Piezoelectric vibrator type test device and fatigue test method

Abstract

The invention provides a piezoelectric vibrator type test device and a fatigue test method, and relates to the technical field of aero-engine tests. 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 connecting rod is in threaded connection with the test base, so that the distance between the piezoelectric vibrator and the test base can be changed by screwing the connecting rod, and the inherent frequency of the device can be adjusted. In this way, the vibration frequency requirements of different tested pieces are met by changing the inherent frequency of the device under the condition that the inherent frequency of the piezoelectric vibrator is not changed, the accuracy and reliability of the test result are guaranteed, frequency adjustment is achieved in a threaded connection mode, continuous change and adjustment quantification of frequency adjustment are achieved, and the test efficiency is improved. And the frequency coverage is wider, so that the frequency adjustment can be more accurately and conveniently realized according to the frequency requirement of the tested piece.

Description

Technical Field

[0001] This invention relates to the field of aero-engine testing technology, and more specifically, to a piezoelectric oscillator testing device and a fatigue testing method. Background Technology

[0002] In the aerospace field, aero-engines, as the core components of aircraft, directly determine the safety and economy of the aircraft through their performance and reliability. Fatigue failure is a common type of failure in aero-engine components. For example, in aero-engines, blades, as critical power-generating components, are subjected to alternating stresses, thermal loads, and other effects under high-speed rotation and complex airflow environments, making them highly susceptible to fatigue failure. Moreover, statistics show that fatigue failures of aero-engine blades account for more than 30% of overall engine failures. Therefore, conducting precise and efficient fatigue tests on blades has become a crucial link in ensuring the safe and stable operation of engines. Traditional fatigue testing methods, such as electromagnetic resonance and hydraulic excitation methods, suffer from problems such as large equipment size, high energy consumption, and slow response speed, making it difficult to meet the high-frequency, high-precision testing requirements of aero-engine blades. With the development of materials science and microelectromechanical systems (MEMS) technology, piezoelectric oscillator testing devices, with their advantages of fast response speed, high energy conversion efficiency, and compact structure, are gradually emerging in engine blade fatigue testing. The piezoelectric oscillator test device is based on the inverse piezoelectric effect. It uses an alternating electric field to induce mechanical vibration in the piezoelectric material, thereby causing the blade to produce the vibration conditions required for fatigue testing.

[0003] However, due to the unique frequency selectivity of piezoelectric materials, their vibration response is closely related to the external excitation frequency. Only when the excitation frequency is close to the natural frequency of the piezoelectric oscillator can efficient vibration output be generated. This characteristic severely limits the operating frequency bandwidth of the device. Due to differences in structural dimensions and material properties, the fatigue testing frequency range required for aero-engine blades typically covers tens of hertz to tens of thousands of hertz. However, existing piezoelectric oscillator-based testing devices often only provide effective excitation within a narrow frequency range, failing to meet the diverse testing needs of different blade models. Furthermore, at non-resonant frequencies, the output acceleration of the device decreases significantly, making it difficult to simulate the high-cycle fatigue stress environment of blades under actual operating conditions, severely affecting the accuracy and reliability of the test results. Therefore, to improve these issues, the testing device can be configured with an adjustable natural frequency structure. However, existing adjustment methods have a narrow adjustment range, making it difficult to meet the frequency requirements in blade testing. Summary of the Invention

[0004] The purpose of this invention is to provide a piezoelectric oscillator-type testing device, which can improve the technical problem that the inherent frequency adjustment coverage of the existing testing device is narrow and it is difficult to meet the frequency requirements in blade testing.

[0005] The present invention also aims to provide a fatigue testing method that can improve the technical problem in the prior art where the frequency requirements in blade testing are difficult to meet due to the narrow inherent frequency adjustment coverage of the testing device.

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

[0007] A piezoelectric oscillator testing device, the piezoelectric oscillator testing device comprising:

[0008] A test base, used for mounting and securing the test piece;

[0009] A piezoelectric vibrator, used to apply a vibrational load to the test base to excite the test specimen to undergo testing; and

[0010] A connecting rod is provided, with its two ends connected to the test base and the piezoelectric vibrator, respectively, to connect the piezoelectric vibrator to the test base; the connecting rod is screwed to the test base so that the distance between the piezoelectric vibrator and the test base can be changed by screwing the connecting rod.

[0011] Optionally, the connecting rod has scale lines.

[0012] Optionally, a locking nut is also installed on the connecting rod, which is used to secure the connection between the connecting rod and the test base.

[0013] Optionally, the piezoelectric vibrator testing device further includes a frequency tuning sleeve, which is detachably fitted onto the connecting rod to change the device's natural frequency by replacing different models of the frequency tuning sleeve.

[0014] Optionally, the frequency tuning sleeve is threadedly connected to the connecting rod.

[0015] Optionally, the test base has multiple connection holes for connecting to the connecting rod, and the multiple connection holes have different radial dimensions to accommodate the connection of connecting rods with different radial dimensions.

[0016] Optionally, the piezoelectric vibrator testing device further includes a fastening bolt, which passes through the piezoelectric vibrator and is fixedly connected to the connecting rod, thereby fastening the piezoelectric vibrator to the connecting rod.

[0017] Optionally, one end of the connecting rod has a limiting protrusion, and the limiting protrusion is also provided with a bolt connection hole. The limiting protrusion is used to abut against the piezoelectric vibrator, and the fastening bolt is used to screw into the bolt connection hole after passing 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 a first side and a second side opposite to each other, and an upper end face located between the first side and the second side; the upper end face has a mounting groove for mounting the test piece; the first side has a clamping hole communicating with the mounting groove; the second side is used to mount the connecting rod;

[0019] The piezoelectric vibrator testing device also includes a clamping bolt, which is installed at the clamping hole and is used to extend into the mounting groove to clamp the test piece into the mounting groove.

[0020] A fatigue testing method, implemented based on the aforementioned piezoelectric oscillator testing device; the fatigue testing method includes:

[0021] Obtain the first natural frequency; wherein, the first natural frequency is the natural frequency of the test piece;

[0022] Obtain the second natural frequency; wherein the second natural frequency is the natural frequency of the piezoelectric oscillator test device;

[0023] Compare the first natural frequency and the second natural frequency; if the deviation between the first natural frequency and the second natural frequency is less than or equal to a threshold, then use the piezoelectric oscillator test device to vibrate the test piece.

[0024] If the deviation between the first natural frequency and the second natural frequency is greater than a threshold, 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 test device is obtained until the deviation from the first natural frequency is less than or equal to the threshold.

[0025] The beneficial effects of the piezoelectric oscillator testing device and fatigue testing method provided by the embodiments of the present invention include:

[0026] Embodiments of the present invention provide a piezoelectric vibrator testing device, which connects a test base and a piezoelectric vibrator via a connecting rod. The connection between the connecting rod and the test base is configured as a threaded connection, thereby allowing the distance between the piezoelectric vibrator and the test base to be changed by rotating the connecting rod, thus adjusting the natural frequency of the device. In this way, the vibration frequency requirements of different test pieces can be met by changing the natural frequency of the device without changing the natural frequency of the piezoelectric vibrator, thereby helping to ensure the accuracy and reliability of the test results. Moreover, the use of a threaded connection for frequency adjustment facilitates continuous change and quantification of frequency adjustment, resulting in a wider frequency coverage. This allows for more precise and convenient frequency adjustment according to the frequency requirements of the test piece.

[0027] The embodiments of the present invention also provide a fatigue testing method based on the above-mentioned piezoelectric vibrator testing device. During the test, the natural frequency of the piezoelectric vibrator testing device can be adjusted according to the natural frequency of the test piece, so that the natural frequency of the piezoelectric vibrator testing device can match the natural frequency of the test piece. This helps to ensure the accuracy and reliability of the test results, and the natural frequency adjustment has a wider coverage, thus enabling more precise and convenient frequency adjustment according to the frequency requirements of the test piece. Attached Figure Description

[0028] The above-described features and advantages of the present invention will be better understood after reading the following detailed description of embodiments of the present disclosure in conjunction with the accompanying drawings. In the drawings, components are not necessarily drawn to scale, and components having similar related characteristics or features may have the same or similar reference numerals.

[0029] Figure 1 A schematic diagram of the structure of a piezoelectric oscillator testing device according to one aspect of the present invention;

[0030] Figure 2 A schematic diagram of the piezoelectric oscillator testing device provided according to one aspect of the present invention from another perspective;

[0031] Figure 3 A schematic diagram of the connection structure between the connecting rod and the piezoelectric vibrator in a piezoelectric vibrator testing device provided according to one aspect of the present invention.

[0032] Figure label:

[0033] 100-Piezoelectric vibrator test device; 110-Test base; 111-First side; 112-Second side; 113-Upper end face; 115-Mounting groove; 116-Clamping bolt; 120-Connecting rod; 121-Scale line; 122-Locking nut; 123-Frequency tuning sleeve; 124-Limiting protrusion; 130-Piezoelectric vibrator; 140-Fastening bolt;

[0034] 200 - Test piece. Detailed Implementation

[0035] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. It should be noted that the aspects described below with reference to the accompanying drawings and specific embodiments are merely exemplary and should not be construed as limiting the scope of protection of the present invention in any way.

[0036] In the description of this invention, it should be noted that if terms such as "upper," "lower," "inner," "outer," or "vertical" appear, the orientation or positional relationship indicated is based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of this invention is usually placed when in use, and does not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0037] At the same time, it should be noted that the terms "first" and "second" are used only for distinguishing descriptions and should not be interpreted as indicating or implying relative importance.

[0038] In the description of this invention, it should also be noted that, unless otherwise explicitly specified or limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, an integral connection, or a detachable connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium, or a connection within two components, etc. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0039] Figure 1 This is a schematic diagram of the piezoelectric oscillator testing device 100 provided in this embodiment. Figure 2 This is a schematic diagram of the piezoelectric oscillator testing device 100 provided in this embodiment from another perspective. Figure 3 This is a schematic diagram of the connection structure between the connecting rod 120 and the piezoelectric vibrator 130 in the piezoelectric vibrator testing device 100 provided in this embodiment. Please refer to the attached diagram. Figures 1-3This embodiment provides a piezoelectric vibrator testing device 100, which includes a test base 110, a piezoelectric vibrator 130, and a connecting rod 120. The test base 110 is used to mount and secure the test piece 200. The two ends of the connecting rod 120 are connected to the test base 110 and the piezoelectric vibrator 130, respectively, thus connecting the piezoelectric vibrator 130 to the test base 110. The piezoelectric vibrator 130 is used to apply a vibration load to the test base 110, thereby exciting the test piece 200 on the test base 110 to perform the test. Meanwhile, the connecting rod 120 is screwed to the test base 110. By screwing the connecting rod 120, the length of the connecting rod 120 screwed into the test base 110 can be changed, thereby changing the distance between the piezoelectric vibrator 130 and the test base 110. This allows for the adjustment of the natural frequency of the piezoelectric vibrator test device 100 as a whole, thus meeting the test requirements of multiple frequencies. This avoids problems such as weak vibration response and low energy conversion efficiency caused by the mismatch between the test frequency and the device's natural frequency, thereby helping to improve the accuracy and reliability of the test results.

[0040] It should be noted that in this embodiment, the test piece 200 is an aero-engine blade. It is understood that in other embodiments, other components may also be tested as needed.

[0041] The piezoelectric oscillator testing device 100 provided in this embodiment will be further described below:

[0042] Please continue to refer to the reference. Figures 1-3 In this embodiment, the test base 110 is generally cuboid in shape, having opposing first side surfaces 111 and second side surfaces 112, and an upper end surface 113 located between the first side surfaces 111 and the second side surfaces 112. The test piece 200 is mounted on the upper end surface 113, and the connecting rod 120 is mounted on the second side surface 112.

[0043] Specifically, a connecting hole with an internal thread is provided at the second side 112, and an external thread is provided on the connecting rod 120. The connecting rod 120 is connected to the test base 110 through the cooperation of the internal and external threads. At the same time, by rotating the connecting rod 120, the distance between the connecting rod 120 and the piezoelectric vibrator 130 can be adjusted by screwing the connecting rod 120 in or out, thereby realizing the natural frequency adjustment of the device. Moreover, since the connecting rod 120 is connected to the test base 110 by threads, the length of the connecting rod 120 screwed in or out can be adjusted more precisely and continuously, which helps to more accurately achieve the adjustment of the natural frequency and the matching with the test piece 200.

[0044] Furthermore, the connecting rod 120 is also provided with a scale line 121, which can be used to mark the distance between the piezoelectric vibrator 130 and the test base 110, thereby facilitating the quantification of frequency adjustment and providing a quantitative reference for subsequent frequency adjustment operations. Specifically, the scale line 121 is a straight scale line 121, which is set along the length direction of the connecting rod 120. Through this straight scale line 121, the length of the connecting rod 120 extending into the connecting hole can be intuitively obtained, which helps to determine the distance between the piezoelectric vibrator 130 and the test base 110.

[0045] Furthermore, in this embodiment, since the length adjustment of the connecting rod 120 extending into the connecting hole is achieved through rotation, in order to obtain a more accurate distance between the piezoelectric vibrator 130 and the test base 110, an angle scale can be provided on the test base 110 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 by combining the thread pitch. Specifically, the angle scale can be set around the connecting hole, and an initial mark can be set on the connecting rod 120.

[0046] Furthermore, in this embodiment, the number of connecting holes is one. It is understood that in some other embodiments, the number of connecting holes on the test base 110 can be set to multiple, and the radial dimensions of the multiple connecting holes can be set to different, so as to match the connection of connecting rods 120 with different radial dimensions. Accordingly, the piezoelectric vibrator test device 100 can be set to include multiple connecting rods 120 with different radial dimensions. When conducting the test, the connecting rod 120 of the appropriate size is selected according to the inherent frequency requirement to realize the connection between the piezoelectric vibrator 130 and the test base 110.

[0047] Furthermore, the piezoelectric vibrator testing device 100 also includes a locking nut 122 mounted on the connecting rod 120. The locking nut 122 is used to secure the connection between the connecting rod 120 and the test base 110. The locking nut 122 engages with the connecting rod 120 through a threaded engagement to generate a preload, ensuring that the test base 110 and the connecting rod 120 are securely connected as a whole. This prevents the connecting rod 120 from moving relative to the test base 110 during the test due to vibration transmission, which could lead to changes in the natural frequency and affect the accuracy of the test results.

[0048] Optionally, the upper end face 113 is provided with a mounting groove 115 for mounting the test piece 200. During the test, the test piece 200 can be inserted into the mounting groove 115. Further, the first side face 111 is also provided with a clamping hole communicating with the mounting groove 115. The piezoelectric vibrator type testing device 100 also includes a clamping bolt 116, which is installed at the clamping hole and is used to extend into the mounting groove 115 to clamp the test piece 200 into the mounting groove 115, thereby ensuring the stable installation of the test piece 200 on the test base 110 and avoiding loosening or other problems that may affect the accuracy of the test during fatigue testing.

[0049] Please continue to refer to the reference. Figures 1-3 In this embodiment, the piezoelectric oscillator testing device 100 also includes a frequency tuning sleeve 123, which is detachably fitted onto the connecting rod 120. This allows for adjustment of the natural frequency of the entire testing device by changing the local stiffness of the connecting rod 120 without altering its radial dimensions, thereby further improving the device's frequency tuning range. Furthermore, the natural frequency of the device can be further altered by replacing the frequency tuning sleeve 123 with one of different radial dimensions, meeting more diverse frequency tuning requirements and achieving precise control of the test parameters.

[0050] Furthermore, the frequency modulation sleeve 123 is threadedly connected to the connecting rod 120, thereby fixing the frequency modulation sleeve 123 to the connecting rod 120 and facilitating the disassembly and replacement of the frequency modulation sleeve 123. It is understood that in some other embodiments, other methods can be used to connect the frequency modulation sleeve 123 to the connecting rod 120, such as by inserting a fixing pin.

[0051] Please continue to refer to the reference. Figures 1-3 In this embodiment, the piezoelectric vibrator 130 is made of piezoelectric ceramic, which can deform under the change of driving voltage based on the piezoelectric inverse effect, thereby converting electrical energy into kinetic energy. The deformation frequency is the same as the driving voltage frequency, thereby generating a vibration load at a certain frequency. The test base 110 and the test piece 200 are installed on the test base 110.

[0052] Furthermore, the piezoelectric vibrator testing device 100 also includes a fastening bolt 140, which passes through the piezoelectric vibrator 130 and is fixedly connected to the connecting rod 120, thereby fastening the piezoelectric vibrator 130 to 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 achieve the excitation of the test piece 200.

[0053] Furthermore, one end of the connecting rod 120 has a limiting protrusion 124, and the limiting protrusion 124 is also provided with a bolt connection hole (not shown in the figure). The limiting protrusion 124 is used to abut against one side of the piezoelectric vibrator 130. During installation, the fastening bolt 140 allows the other side of the piezoelectric vibrator 130 to pass through the piezoelectric vibrator 130 and be screwed into the bolt connection hole on the limiting protrusion 124, thereby clamping and fixing the piezoelectric vibrator 130 between the limiting protrusion 124 and the bolt head of the fastening bolt 140.

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

[0055] An embodiment of the present invention also provides a fatigue testing method based on the piezoelectric oscillator testing device 100 described above.

[0056] Specifically, the fatigue testing method includes the following steps:

[0057] S01: Obtain the first natural frequency.

[0058] Obtain the natural frequency of the test piece 200 and use this natural frequency as the first natural frequency.

[0059] S02: Obtain the second natural frequency.

[0060] Specifically, the second natural frequency is the inherent frequency of the device. The steps for obtaining the second natural frequency include:

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

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

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

[0064] If the deviation between the first natural frequency and the second natural frequency is greater than the threshold, the device needs to be adjusted 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.

[0065] Specifically, the threshold value can be set according to requirements, such that the frequency requirement of the test piece 200 is met when the deviation between the second natural frequency and the first natural frequency is less than or equal to the threshold. At this point, the second natural frequency and the first natural frequency meet the matching requirement. For example, the threshold can be set to 0, meaning that the deviation between the second natural frequency and the first natural frequency is less than or equal to the threshold only when the first natural frequency is equal to the second natural frequency. Alternatively, the threshold can be set to a value with a small deviation from 0, so that the requirement that the deviation between the second natural frequency and the first natural frequency is less than or equal to the threshold is met when the second natural frequency is basically equal to the first natural frequency.

[0066] Furthermore, the step of adjusting the device to change the second inherent frequency value may 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 can be adjusted, thereby adjusting the second natural frequency. After adjustment, the device needs to be securely installed, and then step S02 is executed again to obtain the adjusted natural frequency of the device until the matching requirements are met. Simultaneously, the scale value can be read during adjustment to provide a reference for subsequent frequency adjustment.

[0068] Furthermore, the step of adjusting the device to change the second inherent frequency value may also include:

[0069] When frequency adjustment is limited by simply 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 outside of the connecting rod 120 to increase the stiffness of the connecting rod 120, thereby increasing the frequency adjustment range of the device.

[0070] After the second natural frequency is adjusted to match the first natural frequency, a vibration load can be applied through the piezoelectric vibrator 130 to perform a fatigue test on the test piece 200. At this time, a certain installation torque can be applied to the clamping bolt 116 to install and fix the test piece 200 on the test base 110, and the piezoelectric vibrator 130 can be connected to the test base 110 through the connecting rod 120. After connection, it should be ensured that the connection is firm and without looseness.

[0071] The piezoelectric vibrator testing device 100 and fatigue testing method provided in the embodiments of the present invention achieve dynamic adjustment of the device stiffness by adjusting the length of the connecting rod 120 located between the piezoelectric vibrator 130 and the test base 110, thereby realizing continuous change of the natural frequency. Combined with adjustments such as the diameter of the connecting rod 120 and the setting of the frequency tuning sleeve 123 on it, the natural frequency of the device can cover a wide frequency range from tens of hertz to tens of thousands of hertz, making it suitable for high-cycle fatigue testing of aero-engine blades of different structures, materials, and sizes, significantly improving the applicability and versatility of the device. The application of the frequency tuning sleeve 123 allows for further fine-tuning of the frequency by increasing local stiffness without replacing the connecting rod 120. Furthermore, the connecting rod 120 is equipped with a length scale. The length of the connecting rod 120 between the piezoelectric vibrator 130 and the test base 110 has a clear correspondence with the stiffness of the device. The length value can be set and obtained intuitively through the scale markings, thereby enabling more precise control of the device frequency. This not only improves the flexibility and repeatability of the device but also provides strong support for standardization and parameterization in the test process.

[0072] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A piezoelectric oscillator-type testing device, characterized in that, The piezoelectric oscillator testing device includes: A test base, used for mounting and securing the test piece; A piezoelectric vibrator, used to apply a vibrational load to the test base to excite the test specimen to undergo testing; and A connecting rod is provided, with its two ends connected to the test base and the piezoelectric vibrator, respectively, to connect the piezoelectric vibrator to the test base; the connecting rod is screwed to the test base so that the distance between the piezoelectric vibrator and the test base can be changed by screwing the connecting rod.

2. The piezoelectric oscillator testing device according to claim 1, characterized in that, The connecting rod has scale lines.

3. The piezoelectric oscillator testing device according to claim 1, characterized in that, A locking nut is also installed on the connecting rod, which is used to secure the connection between the connecting rod and the test base.

4. The piezoelectric oscillator testing device according to claim 1, characterized in that, The piezoelectric vibrator testing device also includes a frequency tuning sleeve, which is detachably fitted onto the connecting rod to change the device's inherent frequency by replacing different models of the frequency tuning sleeve.

5. The piezoelectric oscillator testing device according to claim 4, characterized in that, The frequency tuning sleeve is threadedly connected to the connecting rod.

6. The piezoelectric oscillator testing device according to claim 1, characterized in that, The test base has multiple connection holes for connecting to the connecting rod, and the multiple connection holes have different radial dimensions to accommodate the connection of connecting rods with different radial dimensions.

7. The piezoelectric oscillator testing device according to claim 1, characterized in that, The piezoelectric vibrator testing device also includes a fastening bolt, which passes through the piezoelectric vibrator and is fixedly connected to the connecting rod, thereby fastening the piezoelectric vibrator to the connecting rod.

8. The piezoelectric oscillator testing device according to claim 7, characterized in that, One end of the connecting rod has a limiting protrusion, and the limiting protrusion is also provided with a bolt connection hole. The limiting protrusion is used to abut against the piezoelectric vibrator, and the fastening bolt is used to screw into the bolt connection hole after passing 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.

9. The piezoelectric oscillator testing device according to claim 1, characterized in that, The test base has a first side and a second side opposite to each other, and an upper end face located between the first side and the second side; the upper end face has a mounting groove for mounting the test piece; the first side has a clamping hole communicating with the mounting groove; the second side is used to mount the connecting rod; The piezoelectric vibrator testing device also includes a clamping bolt, which is installed at the clamping hole and is used to extend into the mounting groove to clamp the test piece into the mounting groove.

10. A fatigue testing method, characterized in that, The fatigue testing method is implemented based on the piezoelectric oscillator-type testing device as described in any one of claims 1-9; the fatigue testing method includes: Obtain the first natural frequency; wherein, the first natural frequency is the natural frequency of the test piece; Obtain the second natural frequency; wherein the second natural frequency is the natural frequency of the piezoelectric oscillator test device; Compare the first natural frequency and the second natural frequency; if the deviation between the first natural frequency and the second natural frequency is less than or equal to a threshold, then use the piezoelectric oscillator test device to vibrate the test piece. If the deviation between the first natural frequency and the second natural frequency is greater than a threshold, 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 test device is obtained until the deviation from the first natural frequency is less than or equal to the threshold.

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