JPH10123008A - Apparatus and method for vibration test of structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an apparatus and a method in which a vibration test to be executed by combining a partial vibration test with a vibration response numeral analysis can be executed under a wide-range vibration condition. SOLUTION: A reaction force from a structure 2, to be tested, which is vibrated by an exciter 6 is measured by a reaction-force measuring means 9. Data on the reaction force and data on an external force meaning an earthquake or the like are input to a vibration-response analytical function part 13 at intervals of every constant time, an exiciter-displacement computing function part 14 which receives its analyzed result computes an exciter displacement to be added to the exciter 6. An exciter-displacement compensation function part 15 executes a compensation corresponding to an exciter dynamic characteristic. On the basis of the compensated exciter displacement (computed value), an exciter-driving-signal computing function part 16 computes an exciter- displacement estimated value. The estimated value is used as a driving signal so as to drive the exciter 6. Thereby, since the computed result of the exciter-displacement computing function part 14 agrees with an actual displacement applied to the structure 2 to be tested, an error due to the exciter dynamic characteristic is eliminated, and a vibration test can be performed with high accuracy.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration test apparatus and method for a structure in which a vibration test of only a part of the structure and a numerical analysis of the vibration response of the remaining part are combined in real time.

[0002]

2. Description of the Related Art Generally, a vibration test for a small structure is carried out by mounting the whole structure on a vibration table. If the structure is large and exceeds the loading limit of the shaking table, the mounting target is a reduced model or a partial model. The former reduced model test is
This cannot be performed when the similarity rule accompanying the downsizing is difficult to be established due to the non-linear vibration behavior of the target structure and the like. In the case of the latter partial model test, coupling of vibration between the model part and the peripheral part becomes a problem. Large vibration coupling causes an error,
Accurate tests cannot be performed. JP-A-61-34438, JP-A-61-132835, and JP-A-62-2208.
No. 31 discloses a vibration test of a type in which a structure or the like is not mounted on a shaking table. It is a vibration test that proceeds by combining a partial vibration test in which only a part of a structure is vibrated by a vibrator and a numerical analysis of vibration response in the remaining part. Even if it is a large-sized structure of the actual size, it can be executed if partial vibration is applied. For this reason, it is not necessary to consider the similarity rule accompanying the reduction. In addition, since the vibration of the peripheral part which is not affected by the partial excitation is supplemented by numerical calculation,
It approximates the result of a mounted vibration test where the entire structure is placed on a shaking table.

The numerical analysis of the vibration response in the partial excitation type vibration test uses, for example, a numerical calculation method called a central difference method. This will be described with reference to FIG. FIG.
0 of 1 is the whole structure for evaluating the vibration response. A part 2 of them is set as a vibration target. 3 is the rest. 4 is a foundation, 5 is a reaction wall, 6 is a shaker, and 7 is a shaker control device. The equation of motion of the remaining part 3 is

(Equation 1) I can write This equation of motion is calculated numerically in fixed time intervals Δ
Consider solving for every t. The values of the displacement x, the external force F, and the reaction force Q at a certain time ti are expressed as xi, Fi, Qi,

(Equation 2) Becomes Here, time ti-1 = ti-.DELTA.t and time ti + 1
= Ti + Δt, the acceleration is constant.

(Equation 3) Is obtained. Substituting (Equation 2) into (Equation 3) and solving for the relative displacement vector {xi + 1},

(Equation 4) Becomes This is the central difference method. Using (Equation 4),
The relative displacement vector ｛xi at time ti-1 and time ti
From -1} and {xi}, the external force vector {Fi} and the reaction force vector {Qi} at time ti, the relative displacement vector {xi + 1} at time ti + 1 is obtained.

The external force vector {Fi} required for calculating the relative displacement vector {xi + 1} is, for example, an earthquake force or the like. The external force vector {Fi} is stored in the digital computer 8 prior to a vibration test for exciting the entire structure in a normal state. In advance or input to the digital computer 8 at each time. On the other hand, the reaction force vector ｛Q
i｝ is obtained as follows. Based on the calculation result at the time ti-1, a driving signal of the relative displacement for the test object structure 2 is output. The signal is input to the shaker control device 7, and the test target structure 2 is shaken using the shaker 6. The reaction force corresponding to the relative displacement is measured by the reaction force measuring means 9 and taken into the digital computer 8. Thus,
Since data {Fi} and {Qi} at time ti are obtained, the relative displacement vector {xi +
1｝ calculation is possible.

[0005] By the above method, the partial excitation type test can be performed while considering the influence of the vibration response of the whole structure, and the vibration response of the whole structure can be evaluated. However, in the above-described conventional technology, the vibration test in this case is performed with the time axis of the vibration test greatly extended, and only the reaction force related to the relative displacement is used for the vibration response analysis. . The reaction force related to the speed of the relative displacement (reaction force acting to reduce the speed, which is proportional to the speed) and the reaction force related to the acceleration (so-called inertial force) that appear in the other original vibration behavior are ignored. You. Therefore, it is not possible to accurately evaluate the vibration response when these effects are large.

In view of the above, real-time excitation has been considered in which vibration is performed by matching the time axis in the vibration response calculation with the time axis in the vibration test. For example, Japanese Patent Application Laid-Open No. Hei 7-27664 discloses this. The real-time vibration is calculated by a digital computer that performs vibration response analysis, calculates a vibration response after a certain time from the reaction force measurement time, and outputs a vibrator drive signal for realizing the vibration response at a timing after the certain time. And output to the shaker control device.

However, the shaker used for the vibration test is
For example, a hydraulic exciter, which has a slight time delay δt in the actual displacement response corresponding to the drive signal due to the influence of its dynamic characteristics.
Is generated. This time delay δt is as described in the above-mentioned JP-A-7-2766.
As pointed out in Japanese Patent Publication No. 4 (1999), it is equivalent to the occurrence of a negative damping in a structure, and it is known that the test becomes impossible. This problem can be solved by predictively calculating and outputting the shaker drive signal preceding by the delay time δt. FIG. 11 is a conceptual diagram illustrating this point. The upper part of the figure shows the calculated exciter displacement signal. This is subjected to necessary compensation to obtain a vibrator drive signal in the middle part of FIG. The content of the compensation is to predict ahead of time δt. The exciter is driven based on the exciter drive signal in the middle part of the figure, but there is a response delay of time δt during that time, so that the displacement is actually the lower part in the figure. The response delay δt is offset by the predicted amount δt. For this reason, the displacement in the upper part of the figure calculated as the displacement at a certain time is realized at that time, and the vibration is performed in real time.

Next, a description will be given of a method of calculating a predicted value of a shaker driving signal described in the above-mentioned Japanese Patent Application Laid-Open No. 7-27664. Based on the vibration response calculation value up to a certain time t, δ
The shaker drive signal after t is predicted. Therefore, the time δ
An interpolation function that passes data at intervals of t widths is obtained. For example, the number of data used for creating an interpolation function is set to (n + 1), and an nth-order function (nth-order polynomial) relating to time is obtained.
The value of t + δt of the function is set as a predicted value. The above n is n =
Equations (5) to (9) for predicting the exciter drive signal after δt by extrapolation in the case of 1 to 5 are shown.

(Equation 5)

(Equation 6)

(Equation 7)

(Equation 8)

(Equation 9) According to (Equation 5) to (Equation 9), since the predicted value can be calculated by a simple four arithmetic operations, the calculation is completed in a short time period of time of δt width, and the excitation in real time at each time is performed. It becomes possible.

[0009]

However, in the above-described compensation method, a slight error occurs between the actual exciter displacement and the calculated value, so that the apparent attenuation (hereinafter referred to as additional attenuation). ) May be added. The additional damping may be negative depending on conditions, and when the sum of the damping of the structure itself is negative, the vibration response may gradually increase and diverge. The limit at which the additional damping becomes negative can be represented by a parameter τ defined by the product of the circular frequency ω of the sine wave and the delay time δt, where the displacement applied to the shaker is a sine wave. The limit value represented as the value of the parameter τ is a function of the number n of data used for prediction. n = 1 ~
This limit value for No. 5 is as shown in the following (Table 1) as shown in Transactions of the Japan Society of Mechanical Engineers, Vol. 61, No. 584, pp. 1328-1336.

[Table 1] In Table 1 for example, the limit value of the parameter τ when n = 2 is 1.047. This is because the parameter τ is 0
In the range of 1.047, it means that the additional attenuation becomes positive, and when it exceeds that, it becomes negative. As can be seen from (Table 1), when n = 1, negative additional attenuation is applied in the entire region of the parameter τ, so that it cannot be used. The same applies to the case of n = 5. For this reason, n = 2-4 is desirable.

Since the divergence due to the negative additional damping occurs for the eigenmode of the entire structure, the mass of the test object structure
For the largest one of the natural frequencies of the entire structure obtained by assuming rigidity or the like, a condition that is less than the limit value in (Table 1) must be satisfied. If this is not the case, additional damping, which causes divergence, will occur, making stable vibration testing difficult. Therefore, the response delay in the dynamic characteristics of the vibrator limits the vibration test, and the larger the response delay, the lower the natural frequency of the structure that can be tested.

An object of the present invention is to enable a vibration test to be performed under a wide range of vibration conditions by performing a partial vibration test and a numerical analysis of a vibration response, and to provide an accuracy without divergence of the vibration response. And to provide a vibration test apparatus and a test method with high reliability.

[0012]

SUMMARY OF THE INVENTION The present invention provides at least one vibrator for vibrating a structure to be tested, a vibrator control device for controlling the vibrator, and a vibrator attached to the vibrator. And a reaction force measuring means for measuring a reaction force applied to the vibrator from the test object structure. These are for performing a partial excitation type vibration test. It also has a digital computer. The digital computer manages the exciter and shares duties such as numerical analysis of vibration response of the entire structure.
The digital computer has the following functions. (1) A function of inputting the measured value of the reaction force measuring means at regular intervals (2) An external force signal forming function representing an external force such as an earthquake (3) Vibration response of the entire structure including the test object structure Analysis function (4) Exciter displacement calculation function for calculating exciter displacement according to the vibration response analysis result (5) Exciter displacement compensation function for compensating the exciter displacement (6) After the compensation A shaker drive signal calculation function for calculating a shaker drive signal based on the shaker displacement after compensation (7) A data storage function for storing the shaker displacement after compensation (8) The shaker drive signal is Signal output function to output to the shaker control device (9) Time management function for each function

The above functions will be supplemented. The vibration response analysis function is a numerical model of the structure is input,
Further, using the data of the reaction force and the external force, a vibration response of the structure after a predetermined time from the reaction force measurement time is calculated.
The shaker displacement compensation function compensates the shaker displacement for a response delay of the shaker. The shaker drive signal calculation function is performed after a predetermined time using the compensated shaker displacement, the past compensated shaker displacement stored in the data storage function, and a prediction parameter input in advance. Then, a predicted value of the shaker displacement after the compensation is calculated. The time management function and the signal output function output the predicted value as the shaker drive signal after the predetermined time.

The present invention includes a reaction force measuring means for measuring a reaction force applied from the test object structure to the vibrator. In addition, when a shaker displacement measuring means for measuring a shaker displacement of a driving portion of the shaker is provided, the measured value can be used. In this case, the digital computer is provided with an input function for inputting a displacement output value from the shaker displacement measuring means and a prediction parameter correcting function.

The prediction parameter correction function compares the displacement output value with the shaker displacement calculated by the shaker displacement calculation function, and adjusts the prediction parameter of the shaker drive signal calculation function so that the two coincide. It is to be corrected sequentially. It is desirable that the shaker displacement compensating function in the present invention is such that the inverse transfer function of the second-order lag system is a digital filter. Further, the digital computer may be a parallel computer including a plurality of CPUs, and each of the above functions may be shared by each CPU. Further, it is possible to configure the digital computer with a plurality of computers, and to share the above functions with the plurality of computers.

The vibration test method for a structure according to the present invention comprises:
Steps corresponding to the above functions are executed, and the steps are repeated at regular time intervals.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the block diagram of FIG. 1 and the flowchart of FIG. Test target structure 2
Is fixed to the foundation 4. The reaction wall 5 is fixed to the foundation 4,
The vibration exciter 6 is installed on the reaction wall 5. The shaker 6 applies an appropriate displacement to the test object structure 2. Although the number of the vibrators 6 is one or more, it is one here. The vibration response of the vibrator 6 is accompanied by a slight delay time δt due to the influence of its dynamic characteristics. A reaction force measuring means 9 is installed on the vibrator 6.
When a displacement is applied to the test object structure 2, the reaction force from the test object structure 2 to the vibrator 6 can be measured.

An external force such as an earthquake is input via an external force signal input function 11. Instead of inputting the data from outside the digital computer 8, the data stored in the external force time history storage function 12 in the digital computer 8 may be read. In short, it is only necessary to have an external force signal forming function meaning external force, and to be able to refer to the external force signal in the subsequent calculation. By the time management function 19, the external force and the reaction force are
It is input to the vibration response analysis function 13 at regular intervals. The time management function 19 manages the time of each of the other functions, and requests that a series of processing steps be executed in units of a fixed time and repeated. The predetermined time interval is a so-called sampling period, which is set to several msec in order to improve the accuracy of the vibration test. The digital computer 8 has a high-speed operation processing capacity corresponding to the digital computer 8.

A numerical model of the entire structure including the test object 2 is input to the vibration response analysis function 13. It is, for example, a numerical model in the form of a matrix such as (Equation 1). The vibration response analysis function 13 uses the data of the reaction force and the external force input at regular time intervals and, for example, based on an algorithm such as the central difference method or the like, calculates the vibration response of the structure after a certain time from the reaction force measurement time. Is calculated.

Based on the vibration response calculation value, the shaker displacement calculating function 14 calculates a shaker displacement to be added to the shaker installation point of the structure 2 to be tested.

The exciter displacement compensating function 15 receiving the exciter displacement (calculated value) from the exciter displacement calculating function 14
Compensation according to the characteristics of Here, the exciter 6 is modeled as a filter, and its inverse transfer function is compensated for as a digital filter. However, errors due to this modeling are inevitable. Therefore, the shaker displacement compensation function 1
If the shaker displacement (calculated value) after compensation from 5 is used as the shaker drive signal as it is, the shaker displacement (calculated value) from the shaker displacement calculation function 14 and the actual shaker displacement are calculated. Causes a mismatch between

Therefore, the shaker displacement (calculated value) after compensation from the shaker displacement compensation function 15 is stored in the data storage function 17. The shaker drive signal calculation function 16 is the data storage function 1
The latest data and past data of the shaker displacement (computed value) after compensation stored in 7 can be referred to. In addition, a delay time δt specific to the shaker 6 is previously input to the shaker drive signal calculation function 16 as a parameter.
The shaker drive signal calculation function 16 uses the above data and the parameters to perform an interpolation calculation to obtain a shaker displacement predicted value. The interpolation calculation is performed so that the shaker displacement (calculated value) of the shaker displacement calculation function 14 matches the actual shaker displacement. The shaker displacement predicted value is supplied to the shaker control device 7 via the signal output function 18 as a command signal. Thus, the shaker 6 is driven. Then, the actual exciter displacement at the time when a slight delay time δt has elapsed is realized, but this results in a result that matches the exciter displacement (calculated value) output from the exciter displacement calculation function 14 and Excitation of time is realized.

The compensation using the inverse transfer function in the exciter displacement compensating function 15 performed before the exciter drive signal calculating function 16 reduces the response delay to be predicted and expands the application range of the prediction compensation. . For this reason, this vibration test apparatus can be effectively used under a wide range of conditions.

FIG. 3 is a detailed view of the range 13-14-15 of FIG. The shaker displacement compensation function 15 will be described again with reference to FIG. Exciter displacement compensation function 1
In the compensation by 5, the dynamic characteristic of the vibrator 6 is modeled by a transfer function of a second-order lag system, and its inverse transfer function is used as a digital filter. Using the exciter displacement (calculated value) supplied from the exciter displacement calculating function 14 to the exciter displacement compensating function 15 and its first-order differential value and second-order differential value, the compensated excitation displacement x
comp

(Equation 10) And The reason why the exciter 6 is modeled by the second-order delay system is as follows (a) and (b). (A) The vibration response analysis function 13 analyzes the vibration response up to the second-order differential term, so that the analysis value can be used, and noise and noise generated by the differential operation for calculating the differential term necessary for the compensation calculation can be used. No error occurs. (B) Since the operation amount of the secondary digital filter is small and processing can be performed at high speed, it is suitable for the present apparatus which needs to perform processing in each short interval in a short time. According to the compensation function, an error caused by compensation can be avoided, and a vibration test of a structure can be performed with high accuracy.

Another embodiment of the present invention will be described with reference to FIGS. Here, the part numbers in FIGS. 1 and 2 are used as much as possible, and a part of the overlapping description is omitted. The vibrator 6 is provided with a vibrator displacement measuring means 29 for measuring a displacement of a driving part thereof, and measures a vibration response applied to the test object structure 2 by the vibrator 6. A prediction parameter correction function 31 and a signal input function 30 are provided in the digital computer 8.

The predictive parameter correcting function 31 includes a shaker displacement (measured value) from the shaker displacement measuring means 29 input through the signal input function 30, that is, an actual shaker displacement and a shaker displacement. By comparing the shaker displacement obtained by the calculation function 14, the optimum values of the prediction time and the prediction parameter are determined so that they match. The scale constant corresponding to the ratio of the shaker displacement (measured value) to the shaker displacement (calculated value) is sequentially updated, provided to the shaker drive signal calculation function 16, and used as one of the prediction parameters. . The shaker drive signal calculation function 16 multiplies and corrects the latest scale constant when calculating the shaker displacement predicted value from the compensated shaker displacement (calculated value). Thus, it is possible to drive the vibrator 6 with high accuracy.

According to the embodiment shown in FIGS. 4 and 5, the estimated time of the shaker drive signal calculating function 16 which is initialized is generated by the combination of the shaker 6 and the shaker displacement compensation function 15. If the delay time is different from the delay time, or if the dynamic characteristics of the exciter depend on the frequency, amplitude, etc., the prediction time and prediction parameters are changed according to the actual situation. It becomes possible to drive the shaker.

The configuration of the digital computer used for implementing the present invention can be various. Hereinafter, this point will be described.

FIG. 6 shows the functions of the digital computer 8 of FIG.
The first digital computer 20, the second digital computer 21, and the third digital computer 22 share the functions. The first digital computer 20 calculates the shaker displacement and outputs it from the signal output function 23. 2nd digital computer 21
Captures the shaker displacement via a signal input function 24, calculates the compensated excitation displacement, and outputs it to a signal output function 25.
Output from The third digital computer 22 captures the compensated shaker displacement via the signal output function 26, stores the compensated shaker displacement in the data storage function 17, forms a shaker displacement estimated value, and calculates the shaker displacement estimated value. Output through the signal output function 18.

FIG. 7 shows the functions of the digital computer 8 of FIG.
The first digital computer 20, the second digital computer 21, the third digital computer 22, and the fourth digital computer 32 are shared by four members. First digital computer 20 / second
The digital computer 21 and the third digital computer 22 are the same as those in FIG. The fourth digital computer 32 captures the vibration response (measured value) via the signal input function 30,
The displacement (calculated value) of the shaker is fetched via the signal input function 33 to form an optimum value of the prediction time / prediction parameter, which is output from the signal output function 34. The third digital computer 22 captures the optimum value of the prediction time / prediction parameter via the signal input function 35, and outputs the shaker drive signal calculation function 1
Correct the prediction time and prediction parameter of No. 6.

In the embodiment shown in FIG. 6 or FIG. 7, since various functions are shared by the digital computers, the operation load of each digital computer is small, and a series of processes necessary for the vibration test are performed in short time intervals. Can be completed, and the test accuracy is improved. The input / output function in each of the above embodiments is, for example, a D / A or A / D converter, and data transmission therebetween is performed in the form of an analog signal.

In the embodiment shown in FIG. 8, the functions of the digital computer 8 shown in FIG. 1 are shared by a plurality of CPUs 28 belonging to one parallel computer 27. In the embodiment of FIG. 9, the functions of the digital computer 8 of FIG. 4 are shared by a plurality of CPUs 28 belonging to one parallel computer 27.
According to the embodiment of FIG. 8 or FIG. 9, the arithmetic processing capability is increased, and the test accuracy is improved. Further, since data is transmitted in the form of a digital signal via the data bus 36 in the parallel processing computer 27, it is hardly affected by noise or the like as in the case of an analog signal, and a high vibration test can be performed. Each of the above embodiments is a vibration test apparatus and a test method using a uniaxial vibrator, but the same effect can be obtained by using a vibrator having a plurality of vibration degrees of freedom.

[0033]

According to the present invention, the restriction on the applicable range of the vibration test caused by the response delay of the vibrator is reduced. Therefore, a vibration test performed by combining the partial excitation test and the vibration response numerical analysis can be performed under a wide range of vibration conditions, and a highly accurate test result without divergence of the vibration response can be obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram of a vibration test apparatus showing an embodiment of the present invention.

FIG. 2 is a flowchart showing the flow of the main operation.

FIG. 3 is a flowchart showing the flow of the operation of the main part.

FIG. 4 is a block diagram of a vibration test apparatus showing another embodiment of the present invention.

FIG. 5 is a flowchart showing the flow of the main operation.

FIG. 6 is a block diagram of a vibration test apparatus showing another embodiment of the present invention.

FIG. 7 is a block diagram of a vibration test apparatus showing still another embodiment of the present invention.

FIG. 8 is a block diagram of a vibration test apparatus showing still another embodiment of the present invention.

FIG. 9 is a block diagram of a vibration test apparatus showing another embodiment of the present invention.

FIG. 10 is a block diagram showing a conventional vibration test apparatus.

FIG. 11 is an explanatory diagram illustrating the operation.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Structure 2 Test object structure 3 Structure other than test object structure 4 Foundation 5 Reaction wall 6 Exciter 7 Exciter control device 8 Digital computer 9 Reaction force measurement function 10 Signal input function 11 External force signal input function 12 external force time history storage function 13 vibration response analysis function 14 shaker displacement calculation function 15 shaker displacement compensation function 16 shaker drive signal calculation function 17 data storage function 18 signal output function 19 time management function 20 first computer 21 second computer 22 third computer 23 signal output function 24 signal input function 25 signal output function 26 signal input function 27 parallel computer 28 parallel computer CPU 29 shaker displacement measurement function 30 signal input function 31 prediction parameter correction function 32 fourth computer 33 signal input function 34 signal output function 35 signal input function 36 data bus

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Kazuhiro Umekita 502 Machinery, Kandachi-cho, Tsuchiura-shi, Ibaraki Pref.

Claims (4)

[Claims] At least one shaker for exciting a structure to be tested, a shaker control device for controlling the shaker,
A reaction force measuring unit attached to the shaker for measuring a reaction force applied to the shaker from the test object structure; and a digital computer, wherein the digital computer measures the reaction force by the reaction force measurement unit. A function of inputting a value at predetermined time intervals, an external force signal forming function meaning an external force such as an earthquake, a vibration response analysis function of the entire structure including the test object structure, and a function corresponding to the vibration response analysis result. A shaker displacement calculation function for calculating a shaker displacement, and a shaker displacement compensation function for compensating for the shaker displacement,
A shaker drive signal calculation function for calculating a shaker drive signal based on the compensated shaker displacement after the compensation, a data storage function for saving the compensated shaker displacement, A signal output function of outputting a signal to the shaker control device,
A time management function for each of the functions, the vibration response analysis function is a numerical model of a structure is input, and using the reaction force and the external force data, a fixed time from the reaction force measurement time Calculating the vibration response of the structure afterward, wherein the shaker displacement compensation function compensates for the dynamic characteristics of the shaker by the shaker displacement, and the shaker drive signal calculation The function is the post-compensation shaker displacement after a predetermined time using the post-compensation shaker displacement, the past post-compensation shaker displacement stored in the data storage function, and the previously input prediction parameter. Wherein the time management function and the signal output function output the predicted value as a shaker drive signal after the predetermined time. . 2. A vibration test apparatus for a structure according to claim 1, wherein said vibrator is provided with a vibrator displacement measuring means for measuring a displacement of a driving part thereof, and a digital computer is provided with said vibrator displacement measuring means. An input function for inputting the displacement output value of the input device and a prediction parameter correction function are provided. The prediction parameter correction function compares the displacement output value with the shaker displacement calculated by the shaker displacement calculation function, and the two coincide. A vibration test apparatus for a structure, wherein the prediction parameters of the shaker drive signal calculation function are sequentially corrected. 3. A vibration test method for a structure in which a whole or a part of the structure is vibrated by a vibrator, wherein a reaction force from the test object structure to the vibrator is measured and measured at regular intervals. The vibration response of the structure after a certain period of time has been calculated from the measurement time point in consideration of the numerical model of the structure from the reaction force data and the data representing the external force such as an earthquake. Calculating a displacement, obtaining a compensated shaker displacement in which the dynamic characteristics of the shaker are previously compensated from the shaker displacement, storing data of the compensated shaker displacement, Using the displacement, the past vibration response signal stored in the data storage function, and a prediction parameter input in advance, a post-compensation shaker displacement prediction value after a predetermined time is calculated, and the post-compensation exciter displacement value is calculated. The shaker is driven based on the shaker displacement predicted value. And a vibration test method for a structure. 4. The test method according to claim 3, wherein a displacement of the shaker excited by the shaker is measured, and the calculated displacement of the shaker is compared with the measured displacement of the shaker. A vibration test method for a structure in which at least one of a predicted time of a vibration exciter drive signal and a predicted parameter is sequentially corrected so that the two coincide.