JP6973282B2 - Vibration test device and vibration test method - Google Patents

Description

The present invention relates to a vibration test apparatus and a vibration test method.

The following Patent Document 1 discloses a technique for performing a vibration test of a rotor system of a turbomachine (turbo compressor). This technology detects the vibration of the rotor system when the rotor system is swept and vibrated by a vibration exciter based on the FRA (Frequency Response Analyzer) method with a vibration sensor, and analyzes the output of the vibration sensor to analyze the rotor. The frequency response function of the system is obtained, and the vibration characteristics (resonance frequency, attenuation ratio, vibration mode) are calculated from this frequency response function. The sweep vibration is a vibration method in which the vibration frequency is continuously changed within a predetermined range.

Japanese Unexamined Patent Publication No. 2015-108607

By the way, as a method for obtaining a frequency response function based on sweep excitation, there are an FFT (Fast Fourier Transform) method using an FFT analyzer and an FRA (Frequency Response Analyzer) method using a frequency characteristic analyzer (Frequency Response Analyzer). be. In the FFT method, it is necessary to switch the frequency range (frequency range) to several to vibrate the test piece in order to secure the desired resolution, so that there is a problem that the test time becomes long.

On the other hand, in the FRA method, the frequency of the sine wave is continuously changed to sweep and vibrate the test object. Therefore, if the frequency range to be measured is relatively wide, some frequency ranges (frequency) are used. Since it is necessary to perform sweep vibration over the range), there is a problem that the time required for vibration becomes long, and therefore the test time becomes long. In particular, in a turbo machine such as a gas turbine, the number of blades provided in the test object becomes enormous, so that the test time becomes long.

The present invention has been made in view of the above circumstances, and an object of the present invention is to test the vibration characteristics of a test object in a shorter time.

In order to achieve the above object, in the present invention, as a first solution to the vibration test device, the test object is swept and vibrated based on the FRA (Frequency Response Analyzer) method to vibrate the test object. A vibration test device that acquires characteristics, a vibration signal generator that generates a vibration signal by superimposing a sweep sinusoidal signal in a plurality of frequency ranges, and a vibration test object that sweeps the test object based on the vibration signal. A vibration exciter for vibrating, a vibration sensor for detecting the vibration of the test object, and a plurality of analysis units corresponding to the sweep sine wave signal are provided, and the output signal of the vibration sensor is synchronized with the sweep sine wave signal. A means of providing a frequency response analysis device for analyzing the frequency response of the test object is adopted.

In the present invention, as a second solution for the vibration test device, in the first solution, the frequency response analysis device synthesizes and outputs the frequency response characteristics output by the analysis unit on the frequency axis. , Is adopted.

In the present invention, as a third solution according to the vibration test apparatus, the first or second solution further includes an FFT (Fast Fourier Transform) analyzer that frequency-analyzes the output signal of the vibration sensor. Is adopted.

In the present invention, as a fourth solution according to the vibration test apparatus, in any one of the first to third solutions, the test piece is formed as a blisk in which a plurality of wings are integrated with a disk. It is a rotor of a gas turbine, and the exciter adopts a means of vibrating a blade provided in the rotor.

Further, in the present invention, as a solution for the vibration test method, it is a vibration test method for acquiring the vibration characteristics of the test object by sweeping and vibrating the test object based on the FRA (Frequency Response Analyzer) method. Then, the test piece is temporarily sweep-vibrated with a temporary vibration signal superposed with a plurality of temporary sweep sine wave signals whose frequency range is temporarily set, and obtained from the test body based on the temporary sweep vibration. A tentative measurement process for acquiring an outline of the resonance frequency of each vibration mode based on the tentative detection signal, and a formal addition in which a formal sweep sine wave signal whose frequency range is officially set based on the outline of the resonance frequency is superimposed. The measurement step of sweeping and vibrating the test object with a vibration signal and acquiring the resonance frequency of each vibration mode based on the formal detection signal obtained from the test object based on the sweep vibration. Adopt the means of having.

According to the present invention, it is possible to test the vibration characteristics of the test object in a shorter time.

It is a block diagram which shows the whole structure of the vibration test apparatus which concerns on one Embodiment of this invention. It is a schematic diagram which shows the vibration | vibration signal in one Embodiment of this invention. It is a timing chart which shows the 1st to 5th sine wave and the 1st to 5th synchronous pulse signals in one embodiment of the present invention. It is a flowchart which shows the vibration test method which concerns on one Embodiment of this invention.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
As shown in FIG. 1, the vibration test apparatus according to the present embodiment acquires the vibration characteristics of the test object X, and is a vibration signal generator 1, a vibration machine 2, a vibration sensor 3, and a frequency response analysis. It is equipped with an apparatus 4 and an FFT (Fast Fourier Transform) analyzer 5.

The test piece X is, for example, a rotor of a gas turbine formed as a blisk in which a plurality of blades x2 are integrated with a disk x1. This blisk is a metal component such as a titanium alloy constituting the rotor of a gas turbine, and a plurality of blades x2 are radially provided on the outer peripheral surface of the annular disk x1. Note that FIG. 1 shows only a part of the blisk due to space limitations.

The vibration test apparatus according to the present embodiment measures the resonance frequency of each blade x2 in such a test object X as one of the vibration characteristics, and therefore each blade x2 is sequentially swept and excited in a predetermined order. By doing so, the resonance frequency of each blade x2 in some vibration modes is measured. The vibration test apparatus according to the present embodiment measures the resonance frequency of the primary to fifth vibration modes as an example of the vibration mode.

The vibration signal generator 1 is an electronic circuit that generates a vibration signal K by superimposing a plurality of sweep sinusoidal signals, and is an electronic circuit that generates a first oscillator 1a, a second oscillator 1b, a third oscillator 1c, and a fourth oscillator 1d. It includes a fifth oscillator 1e, a signal synthesizer 1f, an oscillation control unit 1g, and an operation unit 1h. As schematically shown in FIG. 2, the first oscillator 1a generates a first sweep sine wave signal SW1 whose frequency changes continuously in the first frequency band F1 and outputs the first sweep sine wave signal SW1 to the signal synthesizer 1f.

As also shown in FIG. 2, the second oscillator 1b generates a second sweep sine wave signal SW2 whose frequency changes continuously in the second frequency band F2 and outputs the second sweep sine wave signal SW2 to the signal synthesizer 1f.
The third oscillator 1c generates a third sweep sine wave signal SW3 whose frequency changes continuously in the third frequency band F3 and outputs it to the signal synthesizer 1f.

The fourth oscillator 1d generates a fourth sweep sine wave signal SW4 whose frequency changes continuously in the fourth frequency band F4 and outputs it to the signal synthesizer 1f. The fifth oscillator 1e generates a fifth sweep sine wave signal SW5 whose frequency changes continuously in the fifth frequency band F5 and outputs it to the signal synthesizer 1f.

The first to fifth frequency bands F1 to F5 have a relationship in which the frequencies increase in the order of the first frequency band F1 → the second frequency band F2 → the third frequency band F3 → the fourth frequency band F4 → the fifth frequency band F5. As shown in FIG. 2, it is a continuous frequency band in the vibration frequency band F0.

Of the first to fifth frequency bands F1 to F5, the first frequency band F1 is for measuring the resonance frequency (first resonance frequency) of the vibration in the primary mode (basic mode) in the blade x2. Is. Further, the second frequency band F2 is for measuring the resonance frequency (second resonance frequency) of the vibration in the secondary mode. The third frequency band F3 is for measuring the resonance frequency (third resonance frequency) of the vibration in the third-order mode. The fourth frequency band F4 is for measuring the resonance frequency (fourth resonance frequency) of the vibration in the fourth-order mode. Further, the fifth frequency band F5 is for measuring the resonance frequency (fifth resonance frequency) of the vibration in the fifth-order mode.

Further, the first to fifth oscillators 1a to 1e start transmission at the same start timing (time t1) based on the reference timing signal input from the oscillation control unit 1g as shown in FIG. The transmission ends at the same end timing (time t2). That is, the timings of the minimum frequencies of the first to fifth sweep sine wave signals SW1 to SW5 on the time axis are all the same, and the timings of the maximum frequencies of the first to fifth sweep sine wave signals SW1 to SW5 are all the same. Is.

The signal synthesizer 1f is an adder that synthesizes (multiplexes) by adding such first to fifth sweep sine wave signals SW1 to SW5, and the vibration signal K obtained by the synthesis (multiplexing). Is output to the vibrator 2. That is, the vibration signal K in the present embodiment is a combination (multiplexing) of the first to fifth sweep sine wave signals SW1 to SW5 at the same timing on the time axis. Such a vibration signal generator 1 outputs the vibration signal K toward the vibration machine 2.

The oscillation control unit 1g generates the reference timing signal and outputs it to the first to fifth oscillators 1a to 1e, and at the same time, synchronizes with the first to fifth sweep sine wave signals SW1 to SW5 as shown in FIG. The 1st to 5th synchronous pulse signals D1 to D5 are generated and output to the frequency response analysis device 4.

In FIG. 3, for convenience, the first to fifth sweeps are made so that the synchronization relationship between the first to fifth sweep sine wave signals SW1 to SW5 and the first to fifth synchronous pulse signals D1 to D5 can be easily understood. The sine wave signals SW1 to SW5 are represented as unswept single frequency sine waves. Of the first to fifth synchronous pulse signals D1 to D5, the first synchronous pulse signal D1 is a second synchronous pulse signal in which rising and falling are synchronized with the zero cross point of the first sweep sinusoidal signal SW1 as shown in the figure. In D2, the rising edge and the falling edge are synchronized with the zero cross point of the second sweep sinusoidal signal SW2.

Further, as shown in FIG. 3, the rise and fall of the third synchronous pulse signal D3 is synchronized with the zero cross point of the third sweep sinusoidal signal SW3, and the rise and fall of the fourth synchronous pulse signal D4 is the fourth. The sweep sine wave signal SW4 is synchronized with the zero cross point, and the rising edge and the falling edge of the fifth synchronous pulse signal D5 are synchronized with the zero crossing point of the fifth sweep sine wave signal SW5.

The operation unit 1h is an operation panel for manually setting various setting values of the vibration signal generator 1. The operation unit 1h manually sets, for example, the above-mentioned first to fifth frequency bands F1 to F5. That is, the test worker of the test object X sets the first to fifth frequency bands F1 to F5, that is, the vibration frequency band F0 in the vibration signal generator 1 by operating the operation unit 1h. The following work may be performed automatically.

Subsequently, the vibrating machine 2 is a kind of signal converter that converts the vibrating signal K input from the vibrating signal generator 1 into a predetermined vibrating medium and irradiates the blade x2. The vibrating machine 2 is a non-contact type that acts on the blade x2 with a vibrating medium whose intensity changes according to the amplitude change of the vibrating signal K, that is, the sinusoidal amplitude change in the first to fifth sweep sinusoidal signals SW1 to SW5. It is a type shaker. The blade x2 is swept and vibrated by the action of the vibration medium and vibrates. The vibration medium is, for example, (ultra) sound wave.

The vibration sensor 3 obtains a detection signal C (output signal) by detecting the vibration of the blade x2 caused by the sweep excitation by the vibration exciter 2. The vibration sensor 3 is, for example, a non-contact vibration sensor that irradiates the blade x2 with a predetermined detection medium and converts the reflected light from the blade x2 of the detection medium into a detection signal C (electric signal). Such a vibration sensor 3 outputs a detection signal C indicating vibration of the blade x2 to the frequency response analysis device 4 and the FFT analyzer 5.

The frequency response analyzer 4 is also called an FRA (Frequency Response Analyzer), and is a vibrator 2 based on the detection signal C input from the vibration sensor 3 and the first to fifth synchronous pulse signals D1 to D5. The frequency response characteristics of each blade x2 to the sweep vibration by the above are analyzed based on the well-known FRA method. As shown in FIG. 1, the frequency response analysis device 4 has five analysis units corresponding to the first to fifth sweep sine wave signals SW1 to SW5, that is, first to fifth analysis units 4a to 4e, and data synthesis unit 4f. It also has an output unit of 4 g.

The first analysis unit 4a corresponds to the first sweep sine wave signal SW1 and is included in the detection signal C by detecting the detection signal C in synchronization with the first synchronous pulse signal D1 (synchronous detection). The vibration component of one frequency band F1 is extracted. That is, the first analysis unit 4a has the first frequency band F1 which is the frequency band of the first sweep sinusoidal signal SW1 among the frequency responses of the blade x2 swept and excited according to the vibration signal K by the shaker 2. The frequency response characteristic (first frequency response characteristic) is calculated. The first frequency response characteristic includes the first resonance frequency of the blade x2.

The second analysis unit 4b corresponds to the second sweep sine wave signal SW2, and is included in the detection signal C by detecting the detection signal C in synchronization with the second synchronous pulse signal D2 (synchronous detection). The vibration component of the two frequency band F2 is extracted. That is, the second analysis unit 4b has the frequency response characteristic (first) of the second frequency band F2, which is the frequency band of the second sweep sinusoidal signal SW2, among the frequency responses of the blade x2 swept and excited according to the vibration signal K. 2 Frequency response characteristics) is calculated. The second frequency response characteristic includes the second resonance frequency of the blade x2.

The third analysis unit 4c corresponds to the third sweep sine wave signal SW3, and is included in the detection signal C by detecting the detection signal C in synchronization with the third synchronous pulse signal D3 (synchronous detection). The vibration component of the three frequency band F3 is extracted. That is, the third analysis unit 4c has the frequency response characteristic (third) of the third frequency band F3, which is the frequency band of the third sweep sinusoidal signal SW3, among the frequency responses of the blade x2 swept and excited according to the vibration signal K. 3 Frequency response characteristics) is calculated. The third frequency response characteristic includes the third resonance frequency of the blade x2.

The fourth analysis unit 4d corresponds to the fourth sweep sine wave signal SW4, and is included in the detection signal C by detecting the detection signal C in synchronization with the fourth synchronous pulse signal D4 (synchronous detection). 4 The vibration component of the frequency band F4 is extracted. That is, the fourth analysis unit 4d has the frequency response characteristic of the fourth frequency band F4, which is the frequency band of the fourth sweep sinusoidal signal SW4, among the frequency responses of the blade x2 swept and excited according to the vibration signal K. 4 Frequency response characteristics) is calculated. The fourth frequency response characteristic includes the fourth resonance frequency of the blade x2.

The fifth analysis unit 4e corresponds to the fifth sweep sine wave signal SW5, and is included in the detection signal C by detecting the detection signal C in synchronization with the fifth synchronous pulse signal D5 (synchronous detection). The vibration component of the 5 frequency band F5 is extracted. That is, the fifth analysis unit 4e has the frequency response characteristic of the fifth frequency band F5, which is the frequency band of the fifth sweep sinusoidal signal SW5, among the frequency responses of the blade x2 swept and excited according to the vibration signal K. 5 Frequency response characteristics) is calculated. The fifth frequency response characteristic includes the fifth resonance frequency of the blade x2.

The data synthesis unit 4f synthesizes the first to fifth frequency response characteristics having different frequency bands on the frequency axis, so that the frequency of the blade x2 over the vibration frequency band F0, that is, the frequency band of the vibration signal K described above. Get the response characteristics. The data synthesis unit 4f outputs the total frequency response characteristic over the vibration frequency band F0 to the output unit 4g as a measurement result.

The output unit 4g includes at least a display unit that displays the total frequency response characteristic as an image. This display unit has a function of displaying a cursor on the measurement result, and additionally has an operation unit for freely moving the cursor on the frequency axis. The test worker can read the resonance frequency of each vibration mode by moving the cursor to the resonance peak of each vibration mode.

The FFT analyzer 5 applies FFT (Fast Fourier Transform) processing to the detection signal C input from the vibration sensor 3, so that the frequency component included in the vibration of the blade x2 and the intensity of the frequency component, that is, the vibration of the blade x2. It is a measuring instrument that acquires the frequency characteristics (vibration frequency characteristics) of. The FFT analyzer 5 displays the vibration frequency characteristic on the screen as an output form of the vibration frequency characteristic. The FFT analyzer 5 is used to grasp the outline of the resonance frequency of the blade x2 in each vibration mode in the preliminary test conducted prior to the formal test of the blade x2.

Next, a vibration test method using such a vibration test device will be described in detail with reference to FIG.

As shown in FIG. 4, the vibration test method according to the present embodiment includes a provisional measurement step and a main measurement step. The tentative measurement process consists of two steps S1 and S2, and the main measurement process consists of two steps S3 and S4. In step S1, the above-mentioned first to fifth frequency bands F1 to F5, that is, the vibration frequency band F0 is provisionally set. That is, the test worker of the test object X can operate the operation unit 1h to set the frequency range in which the resonance frequency of each vibration mode of the blade x2 is estimated to be included based on the past test results and the like. Temporarily set the 1st to 5th frequency bands F1 to F5.

Then, the test worker instructs the vibration test apparatus to start the provisional test by operating the operation unit 1h in such a provisional setting state of the first to fifth frequency bands F1 to F5. As a result, the oscillation control unit 1g controls the first to fifth oscillators 1a to 1e to generate the first to fifth sweep sine wave signals SW1 to SW5 brisk (provisional sweep sine wave signal). Then, these temporary sweep sine wave signals are combined (multiplexed) by the signal synthesizer 1f to become a vibration signal K (temporary vibration signal) and output to the shaker 2.

Then, the blade x2 of the test object X (blisk) is provisionally swept and vibrated by the vibrating machine 2 based on the provisional vibration signal, and vibrates by the provisional sweeping vibration. The vibration of the blade x2 based on this temporary sweep excitation is converted into a detection signal C (temporary detection signal) by the vibration sensor 3 and taken into the FFT analyzer 5. Further, such a temporary detection signal is based on the vibration signal K (temporary vibration signal) generated by the first to fifth sweep sine wave signals SW1 to SW5 (temporary sweep sine wave signal). It contains frequency components corresponding to x2 vibration modes (first to fifth vibration modes).

The FFT analyzer 5 measures the vibration frequency characteristics of the blade x2 by performing FFT processing (frequency analysis processing) on the detection signal C indicating such vibration (step S2). By confirming this vibration frequency characteristic, the test worker grasps the outline of the resonance frequency of each vibration mode of the blade x2.

Here, in the measurement of the vibration frequency characteristics in the FFT analyzer 5, the resonance frequency of each vibration mode included in the detection signal C is confirmed in the temporarily set frequency range of the first to fifth frequency bands F1 to F5. In the frequency range, the lower-order resonance frequency has a lower measurement accuracy of the measured value than the higher-order resonance frequency. This is due to the principle of FFT processing and is a well-known characteristic in the FFT analyzer 5.

Then, the test worker in order to more accurately measure the resonance frequency of each vibration mode, particularly the lower-order resonance frequency, with respect to the measurement result of the FFT analyzer 5, the vibration frequency band F0, that is, the first The 1st to 5th frequency bands F1 to F5 are officially set by finely adjusting the temporarily set value (step S3).

Then, the test worker instructs the vibration test apparatus to start the main test by operating the operation unit 1h in such a formal setting state of the first to fifth frequency bands F1 to F5. As a result, the oscillation control unit 1g controls the first to fifth oscillators 1a to 1e to generate the first to fifth sweep sine wave signals SW1 to SW5 (formal sweep sine wave signals) for this test. Then, these formal sweep sine wave signals are combined (multiplexed) by the signal synthesizer 1f to become a vibration signal K (formal vibration signal) and output to the shaker 2.

Then, the blade x2 of the test object X (blisk) is subjected to the main sweep vibration by the shaker 2 based on the formal vibration signal, and vibrates by the main sweep vibration. The vibration of the blade x2 based on this sweep excitation is converted into a detection signal C (formal detection signal) by the vibration sensor 3 and taken into the frequency response analysis device 4. Further, such a formal detection signal is a vibration signal K (formal vibration signal) generated by synthesizing (multiplexing) the first to fifth sweep sine wave signals SW1 to SW5 (formal sweep sine wave signal). It is based on the above, and contains a frequency component corresponding to the vibration mode (first to fifth vibration modes) of the blade x2.

The frequency response analysis device 4 measures the vibration frequency characteristics of the blade x2 by performing FFT processing (frequency analysis processing) on the detection signal C indicating such vibration (step S4). That is, the detection signal C, which is a time signal, is synchronously detected by the first analysis unit 4a using the first synchronous pulse signal D1, and is converted into the first frequency response characteristic corresponding to the first frequency band F1. .. Further, this detection signal C is converted into a second frequency response characteristic corresponding to the second frequency band F2 by being synchronously detected by the second analysis unit 4b using the second synchronous pulse signal D2.

Further, the detection signal C is synchronously detected by the third analysis unit 4c using the third synchronous pulse signal D3, and is converted into a third frequency response characteristic corresponding to the third frequency band F3. Further, this detection signal C is converted into a fourth frequency response characteristic corresponding to the fourth frequency band F4 by being synchronously detected by the fourth analysis unit 4d using the fourth synchronous pulse signal D4. Further, the detection signal C is synchronously detected by the fifth analysis unit 4e using the fifth synchronous pulse signal D5, and is converted into a fifth frequency response characteristic corresponding to the fifth frequency band F5.

Then, such first to fifth frequency response characteristics are combined on the frequency axis by the data synthesis unit 4f, so that the first to fifth frequency response characteristics become the total frequency response characteristics over the vibration frequency band F0. Then, this total frequency response characteristic is displayed as an image in the output unit 4g. That is, this total frequency response characteristic is composed of a horizontal axis indicating the vibration frequency band F0 and a vertical axis indicating the signal intensity, and the resonance frequency of each vibration mode is indicated as a signal intensity peak. The test worker acquires the resonance frequency of each vibration mode of the blade x2 based on such a total frequency response characteristic.

In this way, the vibration test for the first blade x2 is completed, but the test is completed by acquiring the resonance frequency of each vibration mode for all the blades x2 provided in the test object X (blisk). Therefore, for the test piece X (blisk) provided with a plurality of blades x2, it is determined whether or not this measurement step has been completed for all the blades x2 (step S5), and if this determination is "Yes", it is determined. That is, when the resonance frequency of each vibration mode is acquired for all the blades x2, the vibration test of the test object X (blisk) is completed.

According to this embodiment, the vibration tests for the first to fifth frequency bands F1 to F5 are not sequentially performed in chronological order, but the vibration tests for the first to fifth frequency bands F1 to F5 are performed in chronological order. Since it is performed in parallel, it is possible to acquire the resonance frequency (vibration characteristic) in each vibration mode of the test object X (brisk) in a shorter time.

Further, according to the present embodiment, the main measurement step for the plurality of blades x2 is performed after the provisional measurement step for one blade x2 among the plurality of blades x2 having a relatively close resonance frequency. It is also possible to acquire the resonance frequency (vibration characteristic) in each vibration mode of the test object X (brisk) in a shorter time.

Here, in the provisional measurement step using the FFT analyzer 5, the measurement accuracy can be ensured for the resonance frequency in the higher-order resonance mode as described above, so that the main measurement step for one blade x2 is related to the higher-order resonance mode. It is possible to omit.

The present invention is not limited to the above embodiment, and for example, the following modifications can be considered.
(1) In the above embodiment, the vibration signal K uses the first to fifth sweep sine wave signals SW1 to SW5 having continuous frequencies as shown in FIG. 2, but the present invention is not limited thereto. That is, the first to fifth frequency bands F1 to F5 may be discontinuous as frequencies. For example, a discontinuous section over a predetermined frequency range may be set between the first to fifth frequency bands F1 to F5.

(2) In the above embodiment, as shown in FIG. 2, the start timings (time t1) of the first to fifth sweep sine wave signals SW1 to SW5 are set to the same timing, and the first to fifth sweep sine wave signals SW1 are set to the same timing. The end timing (time t2) of ~ SW5 is set to the same timing, but the present invention is not limited to this. That is, it is not necessary that the entire first to fifth sweep sine wave signals SW1 to SW5 overlap on the time axis. For example, the start timings (time t1) of the first to fifth sweep sine wave signals SW1 to SW5 may be the same, but the end timings may be different.

(3) In the above embodiment, since the excitation signal K obtained by multiplexing the first to fifth sweep sine wave signals SW1 to SW5 is used, when the first to fifth sweep sine wave signals SW1 to SW5 are distorted as a signal. Alternatively, when the vibration medium is distorted with respect to the vibration signal K, the blade x2 has a first distortion frequency component in addition to the vibration medium based on the first to fifth sweep sinusoidal signals SW1 to SW5. A vibration medium based on the harmonics of the fifth sweep sine wave signals SW1 to SW5 acts.

In such a case, the detection signal C includes a vibration component based on the vibration by the harmonics in addition to the vibration component based on the sweep vibration by the original first to fifth sweep sine wave signals SW1 to SW5. Become. For example, when the first sweep sine wave signal SW1 is distorted and a harmonic of a frequency included in the second frequency band F2 of the second sweep sine wave signal SW2 is generated, the vibration component based on this harmonic is the second analysis unit 4b. Acts as a disturbance on the second frequency response characteristic (frequency response characteristic corresponding to the second frequency band F2) output by.

Then, due to this disturbance, the measurement accuracy of the resonance frequency of the second-order vibration mode may decrease. In order to avoid or suppress the deterioration of measurement accuracy due to such harmonics, distortion of the first to fifth sweep sine wave signals SW1 to SW5 with respect to the sine wave and distortion of the vibration medium with respect to the vibration signal K are applied. It is necessary to suppress it as much as possible. Further, it is necessary to set the first to fifth frequency bands F1 to F5 so that the frequencies of the harmonics are not included in the first to fifth frequency bands F1 to F5 as much as possible.

(4) In the above embodiment, the case of measuring the resonance frequency of the first-order to fifth-order vibration modes has been described, but the present invention is not limited thereto. That is, the order of the vibration mode measured in the present invention is not limited to the fifth order, and for example, only the primary and secondary vibration modes may be measured.

(5) In the above embodiment, a provisional measurement step is provided, but the present invention is not limited to this. The resonance frequency of each vibration mode may be measured only by this measurement step. Further, the vibration characteristics to be measured are not limited to the resonance frequency. Attenuation ratios and / and vibration modes may be measured in addition to or in place of the resonant frequency.

X Test subject 1 Vibration signal generator 1a 1st oscillator 1b 2nd oscillator 1c 3rd oscillator 1d 4th oscillator 1e 5th oscillator 1f Signal synthesizer 1g Oscillation control unit 1h Operation unit 2 Vibration sensor 4 Frequency Response analyzer 4a 1st analysis unit 4b 2nd analysis unit 4c 3rd analysis unit 4d 4th analysis unit 4e 5th analysis unit 4f Data synthesis unit 4g Output unit 5 FFT oscillator

Claims (5)

It is a vibration test device that acquires the vibration characteristics of the test object by sweeping and vibrating the test object based on the FRA (Frequency Response Analyzer) method.
A vibration signal generator that generates a vibration signal by superimposing a sweep sine wave signal in multiple frequency ranges,
A vibrating machine that sweeps and vibrates the test piece based on the vibrating signal,
A vibration sensor that detects the vibration of the subject and
It is provided with a plurality of analysis units corresponding to the sweep sine wave signal, and a frequency response analysis device for analyzing the frequency response of the test object by synchronizing the output signal of the vibration sensor with the sweep sine wave signal. A characteristic vibration test device. The vibration test device according to claim 1, wherein the frequency response analysis device synthesizes and outputs the frequency response characteristics output by the analysis unit on the frequency axis. The vibration test apparatus according to claim 1 or 2, further comprising an FFT (Fast Fourier Transform) analyzer that frequency-analyzes an output signal of the vibration sensor. The test piece is a rotor of a gas turbine formed as a blisk in which a plurality of blades are integrated on a disk.
The vibration test apparatus according to any one of claims 1 to 3, wherein the vibrating machine vibrates a blade provided on the rotor. It is a vibration test method for acquiring the vibration characteristics of the test object by sweeping and vibrating the test object based on the FRA (Frequency Response Analyzer) method.
The test piece is provisionally sweep-vibrated with a temporary vibration signal superposed with a plurality of temporary sweep sine wave signals whose frequency range is temporarily set, and the test piece obtained from the test object based on the temporary sweep vibration. A tentative measurement process to obtain an overview of the resonance frequency of each vibration mode based on the detected signal,
The subject is swept and vibrated with a formal vibration signal superposed with a formal sweep sine wave signal whose frequency range is officially set based on the outline of the resonance frequency, and the subject is subjected to the sweep vibration based on the main sweep vibration. A vibration test method comprising the present measurement step of acquiring the resonance frequency of each vibration mode based on a formal detection signal obtained from a test body.

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