CN110702313A - Method for high-precision identification of unbalanced excitation force of flexible rotor based on variable-speed starting - Google Patents
Method for high-precision identification of unbalanced excitation force of flexible rotor based on variable-speed starting Download PDFInfo
- Publication number
- CN110702313A CN110702313A CN201910956054.8A CN201910956054A CN110702313A CN 110702313 A CN110702313 A CN 110702313A CN 201910956054 A CN201910956054 A CN 201910956054A CN 110702313 A CN110702313 A CN 110702313A
- Authority
- CN
- China
- Prior art keywords
- rotor
- excitation force
- transient
- unbalanced excitation
- rotor system
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 230000005284 excitation Effects 0.000 title claims abstract description 41
- 238000000034 method Methods 0.000 title claims abstract description 41
- 230000001052 transient effect Effects 0.000 claims abstract description 40
- 239000011159 matrix material Substances 0.000 claims abstract description 14
- 238000006243 chemical reaction Methods 0.000 claims abstract description 5
- 230000010354 integration Effects 0.000 claims abstract description 5
- 230000003595 spectral effect Effects 0.000 claims abstract description 5
- 238000012546 transfer Methods 0.000 claims abstract description 5
- 230000001133 acceleration Effects 0.000 claims abstract description 4
- 238000010586 diagram Methods 0.000 claims description 7
- 239000000126 substance Substances 0.000 claims description 6
- 238000013016 damping Methods 0.000 claims description 3
- 238000001228 spectrum Methods 0.000 abstract description 4
- 238000001914 filtration Methods 0.000 abstract description 2
- 238000011160 research Methods 0.000 description 3
- 230000003321 amplification Effects 0.000 description 2
- 238000003199 nucleic acid amplification method Methods 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000010606 normalization Methods 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 230000000087 stabilizing effect Effects 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
- G01M1/00—Testing static or dynamic balance of machines or structures
- G01M1/14—Determining imbalance
- G01M1/16—Determining imbalance by oscillating or rotating the body to be tested
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Testing Of Balance (AREA)
Abstract
The invention provides a method for identifying unbalanced excitation force of a flexible rotor based on variable-speed starting high precision. Firstly, establishing a transient motion equation of a rotor system by adopting a transfer matrix method, and calculating by a Newmark integration method to obtain transient motion response data; then, calculating to obtain a frequency domain load spectral vector of the unbalanced excitation force of the rotor system by utilizing a method combining load identification and modal coordinate conversion; and finally, carrying out inverse Fourier transform on the spectrum vector and filtering the spectrum vector by using a specific filter to obtain the transient unbalance excitation force of the rotor. The method only utilizes the motion response data of the rotor in the process of one-time acceleration starting, has high solving efficiency, has high balancing precision of the rotor by solving the unbalanced excitation force, and can be used for transient balancing of the rotor.
Description
Technical Field
The invention belongs to the technical field of mechanical vibration, and particularly relates to a method for identifying unbalanced excitation force of a flexible rotor based on variable-speed starting high-precision.
Background
The vibration problem is a difficult problem which must be faced in the development process of the aeroengine. Excessive vibration can cause the rotor to generate larger deformation and stress, so that connection looseness, excessive bearing load, poor work and damage are caused, and a flight accident is caused in serious cases. Engine vibration is caused by a variety of causes, and research and engineering practice has shown that rotor imbalance is a major cause. These faults will also disappear once the rotor equilibrium conditions are improved by various means. Therefore, a balancing method is required to regulate the unbalance of the rotor.
Because the unbalance amount of the rotor system exists in the unbalanced excitation force, the unbalance excitation force of the rotor only needs to be calculated, and then the rotor can be balanced according to the calculated unbalance excitation force, which is a step that needs to be carried out before the rotor is put into use. The unbalance excitation force of the rotor is difficult to directly measure due to the limitation of technical and economic conditions, and no research report of actually measuring the unbalance excitation force of the rotor is found at present. Therefore, the method is an important technical problem in the field of rotor transient balance by calculating the instantaneous unbalance excitation force of the rotor by using the actually measured rotor transient motion response data and further solving the unbalance of the rotor.
Meanwhile, the existing load identification methods are all load identification processes with system input as steady-state response data, and the identification effect is good. However, for the research of multi-frequency load identification of the system input of actually measured transient response data, the problems that too many doped frequency components exist in signals, and non-dominant frequency and high-frequency signals are easy to mix, so that the identification precision of the system output response is low are caused. Therefore, how to improve the accuracy of load identification of transient response data input by a system is an important technical problem facing the field of load identification.
Disclosure of Invention
In order to overcome the defects of the prior art, the invention provides a method for identifying the unbalanced excitation force of a flexible rotor based on variable-speed starting high precision. Firstly, establishing a transient motion equation of a rotor system by adopting a transfer matrix method, and calculating by a Newmark integration method to obtain transient motion response data; then, calculating to obtain a frequency domain load spectral vector of the unbalanced excitation force of the rotor system by utilizing a method combining load identification and modal coordinate conversion; and finally, carrying out inverse Fourier transform on the spectrum vector and filtering the spectrum vector by using a specific filter to obtain the transient unbalance excitation force of the rotor.
A method for identifying unbalanced excitation force of a flexible rotor based on variable-speed starting high precision is characterized by comprising the following steps:
step 1: establishing a transient motion equation of the N-disk rotor system with normalized mass by adopting a transfer matrix method, and calculating transient motion information of the rotor system under constant angular acceleration by using a Newmark integration method, wherein the transient motion information comprises rotor transient response, a rotor Bode diagram and a modal shape; intercepting transient response data U (t) in any time period before the rotor reaches the critical rotating speed as load identification input data;
step 2: by utilizing a method combining load identification and modal coordinate conversion, calculating to obtain a frequency domain load spectral vector F (omega) of the unbalanced excitation force of the rotor system, namely:
F(ω)＝U(ω)/Φhq(ω)ΦT(1)
wherein U (ω) is the fourier transform of U (t), ω represents the frequency domain frequency; Φ is the rotor mode shape matrix, expressed as:
wherein the content of the first and second substances,
the rotor system is the r-th order modal shape, and N is the number of the rotor characteristic disks;
hq(ω) is the modal admittance matrix of the rotor system, expressed as:
hq(ω)＝diag[h1(ω),h2(ω),···,hr(ω),···,h4N(ω)](3)
hr(ω)＝1/(ωr 2-ω2+2jωξrωr)，(r＝1,2,···,4N) (4)
wherein, ω isrAnd xirThe order r of the system is natural frequency and modal damping ratio respectively;
and step 3: performing inverse Fourier transform on the F (omega) to obtain the rotor system unbalanced excitation force F (t) with normalized mass, wherein the rotor system unbalanced excitation force F (t) is as follows:
F(t)＝M·f(t) (5)
wherein M is a mass matrix of the rotor;
then, using a cut-off frequency fmaxThe FIR filter filters the F (t) to obtain the final rotor unbalance exciting force; wherein the content of the first and second substances,the maximum angular velocity value of the rotor for the intercepted transient response time period.
The invention has the beneficial effects that: the whole solving process only takes the transient motion response of the rotor as input, so that the solving efficiency is high; because the unbalanced excitation force of the rotor contains the unbalanced information thereof, the rotor balancing precision is high by solving the unbalanced excitation force, and the guidance can be provided for the transient balance of the rotor; the transient motion response of the rotor corresponds to a plurality of frequencies, so that the practical application of engineering can be expanded, and the unbalanced excitation force of the rotor can be monitored in real time; the FIR filter is suitable for the transient motion process of multiple frequencies, and has stable data, good digital property and high operation speed, so that the solving precision and the solving efficiency of the transient unbalanced excitation force can be greatly improved.
Drawings
FIG. 1 is a flow chart of a method for identifying the unbalanced excitation force of a flexible rotor based on variable-speed starting high precision in the invention
FIG. 2 is a diagram of a single disk cantilever rotor model according to an embodiment of the present invention
In the figure, 1-rotor feature disk; 2-rotor left end bearing; 3-rotor right end support; 4-rotor end.
FIG. 3 is a graph of rotor system x-direction transient response
FIG. 4 is a y-direction transient response diagram of a rotor system
FIG. 5 is a Bode diagram of a rotor system
FIG. 6 is a modal shape diagram of a rotor system
FIG. 7 is a graph of the x-direction transient response of a rotor system before the selection of the critical speed
FIG. 8 is a y-direction transient response diagram of a rotor system before selecting a critical speed
FIG. 9 is a Fourier transformed rotor x-direction transient response plot
FIG. 10 is a Fourier transformed rotor y-direction transient response plot
FIG. 11 is a comparison graph of the x-direction unbalanced excitation force results obtained by the method of the present invention and the real results
FIG. 12 is a comparison graph of the y-direction unbalanced excitation force results obtained by the method of the present invention and the real results
FIG. 13 is a comparison graph of the local amplification of the x-direction unbalanced excitation force result and the real result obtained by the method of the present invention
FIG. 14 is a partial enlarged comparison graph of the Y-direction unbalanced excitation force result and the real result obtained by the method of the present invention
Detailed Description
The present invention will be further described with reference to the following drawings and examples, which include, but are not limited to, the following examples.
As shown in fig. 1, the present invention provides a method for identifying unbalanced excitation force of a flexible rotor based on variable speed starting with high accuracy. In this embodiment, an isotropic single-disk cantilever rotor model shown in fig. 2 is used as a processing object, and the structural parameters of the rotor are shown in table 1.
TABLE 1
Step 1: the transient motion equation of the rotor system with the mass normalization is established by adopting a transfer matrix method, and the constant angular acceleration of the rotor system is calculated by a Newmark integration method to obtain 20rad/s2Transient motion information of rotor including rotor transient response, rotor Bode plot and mode shape, as shown in fig. 3, 4, 5, 6. Wherein the axis of abscissa of fig. 3 and 4 represents time and the axis of ordinate represents the rotor system transient response; the axis of abscissa in fig. 5 represents the rotational speed, and the axis of ordinate represents the rotor system amplitude. The critical speed of the rotor was 2960rpm and the natural frequency was 50.17 Hz.
In engineering practice, the rotor hardly reaches the critical speed due to the influence of unbalance, and the system has a stabilizing process in the initial starting process, so the transient response data in a certain time period before the rotor reaches the critical speed is intercepted as load identification input data, and for the embodiment, the transient response data U (t) before the rotor is critical (3s-10s) is intercepted, as shown in fig. 7 and 8. The angular speed of the rotor system during this period is 60rad/s to 200 rad/s.
Step 2: by utilizing a method combining load identification and modal coordinate conversion, calculating to obtain a rotor system frequency domain load spectral vector F (omega), namely:
F(ω)＝U(ω)/Φhq(ω)ΦT(6)
wherein U (ω) is the fourier transform of U (t), ω represents the frequency domain frequency; Φ is the rotor mode shape matrix, expressed as:
wherein the content of the first and second substances,
the mode shape of the r-th order of the rotor system is, N is the number of characteristic disks of the rotor, and the embodiment is an isotropic single-disk cantilever rotor system, so that N is 1, and the main mode shapes of all orders in phi are the same;
hq(ω) is the modal admittance matrix of the rotor system, expressed as:
hq(ω)＝diag[h1(ω),h2(ω),···,hr(ω),···,h4N(ω)](8)
hr(ω)＝1/(ωr 2-ω2+2jωξrωr)，(r＝1,2,···,4N) (9)
wherein, ω isrAnd xirThe system's r order natural frequency and modal damping ratio, h1(ω)＝h2(ω)＝h3(ω)＝h4(ω)，ω1＝50.17Hz。
And step 3: performing inverse Fourier transform on the F (omega) to obtain the rotor system unbalanced excitation force F (t) with normalized mass, wherein the rotor system unbalanced excitation force F (t) is as follows:
F(t)＝M·f(t) (10)
where M is the rotor mass matrix.
Then, using a cut-off frequency fmaxThe FIR filter (F), (t) filters the frequency (F), (t) to obtain the final rotor unbalance excitation force. Wherein the content of the first and second substances,
for the maximum angular velocity value, f, of the rotor in the time interval 3s-10s before the rotor reaches the critical speedmaxI.e. the highest frequency of the truncated transient response U (ω) in the frequency domain, U (ω) is shown in fig. 9 and 10 (the abscissa axis represents frequency and the ordinate axis represents response amplitude after fourier transform), in this embodiment fmax＝31.83Hz。
The comparison between the rotor imbalance excitation force calculated by the method of the present invention and the actual rotor imbalance excitation force is shown in fig. 11 and 12 (the abscissa axis represents time, and the ordinate axis represents the imbalance excitation force), and the local amplification result is shown in fig. 13 and 14. As can be seen from fig. 11, 12, 13, and 14, the fitting situation of the solution result and the actual rotor imbalance excitation force is good, the accuracy is high, and the effectiveness of the method of the present invention is illustrated.
Claims (1)
1. A method for identifying unbalanced excitation force of a flexible rotor based on variable-speed starting high precision is characterized by comprising the following steps:
step 1: establishing a transient motion equation of the N-disk rotor system with normalized mass by adopting a transfer matrix method, and calculating transient motion information of the rotor system under constant angular acceleration by using a Newmark integration method, wherein the transient motion information comprises rotor transient response, a rotor Bode diagram and a modal shape; intercepting transient response data U (t) in any time period before the rotor reaches the critical rotating speed as load identification input data;
step 2: by utilizing a method combining load identification and modal coordinate conversion, calculating to obtain a frequency domain load spectral vector F (omega) of the unbalanced excitation force of the rotor system, namely:
F(ω)＝U(ω)/Φhq(ω)ΦT(1)
wherein U (ω) is the fourier transform of U (t), ω represents the frequency domain frequency; Φ is the rotor mode shape matrix, expressed as:
wherein the content of the first and second substances,
the rotor system is the r-th order modal shape, and N is the number of the rotor characteristic disks;
hq(ω) is the modal admittance matrix of the rotor system, expressed as:
hq(ω)＝diag[h1(ω),h2(ω),···,hr(ω),···,h4N(ω)](3)
hr(ω)＝1/(ωr 2-ω2+2jωξrωr)，(r＝1,2,···,4N) (4)
wherein, ω isrAnd xirThe order r of the system is natural frequency and modal damping ratio respectively;
and step 3: performing inverse Fourier transform on the F (omega) to obtain the rotor system unbalanced excitation force F (t) with normalized mass, wherein the rotor system unbalanced excitation force F (t) is as follows:
F(t)＝M·f(t) (5)
wherein M is a mass matrix of the rotor;
then, using a cut-off frequency fmaxThe FIR filter filters F (t) to obtain the final rotor unevennessBalancing the exciting force; wherein the content of the first and second substances,
the maximum angular velocity value of the rotor for the intercepted transient response time period.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910956054.8A CN110702313B (en) | 2019-10-10 | 2019-10-10 | Method for high-precision identification of unbalanced excitation force of flexible rotor based on variable-speed starting |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910956054.8A CN110702313B (en) | 2019-10-10 | 2019-10-10 | Method for high-precision identification of unbalanced excitation force of flexible rotor based on variable-speed starting |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110702313A true CN110702313A (en) | 2020-01-17 |
| CN110702313B CN110702313B (en) | 2021-07-06 |
Family
ID=69200094
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910956054.8A Active CN110702313B (en) | 2019-10-10 | 2019-10-10 | Method for high-precision identification of unbalanced excitation force of flexible rotor based on variable-speed starting |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110702313B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112765771A (en) * | 2020-12-24 | 2021-05-07 | 中国飞行试验研究院 | Real-time monitoring algorithm for vibration data of aircraft engine in transition state |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1132323A (en) * | 1995-03-27 | 1996-10-02 | 东北电力学院 | Dynamic rigidity coefficient method and appts. of rotary machinery dynamic balance |
| CN101949753A (en) * | 2010-09-16 | 2011-01-19 | 西北工业大学 | High-speed flexible rotor dynamic balance method |
| CN102880796A (en) * | 2012-09-18 | 2013-01-16 | 西安交通大学 | Method for calculating rotor dynamics performance of multi-parallel-axis system |
| CN103292958A (en) * | 2013-05-28 | 2013-09-11 | 西安交通大学 | Model based rotor non-trial-mass unbalance parameter identification method |
| CN109115407A (en) * | 2018-08-09 | 2019-01-01 | 大唐东北电力试验研究院有限公司 | A kind of method for correcting balance of 1000MW Turbo-generator Set |
| CN109948218A (en) * | 2019-03-12 | 2019-06-28 | 辽宁科技大学 | A kind of dynamic analysis method based on blower fan system |
-
2019
- 2019-10-10 CN CN201910956054.8A patent/CN110702313B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1132323A (en) * | 1995-03-27 | 1996-10-02 | 东北电力学院 | Dynamic rigidity coefficient method and appts. of rotary machinery dynamic balance |
| CN101949753A (en) * | 2010-09-16 | 2011-01-19 | 西北工业大学 | High-speed flexible rotor dynamic balance method |
| CN102880796A (en) * | 2012-09-18 | 2013-01-16 | 西安交通大学 | Method for calculating rotor dynamics performance of multi-parallel-axis system |
| CN103292958A (en) * | 2013-05-28 | 2013-09-11 | 西安交通大学 | Model based rotor non-trial-mass unbalance parameter identification method |
| CN109115407A (en) * | 2018-08-09 | 2019-01-01 | 大唐东北电力试验研究院有限公司 | A kind of method for correcting balance of 1000MW Turbo-generator Set |
| CN109948218A (en) * | 2019-03-12 | 2019-06-28 | 辽宁科技大学 | A kind of dynamic analysis method based on blower fan system |
Non-Patent Citations (3)
| Title |
|---|
| 傅超等: "基于加速不平衡响应的柔性转子无试重动平衡", 《西北工业大学学报》 * |
| 岳聪等: "基于升速响应信息柔性转子系统的多阶多平面瞬态动平衡方法", 《航空动力学报》 * |
| 岳聪等: "柔性转子加速过临界瞬态响应特征分析", 《机械科学与技术》 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112765771A (en) * | 2020-12-24 | 2021-05-07 | 中国飞行试验研究院 | Real-time monitoring algorithm for vibration data of aircraft engine in transition state |
| CN112765771B (en) * | 2020-12-24 | 2023-04-14 | 中国飞行试验研究院 | Real-time monitoring algorithm for vibration data of aircraft engine in transition state |
Also Published As
| Publication number | Publication date |
|---|---|
| CN110702313B (en) | 2021-07-06 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101949753B (en) | High-speed flexible rotor dynamic balance method | |
| US8291764B2 (en) | Method and apparatus for in situ unbalance and corrective balance determination for a non-vertical axis rotating assembly | |
| CN101487756B (en) | Harmonic component rotational speed balancing method in rotating machinery vibration analysis | |
| CN101915607B (en) | Phase difference aided diagnosis method for shafting vibration of turbo generator unit and system thereof | |
| CN104236799A (en) | Dynamic balance method for fast eliminating vibration, in horizontal direction, of bearing pedestals | |
| CN110702313B (en) | Method for high-precision identification of unbalanced excitation force of flexible rotor based on variable-speed starting | |
| CN111382544A (en) | Compressor blade accelerated life test method based on equivalent fatigue life | |
| CN108593229A (en) | Integral impeller blade vibration measurement device and measurement method | |
| CN102721462A (en) | Method for quickly computing Bode plot and Nyquist plot of rotary mechanical vehicle starting and parking processes | |
| CN104101464A (en) | Multi-wheel-disc rotor dynamic balancing test method based on rotating coordinate system | |
| CN102778335A (en) | Anisotropic rotor holographic dynamic balancing method based on equivalent initial phase vector | |
| CN108225783B (en) | Method and device for balancing fan rotor of aviation turbofan engine | |
| CN112327957B (en) | Method and device for controlling low-frequency vibration multi-order line spectrum of rotor | |
| CN110702314B (en) | Non-trial-weight transient high-speed dynamic balancing method based on flexible rotor acceleration response information | |
| CN105403364A (en) | Dual-trail-weight balancing method of asymmetric rotor | |
| CN104236798B (en) | The one side diagram balance method of the pure test mass nyquist diagram of rotating machinery start and stop car | |
| CN112623143B (en) | Ship dynamic shafting torsional vibration fatigue parameter fitting method based on dynamics | |
| Wallace | Modal response of a transonic fan blade to periodic inlet pressure distortion | |
| CN105547591A (en) | Asymmetric rotor balancing method without phase position | |
| CN113642131B (en) | Engine stress simulation method | |
| Chen et al. | Simulation study on unbalance vibration characteristics of dual-rotor system | |
| CN1395085A (en) | Extraction and monitoring method of half-speed vortex on-line stability characteristics of high-speed rotating machine | |
| CN115014637B (en) | Modal dynamic balance method based on low-rotation-speed measurement | |
| CN109583063B (en) | Dynamic characteristic similarity design method of fan rotor test model | |
| Gao et al. | Resonance speed measurement of high-speed spindle using an instruction-domain-based approach |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |