JP7307671B2 - Vibration test apparatus and control method for vibration test apparatus - Google Patents

Description

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

In order to investigate the durability of structures against earthquakes, experiments are conducted in which a test specimen is placed in the vibration exciter of a vibration tester and simulated earthquakes are applied.
When a vibration test is performed by determining a time history waveform to be input in advance, the seismic performance expected of the structure to be tested is often presented as a response spectrum (for example, see Patent Document 1. ).

The user of the vibrating device needs to set the envelope function and phase of the time history waveform to generate a time history waveform corresponding to the expected seismic resistance performance. This waveform generation method is called "sine wave synthesis method".

As a specific method of the "sine wave synthesis method", for example, the user of the vibration test equipment inputs the expected response spectrum of the time history waveform to be generated, selects the envelope function, and generates the waveform. , a method of calculating the response spectrum and performing a test to confirm whether the difference from the expectation is within the user's acceptable range has been proposed. Then, waveform generation and verification are repeated to generate one time-history waveform of the simulated seismic ground motion that matches the target response spectrum.
This method is effective when the performance of the shaking table of the shaker has a margin for the time history waveform of the simulated seismic motion that matches the target response spectrum.

JP 2012-237634 A

However, there is a limit to the load that can be generated by the vibration exciter of the vibration test apparatus, and the maximum acceleration that can be generated is limited according to the weight of the test object to be mounted.
On the other hand, demand for seismic resistance continues to increase, and there are cases in which it is not possible to carry out excitation tests with existing shakers using time history waveforms that only conform to the target response spectrum. Therefore, when generating the time history waveform of the simulated seismic motion, in addition to being sufficient for the target response spectrum, the time history waveform of the simulated seismic motion that can be excited by the shaker to be used is generated. It is hoped that

In the conventional sine wave synthesis method, when generating a waveform that has no margin for the performance of the shaker, the user checks the generated waveform to ensure that the maximum acceleration and maximum displacement are within the performance of the shaker. If it is out of the range of , there arises a problem that the waveform generation setting needs to be fine-tuned and regenerated for confirmation, and the time required for waveform generation increases.
In addition, even if the waveform can be generated, the time history waveform generated in a situation close to the limit will reduce the probability of successful excitation, such as touching the limiter of the shaking table due to errors during actual excitation. .

In order to generate a time history waveform applicable to multi-directional excitation with the conventional sine wave synthesis method, the time history waveform is within the performance range of the shaker and sufficient for the target response spectrum. It is necessary to prepare as many as the number of excitation directions. Therefore, if the performance of the vibrator does not have enough margin, it takes more time to generate the waveform. Especially when modifying the target spectrum, it also becomes necessary to indicate that the generated waveform is at or very close to the limits of the shaker.

SUMMARY OF THE INVENTION An object of the present invention is to provide a vibration test apparatus that generates a time history waveform of a simulated seismic motion that has been verified against a target response spectrum and is within the vibration limit range of a shaker, and a control method thereof. be. Exciter excitation limits are assumed for acceleration, velocity and displacement.

Moreover, the above objects, other objects and novel features of the present invention will be made clear by the description of the present specification and the accompanying drawings.

A vibration test apparatus of the present invention comprises a vibration table on which a test specimen is mounted, a vibration exciter provided with a drive mechanism for vibrating the vibration vibration table, a control section for controlling the driving of the drive mechanism of the vibration exciter, a calculation unit that generates a waveform of vibration to be applied to the shaker and provides the generated waveform to the control unit.
Further, the vibrator includes a drive mechanism that vibrates the vibration table in at least two different directions in the horizontal plane.
In addition, the calculation unit edits the Lissajous curve so that the envelope of the Lissajous curve of the two waveforms for vibrating the shaking table in two directions falls within the excitation range of the shaker, and then edits the edited Lissajous curve. The curve is returned to the two waveforms, and it is tested whether the resultant response spectrum obtained by analyzing the response spectra of the returned two waveforms matches the target response spectrum input to the calculation unit.
Then, the calculation unit generates vibration waveforms in which the vibration ranges of the two waveforms are within the vibration possible range of the vibration exciter.

A control method for a vibration test apparatus according to the present invention comprises a vibration table on which a test piece is mounted, a vibration exciter having a drive mechanism for vibrating the vibration vibration table, and a control unit for controlling the driving of the vibration vibration machine drive mechanism. and a computing unit that generates a waveform of vibration to be applied to the vibrator and gives the generated waveform to a control unit.
The vibration exciter includes a drive mechanism that vibrates the vibration table in at least two different directions in the horizontal plane.
Then, as waveforms, a step of generating two waveforms for vibrating the shaking table in two directions, and a step of verifying whether or not the excitation range of the generated two waveforms falls within the vibration possible range of the shaker. and generating two waveforms again if the excitation range does not fit within the vibratory range as a result of the test.

According to the vibration test apparatus of the present invention described above, the calculation unit vibrates the vibration table in two different directions in the horizontal plane. Generate a waveform.
As a result, the excitation range of the two generated waveforms is reliably within the excitation possible range of the shaker. Therefore, it is possible to avoid errors such as contacting the limiter of the vibration exciter due to the above-described error during excitation, and it is possible to achieve successful excitation with a high probability.
Then, it is possible to easily generate a time-history waveform of the simulated seismic motion that matches the target response spectrum and that can be excited by the vibrator to be used.

According to the control method of the vibration test apparatus of the present invention described above, the step of generating two waveforms for vibrating the vibration table in two different directions in the horizontal plane as waveforms, and the excitation ranges of the two generated waveforms are: It has a step of verifying whether or not it falls within the possible vibration range of the vibration exciter, and a step of generating two waveforms again when the vibration range does not fall within the possible vibration range as a result of the verification.
As a result, if the excitation range of the two generated waveforms does not fit within the vibrating range, the two waveforms are generated again, so the excitation range of the two generated waveforms is the vibratory range of the shaker. fits securely inside. Therefore, it is possible to avoid errors such as contacting the limiter of the vibration exciter due to the above-described error during excitation, and it is possible to achieve successful excitation with a high probability.
Then, it is possible to easily generate a time-history waveform of the simulated seismic motion that matches the target response spectrum and that can be excited by the vibrator to be used.

Problems, configurations, and effects other than those described above will be clarified by the following description of the embodiments.

1 is a schematic configuration diagram (block diagram) of an embodiment of a vibration test apparatus; FIG. 4 is a flowchart for explaining a waveform generation method in Example 1. FIG. 9 is a flowchart for explaining a waveform generation method in Example 2; 10 is a flowchart for explaining a waveform generation method in Example 3; 2 is a flowchart for explaining a waveform generation method by a conventional sine wave synthesis method;

Hereinafter, embodiments and examples according to the present invention will be described with reference to sentences or drawings. However, the structure, materials, and various other specific configurations shown in the present invention are not limited to the embodiments and examples taken up here, and can be appropriately combined and improved within the scope of not changing the gist. is. Elements that are not directly related to the present invention are omitted from the drawing.

In many vibration testers, when vibration is applied in two directions in a horizontal plane, the maximum vibration force is smaller than in the case of horizontal vibration in one direction. This is because actuators for driving the vibration table are installed in three orthogonal directions in many vibration exciters. For this reason, for horizontal excitation, when one-directional excitation is performed in the direction of 45° for two horizontal actuators, two orthogonal actuators are driven in the same phase, thereby Vibration can be performed with an excitation force approximately 1.4 times greater than when only an actuator is used.
However, when two time history waveforms are generated to drive an actuator in two horizontal directions, the characteristics differ depending on the driving direction of the actuator with respect to the horizontal control axis of the vibration table.

If two time-history waveforms are generated as acceleration in two horizontal directions and a Lissajous curve is drawn, the Lissajous curve is generally within the range of a circular shape in many cases. However, on rare occasions, two horizontal directions reach maximum values simultaneously, and an acceleration 1.4 times the maximum value of each time history waveform is generated in the direction of 45° from the horizontal control axis of the vibration table. .

Here, in a vibration exciter in which the actuator is installed parallel to the horizontal control axis of the vibration table, vibration can be generated even if two horizontal directions have maximum values at the same time.
On the other hand, with a vibration exciter in which the actuator is installed in the direction of 45° with respect to the horizontal control axis of the vibration table, when performing multi-axis vibration, the limit value of single-axis vibration is 1/1.4 times should be the maximum value. In addition, when the two horizontal directions are at maximum values at the same time, the vibration in the direction in which the actuator is installed is one times that of the single-axis vibration. In order to avoid this situation, it is necessary to generate two waves that do not have maximum values in both horizontal directions at the same time.

In the conventional sine wave synthesis method, when generating a waveform that has no margin for the performance of the shaker, the user checks the generated waveform to ensure that the maximum acceleration and maximum displacement are within the performance of the shaker. If it is out of the range of , there arises a problem that the waveform generation setting needs to be fine-tuned and regenerated for confirmation, and the time required for waveform generation increases.
In addition, even if the waveform can be generated, the time history waveform generated in a situation close to the limit will reduce the probability of successful excitation, such as touching the limiter of the shaking table due to errors during actual excitation. .

In order to generate a time history waveform applicable to multi-directional excitation with the conventional sine wave synthesis method, the time history waveform is within the performance range of the shaker and sufficient for the target response spectrum. It is necessary to prepare as many as the number of excitation directions. Therefore, if the performance of the vibrator does not have enough margin, it takes more time to generate the waveform. Especially when modifying the target spectrum, there is also a need to show that the generated waveform is within or within the limits of the shaker.

In order to solve such problems, in the vibration test apparatus and the control method thereof according to the present invention, two waveforms are generated for vibrating the vibration table in two different directions in the horizontal plane. The generation of the two waveforms is continued until the excitation range falls within the excitation possible range of the shaker.

A vibration test apparatus of the present invention comprises a vibration table on which a test specimen is mounted, a vibration exciter provided with a drive mechanism for vibrating the vibration vibration table, a control section for controlling the driving of the drive mechanism of the vibration exciter, a calculation unit that generates a waveform of vibration to be applied to the shaker and provides the generated waveform to the control unit.
Further, the vibrator includes a drive mechanism that vibrates the vibration table in at least two different directions in the horizontal plane.
Then, the calculation unit generates vibration waveforms in which the vibration ranges of the two waveforms for vibrating the vibration table in two directions are within the vibration possible range of the vibration exciter.

In the above vibration test apparatus, the calculation unit further calculates the expected values of the maximum acceleration, maximum velocity, and maximum displacement for the generated waveform, and from the calculated expected values, It is possible to predict the time required to generate a waveform that fits within the range, and correct the input target response spectrum if the predicted time is longer than the allowable calculation time.
In the vibration test apparatus having this configuration, when the predicted time is equal to or less than the allowable calculation time, the calculation unit may calculate the ratio between the calculated expected value and the excitation limit as the limit ratio. can.

In the above vibration test apparatus, the calculation unit further calculates an expected value of the excitation range for the generated waveform, and generates a waveform that falls within the possible excitation range from the calculated expected value of the excitation range. If the estimated time is longer than the allowable computation time, the input target response spectrum can be corrected.

In the vibration test apparatus having this configuration , when the predicted time is equal to or less than the allowable calculation time, the calculation unit calculates the ratio between the calculated expected value and the possible vibration range as the limit ratio. can be done.

In the above-described vibration test apparatus, the calculation unit further corrects the Lissajous curves so that the envelopes of the Lissajous curves of the two waveforms fall within the vibrating range of the vibrator , and then vibrates the two waveforms. It can be configured to test whether or not the range is within the vibrable range.

A control method for a vibration test apparatus according to the present invention comprises a vibration table on which a test piece is mounted, a vibration exciter having a drive mechanism for vibrating the vibration vibration table, and a control unit for controlling the driving of the vibration vibration machine drive mechanism. and a computing unit that generates a waveform of vibration to be applied to the vibrator and gives the generated waveform to a control unit.
The vibration exciter includes a drive mechanism that vibrates the vibration table in at least two different directions in the horizontal plane.
Then, as waveforms, a step of generating two waveforms for vibrating the shaking table in two directions, and a step of verifying whether or not the excitation range of the generated two waveforms falls within the vibration possible range of the shaker. and generating two waveforms again if the excitation range does not fit within the vibratory range as a result of the test.

In the vibration test apparatus control method described above, the step of calculating the expected values of the maximum acceleration, the maximum velocity, and the maximum displacement of the generated waveform; A configuration further comprising a step of predicting the time required to generate a waveform that fits, and a step of correcting the target response spectrum to be input when the predicted time is longer than the allowable calculation time. can be done.

In the vibration test apparatus control method described above, for the waveform to be generated, a step of calculating the expected value of the excitation range, and from the calculated expected value of the excitation range to the generation of the waveform within the possible excitation range. and, if the predicted time is longer than the allowable calculation time, correcting the input target response spectrum.

In the above control method for the vibration test apparatus, if the predicted time is equal to or less than the allowable calculation time, the ratio between the calculated expected value and the possible vibration range is calculated as a limit ratio. be able to.

In the above control method for the vibration test apparatus, a step of correcting the Lissajous curves is further performed so that the envelopes of the Lissajous curves of the two waveforms fall within the vibrating range of the vibrator , and then the two waveforms It can be configured to perform a step of verifying whether or not the vibration range is within the vibratable range.

The vibration test apparatus according to the present invention is suitable, for example, for seismic testing of nuclear equipment and the like, but the application of the specimen that is the test sample is not particularly limited, and it can be applied to specimens in various technical fields. It is possible.

In the vibration test apparatus described above, the vibrator includes a vibration table on which the test object is mounted, and a drive mechanism for vibrating the vibration table.
The vibrating table is composed of a vibrating table having a planar upper surface, or a table having another shape on which a specimen can be mounted.
The driving mechanism can be composed of an actuator or the like that vibrates the vibration table by expanding and contracting in one-dimensional direction.

The vibration exciter includes a drive mechanism that vibrates the vibration table in at least two different directions in the horizontal plane. The two different directions can be, for example, directions orthogonal to each other, such as X-axis direction and Y-axis direction in a horizontal plane, directions at 45° to the X-axis and Y-axis, or directions oblique to each other.
In addition to the drive mechanism that vibrates the vibration table in two different directions in the horizontal plane, it is also equipped with a drive mechanism that vibrates the vibration table in the vertical direction, making it possible to vibrate the vibration table in three dimensions. configuration.

The control unit controls driving of the drive mechanism of the vibrator.
The control unit includes, for example, a control circuit. Also, the control unit can be configured to operate by a computer program.

The calculation unit generates a waveform of vibration to be applied to the vibrator and applies the generated waveform to the control unit.
The calculation unit includes, for example, a CPU (Central Processing Unit), a memory (storage device), etc., and can be configured to operate with a computer program.

A sinusoidal synthesis method is preferably employed in generating the two waveforms that vibrate the table in two different directions in the horizontal plane.
Then, a target response spectrum and an envelope function are input, and a time history waveform is generated by a sine wave synthesis method, that is, by superimposing a large number of sine waves. The generated time history waveform is tested to see if it matches the inputted target response spectrum, and the time history waveform that has passed the test is used.
If the test fails, the Fourier amplitude spectrum that constitutes the sine wave is modified to produce a time history waveform.

For the two waveforms that vibrate the shaking table in two different directions in the horizontal plane, after generating the time history waveforms that pass the above test, the excitation range of the two waveforms generated is the excitation of the shaker. It is determined whether or not it falls within the vibrating range.
As a result of the determination, when it falls within the vibrating possible range, the determined two waveforms are adopted as a time-history waveform set, and the time-history waveform set is given to the control unit to perform the vibration test.
As a result of the determination, if it does not fit within the vibrating vibrating range, it is regarded as a failure and generation of two waveforms is continued. Here, the waveforms may be generated from the beginning. It is also possible to select one and, if the decision fails, select another two waveforms.

Calculate the expected values for the maximum acceleration, maximum velocity, and maximum displacement of the generated waveform, and calculate the time required to generate a waveform that is within the excitation limits of the shaking table from the calculated expected values. When it is configured to predict, for example, from the expected value and the excitation limit of the vibration exciter, the number of trials until a waveform that passes the judgment is obtained, and the time required for one trial is multiplied. , to derive the predicted time.

For the waveform to be generated, the expected value of the excitation range is calculated, and from the calculated expected value of the excitation range, when it is configured to predict the time required to generate a waveform that falls within the possible excitation range, For example, from the expected value of the excitation range and the possible excitation range of the vibrator, the number of trials until obtaining a waveform set that passes the judgment is calculated, and the time required for one trial is multiplied, Derive the estimated time.

In each configuration for predicting the required time, if the predicted time is longer than the allowable calculation time, the input target response spectrum is corrected.
Correction of the target response spectrum is made so as to shorten the calculation time. Preferably, the low frequency components of the target response spectrum are reduced. As a method of reducing the low-frequency component of the target response spectrum, for example, a method of deleting the component with a predetermined frequency width from the lowest frequency side, or a method of reducing the amplitude of the component can be considered.

When the Lissajous curve is modified so that the envelope of the Lissajous curve of the two waveforms falls within the excitation possible range of the vibrator , the Lissajous curve is modified, for example, by envelope processing. Specifically, for example, the Lissajous curve is multiplied by the ratio of the possible vibration range and the envelope of the created waveform. As a result, even if the created waveform has a larger envelope, the corrected Lissajous curve falls within the vibrating range.

According to the vibration test apparatus having the above configuration, the calculation unit vibrates the vibration table in two different directions in the horizontal plane. is generated, the excitation range of the two generated waveforms reliably falls within the excitation possible range of the shaker. Therefore, it is possible to avoid errors such as contacting the limiter of the vibration exciter due to the above-described error during excitation, and it is possible to achieve successful excitation with a high probability.
Then, it is possible to easily generate a time-history waveform of the simulated seismic motion that matches the target response spectrum and that can be excited by the vibrator to be used.

According to the method for controlling the vibration test apparatus described above, the steps of generating two waveforms for vibrating the vibration table in two different directions in the horizontal plane as waveforms, and and a step of generating two waveforms again if, as a result of the test, the excitation range does not fit within the vibratory range. If the excitation range does not fit within the excitation possible range, two waveforms are generated again. Therefore, the excitation range of the two generated waveforms is reliably within the excitation range of the shaker, avoiding errors such as touching the limiter of the shaker due to the above-mentioned error during excitation. By doing so, the excitation can be successfully performed with a high probability.
Then, it is possible to easily generate a time-history waveform of the simulated seismic motion that matches the target response spectrum and that can be excited by the vibrator to be used.

In the vibration test equipment and its control method described above, the expected values of the maximum acceleration, maximum velocity, and maximum displacement of the generated waveform are calculated, and from the calculated expected values, the waveform that falls within the excitation limit of the shaking table is determined. When the time required for generation is predicted, and if the predicted time is longer than the allowable calculation time, the target response spectrum to be input is corrected, the calculation is performed by correcting the target response spectrum By shortening the time, it is possible to improve the possibility of acquiring a waveform that falls within the vibrating possible range within the allowable calculation time.
In addition, even if the initial target response spectrum is set unreasonably, it is possible to prevent the generated waveform from falling into an infinite loop because the generated waveform never stays within the excitation possible range.

In the vibration test equipment and control method of the vibration test equipment described above, the expected value of the excitation range is calculated for the generated waveform, and from the calculated expected value of the excitation range, the waveform that falls within the vibratory range is generated. If the predicted time is longer than the allowable computation time, the input target response spectrum is corrected. can be shortened to improve the possibility of acquiring a waveform that falls within the excitation possible range within the allowable calculation time.
In addition, even if the initial target response spectrum is set unreasonably, it is possible to prevent the generated waveform from falling into an infinite loop because the generated waveform never stays within the excitation possible range.

In the above-described vibration test apparatus and vibration test apparatus control method, further, when the predicted time is equal to or less than the allowable calculation time, the ratio between the calculated expected value and the excitation limit is calculated as a limit ratio, or , When the ratio between the calculated expected value and the possible vibration range is calculated as the limit ratio, the calculation of the limit ratio makes it clear how severe the generated waveform is with respect to the vibration limit of the vibration exciter. can be shown.

In the vibration test apparatus and the control method of the vibration test apparatus described above, the Lissajous curves are corrected so that the envelopes of the Lissajous curves of the two waveforms fall within the excitation range of the shaker , and then the two waveforms are added. When it is configured to test whether or not the vibration range falls within the possible vibration range, the vibration range of the two waveforms after the correction of the Lissajous curve surely falls within the possible vibration range. As a result, the excitation can be successfully performed with a high probability.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Example 1)
FIG. 1 shows a schematic configuration diagram (block diagram) of one embodiment of a vibration test apparatus as a configuration of a vibration test apparatus to which an embodiment of the present invention is applied.
The vibration test apparatus shown in FIG. 1 includes a vibration exciter 10, a control unit 110 that controls the operation of the vibration exciter 10, and an input waveform generation system 300 that generates a time history waveform set 120 to be input to the control unit 110. It is

The vibration exciter 10 includes a vibration table 100 , an actuator 101 that is a driving mechanism for driving the vibration table 100 , and a base 102 that fixes one end of the actuator 101 .
The vibrating table 100 is a vibrating table having a flat upper surface, on which a test object (a sample to be subjected to a vibration test) 104 is mounted and fixed.
One actuator 101 is connected to each corner of the vibration table 100 having a square planar shape, and a total of four actuators 101 are provided. Each actuator 101 has one end connected to the corner of the vibration table 100 and the other end connected to the base 102 .
A total of two foundations 102 are provided on the left and right sides of the vibration table 100 . A vibration table 100 is fixed to a foundation 102 via an actuator 101 .

The controller 110 drives the four actuators 101 of the vibration exciter 10 .
In addition, the control unit 110 drives the actuator 101 by controlling hydraulic pressure, current, etc. so that the time history waveform of the time history waveform set 120 input from the input waveform generation system 300 is reproduced on the vibration table 100. do.
The control unit 110 includes, for example, a control circuit and the like, and is configured to drive the actuator 101 by a control signal supplied to the control circuit.

The input waveform generation system 300 generates a time history waveform set 120 to be input to the control section 110 from the input target response spectrum 1 by calculation.
That is, the input waveform generation system 300 functions as a calculation section that performs calculations for generating waveforms to be input to the control section 110 .
The input waveform generation system 300 includes a CPU (Central Processing Unit), a memory (storage device), etc., and operates with a computer program. Then, the input waveform generation system 300 generates the time-history waveform set 120 to be input to the control unit 110 through the steps shown in the flowchart to be described later.

The time history waveform set 120 is a set of two waveforms. Vibration based on each waveform of the time history waveform set 120 is applied to the four actuators 101 via the control unit 110 .

FIG. 1 shows a schematic diagram of the vibrating table 100 of the vibrator 10 as viewed from above.
In FIG. 1, as an example, each actuator 101 is installed in a direction of 45° with respect to the horizontal control axis of the vibration table 100 (diagonal direction of the vibration table 100 having a square planar shape). 1 shows a vibration exciter 10 of the type shown.

When the actuators 101 are attached to the vibration table 100 orthogonally, the direction in which the maximum vibration force can be generated is the direction of 45° with respect to the two orthogonal directions of the actuators 101 . In the arrangement of the four actuators 101 shown in FIG. 1, the direction in which the maximum excitation force can be generated is the horizontal direction in the drawing.

When displaying the maximum vibration acceleration when vibrating in two directions as the specifications of the vibration exciter 10, it is assumed that the envelope of the Lissajous curve of the input acceleration is generally circular, and is indicated by the dotted line in the figure. In many cases, the range of the isotropic vibration possible range 106 is shown.
However, in practice, excitation is possible up to a direction-dependent excitation possible range 107 indicated by a dashed line in the drawing.

The vibration exciter 10 shown in FIG. 1 is of a type in which an actuator 101 is installed parallel to a horizontal control axis of a vibration table 100 .
When inputting an acceleration waveform for control to the vibration exciter 10 , regardless of the direction of the control coordinates 103 of the vibration table 100 , the coordinate axis 105 of the test object 104 is aligned with the control coordinates 103 of the vibration table 100 . Install it at an angle to the direction. Then, the control waveform is input after coordinate transformation in the horizontal plane.

Here, FIG. 5 shows a flowchart for explaining a waveform generation method by a conventional sine wave synthesis method as a configuration to be compared.

The sine wave synthesis method is a method of creating a certified time history waveform with a target response spectrum as an input, and reproduces the acceleration waveform at the time of an earthquake at a specific position where the object of the vibration test is installed on the safe side. The purpose is to generate characteristic time history waveforms. The characteristics of the acceleration waveform during an earthquake are expressed by the target response spectrum and the envelope function.

In the sine wave synthesis method, a target response spectrum and an envelope function are input as characteristics of seismic waves, and a time history waveform is generated by superimposing many sine waves. A Fourier spectrum consisting of a Fourier amplitude spectrum and a Fourier phase spectrum represents the magnitude ratio and phase of the superimposed sine waves. The first step in waveform generation requires some Fourier spectrum.

The Fourier amplitude spectrum is set to a suitable initial value in the starting stage, eg normalized response spectrum. In the flowchart of FIG. 5, the normalized target response spectrum is used as the initial value of the Fourier amplitude spectrum (initial Fourier amplitude spectrum), as will be described later.

The Fourier phase spectrum includes cases where random numbers are used and cases where observed wave data is used, but the vibration test apparatus of the present invention deals with cases where random numbers are used for the Fourier phase spectrum.

In the flowchart shown in FIG. 5, waveforms are generated as described below.
In the following description, a method of generating a waveform when applying the conventional sine wave synthesizing method shown in the flow chart of FIG. 5 to the vibration test apparatus shown in FIG. 1 will be described.

First, in step S101, a target response spectrum is input. Also, in step S102, an envelope function is input.
In the vibration test apparatus of FIG. 1, a target response spectrum 1 and an envelope function (not shown) are input to an input waveform generation system 300, respectively.

Next, in step S103, the target response spectrum input in step S101 is normalized.
As a result, the initial Fourier amplitude spectrum shown in step S104 is obtained.
Also, by generating random numbers in step S105, the Fourier phase spectrum shown in step S106 is obtained.

Next, in step S107, the initial Fourier amplitude spectrum of step S104 and the Fourier phase spectrum of step S106 are subjected to inverse Fourier transform.
As a result, a time history waveform with a constant amplitude is generated as shown in step S108.

Next, in step S109, the envelope function input in step S102 is introduced into the time history waveform of constant amplitude in step S108.
Further, in step S110, the time history waveform of constant amplitude into which the envelope function is introduced is subjected to blanking correction.
As a result, a time-history waveform whose amplitude changes in the time direction shown in step S111 is obtained.

Next, in step S112, response spectrum analysis is performed on the time history waveform whose amplitude changes in the time direction in step S111, and the resulting response spectrum shown in step S113 is obtained.

Subsequently, in step S114, it is checked whether the resulting response spectrum of step S113 matches the target response spectrum input in step S101. For example, it searches for the maximum value of the error in the frequency direction and tests whether the error is within the set range.
If the test fails, the process proceeds to step S115, a corrected Fourier amplitude spectrum is created by correcting the Fourier amplitude spectrum, and the process is performed again. Specifically, the initial Fourier amplitude spectrum or the Fourier amplitude spectrum is modified by multiplying the target response spectrum divided by the resulting response spectrum. Then, in step S107, the modified Fourier amplitude spectrum created in step S115 and the Fourier phase spectrum in step S106 are subjected to inverse Fourier transform. After that, the same process is repeated until the test in step S114 is passed.
If the verification is passed, the process proceeds to step S116, the verified time history waveform is obtained, and the generation of the input waveform by the sine wave synthesis method ends.

When the sine wave synthesis method whose flow chart is shown in FIG. 5 is applied to the vibration test apparatus of FIG. ) are executed in the input waveform generation system 300 .
Then, the acquired verified time history waveforms are input to the control unit 110 as the time history waveform set 120 shown in FIG.

In the case of this conventional sine wave synthesis method, as described above, when generating a waveform that has no margin for the performance of the shaker, the generated waveform should be checked by the user to determine the maximum acceleration and maximum acceleration. If the displacement is out of the performance range of the vibration exciter, it will be necessary to fine-tune the waveform generation settings and regenerate the waveform for confirmation, resulting in an increase in the time required to generate the waveform.
In addition, even if the waveform can be generated, the time history waveform generated in a situation close to the limit will reduce the probability of successful excitation, such as touching the limiter of the shaking table due to errors during actual excitation. .

Next, FIG. 2 shows a flowchart for explaining the input waveform generation method in the first embodiment.
In this embodiment, as shown in the flow chart of FIG. 2, the vibration limit of the vibration exciter to be used is input to the waveform generation method by the conventional sine wave synthesis method shown in the flow chart of FIG. Add content.

In the flowchart shown in FIG. 2, waveforms are generated as described below.
In the following description, a method of generating a waveform when the method of the first embodiment shown in the flowchart of FIG. 2 is applied to the vibration test apparatus shown in FIG. 1 will be described.
In the flowchart shown in FIG. 2, in step S4, the sine wave synthesis method is performed in the same manner as steps S101 to S115 shown in the flowchart in FIG. Similar to S116, a verified time history waveform is obtained.

First, in step S1, a target response spectrum is input as in step S101 shown in FIG. Also, in step S2, the excitation limit L is input. Further, in step S13, the vibration possible range is input. Also, although not shown, an envelope function is input in the same manner as in step S102 shown in FIG.
In the vibration test apparatus of FIG. 1, a target response spectrum 1, a vibration limit (not shown) L, a possible vibration range (not shown), and an envelope function (not shown) are input to the input waveform generation system 300. do.

Next, in step S3, a random number is generated in the same manner as in step S105 shown in FIG.
Then, in step S4, using the target response spectrum input in step S1 and the random number generated in step S3, sine wave synthesis is performed in the same manner as steps S103 to S115 shown in FIG.
As a result, in step S5, similarly to step S116 shown in FIG. 5, a verified time history waveform is obtained.

Next, in step S6, a feature parameter P consisting of the maximum acceleration, maximum velocity, and maximum displacement of the verified time history waveform obtained in step S5 is extracted.
Next, in step S7, limit determination is performed by comparing the characteristic parameter P extracted in step S6 and the excitation limit L input in step S2.
If the characteristic parameter P exceeds the excitation limit L (P>L), the determination is rejected, the process returns to step S3, the random number set as the Fourier phase spectrum is updated, and the verified time history waveform is obtained. Repeat generation.
If the characteristic parameter P is equal to or less than the vibration limit L (P≦L), the determination is passed, and the process proceeds to step S9, where the verified time history waveform at this time is set as the within-limits time history waveform.

In addition, in order to make the execution of the program more efficient, by setting different Fourier phase spectra and simultaneously executing a plurality of waveform generations, the verified time history waveforms shown in step S8 are obtained as a set of verified time history waveforms shown in step S5. Generating groups and continuing until an in-limit time history waveform is generated that passes the limit determination of step S7.

After generating a single qualified time history waveform as described above, a set of bidirectional time history waveforms in the horizontal plane is subsequently generated.
When the vibration exciter is driven using time history waveforms in two directions in the horizontal plane, the envelope of the Lissajous curve of acceleration, velocity, and displacement is the excitation range of the two selected waves.

In step S10, as a set of in-limit time history waveforms shown in step S9 that have passed the limit determination in step S7, a group of in-limit time history waveforms composed of a plurality of (two or more) in-limit time history waveforms is selected. Generate.
Then, in step S11, two waves each are selected in round-robin from the within-limit time history waveform group generated in step S10, and in step S12, the excitation range is obtained for the selected two waves.

Next, in step S14, in-plane vibration limit determination is performed using the vibration range obtained in step S12 and the possible vibration range input in step S13.
If the excitation range exceeds the excitation possible range, the determination is rejected, the process returns to step S11, and a new combination of two waves is selected.
If the excitation range is within the excitation possible range, the determination is passed, the process proceeds to step S15, a two-directional time history waveform set is obtained, and waveform generation is completed.

In the vibration test apparatus of FIG. 1, the input waveform generation system 300 executes each step from random number generation (step S3) to acquisition of the time history waveform set (step S15) in the flowchart shown in FIG.
1, the time history waveform set obtained in step S15 is input from the input wave generation system 300 to the control unit 110 as the bidirectional time history waveform set 120 shown in FIG.

According to the present embodiment described above, the in-plane vibration limit determination in step S14 determines whether the excitation range obtained for the two waves selected from the within-limit time history waveform group is within the vibration possible range of the vibration exciter. to obtain a bidirectional time history waveform set that passes the in-plane vibration limit determination. Further, by the in-plane excitation limit determination in step S14, the selection of two waves from the within-limit time-history waveform group shown in step S11 is continued until the excitation possible range (accepted) input in step S13 is satisfied. Repeated. That is, the generation of the bidirectional time history waveform set that passes the in-plane excitation limit determination is continued.
As a result, the excitation range of the acquired two-directional time history waveform set is reliably within the excitation possible range of the vibrator 10 . Therefore, it is possible to avoid an error such as touching the limiter of the vibration exciter 10 due to the above-described error during vibration, and the vibration can be successfully performed with a high probability.
Then, it is possible to easily generate a time-history waveform of the simulated seismic motion that matches the target response spectrum and that can be excited by the vibrator to be used.

(Example 2)
In the first embodiment, the limit determination in step S7 and the in-plane excitation limit determination in step S14 are repeated until a time history waveform that passes the determination is obtained. end up
In the event of an infinite loop, the user must decide to stop the waveform generating system, and to continue, the user must decide to change the input such as the target response spectrum.

Therefore, in this embodiment, in order to avoid an infinite loop, when the number of verified time history waveform groups reaches a predetermined number (for example, 10 waves), the estimated time until one within-limit time history waveform is obtained is demand. Specifically, for example, the number of trials for obtaining an in-limit time history waveform that passes the limit judgment with a probability of 95% or more is calculated, and the time required by the computer to create one waveform and perform the limit judgment. Multiply to derive the predicted time until one within-limit time history waveform is obtained.

The time required by the computer to create one waveform and perform limit determination is calculated by dividing the time required up to that point by the number of verified time history waveforms generated.
Then, the user inputs in advance the allowable operation time until the calculation is completed, and the waveform is generated from the input allowable operation time and the predicted time until one time history waveform within the limit is obtained. Whether to continue or not, continuation determination is performed.
In addition, the estimated time until a time history waveform set that passes the in-plane excitation limit judgment is obtained from the input possible excitation range and the expected value of the excitation range calculated from the within-limit time history waveform group. Ask for Then, based on the input allowable calculation time and the predicted time until a time history waveform set that passes the above-described in-plane vibration limit determination is obtained, a continuation determination is made as to whether to continue waveform generation.
As a result of these continuation determinations, if there is a high possibility that the waveform cannot be generated within the allowable calculation time, the low-frequency component of the target response spectrum is reduced, and waveform generation is re-executed.

Specific methods for reducing low-frequency components include, for example, a method of setting the lowest side of the frequency range of the current target response spectrum to 0 by 1% (corresponding to high-pass filtering the resulting waveform), Several options are set and selected by the user in advance, such as a method of reducing the frequency components lower than 1/3 of the next natural frequency by 1%.

If the allowable calculation time and low-frequency component reduction are not input in advance, the predicted time is continuously presented, and the waveform generation is interrupted and the target response spectrum is edited according to the user's judgment.

Moreover, even if a time history waveform within limits or a time history waveform set is obtained, it may be created under conditions where the probability of being within the vibration limit or vibration possible range is extremely low.
In this case, even a slight error when actually driving the vibration table can cause the behavior of the vibration table to deviate from the control target. the possibility increases.
Therefore, in this embodiment, in order to avoid such an undesirable situation, the ratio between the expected value of the feature parameter and the excitation limit is calculated as the limit ratio in the continuation determination stage. Similarly, the ratio between the expected vibration range and the possible vibration range is calculated as the limit ratio. Then, the calculated limit ratio is presented to the user of the vibration test apparatus.
The limit ratio is an index showing how severe the time history waveform set is with respect to the limit of the shaker, and is presented as the limit ratio in the test plan document and the test result report document.

FIG. 3 shows a flow chart for explaining the input waveform generation method in the second embodiment.
In the flowchart shown in FIG. 3, waveforms are generated as described below.

First, in step S21, a target response spectrum is input in the same manner as in step S1 shown in FIG. Further, in step S22, similarly to step S2 shown in FIG. 2, the excitation limit L is inputted. Further, in step S33, similarly to step S13 shown in FIG. 2, an excitation possible range is input. Also, in step S38, the above-described allowable calculation time is input. Furthermore, although not shown, an envelope function is input in the same manner as in step S102 shown in FIG.
In the vibration test apparatus of FIG. 1, a target response spectrum 1, a vibration limit (not shown) L, a possible vibration range (not shown), an allowable calculation time (not shown), and an envelope function (not shown) are , respectively to the input waveform generation system 300 .

In each process of steps S23 to S35, similarly to each process of steps S3 to S15 of the first embodiment shown in FIG. to obtain a set of time history waveforms.
A detailed description of each of these steps is omitted.

In step S28, a verified time history waveform group is obtained in the same manner as in step S8 of the first embodiment shown in FIG.
Next, in step S36, expected values of characteristic parameters including maximum acceleration, maximum velocity, and maximum displacement are obtained from the verified time history waveform group obtained in step S28.

Next, in step S37, an expected limit judgment pass time is calculated from the excitation limit input in step S22 and the expected value of the feature parameter obtained in step S36.
Then, in step S39, it is determined whether or not the waveform can be formed within the allowable calculation time and the waveform generation can be continued, based on the limit judgment pass expected time calculated in step S37 and the allowable calculation time input in step S38. (Continue determination).

On the other hand, in step S30, similarly to step S10 of the first embodiment shown in FIG. 2, a group of in-limit time history waveforms is obtained.
Next, in step S40, an expected value of the excitation range is obtained from the within-limit time history waveform group obtained in step S30.
Next, in step S41, the time expected to pass the in-plane limit determination in step S34 based on the expected value of the excitation range obtained in step S40 and the possible excitation range input in step S33, i.e. Estimated in-plane limit judgment pass time is calculated.
Then, in step S42, it is determined whether or not the waveform can be formed within the allowable calculation time and the waveform generation can be continued, based on the in-plane limit determination pass expected time calculated in step S41 and the allowable calculation time input in step S38. Judgment (continuous judgment).

If it is determined in the continuation determinations in steps S39 and S42 that the waveform cannot be formed within the allowable calculation time and the waveform generation cannot be continued, the process proceeds to step S43 to reduce the low frequency components. After reducing the low-frequency components, the process returns to step S21 to re-execute waveform generation.
On the other hand, if it is determined in the continuation determination in step S39 that waveform formation is possible within the allowable calculation time and that waveform generation can be continued, the flow advances to step S44, and the expected value of the feature parameter obtained in step S36 and , and the vibration limit input in step S22 is calculated as the limit ratio.
Further, in the continuation determination in step S42, if it is determined that waveform formation is possible within the allowable calculation time and that waveform generation can be continued, the process proceeds to step S44, and the expected value of the excitation range obtained in step S40 , and the possible vibration range input in step S33 is calculated as the limit ratio.

In the vibration test apparatus of FIG. 1, the input waveform generation system 300 executes each step from the random number generation (step S23) to the limit ratio calculation (step S44) in the flowchart shown in FIG.
1, the time history waveform set obtained in step S35 is input from the input wave generation system 300 to the control unit 110 as the bidirectional time history waveform set 120 shown in FIG.

The limit ratio calculated in step S44 is presented to the test plan document and the test result report document. Specifically, for example, although not shown, it is displayed on a display device such as a display or a display unit provided in the input waveform generation system 300, stored in a storage device such as a memory, or printed on paper. , to the user of the vibration test equipment.
Note that, in this embodiment, waveform generation is continued until the program is stopped in order to calculate the limit ratio.

In this embodiment, even if the permissible calculation time in step S38 is input for each test or a plurality of times, a value of a certain time is input in advance and the time is set for a large number of tests. Both are possible, even if they share the value of

According to the present embodiment described above, in step S34, similar to step S14 of the first embodiment, in-plane vibration limit determination is performed and confirmed, and time history waveforms in two directions that pass the in-plane vibration limit determination get the set.
As a result, as in the first embodiment, the excitation range of the obtained two-direction time history waveform set is reliably within the excitation possible range of the shaker 10 . Therefore, it is possible to avoid an error such as touching the limiter of the vibration exciter 10 due to the above-described error during vibration, and the vibration can be successfully performed with a high probability.

Further, according to the present embodiment, the allowable operation time input in step S38 and the in-plane limit calculated in step S41 are calculated from the allowable operation time input in step S38 and the expected limit determination passing time calculated in step S37. The continuation determination is performed based on the expected time for passing the determination. As a result of the continuation determination, if there is a high possibility that the waveform cannot be generated within the allowable calculation time, the low frequency component is reduced in step S43, and the process returns to step S21 to re-execute waveform generation.
As a result, the target response spectrum with the low-frequency components reduced takes less time to calculate than the previous target response spectrum before the low-frequency components were reduced. The possibility of acquiring a waveform set within the allowable computation time can be improved.
Therefore, when the target response spectrum is set unreasonably, the generated waveform does not pass the limit determination in step S27 or the in-plane excitation limit determination in step S34, thereby avoiding falling into an infinite loop. can.

Further, according to the present embodiment, when it is determined that waveform formation is possible within the allowable calculation time and that waveform generation can be continued as a result of the continuation determination, the expected value of the feature parameter and the excitation limit are determined. Alternatively, the ratio between the expected value of the vibration range and the vibration possible range is calculated as the limit ratio.
By calculating these ratios as limit ratios, it is possible to clearly show how severe the generated time history waveform is with respect to the vibration limit of the vibration exciter.
In addition, by presenting the calculated limit ratio, it is possible to quantitatively indicate that the selected time history waveform is the maximum waveform that can be excited by the vibration exciter to be used.

The user sees the limit ratio presented and the generated time history waveform is too tight for the shaker limits, creating an undesired situation such as tripping the shaker limiter and aborting the test. If it is determined that the possibility is high, it is possible to change the time history waveform.
Then, by changing the time history waveform so that the critical ratio is lowered, the possibility of causing the above-described undesirable situation can be reduced.

(Example 3)
In Example 1 and Example 2, regarding the restriction on the Lissajous curve of the time history waveform in two horizontal directions, since there is no element that changes the shape other than changing the random number of the phase spectrum, many trials were performed to satisfy the restriction. times may be required.

Therefore, in this embodiment, in order to realize a Lissajous curve that is difficult to create by repeating waveform generation at random, the Lissajous curve is edited and then tested.

FIG. 4 shows a flow chart for explaining the input waveform generation method in the third embodiment.
In the flowchart shown in FIG. 4, waveforms are generated as described below.
Each step for generating a waveform is the same as that of the first embodiment shown in FIG. 2, so illustration and detailed description in FIG. 4 are omitted.

First, in step S51, a target response spectrum is input as in step S1 shown in FIG.
In addition, in step S54, similarly to step S13 of the first embodiment shown in FIG. 2, an excitation possible range is input.
In the vibration test apparatus of FIG. 1, a target response spectrum 1 and a possible vibration range (not shown) are input to an input waveform generation system 300, respectively. Further, since each step for generating a waveform is performed in the same manner as in the first embodiment, the excitation limit, envelope function, etc. are also input to the input waveform generation system 300 respectively.

Next, in step S52, the sine wave synthesis method is performed for the two waves. The sinusoidal wave synthesizing method in step S52 can be performed in the same manner as in step S4 of the first embodiment shown in FIG. 2 and step S24 of the second embodiment shown in FIG.

Next, in step S53, an excitation range is obtained from the above two waves.
For example, as shown in the right diagram of step S53, a circular Lissajous curve 302 is obtained as the excitation range from the locus 301 of the two waves.

Next, in step S55, the Lissajous curve is edited using the excitation possible range input in step S54. That is, the Lissajous curve is edited so that it falls within the possible vibration range of the vibrator input in step S54.
Specifically, the Lissajous curve 302 with two waves in step S52 is subjected to envelope processing. Then, the Lissajous curve of the time history waveform is edited by multiplying the ratio of the vibratorable range and the envelope of the generated waveform by the Lissajous curve of the time history waveform.
For example, as shown in the right diagram of step S55, the circular Lissajous curve 302 in the upper diagram is edited as indicated by arrow 303 to obtain a substantially square Lissajous curve 304. FIG. By this editing, the trajectory 301 of the two waves in the above figure is also changed to become a trajectory 305. FIG.

Next, in step S56, the Lissajous curve edited in step S55 is restored to a two-wave waveform.
Next, in step S57, the response spectra of the two waves are analyzed.
As a result, the resultant response spectrum shown in step S58 is obtained.

Next, in step S59, it is tested whether the resulting response spectrum obtained in step S58 matches the target response spectrum input in S51.
If the test fails, go to step S60 to modify the Fourier amplitude spectrum.
Using the corrected Fourier amplitude spectrum obtained by correction, the process returns to step S52 to perform the sine wave synthesis method.
If the test is passed, the process proceeds to step S61 to obtain a (bi-directional) time history waveform set.

In the vibration test apparatus of FIG. 1, in the input waveform generation system 300, in the flow chart shown in FIG. perform each step of
1, the time history waveform set obtained in step S61 is input from the input wave generation system 300 to the control unit 110 as the bidirectional time history waveform set 120 shown in FIG.

According to the present embodiment described above, in step S55, the vibratable range obtained in step S54 is used to edit the two-wave Lissajous curve so as to fit within the vibratable range. Then, the edited Lissajous curve is restored to the waveform, and the response spectrum obtained by performing the response spectrum analysis of the waveform is tested to see if it matches the target response spectrum, and a time history waveform set that has passed the test is obtained.
As a result, the excitation range of the acquired (two-direction) time history waveform set is reliably within the excitation possible range of the vibrator 10 . Therefore, it is possible to avoid an error such as touching the limiter of the vibration exciter 10 due to the above-described error during vibration, and the vibration can be successfully performed with a high probability.
Then, it is possible to easily generate a time-history waveform of the simulated seismic motion that matches the target response spectrum and that can be excited by the vibrator to be used.

That is, in this embodiment, by editing two Lissajous curves, a step of obtaining a two-directional time history waveform set that passes the in-plane excitation limit determination of the first and second embodiments is performed. A similar effect can be obtained.

Moreover, in this embodiment, the Lissajous curve of the wave is directly edited so as to be within the vibrating range.
As a result, even if the initially input target response spectrum is a waveform that requires a large number of trials until it passes the in-plane excitation limit determination of the first and second embodiments, the Lissajous curve By editing, it can be quickly corrected to fit within the vibrating range.

(Modification)
In FIG. 1, the actuator 101 is arranged to vibrate the vibration table 100 in a direction of 45° (upper left/lower right direction, upper right/lower left direction) with respect to the coordinate axis of the control coordinates 103 of the vibration table 100 . was
In the present invention, a drive mechanism such as an actuator for vibrating a vibration table such as a vibration table may be configured to vibrate the vibration table in at least two different directions in a horizontal plane. It is not limited to the actuator 101 in the direction of °.
For example, a driving mechanism may be arranged so as to vibrate a vibration table such as a vibration table in directions parallel to the coordinate axes of the control coordinates of the vibration table (vertical direction and horizontal direction in FIG. 1).
In addition, the two different directions in the horizontal plane in which the driving mechanism is arranged to vibrate the vibration table are not limited to the two orthogonal directions shown in FIG. is.

In each of the above-described embodiments, the configuration for vibrating the vibration table 100 in two different directions within the horizontal plane has been described.
The present invention can also be applied to a vibration test apparatus equipped with a vibrator that vibrates a test object in three directions including vertical directions, that is, vibrates in three dimensions. In that case, a driving mechanism for vibrating a vibration table such as a vibration table in two directions in the horizontal plane is added with a driving mechanism for vibrating the vibration table in the vertical direction. is generated, and the generated waveform is applied to the control unit that controls the drive mechanism.

In the second embodiment, when the allowable calculation time is input, and the predicted pass judgment time does not fit within the allowable calculation time, it is determined that waveform generation cannot be continued, and the low-frequency component of the target response spectrum is reduced. and generated the waveform again. This avoids infinite loops.
On the other hand, for example, in the configuration of the first embodiment, since the calculation time is not predicted, if the target response spectrum is set unreasonably with respect to the limit of the vibration exciter, there is a possibility of falling into an infinite loop.
Therefore, in the configuration of the first embodiment, if an infinite loop occurs, the generation of the time history waveform set will never end, so the user of the vibration test apparatus forcibly terminates the generation of the waveform. The target response spectrum is then modified to fit within the limits of the shaker and waveform generation resumes.

FIG. 1 shows a top view of the vibration table 100, and the vibration table 100 is assumed to be flat.
A vibrating table such as a vibrating table is not limited to a flat plate shape, and may have another shape. For example, a configuration having a configuration (protrusions, etc.) for fixing the test piece to the vibration table, which is adopted in a known vibration tester, is also possible.

The present invention is not limited to the above-described embodiments and examples, and includes various modifications. For example, the above-described embodiments and examples have been described in detail in order to explain the present invention in an easy-to-understand manner, and are not necessarily limited to those having all the configurations described.

1 Target response spectrum 10 Vibrator 100 Vibration table 101 Actuator 102 Foundation 103 Control coordinates of vibration table 104 Specimen 105 Coordinate axis of specimen 106 Isotropic excitation possible range 107 Direction dependence Excitation possible range 110 control unit 120 time history waveform set 300 waveform generation system 302, 304 Lissajous figure L excitation limit P feature parameter

Claims (3)

a vibration table on which a test object is mounted, and a vibration exciter provided with a drive mechanism for vibrating the vibration table;
a control unit that controls driving of the drive mechanism of the vibrator;
A vibration testing apparatus comprising a computing unit that generates a waveform of vibration to be applied to the vibrator and applies the generated waveform to the control unit,
The vibration exciter includes a drive mechanism that vibrates the vibration table in at least two different directions in a horizontal plane,
The computing unit edits the Lissajous curve so that the envelope of the Lissajous curve having two waveforms for vibrating the shaking table in the two directions falls within the vibrable range of the vibrator, Return the edited Lissajous curve to two waveforms, and test whether the resulting response spectrum obtained by analyzing the response spectra of the returned two waveforms matches the target response spectrum input to the calculation unit,
The calculation unit generates a vibration waveform in which the vibration range of the two waveforms is within the vibration possible range of the vibration exciter. Vibration test apparatus. a vibration table on which a test object is mounted, and a vibration exciter provided with a drive mechanism for vibrating the vibration table;
a control unit that controls driving of the drive mechanism of the vibrator;
A control method for a vibration test apparatus, comprising: a calculation unit that generates a waveform of vibration to be applied to the vibrator and applies the generated waveform to the control unit,
The vibration exciter includes a drive mechanism that vibrates the vibration table in at least two different directions in a horizontal plane,
generating, as the waveforms, two waveforms that vibrate the shaking table in the two directions;
a step of verifying whether or not the excitation range of the two generated waveforms falls within the excitation possible range of the shaker;
a step of generating two waveforms again if the excitation range does not fit within the possible excitation range as a result of the test. A step of editing the Lissajous curve so that the envelope of the Lissajous curve of the two waveforms falls within the excitation possible range of the vibrator , and then returning the edited Lissajous curve to the two waveforms; and verifying whether the resulting response spectrum obtained by analyzing the returned response spectrum of the two waveforms matches the target response spectrum input to the computing unit.
A control method for the vibration test apparatus according to claim 2 .

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