motor is started, and the free end of the motor rotates, driving the crank plate to move in a circular motion, thereby causing the rolling bearing to roll in the annular guide groove. In other words, the circular motion of the free end of the motor is converted into simple harmonic motion of the rolling bearing in the annular guide groove. The vibration system to be calibrated reads the vibration signal with a predetermined frequency and amplitude value, and the system is calibrated based on this vibration signal.

[0030] The beneficial effects of this invention are:

[0031] (1) This invention mainly utilizes the rolling bearing driven by the motor and crank plate to roll in the annular guide groove on the guide plate, so that the rolling bearing can move smoothly in the annular guide groove. The annular guide groove converts the rolling bearing from rotational motion to simple harmonic motion in the horizontal direction. Then, the two push rods perform simple harmonic motion with the assistance of linear bearings. The vibration sensor is used to detect the simple harmonic motion data of the push rods in the horizontal direction, and the laser rangefinder is used to synchronously acquire the displacement data of the simple harmonic motion in real time, so as to meet the needs of this test device.

[0032] (2) The present invention uses two push rods connected to a fixed plate. The annular guide groove, the two push rods, the two pairs of linear bearings and the fixed plate together form a stable structure. When the push rod moves in the horizontal direction, the structure is stable without shaking or deformation, thereby improving the accuracy of the experimental device in measuring the vibration frequency and amplitude.

[0033] (3) The present invention uses aluminum alloy for both the test platform and the vertical support to ensure that the device can move smoothly during the test while also ensuring good structural strength and rigidity.

[0034] (4) The test device in this invention can be used to perform displacement vibration test, and the vibration frequency can be measured as low as 0.05 Hz; the amplitude value can be adjusted to 400 mm.

[0035] (5) The test device in this invention can be used to calibrate an uncalibrated vibration system. The device can read the vibration signal of the vibration system to be calibrated with a predetermined vibration frequency and amplitude value, and calibrate the system based on the vibration signal. Attached Figure Description

[0036] Figure 1 This is a front view of the experimental apparatus of the present invention;

[0037] Figure 2 for Figure 1 A structural diagram of section B;

[0038] Figure 3 for Figure 1 A structural diagram of section C;

[0039] Figure 4 This is a top view of the experimental apparatus of the present invention, and also... Figure 1 Cross-sectional view along the AA direction;

[0040] Figure 5 for Figure 4 A structural diagram of section E in the middle;

[0041] Figure 6 for Figure 4 Schematic diagram of the structure of section F;

[0042] Figure 7 This is a left view of the experimental apparatus of the present invention, and also... Figure 2 Cross-sectional view along the DD direction;

[0043] Figure 8 for Figure 7 A schematic diagram of the structure of section G;

[0044] Figure 9 This is a schematic diagram of the decomposition of simple harmonic motion according to the present invention;

[0045] Figure 10 A photograph of the three-dimensional structure in this invention;

[0046] Figure 11 The figure shows the test results of this invention;

[0047] In the diagram: Back plate 1, push rod 2, guide plate 3, annular guide groove 4, motor 5, crank plate 6, rolling bearing 7, vibration sensor 8, laser rangefinder 9, linear bearing 10, base 1001, linear bearing unit 1002, fixing plate 11, laser reflector 12, bracket 13, vertical bracket 14, column 141, horizontal plate 142, test platform 15, upper crossbeam 151, support leg 152, lower crossbeam 153, auxiliary hanging part 154, reinforcing beam 155, base plate 156. Detailed Implementation

[0048] To facilitate a clear understanding of the technical means, creative features, objectives, and effects of this invention, the invention will be further described below in conjunction with specific illustrations and embodiments.

[0049] Example 1

[0050] like Figure 1-10 As shown, the ultra-low frequency large displacement simple harmonic vibration test device includes a back plate 1 arranged vertically. The back plate 1 has a length direction and a width direction, and the width direction of the back plate 1 coincides with the vertical direction. A push rod 2 is slidably mounted on the back plate 1 through a linear bearing assembly. The push rod 2 extends along the length direction of the back plate 1, and a guide groove plate 3 is installed at one end of the push rod 2. The guide groove plate 3 has an annular guide groove 4 in the vertical direction. The linear bearing assembly consists of two pairs of linear bearings 10 composed of a base 1001 and a linear bearing unit 1002 (it should be noted that the linear bearings 10 can adopt existing technology, therefore, the connection relationship between the base 1001 and the linear bearing unit 1002 is not described in detail in this paper). Both pairs of linear bearings 10 are mounted on the back plate 1, and the direction of movement of the linear bearing unit 1002 in the linear bearing 10 is consistent with the length direction of the back plate 1. Each push rod 2 is installed in the linear bearing unit 1002.

[0051] The purpose of this scheme is to use the annular guide groove 4 on the guide plate 3, the two push rods 2, the two pairs of linear bearings 10, and the fixing plate 11 to form a stable structure, so that the structure is stable without shaking or deformation when the push rod 2 moves in the horizontal direction.

[0052] A motor 5 is installed on the back plate 1. The output end of the motor 5 extends horizontally and is equipped with a crank plate 6. A rolling bearing 7 is rotatably installed at the end of the crank plate 6. The annular guide groove 4 is slidably sleeved with the rolling bearing 7 (the purpose is to adjust the amplitude of the simple harmonic vibration by adjusting the position of the rolling bearing 7 on the crank plate 6). There are two push rods 2. The two push rods 2 are parallel to the crank plate 6 and are located on both sides of the crank plate 6 in the vertical direction. The ends of the two push rods 2 are jointly fixed to the guide groove plate 3.

[0053] A rolling bearing 7 is installed at one end of the crank plate 6, so that the rolling bearing 7 rotates with the free end of the motor as the center and the relative position of the rolling bearing 7 and the axis of the free end of the motor as the radius.

[0054] The rolling bearing 7 is rolled in the annular guide groove 4 and driven by the free end of the motor 5. With the crank plate connection, the rotational motion of the rolling bearing 7 is transformed into the horizontal simple harmonic motion of the rolling bearing 7 in the annular guide groove 4.

[0055] A vibration sensor 8 is installed at the other end of the push rod 2 to measure the simple harmonic vibration data of the push rod 2 in the horizontal direction. The vibration sensor 8 is installed on the laser reflector plate 12 to measure the simple harmonic vibration data of the push rod 2 in the horizontal direction.

[0056] A laser rangefinder 9 is installed on the back plate 1 to acquire displacement data of simple harmonic motion in real time; specifically, a fixing plate 11 is installed on the other end of the two push rods 2, and a laser reflector 12 is installed on the fixing plate 11, with the laser reflector 12 corresponding to the emitting end of the laser rangefinder 9.

[0057] Using the above scheme, the annular guide groove 4 pushes the two sets of push rods 2 to slide. The annular guide groove 4 is closely connected to the two push rods 2. Each push rod 2 is embedded in two linear bearing units 1002, and the other end is connected to the fixing plate 11, which together form a stable and sturdy frame system to prevent structural deformation during the test and ensure that the device is free from stray abnormal vibration.

[0058] The top cross-section of the laser reflector 12 is elongated, and the laser reflector 12 extends along its length, with the vibration sensor 8 mounted on the laser reflector 12.

[0059] A bracket 13 is mounted on the back plate 1, and a laser rangefinder 9 is mounted on the bracket 13, with the measuring end of the laser rangefinder 9 corresponding to the laser reflector 12.

[0060] The backplate 1 is mounted on the aluminum alloy test stand 15 via an aluminum alloy vertical bracket 14, specifically as follows:

[0061] The test platform 15 includes an upper crossbeam 151, support legs 152, and a lower crossbeam 153. There are four support legs 152, all of which are fixed to the bottom of the upper crossbeam 151. The lower crossbeam 153 is fixed to the support legs 152 and is located below the upper crossbeam 152, and the two are parallel. A base plate 156 is installed above the lower crossbeam 153. A reinforcing beam 155 is also provided between the four support legs 152. The reinforcing beam 155 is located between the upper crossbeam 152 and the base plate 156. An auxiliary hanger 154 is installed at the end of the upper crossbeam 151. (It should be noted that the upper crossbeam 151, support legs 152, lower crossbeam 153, reinforcing beam 155, and base plate 156 are all made of aluminum alloy. The purpose is to ensure the strength and rigidity of the structure while ensuring its lightweight nature.)

[0062] The aluminum alloy vertical support 14 includes a horizontal plate 142 and at least two uprights 141. The horizontal plate 142 is fixed on the base plate 156, and the at least two uprights 141 are fixed together on the top of the horizontal plate 142. The back plate 1 is fixed on the uprights 141.

[0063] Vibration sensor 8 is a capacitive sensor or a low-frequency piezoelectric sensor, used to accurately capture the simple harmonic vibration data generated by this device. It should be noted that the working principle of vibration sensor 8 is as follows: the driving torque output by motor 5 generates the driving force for the reciprocating motion of push rod 2. The driving force of push rod 2 causes push rod 2, fixed plate 11 and laser reflector 12 to generate inertia, thereby causing fixed plate 11 to vibrate under reciprocating motion, causing laser reflector 12 to vibrate, and finally causing vibration sensor 8 to generate a signal.

[0064] like Figure 9 As shown, this is a breakdown of the actions of the device during operation. When motor 5 is at the left dead center, as shown... Figure 9 As shown in state I, the device is currently at the left stop point;

[0065] After the free end of motor 5 is rotated 45 degrees clockwise, it is as follows Figure 9 As shown in state II;

[0066] The free end of motor 5 rotates 90 degrees clockwise relative to state I, as follows: Figure 9 As shown in state III;

[0067] The free end of motor 5 rotates 135 degrees clockwise relative to state I, as follows: Figure 9 As shown in state IV;

[0068] The free end of motor 5 rotates 180 degrees clockwise relative to state I, as follows: Figure 9As shown in state V, the device is currently at the right-side stop point.

[0069] The free end of motor 5 rotates 270 degrees clockwise relative to state I. Figure 9 As shown in state VI;

[0070] When the free end of motor 5 rotates 360 degrees clockwise relative to state I, the device returns to its initial state.

[0071] Example 2

[0072] A displacement vibration testing method, implemented using the above-mentioned device, includes the following steps: fixing a vibration sensor 8 to a fixing plate 11, fixing a laser rangefinder 9 to a bracket 13, and connecting both the vibration sensor 8 and the laser rangefinder 9 to the displacement vibration testing equipment (specifically, the measurement signals of the vibration sensor 8 and the laser rangefinder 9 are input into the measurement system of the displacement vibration testing equipment to form a measurement closed loop).

[0073] When motor 5 is started, its free end rotates, driving crank plate 6 to move in a circular motion, thereby causing rolling bearing 7 to roll within an annular guide groove 4. This transforms the circular motion of the free end of motor 5 into simple harmonic motion of rolling bearing 7 within the annular guide groove 4 (e.g., ...). Figure 10 (as shown); the frequency of simple harmonic vibration is adjusted by adjusting the speed of motor 5 and the displacement amplitude is adjusted by changing the position of rolling bearing 7 on crank plate 3, wherein: the lowest vibration frequency can be as low as 0.05Hz; the amplitude value can be adjusted within a range of 400mm.

[0074] The specific experimental steps are as follows:

[0075] According to Embodiment 1, one end of the crank plate 6 is connected to the free end of the motor 5. The crank plate 6 is designed with a guide groove, and the rolling bearing 7 is installed in the guide groove of the crank plate 6. The rolling bearing 7 rotates with the free end of the motor 5 as the center and the relative position of the rolling bearing 7 and the axis of the free end as the radius.

[0076] The scale marked on the crank plate 6 allows for easy adjustment of the vibration amplitude by adjusting the position of the rolling bearing 7 within the crank plate 6. The output vibration displacement peak-to-peak value is ±200mm.

[0077] The laser rangefinder 9 is mounted on the laser rangefinder mounting bracket 13 for real-time measurement of vibration displacement data.

[0078] 1. The communication cable connecting the frequency converter to the computer, the cable connecting the laser rangefinder 9 (model Panasonic HGC-1400) to the data acquisition unit, and the communication cable connecting the data acquisition unit (NI CompactDAQ Systems) to the computer.

[0079] 2. Open the calibration settings software (Vibration Generator), set the vibration displacement frequency of the test device to 0.05Hz, 0.06Hz, 0.07Hz, 0.08Hz, 0.09Hz, 0.1Hz, 0.12Hz, 0.15Hz, 0.18Hz, 0.2Hz, 0.3Hz, 0.4Hz, and 0.5Hz respectively, set the sampling frequency of the acquisition software to 100Hz, read the data from the laser rangefinder sensor in real time, and store the acquired data.

[0080] Vibration displacement data at three frequency points of 0.05Hz, 0.1Hz, and 0.15Hz are selected, and the collected data curves are plotted as follows. Figure 11 As shown in Table 1, the errors between the set values ​​and the measured values ​​are as follows:

[0081] Table 1

[0082]

[0083]

[0084] From Table 1 and Figure 10 As can be seen, when the set frequency decreases from 0.15Hz to 0.05Hz, the reading error increases from 3.3% to 5%. This is consistent with the characteristics of vibration calibration devices; the lower the frequency, the greater the error. However, the error does not exceed 5%, which is still within a reasonable range. The comparison error between the set amplitude and the actual amplitude is relatively stable, with an error of only 0.25%. Therefore, the amplitude and frequency measured by this device have small differences from the actual amplitude and frequency, indicating that the amplitude and frequency measured by this device are highly accurate.

[0085] Example 3

[0086] The above-described test apparatus is used for calibrating vibration systems with uncalibrated vibration signals.

[0087] Based on the above application, calibration is performed using the following steps:

[0088] The calibrated vibration sensor 8 is fixed on the fixing plate 11, and the vibration sensor 8 is connected to the displacement vibration test system to be calibrated.

[0089] Start motor 5, the free end of motor 5 rotates, driving crank plate 6 to move in a circular motion, thereby causing rolling bearing 7 to roll in an annular guide groove 4, that is, the circular motion of the free end of motor 5 is converted into simple harmonic motion of rolling bearing 7 in an annular guide groove 4; the vibration system to be calibrated reads the vibration signal with the predetermined vibration frequency and amplitude value, and calibrates the system based on this vibration signal.

[0090] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments, and various changes and modifications can be made without departing from the spirit and scope of the invention, all of which fall within the scope of the claims. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. Ultra-low frequency large displacement simple harmonic vibration test device, characterized by: The back plate includes a back plate arranged in a vertical direction, the back plate has a length direction and a width direction, and the width direction of the back plate coincides with the vertical direction. The back plate is slidably mounted with a push rod through a linear bearing group, the push rod extends along the length direction of the back plate, and a guide groove plate is mounted at one end thereof, and the guide groove plate is provided with an annular guide groove along the vertical direction; The back plate is mounted with a motor, the output end of the motor extends in the horizontal direction and is mounted with a crank plate, the end of the crank plate is rotatably mounted with a rolling bearing, the rolling bearing slides in the annular guide groove, the rolling bearing is in line contact with the inner wall of the annular guide groove, the rolling bearing is rotated with the free end of the motor as the center and the relative position of the axis of the rolling bearing and the free end of the motor as the radius, and the rotational motion of the rolling bearing is converted into a horizontal simple harmonic vibration of the rolling bearing in the annular guide groove under the connection of the crank plate; A vibration sensor is installed at the other end of the push rod to measure the simple harmonic vibration data of the push rod in the horizontal direction; A laser distance measuring sensor is installed on the back plate to synchronously acquire the displacement data of simple harmonic oscillation in real time.

2. The ultra-low frequency large displacement simple harmonic vibration test device according to claim 1, characterized in that: There are two push rods, and the two push rods are respectively located on both sides of the crank plate in the vertical direction, and the ends of the two push rods are commonly fixed to the guide groove plate; The linear bearing group is composed of two pairs of linear bearings, both pairs of the linear bearings are installed on the back plate, and the moving direction of the linear bearing units in the linear bearings is consistent with the length direction of the back plate, and each push rod is installed in the linear bearing unit.

3. The ultra-low frequency large displacement simple harmonic vibration test device according to claim 2, characterized in that: A fixing plate is installed on the other ends of the two push rods, and a laser reflecting plate is installed on the fixing plate. The laser reflecting plate corresponds to the transmitting end of the laser ranging sensor, and is used to synchronously acquire the displacement data of simple harmonic oscillation in real time; The vibration sensor is installed on the laser reflection plate and is used to measure the simple harmonic vibration data of the push rod in the horizontal direction.

4. The ultra-low frequency large displacement simple harmonic vibration test device according to claim 3, characterized in that: The top cross-section of the laser reflection plate is in the shape of an elongated strip. The laser reflection plate extends along its length direction, and the vibration sensor is mounted on the laser reflection plate.

5. The ultra-low frequency large displacement simple harmonic vibration test device according to claim 2, characterized in that: A bracket is installed on the back plate, the laser distance measuring sensor is installed on the bracket, and the emitting end of the laser distance measuring sensor corresponds to the laser reflecting plate.

6. A displacement vibration test method, implemented by the device according to any one of claims 1 to 5, characterized in that: The following steps are involved: Fix the vibration sensor on the fixing plate, fix the laser distance sensor on the bracket, and connect the vibration sensor and the laser distance sensor to the displacement vibration test equipment signal; Start the motor, the free end of the motor rotates, driving the crank plate to move in a circular motion, thereby causing the rolling bearing to roll in the annular guide groove, that is, converting the circular motion of the free end of the motor into a simple harmonic vibration of the rolling bearing in the annular guide groove; adjusting the speed of the motor to adjust the frequency of the simple harmonic vibration and adjusting the displacement amplitude by changing the position of the rolling bearing on the crank plate.

7. The testing method according to claim 6, characterized in that: The lowest vibration frequency can be as low as 0.05Hz; the adjustable amplitude range is 100mm~400mm.

8. Use of the test device according to any one of claims 1 to 5 in calibrating a vibration system with uncalibrated vibration signals.

9. The use according to claim 8, characterized in that: Follow these steps: The calibrated vibration sensor is fixed on a fixed plate, and the vibration sensor is connected to the displacement vibration test system signal to be calibrated; Start the motor, the free end of the motor rotates, driving the crank plate to move in a circular motion, thereby causing the rolling bearing to roll in the annular guide groove, that is, converting the circular motion of the free end of the motor into a simple harmonic vibration of the rolling bearing in the annular guide groove; the vibration system to be calibrated reads the vibration signal of a predetermined frequency and amplitude value, and calibrates the system based on this vibration signal.

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