Piezoelectric vibrator type test device and fatigue test method

Abstract

The application provides a piezoelectric vibrator type test device and a fatigue test method, and relates to the technical field of aero-engine test. The piezoelectric vibrator type test device comprises a test base, a piezoelectric vibrator and a connecting rod. The test base and the piezoelectric vibrator are connected through the connecting rod, and the connection between the connecting rod and the test base is screw connection, so that the distance between the piezoelectric vibrator and the test base can be changed by screwing the connecting rod, and then the adjustment of the device inherent frequency is realized. In this way, the vibration frequency requirements of different test pieces can be met by changing the device inherent frequency without changing the piezoelectric vibrator inherent frequency, so as to help ensure the accuracy and reliability of the test results. Moreover, the frequency adjustment is realized in the form of screw connection, which helps realize the continuous change and quantization of the frequency adjustment, and the frequency coverage is wider, so that the frequency adjustment can be more accurately and conveniently realized according to the frequency requirements of the test pieces.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of aero-engine testing, in particular to a piezoelectric vibrator type testing device and a fatigue testing method. BACKGROUND

[0002] In the field of aerospace, as the core component of an aircraft, the performance and reliability of an aero-engine directly determine the safety and economy of the aircraft. Fatigue failure is a common failure type in aero-engine components. For example, in an aero-engine, a blade is a key power component, which is subjected to alternating stress, thermal load and other multiple actions under high-speed rotation and complex airflow environment, and is prone to fatigue failure. According to statistics, the fatigue failure of aero-engine blades accounts for more than 30% of the overall failure of the engine. Therefore, carrying out precise and efficient fatigue testing on the blades is a key link to ensure the safe and stable operation of the engine. Traditional fatigue testing methods, such as electromagnetic resonance method and hydraulic excitation method, have problems such as large equipment size, high energy consumption and slow response speed, which cannot meet the testing requirements of high frequency and high precision of aero-engine blades. With the development of material science and micro-electromechanical technology, piezoelectric vibrator type testing devices have gradually emerged in the field of aero-engine blade fatigue testing due to their fast response speed, high energy conversion efficiency and compact structure. The piezoelectric vibrator type testing device is based on the inverse piezoelectric effect, which generates mechanical vibration by applying an alternating electric field to the piezoelectric material, and then drives the blade to generate the vibration working condition required for fatigue testing.

[0003] However, due to the unique frequency selectivity of piezoelectric materials, the vibration response is closely related to the external excitation frequency. Only when the excitation frequency is close to the natural frequency of the piezoelectric vibrator, can high-efficiency vibration output be generated. This characteristic limits the working frequency bandwidth of the device. Due to differences in structural size and material properties, the required fatigue test frequency range of aero-engine blades usually covers tens of hertz to tens of thousands of hertz, but existing piezoelectric vibrator type testing devices can only provide effective excitation in a relatively narrow frequency range, which cannot meet the diversified testing requirements of different types of blades. At the same time, at non-resonant frequencies, the output acceleration of the device is significantly reduced, making it difficult to simulate the high-cycle fatigue stress environment of the blade under actual working conditions, which seriously affects the accuracy and reliability of the test results. Therefore, in order to improve the above problems, the testing device can be set to have an adjustable natural frequency, but the existing adjustment method has a narrow adjustment coverage, which cannot meet the frequency requirements in blade testing. SUMMARY

[0004] The present application aims to provide a piezoelectric vibrator type testing device that can improve the technical problem of the narrow adjustment coverage of the natural frequency of the testing device in the prior art, which cannot meet the frequency requirements in blade testing.

[0005] The present application also aims to provide a fatigue test method, which can improve the technical problem that the frequency requirement in blade test is difficult to meet due to the narrow coverage of the inherent frequency adjustment of the test device in the prior art.

[0006] Embodiments of the present application can be implemented in the following ways:

[0007] A piezoelectric vibrator type test device comprises:

[0008] A test base for mounting and fastening a test piece;

[0009] A piezoelectric vibrator for applying a vibration load to the test base to excite the test piece for test; and

[0010] A connecting rod, two ends of which are connected with the test base and the piezoelectric vibrator respectively to realize the connection of the piezoelectric vibrator and the test base; the connecting rod is screwed with the test base to change the distance between the piezoelectric vibrator and the test base by screwing the connecting rod.

[0011] Optionally, the connecting rod has a scale line thereon.

[0012] Optionally, a locking nut is further mounted on the connecting rod, which is used to fasten the connection of the connecting rod and the test base.

[0013] Optionally, the piezoelectric vibrator type test device further comprises a frequency adjustment sleeve, which is detachably sleeved on the connecting rod to change the inherent frequency of the device by replacing different models of the frequency adjustment sleeve.

[0014] Optionally, the frequency adjustment sleeve is threadedly connected with the connecting rod.

[0015] Optionally, the test base has a connecting hole for connecting with the connecting rod, the number of the connecting holes is multiple, and the radial sizes of the multiple connecting holes are different to adapt to the connection of connecting rods with different radial sizes.

[0016] Optionally, the piezoelectric vibrator type test device further comprises a fastening bolt, which is fixedly connected through the piezoelectric vibrator and the connecting rod to fasten the piezoelectric vibrator on the connecting rod.

[0017] Optionally, one end of the connecting rod is provided with a limiting protrusion, and a bolt connecting hole is further arranged on the limiting protrusion, the limiting protrusion is used for abutting against the piezoelectric vibrator, and the fastening bolt is used for being screwed with the bolt connecting hole after penetrating through the piezoelectric vibrator, so as to clamp and fix the piezoelectric vibrator between the limiting protrusion and the bolt head of the fastening bolt.

[0018] Optionally, the test base has opposite first and second side surfaces and an upper end surface between the first and second side surfaces; the upper end surface is provided with a mounting groove for mounting the to-be-tested piece; the first side surface is provided with a pressing hole in communication with the mounting groove; and the second side surface is provided with a connecting rod mounting portion;

[0019] The piezoelectric vibrator type test device further comprises a pressing bolt installed at the pressing hole and used for penetrating into the mounting groove to press the to-be-tested piece in the mounting groove.

[0020] A fatigue test method is realized based on the piezoelectric vibrator type test device, and the fatigue test method comprises the following steps.

[0021] A first natural frequency is obtained, wherein the first natural frequency is the natural frequency of the to-be-tested piece;

[0022] A second natural frequency is obtained, wherein the second natural frequency is the natural frequency of the piezoelectric vibrator type test device;

[0023] The first natural frequency and the second natural frequency are compared, and if the deviation between the first natural frequency and the second natural frequency is less than or equal to a threshold value, the piezoelectric vibrator type test device is used to vibrate and excite the to-be-tested piece.

[0024] If the deviation between the first natural frequency and the second natural frequency is greater than the threshold value, the length of the connecting rod screwed into the test base is adjusted to change the distance between the piezoelectric vibrator and the test base, and the natural frequency of the adjusted piezoelectric vibrator type test device is obtained until the deviation from the first natural frequency is less than or equal to the threshold value.

[0025] The piezoelectric vibrator type test device and the fatigue test method have the following beneficial effects.

[0026] The piezoelectric vibrator type test device provided by the embodiment of the present application connects the test base and the piezoelectric vibrator through the connecting rod, and sets the connection between the connecting rod and the test base as a threaded connection, so that the distance between the piezoelectric vibrator and the test base can be changed by screwing the connecting rod, and the adjustment of the device inherent frequency is realized, so that the vibration frequency requirement of different test pieces can be met by changing the device inherent frequency without changing the piezoelectric vibrator inherent frequency, thereby helping to ensure the accuracy and reliability of the test results, and the threaded connection is used to realize the frequency adjustment, which helps to realize the continuous change and quantization of the frequency adjustment, and the frequency coverage is wider, so that the frequency adjustment can be realized more accurately and conveniently according to the frequency requirement of the test piece.

[0027] The embodiment of the present application also provides a fatigue test method, which is realized based on the piezoelectric vibrator type test device, and the inherent frequency of the piezoelectric vibrator type test device can be adjusted according to the inherent frequency of the test piece during the test, so that the inherent frequency of the piezoelectric vibrator type test device can be matched with the inherent frequency of the test piece, thereby helping to ensure the accuracy and reliability of the test results, and the coverage of the inherent frequency adjustment is wider, so that the frequency adjustment can be realized more accurately and conveniently according to the frequency requirement of the test piece. BRIEF DESCRIPTION OF DRAWINGS

[0028] The above features and advantages of the present application can be better understood by reading the detailed description of embodiments of the present application in conjunction with the following drawings, in which: the components are not necessarily drawn to scale, and the components having similar related properties or features can have the same or similar reference numerals.

[0029] Figure 1 A structural schematic diagram of a piezoelectric vibrator type test device provided according to an aspect of the present application;

[0030] Figure 2 A structural schematic diagram of a piezoelectric vibrator type test device provided according to an aspect of the present application from another perspective;

[0031] Figure 3 A connection structure schematic diagram of a connecting rod and a piezoelectric vibrator in a piezoelectric vibrator type test device provided according to an aspect of the present application.

[0032] Reference signs:

[0033] 100-piezoelectric vibrator type test device; 110-test base; 111-first side; 112-second side; 113-upper end face; 115-mounting groove; 116-pressing bolt; 120-connecting rod; 121-scale line; 122-locking nut; 123-frequency modulation sleeve; 124-limiting protrusion; 130-piezoelectric vibrator; 140-fastening bolt;

[0034] 200-pieces to be tested. DETAILED DESCRIPTION

[0035] The present application will be described in detail below in conjunction with the accompanying drawings and specific embodiments. Note that the aspects described below in conjunction with the accompanying drawings and specific embodiments are merely exemplary and should not be understood as limiting the scope of protection of the present application in any way.

[0036] In the description of the present application, it should be noted that if the terms "upper", "lower", "inner", "outer", "vertical" and the like indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the present application is usually placed, and do not indicate or imply that the device or element referred to must have a particular orientation or be constructed and operated in a particular orientation, and therefore should not be understood as limiting the present application.

[0037] At the same time, it should be noted that if the terms "first", "second" and the like appear, they are only used for differentiation and description, and should not be understood as indicating or implying relative importance.

[0038] In the description of the present application, it should also be noted that unless otherwise explicitly specified or limited, the terms "mounting", "connecting", "connecting" should be understood broadly, for example, it can be fixedly connected, integrally connected, or detachably connected; it can be mechanically connected, or electrically connected; it can be directly connected, or indirectly connected through an intermediate medium, or the communication between two elements, etc. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0039] Figure 1 A structural schematic diagram of the piezoelectric vibrator type test device 100 provided for the present embodiment is shown in the figure, Figure 2 A structural schematic diagram of the piezoelectric vibrator type test device 100 provided for the present embodiment is shown in the figure, Figure 3 A structural schematic diagram of the connection between the connecting rod 120 and the piezoelectric vibrator 130 in the piezoelectric vibrator type test device 100 provided for the present embodiment is shown in the figure. Please refer to Figures 1-3The embodiment provides a piezoelectric vibrator type test device 100, which comprises a test base 110, a piezoelectric vibrator 130 and a connecting rod 120. The test base 110 is used for mounting and fastening a test piece 200. The two ends of the connecting rod 120 are connected with the test base 110 and the piezoelectric vibrator 130 respectively, so that the piezoelectric vibrator 130 and the test base 110 are connected through the connecting rod 120. The piezoelectric vibrator 130 is used for applying a vibration load to the test base 110, so as to excite the test piece 200 on the test base 110 to perform a test. Meanwhile, the connecting rod 120 is screwed with the test base 110, so that the length of the connecting rod 120 screwed into the test base 110 can be changed by screwing the connecting rod 120, and then the distance between the piezoelectric vibrator 130 and the test base 110 is changed, the adjustment of the natural frequency of the whole piezoelectric vibrator type test device 100 is realized, so as to meet the test requirements of various frequencies, avoid the problems of weak vibration response and low energy conversion efficiency caused by the mismatch between the required test frequency and the natural frequency of the device, and then help to improve the accuracy and reliability of the test results.

[0040] It should be noted that, in the embodiment, the test piece 200 is a blade of an aero-engine, and it can be understood that, in some other embodiments, tests of other parts can be performed according to requirements.

[0041] The piezoelectric vibrator type test device 100 provided by the embodiment will be further described below:

[0042] Please continue to refer to Figures 1-3 In the embodiment, the test base 110 is roughly in the shape of a cuboid, which has a first side surface 111 and a second side surface 112 opposite to each other, and an upper end surface 113 between the first side surface 111 and the second side surface 112. The test piece 200 is mounted at the upper end surface 113, and the second side surface 112 is used for mounting the connecting rod 120.

[0043] Specifically, a connecting hole is formed in the second side surface 112, and an internal thread is arranged in the connecting hole. An external thread is arranged on the connecting rod 120, the connecting rod 120 is connected with the test base 110 through cooperation of the internal thread and the external thread, and the distance between the connecting rod 120 and the piezoelectric vibrator 130 is adjusted by rotating the connecting rod 120 to screw the connecting rod 120 in or out, so as to realize the adjustment of the natural frequency of the device. Moreover, since the connecting rod 120 is connected with the test base 110 through the thread, the length of the connecting rod 120 screwed in or out can be more accurately and continuously adjusted, so as to help to more accurately realize the adjustment of the natural frequency and the matching with the test piece 200.

[0044] Further, the connecting rod 120 is further provided with a scale line 121, through which the distance between the piezoelectric vibrator 130 and the test base 110 can be identified, so as to facilitate the quantization of the frequency adjustment and provide a quantitative reference basis for subsequent frequency adjustment operation. Specifically, the scale line 121 is a straight line scale line 121, which is arranged along the length direction of the connecting rod 120. Through the straight line scale line 121, the length of the connecting rod 120 extending into the connecting hole can be directly obtained, and thus the distance between the piezoelectric vibrator 130 and the test base 110 can be obtained.

[0045] Further, in the embodiment, since the length adjustment of the connecting rod 120 extending into the connecting hole is achieved by rotation, in order to more accurately obtain the distance between the piezoelectric vibrator 130 and the test base 110, an angle scale can also be arranged on the test base 110, so as to obtain the angle of rotation of the connecting rod 120 relative to the test base 110, and a more accurate distance value can be obtained in combination with the thread pitch. Specifically, the angle scale can be arranged around the connecting hole, and an initial mark can be arranged on the connecting rod 120.

[0046] Further, in the embodiment, the number of connecting holes is one. It can be understood that in some other embodiments, the number of connecting holes on the test base 110 can be set to be multiple, and the radial dimensions of the multiple connecting holes are different. In this way, the connection of the connecting rods 120 with different radial dimensions can be matched. Correspondingly, the piezoelectric vibrator type test device 100 can be provided with multiple connecting rods 120 with different radial dimensions. When performing a test, a connecting rod 120 with a corresponding size can be selected according to the natural frequency requirement to realize the connection between the piezoelectric vibrator 130 and the test base 110.

[0047] Further, the piezoelectric vibrator type test device 100 further comprises a locking nut 122 mounted on the connecting rod 120, which is used to fasten the connection between the connecting rod 120 and the test base 110. The locking nut 122 is threadedly engaged with the connecting rod 120 to generate a pre-tightening force, so that the test base 110 and the connecting rod 120 are fastened and connected as a whole, thereby avoiding the problem that the vibration transmission during the test causes the connecting rod 120 to move relative to the test base 110, resulting in changes in the natural frequency and thus affecting the accuracy of the test results.

[0048] Optionally, the upper end surface 113 is provided with a mounting groove 115 for mounting the test piece 200, and when the test is performed, the test piece 200 can be inserted into the mounting groove 115. Further, the first side surface 111 is also provided with a pressing hole in communication with the mounting groove 115, and the piezoelectric vibrator test device 100 further comprises a pressing bolt 116 mounted at the pressing hole and used to extend into the mounting groove 115 to press the test piece 200 in the mounting groove 115, so as to ensure the stable mounting of the test piece 200 on the test base 110 and avoid the problem of loosening during the fatigue test, which affects the test accuracy.

[0049] Please continue to refer to Figures 1-3 In the embodiment, the piezoelectric vibrator test device 100 further comprises a frequency adjustment sleeve 123 which is detachably sleeved on the connecting rod 120, so as to change the local stiffness of the connecting rod 120 without changing the radial size of the connecting rod 120, and then adjust the natural frequency of the entire experimental device, further improve the frequency adjustment range of the device. Moreover, the natural frequency of the device can be further changed by replacing the frequency adjustment sleeve 123 with different radial sizes to meet more diversified frequency adjustment requirements and realize accurate control of test parameters.

[0050] Further, the frequency adjustment sleeve 123 is threadedly connected with the connecting rod 120, so as to fixedly connect the frequency adjustment sleeve 123 on the connecting rod 120 and facilitate the disassembly and replacement of the frequency adjustment sleeve 123. It can be understood that in other embodiments, other ways can be used to connect the frequency adjustment sleeve 123 with the connecting rod 120, such as connecting the frequency adjustment sleeve 123 with the connecting rod 120 through a fixed pin.

[0051] Please continue to refer to Figures 1-3 In the embodiment, the piezoelectric vibrator 130 adopts piezoelectric ceramic which can generate deformation under the change of driving voltage based on the piezoelectric inverse effect, so as to convert electrical energy into kinetic energy. The deformation frequency is the same as the driving voltage frequency, and then vibration load under a certain frequency is generated to excite the test base 110 and the test piece 200 mounted on the test base 110.

[0052] Further, the piezoelectric vibrator test device 100 further comprises a fastening bolt 140 which is fixedly connected with the connecting rod 120 through the piezoelectric vibrator 130, so as to fasten the piezoelectric vibrator 130 on the connecting rod 120. In this way, the vibration load generated by the piezoelectric vibrator 130 can be transmitted to the test base 110 through the connecting rod 120 to excite the test piece 200.

[0053] Further, one end of the connecting rod 120 is provided with a limiting protrusion 124, and a bolt connecting hole (not shown in the figure) is further arranged on the limiting protrusion 124. The limiting protrusion 124 is used for abutting against one side of the piezoelectric vibrator 130. When the piezoelectric vibrator 130 is installed, the fastening bolt 140 is used for screwing with the bolt connecting hole on the limiting protrusion 124 after the piezoelectric vibrator 130 passes through the piezoelectric vibrator 130, so that the piezoelectric vibrator 130 is clamped and fixed between the limiting protrusion 124 and the bolt head of the fastening bolt 140.

[0054] It should be noted that the connection structure of the connecting rod 120 and the piezoelectric vibrator 130 is not limited here. It can be understood that in some other embodiments, the connection structure of the connecting rod 120 and the piezoelectric vibrator 130 can be specifically set according to the needs, and even the connecting rod 120 can be set as an integrated structure with the piezoelectric vibrator 130.

[0055] The embodiment of the application also provides a fatigue test method, which is based on the piezoelectric vibrator type test device 100 described above.

[0056] Specifically, the fatigue test method comprises the following steps:

[0057] S01: obtaining a first natural frequency.

[0058] The natural frequency of the test piece 200 is obtained, and the natural frequency is taken as the first natural frequency.

[0059] S02: obtaining a second natural frequency.

[0060] Specifically, the second natural frequency is the natural frequency of the device. The step of obtaining the second natural frequency comprises:

[0061] The piezoelectric vibrator 130 is provided with a driving voltage by the vibration table power amplifier, and the natural frequency of the device, i.e. the second natural frequency, is measured by the corresponding vibration measuring equipment, and is recorded.

[0062] S03: comparing the first natural frequency and the second natural frequency.

[0063] The first natural frequency and the second natural frequency are compared and analyzed, and the frequency deviation between the two is evaluated. If the deviation between the first natural frequency and the second natural frequency is less than or equal to a threshold value, the piezoelectric vibrator type test device 100 in this state can be used to vibrate and excite the test piece 200.

[0064] If the deviation between the first natural frequency and the second natural frequency is greater than the threshold value, the device needs to be adjusted, so as to change the value of the second natural frequency, until the deviation between the second natural frequency and the first natural frequency is less than or equal to the threshold value.

[0065] Specifically, the specific value of the threshold value can be set according to the requirements, so that the frequency requirements of the test piece 200 can be met when the deviation of the second natural frequency from the first natural frequency is less than or equal to the threshold value, and at this time the second natural frequency and the first natural frequency meet the matching requirements. For example, the threshold value can be set to 0, that is, only when the first natural frequency is equal to the second natural frequency, the deviation of the second natural frequency from the first natural frequency is less than or equal to the threshold value, or the threshold value can also be set to a value with a small deviation from 0, so that when the second natural frequency is substantially equal to the first natural frequency, the requirement that the deviation of the second natural frequency from the first natural frequency is less than or equal to the threshold value can be met.

[0066] Further, the step of adjusting the device to change the second natural frequency value can include:

[0067] By adjusting the length of the connecting rod 120 screwed into the test base 110, the distance between the piezoelectric vibrator 130 and the test base 110 is adjusted, and then the second natural frequency is adjusted. After adjustment, the device needs to be fastened and installed, and then step S02 is executed again to obtain the natural frequency of the adjusted device until the matching requirement is met. At the same time, the scale value can be read during adjustment to provide a reference for subsequent frequency adjustment.

[0068] Further, the step of adjusting the device to change the second natural frequency value can also include:

[0069] When the frequency adjustment is limited by only adjusting the length of the connecting rod 120 screwed into the connecting hole of the test base 110, and cannot further meet the frequency requirements of the test piece 200, a sleeve can be screwed onto the connecting rod 120 to increase the stiffness of the connecting rod 120, thereby increasing the adjustment range of the device frequency.

[0070] After the second natural frequency is adjusted to match the first natural frequency, the piezoelectric vibrator 130 can be used to apply a vibration load, thereby performing a fatigue test on the test piece 200. At this time, a certain installation torque can be applied to the compression bolt 116, so that the test piece 200 is installed and fixed on the test base 110 by the compression bolt 116, and the piezoelectric vibrator 130 is connected to the test base 110 by the connecting rod 120, and the connection should be firm and not loose.

[0071] The piezoelectric vibrator type test device 100 and the fatigue test method provided by the embodiment of the application realize dynamic adjustment of the rigidity of the device by adjusting the length of the connecting rod 120 between the piezoelectric vibrator 130 and the test base 110, thereby realizing continuous change of the natural frequency, and in combination with the adjusting mode of the diameter of the connecting rod 120 and the frequency adjustment sleeve 123 arranged thereon, the natural frequency of the device can cover a wide frequency range from tens of hertz to tens of thousands of hertz, and the device is suitable for high-cycle fatigue test of aero-engine blades of different structures, materials and sizes, and the applicability and universality of the device are significantly improved. The frequency adjustment sleeve 123 is applicable to further realize fine adjustment of the frequency by increasing the local rigidity without replacing the connecting rod 120. Moreover, the connecting rod 120 is provided with a length scale, and there is a clear corresponding relationship between the length of the connecting rod 120 between the piezoelectric vibrator 130 and the test base 110 and the rigidity of the device, and the length value can be intuitively set and obtained through the scale mark, so that the frequency of the device can be more accurately controlled, the flexibility and repeatability of the device are improved, and strong support is provided for standardization and parameterization in the test process.

[0072] The above merely illustrates the specific embodiments of the application, but the protection scope of the application is not limited thereto, and any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the application, which should be covered within the protection scope of the application.

Claims

1. A piezoelectric oscillator-type testing device, characterized in that, The piezoelectric vibrator type test device comprises: a test base for mounting a fastened test piece; a piezoelectric vibrator for applying a vibration load to the test base to excite the test piece for testing; and a connecting rod, the two ends of which are connected with the test base and the piezoelectric vibrator respectively to realize the connection of the piezoelectric vibrator and the test base; the connecting rod is screwed with the test base to change the distance between the piezoelectric vibrator and the test base by screwing the connecting rod; The piezoelectric vibrator type test device further comprises a frequency adjusting sleeve, which is detachably sleeved on the connecting rod to change the natural frequency of the device by replacing different models of the frequency adjusting sleeve; The piezoelectric vibrator type test device further comprises a fastening bolt, which is fixedly connected through the piezoelectric vibrator and the connecting rod, so as to fasten the piezoelectric vibrator on the connecting rod.

2. The piezoelectric vibrator type test device according to claim 1, wherein the connecting rod has a scale line.

3. The piezoelectric vibrator type test device according to claim 1, wherein the connecting rod is further provided with a locking nut for fastening the connection of the connecting rod and the test base.

4. The piezoelectric vibrator type test device according to claim 1, wherein the frequency adjusting sleeve is threadedly connected with the connecting rod.

5. The piezoelectric vibrator type test device according to claim 1, wherein the test base is provided with a connecting hole for connecting with the connecting rod, the number of the connecting hole is multiple, and the radial sizes of the multiple connecting holes are different to adapt to the connection of connecting rods with different radial sizes.

6. The piezoelectric vibrator type test device according to claim 1, wherein one end of the connecting rod is provided with a limiting protrusion, the limiting protrusion is further provided with a bolt connecting hole, the limiting protrusion is used for abutting against the piezoelectric vibrator, and the fastening bolt is used for being screwed with the bolt connecting hole after passing through the piezoelectric vibrator to clamp and fix the piezoelectric vibrator between the limiting protrusion and the bolt head of the fastening bolt.

7. The piezoelectric vibrator type test device according to claim 1, wherein the test base has opposite first and second side surfaces and an upper end surface between the first and second side surfaces; the upper end surface is provided with a mounting groove for mounting the test piece; the first side surface is provided with a pressing hole in communication with the mounting groove; and the second side surface is provided with a connecting hole for mounting the connecting rod. The piezoelectric vibrator type test device further comprises a pressing bolt mounted at the pressing hole and used for extending into the mounting groove to press the test piece in the mounting groove. The fatigue test method is realized based on the piezoelectric vibrator type test device according to any one of claims 1-7, and comprises: obtaining a first natural frequency; wherein the first natural frequency is the natural frequency of the test piece; ​ ​ ​ ​ 8. A fatigue test method characterized by, ​ ​ acquiring a second natural frequency; wherein the second natural frequency is a natural frequency of the piezoelectric vibrator type test device; comparing the first natural frequency and the second natural frequency; if a deviation between the first natural frequency and the second natural frequency is less than or equal to a threshold value, then using the piezoelectric vibrator type test device to perform vibration excitation on the test piece; if the deviation between the first natural frequency and the second natural frequency is greater than the threshold value, then adjusting a length of the connecting rod screwed into the test base to change a distance between the piezoelectric vibrator and the test base; and acquiring a natural frequency of the piezoelectric vibrator type test device after adjustment, until the deviation from the first natural frequency is less than or equal to the threshold value.

Images