Blade disk dynamic vibration absorber vibration reduction performance test system

Abstract

The present invention discloses a vibration reduction performance test system for a blade disk dynamic vibration absorber, comprising a blade disk, a dynamic vibration absorbing device, a traveling wave excitation unit and a vibration measuring unit for data acquisition; the blade disk is an integrated structure of a wheel disk and blades, the dynamic vibration absorbing device is a dynamic vibration absorber uniformly distributed along the circumference of the wheel disk surface; the traveling wave excitation unit is a signal generator that generates multiple groups of analog signals for driving a piezoelectric ceramic sheet to excite the entire blade disk to form vibration, and adjusting the phase difference of the analog signal to simulate traveling wave excitations of different orders; the present invention simulates the random detuning phenomenon of the blade disk by randomly adjusting the front end mass of each blade, adjusts the mass and damping of the dynamic vibration absorber to realize the vibration reduction performance experiment of the dynamic vibration absorber under different mass ratios and damping ratios; sets the natural frequency of the dynamic vibration absorber to realize the single-mode and multi-mode vibration reduction performance analysis of the blade disk, and provides technical support for the development of dynamic vibration absorption and vibration reduction devices.

Description

Technical Field

[0001] The invention relates to the technical field of vibration control experiments, and more specifically to a vibration reduction performance experimental device for a dynamic vibration absorber of an integral blade disk. Background Art

[0002] The blade disk is a key component of large rotating machinery such as aircraft engines, large compressors, and steam turbines. With the development of material science and the advancement of processing and manufacturing technology, the integral blade disk structure has begun to be widely used. The integral blade disk structure is compact, light, and has good reliability and durability. However, due to the lack of a reliable damping source, the blade disk structure often exhibits low damping characteristics and can only rely on its own weak material damping to dissipate energy, resulting in excessive amplitude when passing through the resonance area. In addition, the blade disk has variable working conditions, complex vibration forms, and a wide excitation frequency band, which easily leads to broadband vibration problems of the blade disk. In addition, due to the influence of factors such as manufacturing tolerances, uneven materials, and uneven operating wear, the actual blade disk structure inevitably has detuning phenomena, which causes the blade disk structure to produce localized vibration and induce high-cycle fatigue damage. With the continuous improvement of the performance of rotating machinery such as aircraft engines and large compressors, the vibration problem of the blade disk has become increasingly prominent and has become a bottleneck problem restricting the further development of this machinery.

[0003] Dynamic vibration absorbers are one of the most widely used vibration control methods in engineering. The principle is to achieve the purpose of vibration reduction by transferring and consuming the energy of the controlled object. It can effectively control the vibration of complex structures with a smaller mass. Dynamic vibration absorbers have the characteristics of reliable performance, simple structure, and low cost. They are widely used in many fields such as machinery, construction, and transportation. However, the application of dynamic vibration absorbers in the field of integral blade vibration control is relatively small, and there is a lack of effective experimental verification devices, which cannot provide reliable technical support for the development of effective dynamic vibration absorption and vibration reduction devices. Summary of the invention

[0004] In order to avoid the deficiencies of the above-mentioned prior art, the present invention provides a blade disk dynamic vibration absorber vibration reduction performance test system for the dynamic vibration absorber vibration reduction performance test of the integral blade disk, thereby further realizing the vibration reduction performance experimental analysis of the dynamic vibration absorber of the integral blade disk, and providing technical support for the development of effective dynamic vibration absorption and vibration reduction devices.

[0005] The present invention adopts the following technical solutions to achieve the purpose of the invention:

[0006] The characteristics of the vibration reduction performance experimental system of the blade disk dynamic vibration absorber of the present invention are: the experimental system comprises a blade disk, a dynamic vibration absorption device, a traveling wave excitation unit and a vibration measurement unit;

[0007] The wheel disc and the blades in the blade disc are integrated into a structure to form an integral blade disc, and the blades are evenly distributed around the wheel disc, and the mass of the front end of each blade can be adjusted;

[0008] The dynamic vibration absorbing device is a plurality of dynamic vibration absorbers evenly distributed on the surface of the wheel disc in the circumferential direction; the dynamic vibration absorber is a mass block fixedly connected to the front end of an elastic beam, and the rear end of the elastic beam is fixedly arranged on the wheel disc through a support seat to form a cantilever beam structure, and the elastic beam and the mass block in the cantilever beam structure do not contact the surface of the blade disc when vibrating; the mass and damping of the dynamic vibration absorber can be adjusted;

[0009] The traveling wave excitation unit is composed of a signal generating device, a multi-channel power amplifier and a piezoelectric ceramic sheet; the piezoelectric ceramic sheet is fixedly arranged on the leaf disk;

[0010] The vibration measurement unit is composed of a data acquisition unit and a vibration measurement device, and the vibration measurement device adopts a laser vibrometer or an acceleration sensor to realize the collection of experimental data;

[0011] The adjustment method of the experimental system is:

[0012] The front-end mass of each blade is randomly adjusted to make the mass of each blade different, which is used to simulate the random detuning phenomenon of the blade disk. Through the vibration experimental analysis of the blade disk under different detuning modes, the robustness of the dynamic vibration absorption device to the vibration reduction performance of the random detuned blade disk is verified.

[0013] Adjust the mass and damping of each dynamic vibration absorber to realize vibration reduction performance experiments of the dynamic vibration absorber under various mass ratios and damping ratios. The mass ratio is the ratio of the mass of the dynamic vibration absorber to the mass of the entire blade disk. The damping ratio is an index describing the damping characteristics of the dynamic vibration absorber and is measured by experimental modal analysis.

[0014] The natural frequency of the dynamic vibration absorber is set to match the natural frequency of the integral blade disk, so as to realize the single-mode and multi-mode vibration reduction performance analysis of the integral blade disk;

[0015] A signal generator generates multiple groups of analog signals with different phases. The analog signals are output as control signals through a multi-channel power amplifier. The control signals are used to drive the piezoelectric ceramics to excite the entire blade disk to vibrate. The phase difference of each analog signal is adjusted to simulate multiple traveling wave excitations of different orders.

[0016] The vibration reduction performance experimental system of the blade disk dynamic vibration absorber of the present invention is also characterized in that each dynamic vibration absorber is set to have the same natural frequency, and the single-mode vibration reduction performance analysis of the blade disk is achieved by matching the natural frequency of the dynamic vibration absorber with a certain order natural frequency of the blade disk.

[0017] The characteristics of the vibration reduction performance experimental system of the blade disk dynamic vibration absorber of the present invention are also: all dynamic vibration absorbers are divided into multiple dynamic vibration absorber groups, each dynamic vibration absorber in each dynamic vibration absorber group has the same natural frequency, each dynamic vibration absorber group has a different natural frequency, and corresponds one-to-one with the multi-order natural frequencies of the blade disk, and multiple dynamic vibration absorber groups are used to match multi-order modal vibration shapes to achieve multi-modal vibration reduction performance analysis of the entire blade disk.

[0018] The characteristics of the vibration reduction performance experimental system of the blade disk dynamic vibration absorber of the present invention are also: an additional mass block is installed at the front end of the blade by magnet adsorption, gluing or bolt connection to adjust the front end mass of the blade; a through hole is set on the mass block, and an additional micro mass block is installed in the through hole to adjust the mass of the dynamic vibration absorber; a damping block is pasted on the elastic beam, and the damping of the dynamic vibration absorber is adjusted by adjusting the size or material of the damping block, and the support seat is installed on the blade disk by bolt connection, welding or gluing.

[0019] The characteristics of the vibration reduction performance experimental system of the blade disk dynamic vibration absorber of the present invention are also that: the piezoelectric ceramic sheets are installed on the blade disk by gluing, and the piezoelectric ceramic sheets are evenly arranged along the circumferential direction of the blade disk, and are pasted one by one on the root of each blade, or on the corresponding position on the surface of the wheel disk; the number of the piezoelectric ceramic sheets is equal to the number of blades or is an integer multiple of the number of blades.

[0020] The characteristics of the vibration reduction performance test system of the blade disk dynamic vibration absorber of the present invention are also that: the dynamic vibration absorbers are interconnected through the support seats to form a complete ring; or the support seats are independently arranged; the elastic beam is a beam of uniform cross-section or a beam of non-uniform cross-section.

[0021] Compared with the prior art, the beneficial effects of the present invention are embodied in:

[0022] 1. The experimental system of the present invention can simulate the typical characteristics of actual integral blade vibration, simulate various vibration modes of the integral blade, carry out comprehensive experimental analysis of the vibration reduction performance of the dynamic vibration absorber, and provide an effective experimental platform for the design and development of the integral blade dynamic vibration absorber.

[0023] 2. The experimental system of the present invention can provide a powerful tool for clarifying the vibration reduction characteristics and vibration reduction mechanism of the dynamic vibration absorber by adjusting various parameters, including: detuned mass, natural frequency and frequency distribution of the dynamic vibration absorber, the number of dynamic vibration absorbers, natural frequency, mass ratio and damping ratio.

[0024] 3. The experimental system of the present invention has a simple structure, low cost and rich functions. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the experimental system of the present invention;

[0026] Figure 2 It is a schematic diagram of the structure of a blade disk equipped with a dynamic vibration absorbing device and a piezoelectric ceramic sheet in the experimental system of the present invention;

[0027] Figure 3 It is a schematic diagram of the structure of the integrated dynamic vibration absorbing device in the present invention;

[0028] Figure 4 It is a schematic diagram of the structure of the independent dynamic vibration absorbing device in the present invention.

[0029] Numbers in the figure: 1 blade disk, 1a blade, 1b wheel disk, 2 dynamic vibration absorbing device, 3 dynamic vibration absorber, 3a mass block, 3b elastic beam, 3c support seat, 4 piezoelectric ceramic sheet, 5 fixing device. Specific implementation plan

[0030] See also Figure 1 and Figure 2 In this embodiment, the vibration reduction performance experimental system of the blade disk dynamic vibration absorber includes a blade disk 1, a dynamic vibration absorption device 2, a traveling wave excitation unit and a vibration measurement unit. The entire experimental system is fixed on the experimental table by a fixing device 5.

[0031] The wheel disc 1a and blades 1b in the blade disc 1 are an integrated structure to form an integral blade disc, and the blades 1b are evenly distributed around the wheel disc 1a, and the mass of the front end of each blade 1b can be adjusted; the dynamic vibration absorbing device 2 is a plurality of dynamic vibration absorbers 3 evenly distributed on the surface of the wheel disc 1a along the circumferential direction; a single dynamic vibration absorber can only absorb the local vibration of the blade disc, and the vibration reduction effect is limited, and it will destroy the tuning structure of the blade disc. The dynamic vibration absorbing device composed of multiple dynamic vibration absorbers evenly arranged along the circumference can avoid the shortcomings of a single dynamic vibration absorber and has a significant vibration reduction effect; the dynamic vibration absorber 3 is a mass block 3a fixedly connected to the front end of the elastic beam 3b, and the elastic beam 3b The tail end is fixedly arranged on the wheel disc 1a through the support seat 3c to form a cantilever beam structure. The elastic beam 3b and the mass block 3c in the cantilever beam structure do not contact the surface of the blade disc 1 during vibration; the mass and damping of the dynamic vibration absorber 3 can be adjusted; the cantilever beam structure is light in weight, flexible, and can quickly absorb the energy of the controlled object to achieve the purpose of vibration reduction; the mass block, the elastic beam and the support seat can be processed and welded into a whole with different materials, or they can be integrally formed with the same material; the support seat 3c is fixedly installed on the blade disc by bolt connection, adhesive connection or welding, so as to minimize the impact on the performance of the blade disc, and the installation method is simple and easy to implement.

[0032] The traveling wave excitation unit is composed of a signal generating device, a multi-channel power amplifier and a piezoelectric ceramic piece 4; the piezoelectric ceramic piece 4 is fixedly arranged on the blade disk 1; the vibration measurement unit is composed of a data acquisition unit and a vibration measurement device, and the vibration measurement device adopts a laser vibrometer or an acceleration sensor to realize the acquisition of experimental data.

[0033] In this embodiment, the adjustment method of setting the experimental system is:

[0034] The front end mass of each blade 1a is randomly adjusted to make the mass of each blade 1a different, which is used to simulate the random detuning phenomenon of the blade disk 1. The robustness of the dynamic vibration absorption device to the vibration reduction performance of the random detuned overall blade disk is verified through the experimental analysis of the blade disk vibration under different detuning modes.

[0035] The mass and damping of each dynamic vibration absorber 3 are adjusted to realize vibration reduction performance experiments of the dynamic vibration absorber 2 under various mass ratios and damping ratios. The mass ratio is the ratio of the mass of the dynamic vibration absorber 3 to the mass of the integral blade disk 1. The damping ratio is an indicator describing the damping characteristics of the dynamic vibration absorber 3, which is measured by experimental modal analysis. The mass of the mass block is changed while the damping ratio of the dynamic vibration absorber remains unchanged, thereby changing the natural frequency of the dynamic vibration absorber. Alternatively, the damping material is attached to the elastic beam while the mass of the dynamic vibration absorber remains unchanged, thereby optimizing the dynamic vibration absorption design according to the vibration reduction effect.

[0036] The natural frequency of the dynamic vibration absorber 3 is set so that the natural frequency of the dynamic vibration absorber 3 matches the natural frequency of the integral blade disk 1 , thereby realizing single-mode and multi-mode vibration reduction performance analysis of the integral blade disk 1 .

[0037] A signal generator generates multiple groups of analog signals with different phases. The analog signals are alternating voltage signals. The analog signals are output as control signals through a multi-channel power amplifier. The control signals are used to drive the piezoelectric ceramic piece 4 to excite the entire blade disk 1 to vibrate. The piezoelectric ceramic piece produces periodic length deformation after being acted upon by the voltage, and the blade disk is deformed accordingly, thereby causing the blade disk to produce forced vibration. The phase difference between adjacent signals is calculated based on θ=2πe / n, where n is the number of blades and e is the excitation order. The phase difference of each analog signal is adjusted to simulate traveling wave excitations of multiple orders.

[0038] In order to realize the single-mode vibration reduction performance analysis of the blade disk 1, each dynamic vibration absorber 3 is set to have the same natural frequency, and the natural frequency of the dynamic vibration absorber 3 is matched with a certain order natural frequency of the blade disk 1, so that the single-mode vibration reduction performance analysis of the entire blade disk can be carried out. The natural frequency of the blade disk can be determined by installing the blade disk on a test bench for modal testing or by analyzing it through the finite element method.

[0039] In order to realize the multi-modal vibration reduction performance analysis of the integral blade disk 1, all dynamic vibration absorbers 3 are divided into multiple dynamic vibration absorber groups, each dynamic vibration absorber in each dynamic vibration absorber group has the same natural frequency, each dynamic vibration absorber group has a different natural frequency, and corresponds one to one with the multi-order natural frequencies of the blade disk 1. By matching the multi-order modal vibration shapes with multiple dynamic vibration absorber groups, the multi-modal vibration reduction performance analysis of the integral blade disk can be carried out.

[0040] In the specific implementation, the corresponding structural settings also include:

[0041] An additional mass block is installed at the front end of blade 1a by magnet adsorption, gluing or bolt connection to adjust the front end mass of blade 1b; in actual engineering, due to the influence of factors such as manufacturing tolerance, material unevenness, uneven operation wear or human design, the actual rotor blade disk structure is detuned; an additional mass block is installed at the front end of the blade to simulate the random detuning phenomenon of the blade disk.

[0042] A through hole is set on the mass block 3a, and an additional micro-mass block is installed in the through hole to adjust the mass of the dynamic vibration absorber 3. In the experiment, the natural frequency of the dynamic vibration absorber is fine-tuned by adjusting the mass of the mass block, so as to adjust the influence of the error generated during processing on the natural frequency, so as to make the error between the designed natural frequency and the actual natural frequency of the dynamic vibration absorber as small as possible; an angle is set between the elastic beam 3b and the support seat 3c to avoid the elastic beam 3b and the mass block 3c part from contacting the surface of the blade disk, so as to avoid the dynamic vibration absorber vibrating with the blade disk in the experiment to generate additional excitation to the blade disk, thereby weakening the vibration reduction effect; in addition, a damping block is attached to the elastic beam 3b, and the damping of the dynamic vibration absorber 3 is adjusted by adjusting the size or material of the damping block; the damping of the dynamic vibration absorber affects the vibration reduction effect, and the damping consumes the energy of the dynamic vibration absorber, so that the dynamic vibration absorber continues to absorb more energy on the blade disk, so the vibration reduction performance of the dynamic vibration absorber is optimized by changing the damping of the dynamic vibration absorber.

[0043] The piezoelectric ceramic sheets 4 are installed on the blade disk by gluing. The piezoelectric ceramic sheets 4 are evenly arranged along the circumferential direction of the blade disk and are pasted one by one at the root of each blade 1a, or at the corresponding position on the surface of the wheel disk 1b. The piezoelectric ceramic sheets are arranged at the root of the blade or on the surface of the wheel disk, which is more likely to arouse the response of the blade disk; the surface of the piezoelectric ceramic sheet is a normally polarized ceramic layer, and gluing is the optimal connection method, so that the piezoelectric ceramic sheet does not directly contact the metal. An insulating gasket should be set on the bonding surface during pasting; the number of piezoelectric ceramic sheets 4 is equal to the number of blades 1a or is an integer multiple of the number of blades 1a; the materials used for the piezoelectric ceramic sheets are widely used, low in cost, simple in structure, easy to ensure processing accuracy, and the linear distortion of the exciting force is small, the frequency response range is wide, and the dynamic response speed is fast.

[0044] Figure 3As shown, the dynamic vibration absorbers 3 are connected to each other through the support seats 3c to form a whole ring. The ring-shaped overall structure is more suitable for single-mode analysis of the blade disk.

[0045] Figure 4 As shown, each support seat 3c is independently arranged; the independent arrangement is more suitable for multi-modal experiments of blade disks, and independent dynamic vibration absorbers with different natural frequencies can be combined with each other to form a variety of multi-modal dynamic vibration absorbing devices, which can reduce the manufacturing cost of the dynamic vibration absorber and facilitate installation and maintenance; the elastic beam 3b is a uniform cross-section beam or a non-uniform cross-section beam.

Claims

1. A vibration reduction performance test system for a blade disk dynamic vibration absorber, characterized by: The experimental system comprises a blade disk (1), a dynamic vibration absorbing device (2), a traveling wave excitation unit and a vibration measuring unit; The wheel disc (1a) and the blades (1b) in the blade disc (1) are an integrated structure to form an integral blade disc, and the blades (1b) are evenly distributed around the wheel disc (1a), and the mass of the front end of each blade (1b) is adjustable; The dynamic vibration absorbing device (2) is a plurality of dynamic vibration absorbers (3) uniformly distributed along the circumferential direction on the surface of the wheel disc (1a); the dynamic vibration absorber (3) is a mass block (3a) fixedly connected to the front end of an elastic beam (3b), and the rear end of the elastic beam (3b) is fixedly arranged on the wheel disc (1a) through a support seat (3c) to form a cantilever beam structure, and the elastic beam (3b) and the mass block (3c) in the cantilever beam structure do not contact the surface of the blade disc (1) when vibrating; the mass and damping of the dynamic vibration absorber (3) can be adjusted; The traveling wave excitation unit is composed of a signal generating device, a multi-channel power amplifier and a piezoelectric ceramic sheet (4); the piezoelectric ceramic sheet (4) is fixedly arranged on the leaf disk (1); The vibration measurement unit is composed of a data acquisition unit and a vibration measurement device, and the vibration measurement device adopts a laser vibrometer or an acceleration sensor to realize the collection of experimental data; The adjustment method of the experimental system is: The front end mass of each blade (1a) is randomly adjusted so that the mass of each blade (1a) is different, which is used to simulate the random detuning phenomenon of the blade disk (1), and the robustness of the dynamic vibration absorption device to the vibration reduction performance of the random detuning blade disk is verified through the blade disk vibration experimental analysis under different detuning modes; The mass and damping of each dynamic vibration absorber (3) are adjusted to realize vibration reduction performance experiments of the dynamic vibration absorber (2) under various conditions of mass ratio and damping ratio, wherein the mass ratio is the ratio of the mass of the dynamic vibration absorber (3) to the mass of the integral blade disk (1), and the damping ratio is an index describing the damping characteristics of the dynamic vibration absorber (3), which is measured by experimental modal analysis; The natural frequency of the dynamic vibration absorber (3) is set so that the natural frequency of the dynamic vibration absorber (3) matches the natural frequency of the integral blade disk (1), thereby realizing single-mode and multi-mode vibration reduction performance analysis of the integral blade disk (1); A signal generator generates a plurality of groups of analog signals with different phases, and the analog signals are output as control signals through a multi-channel power amplifier. The control signals are used to drive a piezoelectric ceramic sheet (4) to excite an integral blade disk (1) to form vibrations. The phase difference of each analog signal is adjusted to simulate traveling wave excitations of multiple different orders.

2. The vibration reduction performance test system of the blade disk dynamic vibration absorber according to claim 1 is characterized by: Each dynamic vibration absorber (3) is set to have the same natural frequency, and single-mode vibration reduction performance analysis of the blade disk (1) is achieved by matching the natural frequency of the dynamic vibration absorber (3) with a certain order natural frequency of the blade disk (1).

3. The vibration reduction performance test system of the blade disk dynamic vibration absorber according to claim 1 is characterized by: All dynamic vibration absorbers (3) are divided into a plurality of dynamic vibration absorber groups, each dynamic vibration absorber in each dynamic vibration absorber group has the same natural frequency, each dynamic vibration absorber group has a different natural frequency, and has a one-to-one correspondence with the multi-order natural frequencies of the blade disk (1), and a plurality of dynamic vibration absorber groups are matched with multi-order modal vibration shapes to achieve multi-modal vibration reduction performance analysis of the entire blade disk (1).

4. The vibration reduction performance test system of the blade disk dynamic vibration absorber according to claim 1 is characterized by: An additional mass block is installed at the front end of the blade (1a) by means of magnet adsorption, gluing or bolt connection, so as to adjust the mass of the front end of the blade (1b); a through hole is provided on the mass block (3a), and an additional micro mass block is installed in the through hole, so as to adjust the mass of the dynamic vibration absorber (3); a damping block is attached to the elastic beam (3b), and the damping of the dynamic vibration absorber (3) is adjusted by adjusting the size or material of the damping block; the support seat (3c) is installed on the blade disk by means of bolt connection, welding or gluing.

5. The vibration reduction performance test system of the blade disk dynamic vibration absorber according to claim 1 is characterized by: The piezoelectric ceramic sheets (4) are mounted on the blade disk by gluing, and the piezoelectric ceramic sheets (4) are evenly arranged along the circumferential direction of the blade disk and are glued one by one to the root of each blade (1a) or to the corresponding position on the surface of the wheel disk (1b); the number of the piezoelectric ceramic sheets (4) is equal to the number of blades (1a) or is an integer multiple of the number of blades (1a).

6. The vibration reduction performance test system of the blade disk dynamic vibration absorber according to claim 1 is characterized by: The dynamic vibration absorbers (3) are interconnected via the support seats (3c) to form a complete ring; or the support seats (3c) are independently arranged; and the elastic beam (3b) is a beam with a uniform cross section or a beam with a non-uniform cross section.

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