A contact damping and contact stiffness test apparatus and method

Abstract

The application belongs to the technical field of contact stiffness and contact damping test, and provides a contact damping and contact stiffness test experimental device and method, which comprises a fixing assembly, a knocking assembly and a vibration measuring assembly.The fixing assembly comprises a blade disc fixing seat, which is used for fixedly connecting a measured blade disc structural member.The knocking assembly comprises an experimental table, a top end of which is hingedly connected with a vertical connecting force rod, and a bottom end of the vertical connecting force rod is provided with a vibration excitation member.The vertical connecting force rod is used for driving the vibration excitation member to move towards the measured blade disc structural member, and the vibration excitation member is used for hammering the side wall of the measured blade disc structural member.The vibration measuring assembly is used for measuring the vibration signal of the measured blade disc structural member after hammering.The host computer is used for obtaining a corresponding damping attenuation curve according to the signal measured by the vibration measuring assembly.The application can more conveniently directly measure the blade-blade disc contact stiffness, and obtains the contact damping value through the method combining experiment and simulation.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of contact stiffness and contact damping test, and particularly relates to a contact damping and contact stiffness test experimental device and method. BACKGROUND

[0002] According to statistical analysis of blade accident conditions of steam turbine generator units, direct economic loss caused by each blade accident is up to 10 million yuan RMB on average, and therefore, higher and higher requirements are put forward for safety and reliability of the blade. The causes of blade damage are various, and if the mechanism of occurrence is distinguished, 60%-80% of the damage causes are vibration. Therefore, if the reliability of the steam turbine, especially large steam turbine, is to be improved, the vibration failure problem of the blade must be solved first. In the vibration reduction research of the blade, the research on contact stiffness and contact damping of the contact surface of the blade and the blade disc is one of the most complex problems, and accurate contact stiffness values can provide theoretical basis and technical support for vibration reduction upgrading and reconstruction of the turbine blade, and also have important academic research and engineering application value. SUMMARY

[0003] The application aims to provide a contact damping and contact stiffness test experimental device and method to solve the above problems and achieve the purpose of directly measuring the blade-blade disc contact stiffness more conveniently, obtaining contact damping values through the method combining experiments and simulation, and verifying the damping coefficients through simulation while obtaining the damping coefficients.

[0004] To achieve the above purpose, the application provides the following scheme: a contact damping and contact stiffness test experimental device, comprising:

[0005] A fixing assembly comprising a blade disc fixing seat used for fixedly connecting a measured blade structure;

[0006] A knocking assembly comprising an experimental table, a top end of a vertical connecting force rod being hingedly connected to the top of the experimental table, a vibration excitation member being arranged at a bottom end of the vertical connecting force rod, the vertical connecting force rod being used for driving the vibration excitation member to move towards the measured blade structure, and the vibration excitation member being used for hammering a side wall of the measured blade structure;

[0007] A vibration measuring assembly, when the measured blade structure is hammered and vibrated by the vibration excitation member, the vibration measuring assembly is used for measuring a vibration signal of the measured blade structure;

[0008] A host computer, the host computer being used for deriving a corresponding damping attenuation curve according to the signal measured by the vibration measuring assembly.

[0009] Preferably, the side wall top of the blade fixing seat is fixedly connected with a boss, a stud is fixedly connected with the boss away from the side of the blade fixing seat, the stud penetrates the center of the measured blade structure, and a large locking nut is detachably connected with the end of the stud away from the boss, and the large locking nut is used for fixing the measured blade structure on the blade fixing seat.

[0010] Preferably, the vibration exciter comprises a horizontal connecting force rod, one end of the horizontal connecting force rod is connected with the vertical connecting force rod through a distance adjusting piece, and the other end of the horizontal connecting force rod is fixedly connected with a copper head through a pressure sensor.

[0011] Preferably, the distance adjusting piece comprises a connecting sleeve fixedly connected with the bottom of the vertical connecting force rod, a fastening bolt is threadedly connected with the side wall of the connecting sleeve, the threaded end of the fastening bolt is located in the connecting sleeve, and an arc-shaped pressing plate is rotationally connected with the threaded end of the fastening bolt, and the end of the horizontal connecting force rod away from the copper head is slidingly connected between the inner wall of the connecting sleeve and the arc-shaped pressing plate.

[0012] Preferably, the vibration measuring assembly comprises a laser vibration measuring instrument fixedly connected with the experiment table and a reflective tape fixedly connected with the side wall of the measured blade structure, the reflective tape is arranged in correspondence with the laser vibration measuring instrument, and a data signal acquisition instrument is further arranged and electrically connected with the laser vibration measuring instrument.

[0013] A contact damping and contact stiffness test experiment method, the operation steps comprising:

[0014] The measured blade structure is fixed on the blade fixing seat.

[0015] The vertical connecting force rod is pulled up to a position at a first angle with the plumb line, the vertical connecting force rod is released, the vibration exciter hammers the side wall of the measured blade structure, and the damping attenuation curve A is obtained through the vibration measuring assembly and the upper computer.

[0016] A structural modal simulation model based on an interface connection contact model is established for the friction contact surface of the blade-disc, a relationship curve of the normal contact stiffness and the damping coefficient is obtained, the same simulation curve as the damping attenuation curve A is obtained by adjusting the size of the damping coefficient in the contact simulation model, and a new damping coefficient value is obtained.

[0017] The vertical connecting force rod is pulled up to a position at a second angle with the plumb line, the vertical connecting force rod is released, the vibration exciter hammers the side wall of the measured blade structure, and the damping attenuation curve B is obtained through the vibration measuring assembly and the upper computer.

[0018] Under the structure modal simulation model of the updated damping coefficient value, the friction surface contact pair of the blade-disc is established and the contact stiffness is calculated;

[0019] By adjusting the damping coefficient value of the contact pair, the same simulation curve as the damping attenuation curve B is obtained, and the damping coefficient value of the corresponding contact pair is taken as the final measurement result.

[0020] Preferably, the calculation formula of the contact stiffness is:

[0021]

[0022] Wherein, k is the contact stiffness, R is the blade root radius value, E is the Young's modulus of the blade root material, u is the Poisson's ratio of the blade root material, E2 is the Young's modulus of the blade-disc tenon and slot material, and u2 is the Poisson's ratio of the blade-disc tenon and slot material.

[0023] Preferably, the first angle is 30 degrees, that is, the vertical connecting force rod is pulled to a position of 30 degrees with the vertical line direction, and the second angle is 60 degrees, that is, the vertical connecting force rod is pulled to a position of 60 degrees with the vertical line direction.

[0024] Compared with the prior art, the present application has the following advantages and technical effects:

[0025] 1. The contact damping and contact stiffness test device and method of the present application can directly measure the contact stiffness more conveniently, without repeatedly processing data, and the contact damping value is obtained through the combination of experiment and simulation, so that the damping coefficient can be simulated and verified.

[0026] 2. The test device of the present application has simple working principle, easy installation and high repeatability. BRIEF DESCRIPTION OF DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments. Obviously, the drawings in the following description only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor on the basis of these drawings.

[0028] Figure 1 It is a schematic diagram of the test device of the present application;

[0029] Figure 2 It is a schematic diagram of the vibration exciter of the present application;

[0030] Figure 3 It is a partial enlarged view of the test bench of the present application;

[0031] Figure 4It is a schematic view of the blade fixing seat of the present application.

[0032] Figure 5 It is a schematic view of the distance adjusting member of the present application.

[0033] Wherein, 1, the measured blade structure; 2, the large locking nut; 3, the blade fixing seat; 4, the rigid counterweight; 5, the copper head; 6, the pressure sensor; 7, the horizontal connecting force rod; 8, the vertical connecting force rod; 9, the small locking nut; 10, the test bench; 11, the laser vibration measuring instrument; 12, the data signal acquisition instrument; 13, the test bench base; 14, the reflective tape; 15, the boss; 16, the stud; 17, the connecting sleeve; 18, the arc-shaped pressing plate; 19, the fastening bolt; 20, the reinforcing angle plate. DETAILED DESCRIPTION

[0034] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0035] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the present application will be further described in detail below with reference to the drawings and specific embodiments.

[0036] Reference Figures 1-5 The present application provides a contact damping and contact stiffness test experimental device, comprising:

[0037] The fixing assembly comprises a blade fixing seat 3, and the blade fixing seat 3 is used for fixedly connecting the measured blade structure 1.

[0038] The knocking assembly comprises a test bench 10, the top of the test bench 10 is hingedly connected with the top end of a vertical connecting force rod 8, the bottom end of the vertical connecting force rod 8 is provided with a vibration excitation member, the vertical connecting force rod 8 is used for driving the vibration excitation member to move towards the measured blade structure 1, and the vibration excitation member is used for hammering the side wall of the measured blade structure 1.

[0039] The vibration measuring assembly is used for measuring the vibration signal of the measured blade structure 1 when the measured blade structure 1 is hammered and vibrated by the vibration excitation member.

[0040] The upper computer is used for deriving a corresponding damping attenuation curve according to the signal measured by the vibration measuring assembly.

[0041] The main function of the blade disc fixing seat 3 is to fix the measured blade disc structure 1; the main function of the vertical connecting force rod 8 is to drive the vibration excitation piece to swing around the shaft at the top of the vertical connecting force rod 8, so that the vibration excitation piece can hammer the measured blade disc structure 1; the main function of the vibration excitation piece is to hammer the measured blade disc structure 1 under the limiting of the vertical connecting force rod 8, so that the measured blade disc structure 1 vibrates; the main function of the vibration measuring assembly is to detect the vibration signal of the measured blade disc structure 1; the main function of the upper computer is to create a simulation model, analyze and calculate the vibration signal of the vibration measuring assembly, and generate a corresponding damping attenuation curve. Overall, the measuring device and method of the present application can directly measure the contact stiffness more conveniently, without repeatedly processing data, and the contact damping value is obtained through the combination of experiments and simulation, so that the damping coefficient can be simulated and verified at the same time.

[0042] Further optimization scheme, as shown in Figure 1 The test bench base 13 is further provided, and the blade disc fixing seat 3 and the test bench 10 are fixedly connected to the test bench base 13.

[0043] Further optimization scheme, as shown in Figure 1 The top of the test bench 10 is fixedly connected with a sliding rod through horizontal fixing, the top of the vertical connecting force rod 8 is hingedly connected to the top of the test bench 10, a small locking nut 9 is threadedly connected to the end of the sliding rod away from the test bench 10, and the small locking nut 9 is arranged to prevent the vertical connecting force rod 8 from falling off the sliding rod.

[0044] Further optimization scheme, the side wall of the blade disc fixing seat 3 is fixedly connected with a boss 15 at the top, a stud 16 is fixedly connected to the side of the boss 15 away from the blade disc fixing seat 3, the stud penetrates through the center of the measured blade disc structure 1, and a large locking nut 2 is detachably connected to the end of the stud away from the boss 15, and the large locking nut 2 is used to fixedly connect the measured blade disc structure 1 to the blade disc fixing seat 3.

[0045] As shown in Figure 1 and Figure 4 The center of the measured blade disc structure 1 is sleeved in the stud 16, the side wall of the measured blade disc structure 1 is in contact with the boss 15, and the large locking nut 2 is tightened, so that the measured blade disc structure 1 is pressed between the boss 15 and the large locking nut 2, thereby achieving the effect of fixing the measured blade disc structure 1 to the blade disc fixing seat 3, and at the same time, due to the existence of the boss 15, the measured blade disc structure 1 is in a suspended state except the middle part, so as to ensure that the vibration process of the measured blade disc structure 1 is not affected when it is excited to vibrate.

[0046] Further optimization scheme, as shown in Figure 1As shown, the leaf disc fixing seat 3 is provided with a reinforcing angle plate 20 away from the experimental table 10, and the reinforcing angle plate 20 is provided with a rigid counterweight 4 away from the leaf disc fixing seat 3.

[0047] Further optimization scheme, the vibration exciter includes a horizontal connecting force rod 7, one end of the horizontal connecting force rod 7 is connected with the vertical connecting force rod 8 through a distance adjusting piece, the other end of the horizontal connecting force rod 7 is fixedly connected with the copper head 5 through the pressure sensor 6, and the distance adjusting piece is used for adjusting the distance between the copper head 5 and the measured leaf disc structure 1.

[0048] Further optimization scheme, the distance adjusting piece includes a connecting sleeve 17 fixedly connected at the bottom of the vertical connecting force rod 8, a fastening bolt 19 is threadedly connected on the side wall of the connecting sleeve 17, the threaded end of the fastening bolt 19 is located in the connecting sleeve 17, and the threaded end of the fastening bolt 19 is rotationally connected with an arc-shaped pressing plate 18, and one end of the horizontal connecting force rod 7 away from the copper head 5 is slidingly connected between the inner wall of the connecting sleeve 17 and the arc-shaped pressing plate 18.

[0049] As shown in Figure 3 and Figure 5 , the fastening bolt 19 is arranged at the bottom of the connecting sleeve 17. When the vertical connecting force rod 8 is in the plumb direction and it is needed to move the copper head 5 to the direction close to the measured leaf disc structure 1, the operator only needs to loosen the fastening bolt 19, at this time, a gap is formed between the horizontal connecting force rod 7, the arc-shaped pressing plate 18 and the inner wall of the connecting sleeve 17, the operator can pull the horizontal connecting force rod 7 to a certain distance close to the measured leaf disc structure 1, so that the copper head 5 is moved to the appropriate distance, and then the fastening bolt 19 is tightened, so that the adjustment is completed. Similarly, if it is needed to move the copper head 5 away from the measured leaf disc structure 1, the horizontal connecting force rod 7 is pulled away from the measured leaf disc structure 1. By adjusting the front and back distance between the copper head 5 and the measured leaf disc structure 1, different excitation force sizes can be controlled.

[0050] Further optimization scheme, as shown in Figure 1 , the vertical connecting force rod 8 can be provided with different lengths, and by loosening the small locking nut 9, the vertical connecting force rod 8 with different lengths can be replaced, so that the different hammering points are changed.

[0051] By setting the hammering force and hammering point of the copper head 5 as an adjustable structure, the experimental device of the present application can not only be suitable for the damping coefficient measurement and contact stiffness measurement of the contact pair between the static leaf-disc contact surface, but also can be suitable for the contact damping and contact stiffness measurement of the contact pair in other fields.

[0052] Further optimization scheme, the vibration measuring assembly includes a laser vibration meter 11 fixedly connected on the experiment table 10 and a reflective tape 14 pasted on the side wall of the measured blade disc structure 1, the reflective tape 14 is correspondingly arranged with the laser vibration meter 11, and a data signal acquisition instrument 12 is further arranged, and the data signal acquisition instrument 12 is electrically connected with the laser vibration meter 11.

[0053] As shown in Figure 3 When the measured blade disc structure 1 is hammered to vibrate, the reflective tape 14 is driven to vibrate together, the laser vibration meter 11 can measure the vibration signal of the measuring point covered by the reflective tape 14 through the reflective tape, and transmit the detected vibration signal to the data signal acquisition instrument for analysis.

[0054] A contact damping and contact stiffness test method, the operation steps include:

[0055] The measured blade disc structure 1 is fixed on the blade disc fixing seat 3;

[0056] The vertical connecting force rod 8 is pulled up to a position with a first angle with the plumb line direction, the vertical connecting force rod 8 is released, the vibration exciter hammers the side wall of the measured blade disc structure 1, and the damping attenuation curve A is obtained through the vibration measuring assembly and the host computer operation;

[0057] A structure modal simulation model based on the interface connection contact model is established for the friction contact surface of the blade-disc, the relationship curve of the normal contact stiffness and the damping coefficient is obtained, the same simulation curve as the damping attenuation curve A is obtained by adjusting the size of the damping coefficient in the contact simulation model, and a new damping coefficient value is obtained;

[0058] The vertical connecting force rod 8 is pulled up to a position with a second angle with the plumb line direction, the vertical connecting force rod 8 is released, the vibration exciter hammers the side wall of the measured blade disc structure 1, and the damping attenuation curve B is obtained through the vibration measuring assembly and the host computer operation;

[0059] Under the structure modal simulation model with the updated damping coefficient value, the friction surface contact pair of the blade-disc is established, and the contact stiffness is calculated;

[0060] By adjusting the damping coefficient value of the contact pair, the same simulation curve as the damping attenuation curve B is obtained, and the damping coefficient value of the corresponding contact pair is taken as the final measurement result.

[0061] Further optimization scheme, the calculation formula of the contact stiffness is:

[0062]

[0063] Wherein, k is the contact stiffness, R is the blade root radius value, E1 is the Young's modulus of the blade root material, u1 is the Poisson's ratio of the blade root material, E2 is the Young's modulus of the disc slot material, and u2 is the Poisson's ratio of the disc slot material.

[0064] Further optimization scheme, the first angle is 30 degrees, that is, the vertical connecting force rod 8 is pulled up to the position of 30 degrees with the vertical line direction, and the second angle is 60 degrees, that is, the vertical connecting force rod 8 is pulled up to the position of 60 degrees with the vertical line direction.

[0065] The experimental process of the embodiment is as follows:

[0066] Step 1: The measured blade disc structure 1 is fixed on the blade disc fixing seat 3 through the large locking nut 2, and according to the experimental requirements, the vertical connecting force rod 8 with appropriate length is hinged on the experimental table 10, and the relative position between the horizontal connecting force rod 7 and the vertical connecting force rod 8 is adjusted. Determine the tight connection of each part to avoid loosening during the experiment.

[0067] Step 2: According to the distance interval of each part of the device, the horizontal connecting force rod 7 is pulled up to the appropriate position, so that the vertical connecting force rod 8 and the vertical line form an angle of about 30 degrees, the vertical connecting force rod 8 is released, and the copper head 5 connected with the pressure sensor 6 impacts the measured blade disc structure 1. At this time, the laser vibration meter 11 can measure the vibration signal of the measuring point covered with the reflective tape 14, and the damping attenuation curve A is obtained through data signal acquisition instrument 12 analysis and computer operation.

[0068] Step 3: The simulation model of the application can be established in the host computer according to the finite element simulation software Abaqus, the structure modal simulation model based on the interface connection contact model is established for the friction contact surface of the blade-disc, and the relationship curve of the normal contact stiffness and the damping coefficient is obtained. By adjusting the size of the damping coefficient in the contact simulation model, the same simulation curve as the damping attenuation curve A is obtained, so as to obtain the new damping coefficient value, and the new damping coefficient value is updated to the model synchronously.

[0069] Step 4: The horizontal connecting force rod 7 is pulled up again, so that the vertical connecting force rod 8 and the vertical line form an angle of about 60 degrees, the vertical connecting force rod 8 is released, and the copper head 5 connected with the pressure sensor 6 impacts the measured blade disc structure 1. At this time, the laser vibration meter 11 can measure the vibration signal of the measuring point covered with the reflective tape 14, and the damping attenuation curve B is obtained through data signal acquisition instrument 12 analysis and computer operation.

[0070] Step 5: Under the structure modal simulation model with updated damping coefficient value, the friction surface contact pair of the blade-disc is established, and the contact stiffness is calculated according to the calculation formula of the contact stiffness.

[0071] Step 6: Obtain the same simulation curve as the damping decay curve B by adjusting the damping coefficient value of the contact pair, and the damping coefficient value of the contact pair at this time is taken as the final measurement result.

[0072] In the description of the present application, it should be understood that the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0073] The above-described embodiments are only descriptions of the preferred modes of the present application, and do not limit the scope of the present application. Various modifications and improvements to the technical solutions of the present application made by those skilled in the art without departing from the design spirit of the present application shall fall within the protection scope of the present application as defined by the claims.

Claims

1. A contact damping and contact stiffness test apparatus, characterized by , comprising: A fixed component, comprising a blade disc fixing seat (3) for fixing a measured blade disc structure (1); A knocking component, comprising a test bench (10), the top of the test bench (10) is hingedly connected with the top end of a vertical connecting force rod (8), the bottom end of the vertical connecting force rod (8) is provided with a vibration exciter, the vertical connecting force rod (8) is used to drive the vibration exciter to move towards the measured blade disc structure (1), and the vibration exciter is used to hammer the side wall of the measured blade disc structure (1); A vibration measurement component, when the measured blade disc structure (1) is hammered and vibrated by the vibration exciter, the vibration measurement component is used to measure the vibration signal of the measured blade disc structure (1); A host computer, the host computer is used to obtain a corresponding damping attenuation curve according to the signal measured by the vibration measurement component; The experimental operation steps of the above contact damping and contact stiffness test experimental device include: Fix the measured blade disc structure (1) on the blade disc fixing seat (3); Pull the vertical connecting force rod (8) to a position at a first angle with the plumb line direction, release the vertical connecting force rod (8), make the vibration exciter hammer the side wall of the measured blade disc structure (1), and obtain a damping attenuation curve A through the vibration measurement component and the host computer operation; A structural modal simulation model based on the interface connection contact model is established for the friction contact surface of the blade-disc, the relationship curve of the normal contact stiffness and the damping coefficient is obtained, the same simulation curve as the damping attenuation curve A is obtained by adjusting the size of the damping coefficient in the contact simulation model, and a new damping coefficient value is obtained; Pull the vertical connecting force rod (8) to a position at a second angle with the plumb line direction, release the vertical connecting force rod (8), make the vibration exciter hammer the side wall of the measured blade disc structure (1), and obtain a damping attenuation curve B through the vibration measurement component and the host computer operation; Under the structural modal simulation model with the updated damping coefficient value, the friction surface contact pair of the blade-disc is established, and the contact stiffness is calculated; By adjusting the damping coefficient value of the contact pair, the same simulation curve as the damping attenuation curve B is obtained, and the damping coefficient value of the contact pair at this time is taken as the final measurement result.

2. The contact damping and contact stiffness test apparatus of claim 1, wherein: The side wall top of the blade disc fixing seat (3) is fixedly connected with a boss (15), the side away from the blade disc fixing seat (3) of the boss (15) is horizontally fixedly connected with a stud (16), the stud penetrates through the center of the measured blade disc structure (1), and one end of the stud away from the boss (15) is detachably connected with a large locking nut (2), the large locking nut (2) is used to fixedly connect the measured blade disc structure (1) on the blade disc fixing seat (3).

3. The contact damping and contact stiffness test apparatus of claim 1, wherein: The vibration exciter comprises a horizontal connecting force rod (7), one end of the horizontal connecting force rod (7) is connected with the vertical connecting force rod (8) through a distance adjusting piece, the other end of the horizontal connecting force rod (7) is fixedly connected with a copper head (5) through a pressure sensor (6), and the distance adjusting piece is used to adjust the distance between the copper head (5) and the measured blade disc structure (1).

4. The contact damping and contact stiffness test apparatus of claim 3, wherein: The distance adjustment component includes a connecting sleeve (17) fixedly connected to the bottom of the vertical connecting force rod (8). A fastening bolt (19) is threadedly connected to the side wall of the connecting sleeve (17). The threaded end of the fastening bolt (19) is located inside the connecting sleeve (17), and the threaded end of the fastening bolt (19) is rotatably connected to an arc-shaped pressure plate (18). The end of the horizontal connecting force rod (7) away from the copper head (5) is slidably connected between the inner wall of the connecting sleeve (17) and the arc-shaped pressure plate (18).

5. The contact damping and contact stiffness test apparatus of claim 1, wherein: The vibration measurement assembly includes a laser vibration meter (11) fixedly connected to the experimental platform (10) and reflective tape (14) pasted on the side wall of the bladed disk structure (1) under test. The reflective tape (14) is arranged corresponding to the laser vibration meter (11). A data signal acquisition instrument (12) is also provided, which is electrically connected to the laser vibration meter (11).

6. The contact damping and contact stiffness test apparatus of claim 1, wherein: The formula for calculating contact stiffness is: （1） （2） （3） Where k is the contact stiffness, R is the pseudo-radius of the blade root, E1 is the Young's modulus of the blade root material, u1 is the Poisson's ratio of the blade root material, E2 is the Young's modulus of the blade disk tenon material, and u2 is the Poisson's ratio of the blade disk tenon material.

7. The contact damping and contact stiffness test apparatus of claim 1, wherein: The first angle is 30 degrees, that is, the vertical connecting rod (8) is pulled up to a position 30 degrees from the vertical line. The second angle is 60 degrees, that is, the vertical connecting rod (8) is pulled up to a position 60 degrees from the vertical line.

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