Aero-engine axial load sensor modal test device and method

Abstract

The application provides an aero-engine axial load sensor modal test device and method, relates to the technical field of aero-engines, and can simulate the load that an axial load sensor is subjected to in an engine under the combined action of a loading top seat and a loading bottom seat. The axial load sensor is subjected to an experiment based on this. A sweep exciter is used for frequency sweeping excitation during the experiment. The strain gauge is reasonably distributed by combining a finite element method. The strain response of the sensor under resonance and the corresponding frequency are collected by using the strain gauge. A displacement reconstruction algorithm based on strain data is developed. Therefore, the accurate identification and reconstruction of the vibration mode of the sensor are realized. The multi-angle test of the axial load sensor is realized. The problems of the axial load sensor in the actual use process are comprehensively considered.

Description

Technical Field

[0001] This application relates to the field of aero-engine technology, and in particular to a modal testing device and method for an aero-engine axial load sensor. Background Technology

[0002] The axial load sensor for an aero-engine is installed at the engine's thrust bearing. Since the thrust bearing is the reference point for the aero-engine rotor and a critical component limiting the engine's overhaul life, its reliability is paramount. Excessive axial load and slippage under light load are significant factors causing bearing damage. Because many factors influence axial load, actual measurement is typically the primary method. Furthermore, axial dynamic load provides a direct understanding of the engine's operating status; therefore, real-time monitoring of axial dynamic load is essential to ensuring the engine operates in optimal condition.

[0003] Currently, the most accurate method for testing thrust bearing loads is to use a circular axial load sensor, such as... Figure 1 As shown, this is a method for quasi-static testing placed at the thrust bearing of the engine. However, with the continuous optimization of aero-engine structures, the limited sensor installation space and the design requirements of multi-parameter integrated sensors have led to the gradual expansion of this type of annular axial load sensor to simultaneously possess static and dynamic load testing capabilities. However, there is currently a lack of experimental methods and corresponding devices for studying the inherent vibration characteristics of this type of axial load sensor under its operating environment, including mode shapes and frequencies. Summary of the Invention

[0004] One of the technical problems this application aims to solve is that existing testing environments cannot accurately reflect the working environment of sensors under aircraft engines and obtain the vibration characteristics under this environment as data collection.

[0005] To address the aforementioned technical problems, this application provides a modal testing device for an aero-engine axial load sensor, comprising:

[0006] The loading base has a heat source inside to heat the surface of the loading base, and the surface of the loading base is covered with an oil layer to simulate the oil immersion environment inside an aircraft engine.

[0007] An axial load sensor has a boss at the center of the loading base, and the axial load sensor is located on the surface of the boss. The axial load sensor is circular in shape.

[0008] The loading top seat is connected to the external loading head, and the loading top seat is movable relative to the loading base along the direction of gravity to cooperate with the boss to apply pressure to the axial load sensor.

[0009] The surface of the axial load sensor is provided with a plurality of protrusions, two adjacent protrusions form a test area, and each test area is arranged at intervals in the circumferential direction relative to the axial load sensor. The bottom of the loading top seat is provided with a plurality of pressing strips, and the pressing strips abut against the protrusions in the test area to extrude the axial load sensor.

[0010] A plurality of strain gauges are arranged on the axial load sensor to collect the strain response signal of the axial load sensor.

[0011] A vibration exciter is arranged to apply a vibration excitation force to the axial load sensor.

[0012] In some embodiments, the aforementioned axial load sensor modal test device for an aero-engine, wherein the side wall of the loading base is provided with a through hole, the surface of the through hole is provided with a connecting head, the vibration exciter passes through the through hole and is connected with the connecting head to apply a vibration excitation force to the axial load sensor from the radial direction, and the plurality of strain gauges are arranged on the side wall of the inner circle and the outer circle of the axial load sensor; wherein the positions of the strain gauges arranged on the inner ring correspond to the positions of the strain gauges arranged on the outer ring, and the strain gauges are arranged at positions between any two adjacent test areas.

[0013] In some embodiments, the aforementioned axial load sensor modal test device for an aero-engine, wherein the side wall of the loading base is provided with a through hole, the surface of the through hole is provided with a connecting head, the vibration exciter passes through the through hole and is connected with the connecting head to apply a vibration excitation force to the axial load sensor from the radial direction, and the plurality of strain gauges are arranged on the side wall of the inner circle and the outer circle of the axial load sensor; wherein the positions of the strain gauges arranged on the inner ring correspond to the positions of the strain gauges arranged on the outer ring, and the strain gauges are arranged at positions between any two adjacent test areas.

[0014] In some embodiments, the aforementioned axial load sensor modal test device for an aero-engine, wherein the loading top seat is provided with a plurality of recesses, and the strain gauges are arranged at positions between any two adjacent test areas on the surface of the axial load sensor; wherein the vibration exciter applies a vibration excitation force to the axial load sensor in the axial direction from the recesses.

[0015] The second aspect of the present application provides an axial load sensor modal test method for an aero-engine, which is implemented by using an axial load sensor modal test device for an aero-engine, and includes the following steps.

[0016] S1, determining the position for detecting the axial load sensor, and then connecting the strain gauges with the axial load sensor;

[0017] S2, placing the axial load sensor on the protrusion in the center of the loading base, adding aero lubricating oil to the surface of the loading base to completely cover the axial load sensor, and heating;

[0018] S3, moving the loading top seat towards the axial load sensor by the external loading head to extrude;

[0019] S4, applying a vibration excitation force to the axial load sensor in the axial or radial direction by the vibration exciter, and simultaneously obtaining the frequency of the axial load sensor by the strain gauges.

[0020] S5, calculating the curvature of the test points corresponding to the strain gauge pasting position, calculating the strain of the points other than the test points corresponding to the strain gauge pasting position by quadratic difference, and calculating the curvature by strain, then calculating the curvature function between the two adjacent strain gauge measurement positions, then integrating the curvature function along the arc length to obtain the inflection angle equation, and finally integrating the obtained inflection angle equation to obtain the curve equation, obtaining the coordinates around the curve and fitting, and comparing the fitted curve with the simulation curve.

[0021] In some embodiments, the aforementioned aero-engine axial load sensor modal test method, wherein when the exciter in S4 applies an excitation force to the axial load sensor from the radial direction, and the strain gauges in S1 are located on the inner and outer circles of the axial load sensor, the curvature K of the axial load sensor at this time is:

[0022] ;

[0023] wherein, Rin is the inner radius of the axial load sensor (4), Lini is the initial arc length of the inner circle at the measurement position of the strain gauge (9), Lini' is the arc length after the change of the inner circle at the measurement position of the strain gauge (9), εini is the change strain of the inner circle at the measurement position of the strain gauge (9), Rout is the outer radius of the axial load sensor (4), Louti is the initial arc length of the outer circle at the measurement position of the strain gauge (9), Louti' is the arc length after the change of the outer circle at the measurement position of the strain gauge (9), εouti is the change strain of the outer circle at the measurement position of the strain gauge (9), θi is the central angle after bending deformation at the measurement position of the strain gauge (9), h H is the radial thickness of the axial load sensor (4).

[0024] In some embodiments, the aforementioned aero-engine axial load sensor modal test method, wherein the expression of the curvature function in S5 is:

[0025] ;

[0026] wherein, L is the arc length between any point between the i-th point and the i-1-th point and the i-1-th point, K is the curvature of the point with an arc length of from the i-1-th point, and represent the linear interpolation coefficients of the arc segment between the i-1-th point and the i-th point;

[0027] The expression of the inflection angle equation is:

[0028] ;

[0029] wherein, is the included angle between the tangent of the deflection curve and the x-axis, is the arc length of the infinitesimal segment;

[0030] The expression of the curve equation is:

[0031] ;

[0032] wherein, x ( u ) and y ( u ) represent the x-axis coordinate and the y-axis coordinate of the deflection curve, respectively.

[0033] In some embodiments, the aforementioned aero-engine axial load sensor modal test method, wherein when the exciter in S4 applies an excitation force to the axial load sensor from the axial direction, at this time the strain gauge in S1 is located at a position between any two adjacent test zones, then the curvature K of the axial load sensor at this time is:

[0034] ;

[0035] wherein, is the axial thickness of the axial load sensor (4), L is the length at the measurement of the strain gauge (9), is the central angle of the bending deformation at the measurement of the strain gauge (9), is the end face strain at the measurement of the strain gauge (9).

[0036] In some embodiments, the aforementioned aero-engine axial load sensor modal test method, wherein the expression of the curvature function in S5 is:

[0037] ;

[0038] wherein, s is the length between any point between the i-th point and the i-1-th point and the i-1-th point, is the curvature of the point located at a distance of s from the i-1-th point, and represent the linear interpolation coefficients of the infinitesimal line segment between the i-1-th point and the i-th point;

[0039] The expression of the deflection curve included angle equation is:

[0040] ;

[0041] wherein, Tangent to the deflection curve and xoy Plane angle, The length of the infinitesimal line segment;

[0042] Align the i-th segment with the y-axis of the coordinate system, and then... i The curve integral of the segment is used to calculate the change in the Z-direction at the end of each segment. Value, then check Values ​​rotated by coordinate matrix The transformation yields the true change in the Z-direction at the endpoint of each segment. The value will eventually be The summation of values ​​yields the Z-axis coordinate in the reconstructed mode shape. The magnitude of the value;

[0043] The equation of the curve is expressed as follows:

[0044] ;

[0045] Z-axis coordinates in reconstructed mode The calculation process is as follows:

[0046] ;

[0047] ;

[0048] ;

[0049] Let x be the rotation matrix about the x-axis. Let z be the rotation matrix about the z-axis. For the first i Point coordinate rotation matrix, Let be the initial angle between two adjacent infinitesimal line segments.

[0050] By the technical scheme, the aero-engine axial load sensor modal test device provided by the application can maximize simulation of high temperature and oil immersion environment of the axial load sensor in the engine operation through the oil layer and heat source on the loading base, and can simulate the load of the axial load sensor in the engine, maximize reduction of the use environment of the axial load sensor, and perform the experiment of the axial load sensor based on this, use the exciter to perform sweep excitation during the experiment, combine the finite element method to perform reasonable distribution design on the strain gauge, use the strain gauge to collect the strain response and corresponding frequency of the sensor in the resonance state, and develop a displacement reconstruction algorithm based on the strain data, so as to realize accurate identification and reconstruction of the sensor vibration mode, realize multi-angle test of the axial load sensor, obtain accurate changes of the axial load sensor in this state, and comprehensively consider problems of the axial load sensor in the actual use process. BRIEF DESCRIPTION OF DRAWINGS

[0051] In order to more clearly illustrate the technical schemes in the embodiments of the application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative labor.

[0052] Figure 1 is a structural schematic view of an axial load sensor of the aero-engine axial load sensor modal test device disclosed by the embodiments of the application;

[0053] Figure 2 is a structural schematic view of a loading top base of the aero-engine axial load sensor modal test device disclosed by the embodiments of the application;

[0054] Figure 3 is a structural schematic view of a loading base of the aero-engine axial load sensor modal test device disclosed by the embodiments of the application;

[0055] Figure 4 is a structural schematic view of radial connection of the exciter of the aero-engine axial load sensor modal test device disclosed by the embodiments of the application;

[0056] Figure 5 is a structural schematic view of axial connection of the exciter of the aero-engine axial load sensor modal test device disclosed by the embodiments of the application;

[0057] Figure 6is a structure schematic diagram of strain gauge connection when radially detecting the modal test device of the axial load sensor of the aero-engine disclosed by the embodiment of the present application;

[0058] Figure 7 is a structure schematic diagram of strain gauge connection when axially detecting the modal test device of the axial load sensor of the aero-engine disclosed by the embodiment of the present application;

[0059] Figure 8 is a schematic diagram of the axial load sensor before and after local change when radially detecting the modal test device of the axial load sensor of the aero-engine disclosed by the embodiment of the present application;

[0060] Figure 9 is a schematic diagram of the axial load sensor before and after local change when axially detecting the modal test device of the axial load sensor of the aero-engine disclosed by the embodiment of the present application;

[0061] Figure 10 is a structure schematic diagram of the connection head when connecting the modal test device of the axial load sensor of the aero-engine disclosed by the embodiment of the present application;

[0062] Figure 11 is a comparison schematic diagram of reconstruction calculation and simulation results of the vibration mode change of the axial load sensor when radially exciting in the second embodiment of the present application;

[0063] Figure 12 is a specific structure schematic diagram of a sealing assembly of the modal test device of the axial load sensor of the aero-engine.

[0064] Explanation of reference signs:

[0065] 1, loading base; 2, through hole; 3, connection head; 4, axial load sensor; 5, boss; 6, loading top base; 7, protruding block; 8, pressing strip; 9, strain gauge; 10, exciter; 11, concave boss; 12, sealing assembly; 1201, sealing plate; 1202, sealing rubber. DETAILED DESCRIPTION

[0066] The embodiments of the present application will be further described in detail below in combination with the drawings and examples. The detailed description of the following examples and the drawings are used to exemplarily illustrate the principles of the present application, but cannot be used to limit the scope of the present application, and the present application can be implemented in many different forms, and is not limited to the specific examples disclosed in the text, but includes all technical solutions falling within the scope of the claims.

[0067] The present application provides these examples is to make the present application thorough and complete, and to the person skilled in the art fully express the scope of the present application. It should be noted that: unless otherwise specified, the relative arrangement of components and steps, the composition of materials, numerical expressions and values set forth in these examples should be interpreted as merely exemplary, and not as limiting.

[0068] It should also be noted that, in the description of the present application, unless otherwise specifically defined and limited, the terms "mounting", "connecting", "connecting" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be directly connected, or indirectly connected through an intermediate medium. 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. When it is described that a specific device is located between the first device and the second device, there can be or can not be an intermediate device between the specific device and the first device or the second device.

[0069] All terms used in the present application have the same meaning as understood by those skilled in the art to which the present application belongs, unless otherwise specifically defined. It should also be understood that terms defined in general dictionaries should be interpreted to have meanings consistent with their meanings in the context of the relevant technology, and should not be interpreted in an idealized or excessively formalized sense, unless specifically defined here.

[0070] Techniques, methods and equipment known to those skilled in the relevant art can not be discussed in detail, but in appropriate cases, the techniques, methods and equipment should be considered as part of the specification.

[0071] Embodiment one

[0072] Reference to the attached Figure 1 to the attached Figure 10 and the attached Figure 12 , the present embodiment discloses an aero-engine axial load sensor 4 modal test device, which comprises a loading base 1, an axial load sensor 4, a loading top seat 6, a strain gauge 9 and a vibration exciter 10; wherein the loading base 1 and the loading top seat 6 are hard metal seat bodies, wherein the inner bottom of the loading base 1 is a hollow structure where a heat source can be placed, which can be but not limited to an experimental electric furnace, which can provide a high temperature environment for the detection test of the axial load sensor 4; in addition, the loading base 1 is provided with a boss 5, and the axial load sensor 4 is placed on the boss 5 to perform detection test during the experiment. Due to the height difference formed by the boss 5 on the surface of the loading base 1, aviation lubricating oil can be added and the axial load sensor 4 can be completely immersed in the oil layer, simulating the actual use environment of the axial load sensor 4, and the loading top seat 6 vertically presses the axial load sensor 4 from the top to apply axial load.

[0073] Furthermore, when the loading top seat 6 presses against the axial load sensor 4, the pressure strip 8 on the loading top seat 6 applies pressure to the protrusion 7 on the axial load sensor 4. Combined with the excitation force applied by the vibrator 10, a more pronounced change in the axial load sensor 4 can be observed. Consequently, the axial load sensor 4 receives vibration responses in different directions when subjected to load. To capture these responses, the vibrator 10 needs to apply excitation force to the axial load sensor 4 from different positions, causing the axial load sensor 4 to undergo different vibration mode changes. Similarly, the strain gauge 9, when installed on the axial load sensor 4, also needs to be adjusted according to the excitation. It is understandable that the excitation... When the vibrator 10 applies a radial excitation force to the axial load sensor 4, the strain gauges 9 need to be installed on both the inner and outer circles of the axial load sensor 4. This is because the inner and outer circles will receive excitation simultaneously, requiring the collection of stress changes at both locations. Furthermore, the strain gauges 9 on both the inner and outer circles are located on the same radial extension line to ensure test synchronization and detection at the same location. The strain gauges 9 are arranged circumferentially around the center of the axial load sensor 4, with intervals of up to, but not limited to, 45°, to ensure uniform distribution. Specifically, when the vibrator 10 applies a radial excitation force, it connects to the connector 3 within the through hole 2. Figure 12 As shown, it is understandable that aviation lubricating oil is added inside the loading base 1 to prevent leakage of aviation lubricating oil. The contact surface between the connector 3 and the through hole 2 is also provided with a sealing component 12. The sealing component 12 includes a sealing plate 1201 and a sealing rubber 1202. The sealing plate 1201 is located at the entrance of the through hole 2. The sealing rubber 1202 is used to connect the sealing plate 1201 and the connector 3. It can be, but is not limited to, fluororubber. It can still ensure the stability of performance when the ambient temperature reaches 200℃, which can meet the use requirements under the 150℃ condition of this environment. It is understandable that when the vibrator 10 is connected, it extends through the through hole 2 into the interior of the sealing rubber 1202 and finally connects with the connector 3. The excitation force of the vibrator 10 is transmitted through the connector 3. The vibrator 10 and the connector 3 are connected and finally act together to apply the excitation force to the axial load sensor 4. The sealing rubber 1202 can realize the soft connection between the connector 3 and the sealing plate 1201, realize the free vibration of the vibrator 10 and the connector 3, and realize the lossless transmission of the excitation force.

[0074] Then, when longitudinal excitation is needed to be applied to the axial load sensor 4, i.e. perpendicular to the axial direction of the axial load sensor 4, the exciter 10 is connected to the axial load sensor 4 perpendicularly, wherein the loading top base 6 is provided with a recess 11 between two adjacent pressing strips 8, and the strain gauges 9 are arranged on the axial load sensor 4 at the position where the protrusion 7 is located, and the strain gauges 9 can also be arranged at an angle of, but not limited to, 45° between each other according to the actual situation. In this way, the vibration mode data of the axial load sensor 4 in two directions can be collected completely.

[0075] In addition, after the vibration mode collection is completed, the vibration mode reconstruction algorithm is used to reconstruct the actual vibration mode change of the axial load sensor 4.

[0076] Example Two

[0077] In this embodiment, the exciter is connected to the connector, and the excitation force is applied to the axial load sensor from the radial direction, wherein the inner diameter of the axial load sensor is taken as an example, and the circular ring with an outer diameter of R 1 =95 mm , an outer diameter of R 2 = 103.5 mm , and a thickness of h` = 4.5 mm is taken as an example. The circular ring is evenly divided into 360 microsegments by 360 points, wherein the number of microsegments can be adjusted according to the specific size of the circular ring, and the size of the strain gauge is much larger than the microsegment. The microsegment detected by the strain gauge is the microsegment located at the center position of the strain gauge, and the 360 points are numbered as 0, 1, 2…358, 359. Among them, 8 points are measuring points, the strain of the measuring point has been measured by the strain gauge, and the corresponding measuring point numbers are 0, 45, 90, 135, 180, 225, 270, 315. The strain of the remaining points is obtained by quadratic interpolation.

[0078] Taking the 50th, 51st, and 52nd points as examples for reconstruction calculation, taking the 0th measuring point as the starting point, the strain of the 50th-52nd points needs to be calculated by interpolation with the 45th, 90th, and 135th measuring points as nodes. Let s be the arc length of the measuring point from the starting point, be the strain of the point. According to the simulation, the arc length and strain of the node are shown in Table 1.

[0079] Table 1: Arc length of each measuring point from the starting point and strain of the measuring point;

[0080] ;

[0081] According to the quadratic interpolation formula:

[0082] ;

[0083] Similarly, the outer diameter strain of point 50 should be calculated and the inner and outer strains of points 51 and 52 , whose values are shown in Table 2.

[0084] Table 2: Inner diameter strain and outer diameter strain of points 50, 51 and 52

[0085] ;

[0086] According to the strain-curvature relationship formula, the curvatures of points 50, 51 and 52 can be calculated The calculation formula of point 50 is as follows:

[0087] ;

[0088] According to the above algorithm, the curvatures of points 50, 51 and 52 are calculated as follows: For the curvatures of each point in the micro-element segment between points 50 and 51, linear interpolation fitting is performed, i.e.:

[0089] ;

[0090] The difference fitting coefficients of the micro-element segment are calculated M 50,51 and N 50,51 , wherein is the arc length of the micro-element segment, which is a constant since the micro-element segment is evenly divided . Similarly, the curvature function of the micro-element segment between points 51 and 52 can be calculated, so the curvature functions of the two micro-element segments are calculated as follows:

[0091] ;

[0092] The rotation angle of the axial load sensor deflection curve is obtained by integrating the curvature function along the arc length

[0093] ;

[0094] The rotation angle of point 50 has been calculated from the curvature function between points 49 and 50 , so the rotation angle functions of the micro-element segments between points 50 and 51 and between points 51 and 52 are calculated as follows:

[0095] ;

[0096] According to the rotation angle function, the coordinate expression can be obtained by integrating along the arc length. From the coordinate expression between points 49 and 50, the coordinates of point 50 are calculated as follows: The coordinate functions of the microelement segment between points 50 and 51 and the microelement segment between points 51 and 52 are shown as follows, respectively, and the coordinate data and the rotation angle of points 51 and 52 are shown in Table 3.

[0097]

[0098]

[0099] Table 3: Coordinate data and rotation angle of points 51 and 52

[0100]

[0101] The coordinates of the 360 points are calculated through the above process, and the reconstructed mode of the sensor is fitted and reconstructed, and the reconstructed result is shown in Fig. 3, and the simulation result is shown in Fig. 4. Figure 11 The relative error R between the reconstructed result and the simulation result is 0.95, which meets the required accuracy of the test. 2

[0102] In addition, when the longitudinal excitation is applied to the axial load sensor 4, the y-axis of the i-th segment is first coincided with the y-axis of the coordinate axis in the calculation of the Z-axis of the reconstructed mode, the starting coordinate is (0, 0, 0), and the end coordinate of the microelement segment is (x, y, 0) to perform the flexural curve integral calculation, and the end coordinate after the integral is (x, y, z). The end coordinate is obtained through the coordinate rotation matrix to obtain the change of the z-axis coordinate of each segment. The change of the z-axis coordinate of each segment is obtained by accumulating the changes of the z-axis coordinates of each segment. The relationship between and

[0103] .

[0104] The embodiments of the present application have been described in detail. In order to avoid obscuring the concept of the present application, some details known in the art are not described. Those skilled in the art can fully understand how to implement the technical solutions disclosed herein according to the above description.

[0105] ​​​​​​Although some specific embodiments of the present application have been described in detail by way of examples, one skilled in the art should understand that the above examples are only for the purpose of illustration, but not for the purpose of limiting the scope of the present application. One skilled in the art should understand that the above embodiments can be modified or equivalent replacements can be made to some technical features without departing from the scope and spirit of the present application. In particular, each technical feature mentioned in each embodiment can be combined in any manner as long as there is no structural conflict.

Claims

1. A modal testing device for an axial load sensor of an aero-engine, characterized in that, include: Loading base (1), the loading base (1) is provided with a heat source to heat the surface of the loading base (1), and the surface of the loading base (1) is provided with an oil layer to simulate the oil immersion environment inside the aircraft engine; An axial load sensor (4) is provided with a boss (5) at the center of the loading base (1). The axial load sensor (4) is located on the surface of the boss (5). The axial load sensor (4) is annular. Loading top seat (6) is connected to an external loading head, and the loading top seat (6) is movably set relative to the loading base (1) in the direction of gravity to cooperate with the boss (5) to apply pressure to the axial load sensor (4); The surface of the axial load sensor (4) is provided with a plurality of protrusions (7), and two adjacent protrusions (7) form a test area. Each test area is arranged circumferentially relative to the axial load sensor (4). The bottom of the loading top seat (6) is provided with a plurality of pressure strips (8). The pressure strips (8) abut against the protrusions (7) in the test area to squeeze the axial load sensor (4). A plurality of strain gauges (9) are located on the axial load sensor (4) to acquire the strain response signal of the axial load sensor (4); Vibrator (10), which is used to apply excitation force to the axial load sensor (4).

2. The modal testing device for an aero-engine axial load sensor according to claim 1, characterized in that, The side wall of the loading base (1) is provided with a through hole (2), and the surface of the through hole (2) is provided with a connector (3). The vibrator (10) passes through the through hole (2) and is connected to the connector (3) to apply a vibration force to the axial load sensor (4) in the radial direction. Several strain gauges (9) are located on the side walls of the inner and outer circles of the axial load sensor (4). The position of the strain gauge (9) located on the inner circle corresponds to the position of the strain gauge (9) located on the outer circle, and the strain gauge (9) is located between any two adjacent test areas.

3. The modal testing device for an aero-engine axial load sensor according to claim 2, characterized in that, The through hole (2) is provided with a sealing component (12) on the side facing the loading base (1), and the sealing component (12) is connected to the connector (3) to prevent leakage of the oil layer.

4. The modal testing device for an aero-engine axial load sensor according to claim 1, characterized in that, The loading top seat (6) is provided with several recessed platforms (11), and the strain gauge (9) is located between any two adjacent test areas on the surface of the axial load sensor (4). The vibrator (10) applies an excitation force to the axial load sensor (4) in the axial direction from the recess (11).

5. A modal testing method for an axial load sensor of an aero-engine, characterized in that, The modal testing device for an aero-engine axial load sensor, as described in any one of claims 1 to 4, is used to implement the test, comprising the following steps: S1. Determine the position detected by the axial load sensor (4), and then connect the strain gauge (9) to the axial load sensor (4); S2. Place the axial load sensor (4) on the boss (5) in the center of the loading base (1), and add aviation lubricating oil to the surface of the loading base (1) until it completely covers the axial load sensor (4) and heat it. S3. The external loading head drives the loading top seat (6) to move toward the axial load sensor (4) to squeeze; S4. The exciter (10) applies an excitation force to the axial load sensor (4) in the axial or radial direction, and at the same time obtains the vibration frequency of the axial load sensor (4) through the strain gauge (9). S5. Calculate the curvature of the test points at the adhesive point of the strain gauge (9). Calculate the strain of the points other than the adhesive point of the strain gauge by the second difference, and calculate the curvature of the points by the strain. Then calculate the curvature function between two adjacent test points. Next, integrate the curvature function along the arc length to obtain the equation of the angle between the deflection curves. Integrate the obtained equation of the angle between the deflection curves to obtain the curve equation. Finally, obtain the coordinates of the curve and fit it. Compare the fitted curve with the simulation curve.

6. The modal testing method for an aero-engine axial load sensor according to claim 5, characterized in that, When the exciter (10) in S4 applies an excitation force to the axial load sensor (4) in the radial direction, the strain gauge (9) in S1 is located on the inner and outer circles of the axial load sensor (4), and the curvature K of the axial load sensor (4) is: ； in, The inner radius of the axial load sensor (4) is... The initial arc length of the inner circle at the measurement point of strain gauge (9) is... The arc length of the inner circle after the change at the point measured by strain gauge (9) For the strain gauge (9) to measure the strain variation of the inner circle, The outer radius of the axial load sensor (4) is... The initial arc length of the outer circle at the measurement point of strain gauge (9) The arc length of the outer circle after the change at the point measured by strain gauge (9) For the strain gauge (9) to measure the change in strain on the outer circle, The central angle of the bending deformation at the location measured by strain gauge (9) is... h Radial thickness of axial load sensor (4).

7. The modal testing method for an aero-engine axial load sensor according to claim 6, characterized in that, The expression for the curvature function in S5 is: ； in, Let be the arc length between any point located between point i and point i-1 and point i-1. Let the arc length be the distance from the (i-1)th point. The curvature of the point, and Represents the linear interpolation coefficients of the arc segment between point i-1 and point i; The expression for the equation of the angle between the deflection curves is: ； in, The angle between the tangent to the deflection curve and the x-axis. Let be the arc length of the infinitesimal segment; The equation of the curve is expressed as: ； in, x ( u )and y ( u ) represent the x-axis coordinates and y-axis coordinates of the deflection curve, respectively.

8. The modal testing method for an aero-engine axial load sensor according to claim 5, characterized in that, When the exciter (10) in S4 applies an excitation force to the axial load sensor (4) in the axial direction, and the strain gauge (9) in S1 is located between any two adjacent test areas, then the curvature K of the axial load sensor (4) at this time is: ； in, The axial thickness of the axial load sensor (4) is given by L, and the length of the measurement point of the strain gauge (9) is given by L. The central angle of the bending deformation at the location measured by strain gauge (9) is... The strain gauge (9) measures the strain at the end face.

9. The modal testing method for an aero-engine axial load sensor according to claim 8, characterized in that, The expression for the curvature function in S5 is: ； in, s Let be the length between any point located between point i and point i-1 and point i-1. The distance from the (i-1)th point is s The curvature at the point, and Represents the linear interpolation coefficients of the infinitesimal line segment between point i-1 and point i; The expression for the equation of the angle between the deflection curves is: ； in, Tangent to the deflection curve and xoy Plane angle, The length of the infinitesimal line segment; Align the i-th segment with the y-axis of the coordinate system, and then... i The curve integral of the segment is used to calculate the change in the Z-direction at the end of each segment. Value, then check Values ​​rotated by coordinate matrix The transformation yields the true change in the Z-direction at the endpoint of each segment. The value will eventually be The summation of values ​​yields the Z-axis coordinate in the reconstructed mode shape. The magnitude of the value; The equation of the curve is expressed as follows: ； Z-axis coordinates in reconstructed mode The calculation process is as follows: ； ； ； Let x be the rotation matrix about the x-axis. Let z be the rotation matrix about the z-axis. For the first i Point coordinate rotation matrix, Let be the initial angle between two adjacent infinitesimal line segments.

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