JPH05142089A - Apparatus and method for testing vibration of structure - Google Patents

Abstract

PURPOSE:To evaluate the vibration response of the whole of a structure by the vibration test of a partial model by determining a vibration acceleration waveform during experimentation even when the mutual action of an actual model and a numerical value model is large and a vibration waveform is not determined before a test. CONSTITUTION:The force applied to an actuator 2 from an actual partial model 1 is detected to be latched in a digital calculator 5 and the calculation of the vibration response of the numerical value model programmed in the calculator is performed according to a vibration analyzing algorithm 14 to estimate the vibration acceleration at a boundary point position after a minute time and the actuator 2 is vibrated so as to aim at said acceleration to perform the vibration test of the actual partial model. The relation between the mass of the actual partial model and that of the numerical value model is set so as to satisfy a condition determined by the number of the acceleration calculated values used in the estimation of acceleration.

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 a vibration test method for a structure, and is particularly suitable for a case where a structure to be evaluated by a vibration test is large-scale and it is difficult to perform a vibration test on the whole structure. Vibration test equipment.

[0002]

2. Description of the Related Art Evaluation of vibration response when a structure is vibrated by an earthquake or the like has conventionally been performed by mounting the structure on a vibration table and vibrating it. However, when the structure is very large, it may be difficult to mount the actual object on the vibrating table due to the limitation of the allowable load of the vibrating table. In such a case, perform a vibration test using a scale model that can be installed, or perform a vibration test on only a part of the structure, or
Both were applied to evaluate the vibration response.

However, the former has a problem that it is difficult to safely satisfy the similarity rule in modeling a reduced scale, and the latter has the vibration itself to be input to the structure to be excited. Since it is coupled with the response of the structure to be shaken,
There is a problem in that it is impossible to perform highly accurate vibration, and it is difficult to accurately evaluate vibration response.

Therefore, only a part of the structure is vibrated and the other part is modeled numerically, and the vibration response at the boundary is calculated by a digital computer. With this, the real part model is vibrated and the reaction force is further used. A vibration test method for evaluating the response of a numerical model has been considered.

A vibration test method for vibrating a real part or a model for a part of a structure and numerically modeling the other part for response calculation by a digital computer is disclosed in JP-A-61-13.
There is a technique described in each of 240 and JP-A 61-34438.

[0006] Conventionally, the algorithm used in the vibration response analysis of a structure by the above-mentioned known vibration test method is, for example, Journal of Engineering.
Mechanics, ASC E, Vol. 113, No. 7 (1987) pp. 1014-1032 (Journal of
Engineering Mechanics, ASCE, Vol.113, No.7,
1987), it is a method called the central difference method. In this method, only the displacement within a fixed time after the time when the reaction force from the test object is measured is obtained.

[0007]

According to the conventional method, if the target structure is a weight of several tens of tons, such as a heat exchanger, a pump, or a generator, the whole structure is subjected to a vibration test. As a target, not only is the cost of manufacturing the test body expensive, but a very large vibrating table is required to mount the test body. Therefore, since the model test body reduced to the weight that can be mounted on the vibration table is used, the accuracy of the structure test is inevitably reduced due to the reduced modelization. It is only when the substructure is attached to another part of the structure that the test can be performed by mounting only the substructure on the shaking table, and the weight of the other part of the structure is It was limited to the case where the vibration response of other structures was not affected by the presence or absence of the substructure, which was about ten times that of the substructure. Alternatively, it has been limited to the case where the model for calculating the vibration of the structure is known and the vibration response of the boundary point between the substructure and the other part can be determined by calculation before the test. For example, when the partial structure is the installation device 1 and the other part is the support structure 11 as shown in FIG. 3 and the former is added to the latter, as shown in FIG. The set acceleration waveform is generated by a digital computer via a D / A converter to drive the vibration table.

According to the present invention, in the vibration test of a structure, even if the acceleration waveform to be excited in the partial structure model cannot be determined before the test, the acceleration test of the actuator can be performed so that only the structure can be subjected to the vibration test. It is an object of the present invention to provide a test apparatus capable of determining a waveform during an excitation test. Another object of the present invention is to provide a test method suitable for a vibration test using the test apparatus.

Further, in the conventional central difference method used in the quasi-dynamic vibration test and the like, only the displacement response at the one-hour interval is required, so that it cannot be applied when it is necessary to control the acceleration of the actuator. There was a problem. Another object of the present invention is to provide a vibration test apparatus suitable for such a case.

[0010]

In order to achieve the above object, in order to obtain a reaction force from an actual partial model by vibrating a part of the structure as an actual model (hereinafter referred to as actual partial model) by an actuator. And a digital algorithm with an algorithm for calculating the vibration response including the acceleration of the other part of the structure (hereinafter referred to as a numerical model) numerically modeled at regular time intervals using the detected reaction force. The test equipment is equipped with a computer and has a function of outputting a vibration signal so that at least the calculated acceleration value of the position of the boundary point between the real part model and the numerical model is realized as the acceleration of the actuator.

The digital computer incorporates an algorithm for calculating the vibration response of a numerical model, whereby the force exerted on the supporting structure by the structure obtained from the detector and the known external force such as seismic force acting on the supporting structure. On the other hand, it has a function to calculate at least the acceleration of the boundary point between the real part model and the numerical model.

Since it is necessary to determine the acceleration waveform to be excited during the vibration test, the time required to calculate the vibration response of the numerical model and the signal from the detector are input, and the vibration is applied to realize the calculated acceleration. It is necessary to shorten the time required to output as a signal. Therefore, a digital computer having a function of executing an algorithm for calculating a vibration response and an algorithm for inputting a signal from a detector and outputting an excitation signal in parallel in time is provided.

The vibration response calculation algorithm is the following algorithm instead of the central difference method.
An excitation signal was output to realize a value obtained by adding the known acceleration of the foundation to the estimated value of the acceleration obtained by packaging from the calculated values of the relative acceleration response to the foundation in the past. The vibration response including at least the acceleration at the time when the load is measured by the linear acceleration method or the like using the load on the support structure is calculated. Further, the acceleration at the next time is estimated using the newly calculated relative acceleration with respect to the foundation.

Stable execution of the algorithm is determined by the mass of the actual partial model to be excited and the value obtained from the numerical formula 1 from the numerical model by the number of acceleration values used for acceleration estimation. It is achieved by making it smaller than the value.

[0015]

By using the detector and the digital computer having the above functions, it is possible to detect the load applied as an external force to the numerical model when the actual partial model vibrates during the vibration test. Since the vibration response including the acceleration of the numerical model is calculated and the acceleration response at the boundary point between the real part model and the numerical model is obtained, the acceleration waveform to be realized by the actuator can be determined. Therefore, if the acceleration waveform of the actuator cannot be determined before the vibration test, for example, if the weight of the actual part model is large enough to affect the vibration response of the numerical model, or if the vibration state of the entire structure is determined before the test. If you can't
It is possible to realize, in the real part model, a vibration condition equivalent to that in which the real part model is coupled to the numerical model at the actuator installation position.

From the mass of the actual partial model to be excited and the numerical model used in the digital computer,
The calculation algorithm is stabilized by setting the value obtained by the above to be smaller than the value determined by the number 2 from the number of acceleration values used to estimate the temporary acceleration, and the above vibration test can be stably performed.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. This is an embodiment in which the partial structure is the installation device 1 and the other part is the support structure 11 thereof as shown in FIG. 3, and the former is added to the latter. The boundary point between the real part model and the numerical model is the installation position 11,
The vibration response of the installation device 1 does not depend on the displacement / velocity of the installation position 11, and exists only in its absolute acceleration. Therefore, in this case, the acceleration obtained by the vibration response of the numerical model may be realized by the actuator. In FIG. 1, a structure 1 to be tested is mounted on a vibrating table 2, and the vibrating table 2 is driven by actuators 3a-3c. In the present embodiment, the actuator that vibrates the actual partial model is the vibration table 2 driven by the plurality of actuators 3a-3c. The control circuit 4 uses a digital-to-analog converter (hereinafter D) to generate the vibration signal calculated by the digital computer 5 for realizing the acceleration to be applied to the structure 1.
A / A converter) 6 for controlling the actuators 3a-3c. The digital computer 5 includes a D / A converter 6 and an analog / digital converter (hereinafter abbreviated as D / A converter) 8 for reading the signal from the detector 7.

The digital computer 5 uses the measured value of the load applied to the support structure from the installation structure 1 obtained from the A / D converter 8 at fixed time intervals, and the support structure on which the structure is installed. It has an algorithm 14 for calculating the acceleration after a certain time from the load measurement time, and the principle thereof will be described below.

The mounting structure 1 is attached to the support structure 10 shown in FIG.
Is installed in the installation position 11. The support structure 10 is, for example, a building and has an arbitrary shape. The support structure is numerically modeled by a finite element model or the like, and the vibration of the support structure when an external force acts on the support structure can be obtained by solving the following equation of motion.

[0020]

[Equation 3]

Since {f} is a known external force vector due to an earthquake or the like that has occurred on the foundation 12 of the support structure 10, if the load vector {q} depending on the vibration response of the real part model is obtained, the equation 3 is obtained. By solving, the relative displacement vector {X} of the support structure can be determined. The digital computer 5 has a function of calculating the vibration response of the support structure, that is, the acceleration, the speed, and the displacement at regular time intervals, using the load applied from the installation structure 1 to the installation position 11 based on the algorithm.

The procedure of the calculation algorithm 14 installed in the digital computer of the test apparatus according to the present invention will be described below. Equation (3), which is the equation of motion, is solved for each minute time interval Δt, and assuming that the state is up to n steps at the present moment, the procedure for calculating the vibration of the step after Δt time is performed as follows. Be seen.

A known external force {f} _n applied to the supporting structure such as seismic force in n steps is defined.

With respect to the estimated value of the installation position acceleration,
The load {q} _n applied from the structure to the installation position of the supporting structure is calculated from the test data.

[0025] The relative displacement {X} _n-1 , the relative velocity {X} ' _n-1 , the relative acceleration {X} " _n-1 and {f} _n of the n-1 step support structure before Δt time, Current relative displacement from {q} _n {X}
Calculate _n , relative acceleration {X} ′ _n , and relative acceleration {X} ″ _n .

At this time, various algorithms can be used. For example, if the linear acceleration method is used,

[0027]

[Equation 4]

[0028]

[Equation 5]

[0029]

[Equation 6]

It becomes

Using {X} ″ _n and a predetermined number of calculated acceleration values, an estimate of relative acceleration x ″ relative to the basis of the installation position at step n + 1 after Δt time.
_{n + 1} is obtained, and the basic acceleration in the known n + 1 step is added and output as the target acceleration to be excited by the shaking table.

Save the calculated n + 1 step support structure response for each position.

Go to the next step.

By repeating the above procedure,
A vibration test of the installed structure is performed for a given external force. Various algorithms can be used to solve the equations 4 to 6, and the measured value of the load applied from the installation structure {q}
_Any algorithm that can calculate the acceleration response value at the time when the load is measured by using _n may be used. For example, Wilson's θ method, Newmark's β method, Hoovolt method, etc. can be used.

Further, the estimated value of the acceleration at the installation position x ″ _{n + 1}
If the number of acceleration values to use is one,

[0036]

[Equation 7]

In the case of two,

[0038]

[Equation 8]

In the case of three,

[0040]

[Equation 9]

In the case where the number is larger, it can be obtained by extrapolation in the same manner. However, X ″ _n is a component of the installation position of the calculated relative acceleration vector {X} ″ _n . In addition,
When information other than acceleration, such as displacement and velocity, is required for controlling the actuator, it is similarly obtained by extrapolation.

The load {q} _n applied to the installation position 11 required in the procedure is equal to the load applied from the installation structure 1 to the vibrating table 2 in FIG. The weight calculation algorithm 13 determines {q} _n from the data input to the digital computer. In the embodiment of FIG. 1, the load detectors 7a-7c are inserted between the actuators 3a-3c and the vibration table 2 to detect the load. Since the load detected by the load detectors 7a-7c includes the inertial force of the vibrating table, the acceleration of the vibrating table is detected by the acceleration detector 9a attached to the vibrating table 2 and detected by the load detector. The load is input to the digital computer 5 by the A / D converter 8 and then the inertial force of the vibration table is calculated from the mass of the table and the detected acceleration, and this inertial force is detected by the load detector 7a- By subtracting from the load detected by 7c, the load applied from the structure 1 to the vibration base 2, that is, the load {q} _n applied to the installation position 11 of the support structure 10 can be obtained. Also, the support structure 1
As shown in FIG. 1, it is not necessary to have only one structure installed at 0, and a vibration test can be performed with a similar structure even if there are a plurality of structures.

By using this test apparatus, the vibration of each part of the support structure modeled by the equation of motion 3 can be obtained by the procedure. It is possible to determine the vibration of the support structure that mounts the installation structure 1 and receives an external force {f}, and to evaluate the strength of the support structure.

In order to determine the vibration waveform during the vibration test, if the highest-order natural frequency of the installation structure or the supporting structure is ω, the minute time step Δt of one step is at least 1 / ω. It is required to be within one tenth of. For example, if ω is 10 Hz, the minute time step Δt of one step is within 10 milliseconds, and the vibration after one sweep is calculated within this time, and the actuator must be driven to reach the target displacement. I won't. If the supporting structure has a complicated structure and the degree of freedom of the analytical model when discretized (the number of components of the displacement vector {X}) is large, the time required to calculate the vibration becomes long. It is necessary to calculate a command value for operating the actuator without stopping even within the time. Therefore, the vibration calculation program and the vibration control calculation program are digital computers having algorithms that are executed in parallel in time.

FIG. 4 is an explanatory view showing one embodiment of an algorithm for performing vibration calculation and vibration control calculation in parallel, which is developed in time. Assuming that the current state is at time t _n (n steps), dt time is required to calculate the vibration of the support structure for n + 1 steps after Δt time based on the information obtained up to n steps. It costs. Within this time, the speed of change of the acceleration at the installation position is set to be the same as the speed of change of the acceleration at the time of n steps, and the acceleration of the installation position at each time up to n + 1 steps is calculated and used as the acceleration command for the actuator. When X ″ _{n + 1} is obtained after dt time, the displacement command is calculated so that the acceleration becomes X ″ _{n + 1} at the time t _{n + 1} . As a result, it is possible to drive to the target acceleration for each time step Δt without stopping the actuator.

FIG. 5 shows another embodiment of the calculation algorithm, which can be used when dt is 1/2 or less of Δt. In this case, the vibration can be calculated at a time point shifted by Δt / 2 hours, and the acceleration in the middle of Δt can be interpolated. Furthermore, since the target acceleration during the vibration calculation is obtained one step before, it is possible to perform an experiment with higher accuracy than in the embodiment of FIG.

According to this embodiment, it is possible to detect the force applied to the support structure when the installation structure vibrates during the vibration test, and use it to calculate the acceleration response of the support structure. Since the acceleration response of the position where the installation device is installed is obtained, the acceleration waveform to be realized on the vibrating table can be determined. Therefore, when the acceleration waveform of the installation position cannot be determined before the vibration test, for example, when the weight of the installation structure is large enough to affect the vibration of the support structure, or the vibration state of the installation structure is determined before the test. Even in the case where it is not possible, it is possible to realize the vibration condition equivalent to that when the installation structure is installed in the support structure, in the installation structure installed on the vibrating table.

However, depending on the relationship between the mass of the numerical model and the mass of the real part model, calculation by the algorithm diverges. In addition, the limit of divergence differs depending on the number of calculated acceleration values used for extrapolation of acceleration estimation. The relationship will be described below.

As shown in FIG. 6, as a simple model,
Consider a case where the mass m is added to the mass point of the mass M having one degree of freedom. Further, the damping is set to 0 and the excitation force is also set to 0. Consider the free vibration when an initial velocity is given to this system.

In the case of free oscillation, the numerical integration formula is the time t _n
State {x} from _n of t _{n + 1} state {x} _{n + 1} can be expressed as a recurrence formula obtained. That is,

[0051]

[Equation 10]

The condition for not diverging is that the absolute value of the eigenvalue of the constant matrix (A) is 1 or less. This is because, although having a matrix when (A) is a nonsingular n × n matrix eigenvalues _{λ k (k = 1~n),} λ k
Are all different, the eigenvectors {y _k } corresponding to the eigenvalues λ _k are linearly independent of each other. Therefore, the initial value
{x} ₁ can be written as follows using the eigenvector {y _k }.

[0053]

[Equation 11]

Substituting equation 11 into equation 10

[0055]

[Equation 12]

Using the relation of

[0057]

[Equation 13]

That is, in order to prevent divergence of {x} _{i + 1} (| {x} _{i + 1} | becomes infinite from i → ∞), the absolute values of all eigenvalues are 1 or less. That is,

[0059]

[Equation 14]

Is required.

In the case of the model shown in FIG. 6, equation 4 is equation 15
become that way.

[0062]

[Equation 15]

When only one acceleration calculation value is used for estimation, the reaction force −mx ″ _{n + 1} is replaced by −mx ″ _{n because} of Equation 7. Therefore, Equation 15 is as follows.

[0064]

[Equation 16]

Therefore, the characteristic equation of the matrix (A) is

[0066]

[Equation 17]

It becomes If Δt is small and the term for this is negligible, the equation is approximately

[0068]

[Equation 18]

It becomes That is, for | λ | ≦ 1

[0070]

[Formula 19]

Is a condition.

When using two calculated acceleration values, the reaction force −mx ″ _{n + 1} is −m (2x ″ _n −
x ″ _n−1 ), so that equation 15 becomes as follows.

[0073]

[Equation 20]

Therefore, the characteristic equation of the matrix (A) is

[0075]

[Equation 21]

It becomes If Δt is small and the term for this is negligible, the equation is approximately

[0077]

[Equation 22]

It becomes Therefore, the stable condition is

[0079]

[Equation 23]

It is

In the case of estimating using only three acceleration calculation values, the reaction force −mx ″ _{n + 1} is −m (3x ″ _{n because of the} equation 9.
-3x ″ _n-1 + x ″ _n-2 ). Therefore, Equation 15 is as follows.

[0082]

[Equation 24]

Therefore, the characteristic equation of the matrix (A) is

[0084]

[Equation 25]

It becomes If Δt is small and the term for this is negligible, the equation is approximately

[0086]

[Equation 26]

It becomes Therefore,

[0088]

[Equation 27]

Is obtained as a condition.

Further, when n acceleration calculation values are used for the estimation, the result of Equation 2 is obtained by the same examination. The above results are summarized in Table 1.

[0091]

[Table 1]

When the numerical model is a more complex multi-mass system and the number of boundary points is one, the following is obtained. From the equation of motion 3 of the numerical model, the eigenmode vector
{φ} _i can be obtained by the number of degrees of freedom. Here, i indicates the mode order. Using this vector {φ} _i , the equation of motion can be rewritten as the equation of motion for a system with one degree of freedom as shown below, ignoring the damping term.

[0093]

[Equation 28]

From this, the mass ratio ρ _i for each mode is

[0095]

[Equation 29]

It can be expressed as follows. If this mass ratio is within the divergence limit for all modes, there is no fear of divergence, and the vibration test can be performed by the algorithm.
When there are multiple boundary points, each boundary point shares the mass of the real part model, but in order to obtain the most stable condition, if all the masses are added to each boundary point, an evaluation is performed. Good. Further, when there are a plurality of real part models or when the support points of the real part model have a plurality of degrees of freedom, it is sufficient to evaluate each degree of freedom. In this case, when the degree of freedom is the rotational degree of freedom, the mass replaces the moment of inertia.

Further, another embodiment will be described with reference to FIG. The output of the load converters 7b and 7c of the supporting part of the vibrating table is input to the digital computer via the A / D converter before the vibration test is performed, and the mass of the installed equipment to be excited is measured. Then, the mass ratio determined from the numerical model of the support structure that has been input to the digital computer in advance is calculated, and if the conditions in Table 1 are not satisfied, an alarm is issued and the vibration test cannot be executed. There is a function. With this function, vibration response analysis diverges and excessive acceleration is applied to the vibration table, which destroys the installed equipment that is vibrated, or
There is no fear that accurate vibration response cannot be evaluated. When an alarm is issued, the number of acceleration estimates may be changed or the numerical model may be changed to perform the test so as to meet the conditions.

In the embodiment, the case where the actual partial model is the installation device, the numerical model is the support structure and the actuator is the vibrating table has been described, but the present invention is not limited to this. However, the present invention can be applied even if the configuration of the vibration test is other than that. In short, various configurations can be adopted without departing from the gist of the present invention.

[0099]

According to the present invention, since the acceleration at the boundary point to be excited can be calculated using the load generated when the real part model is excited, the real part model and the numerical model Even if it is not possible to determine the vibration acceleration waveform before the test due to the interaction between them, it is possible to perform the vibration test of the actual part model while calculating the vibration acceleration waveform by the digital computer during the vibration test. .. Conventionally, the vibration test is performed using the entire structure, whereas the vibration test of the structure can be realized by exciting only the partial structure with the actuator. As the scale of the test specimen becomes smaller, it becomes possible to test larger equipment by using limited vibration test equipment.

Further, even when the vibration of the partial model is unknown, the vibration response of the numerical model part can be obtained by the vibration response calculation performed at the same time as the test of the partial model.
Since the numerical model part can be easily changed, it is possible to know the change in the vibration applied to the partial model and the vibration of the numerical model part itself caused by the design change, without making and experimenting with the numerical model substructure. Becomes

In addition, according to the test method of the present invention, the relationship between the mass of the actual partial model to be excited and the numerical model satisfies the condition determined by the number of calculated acceleration values used for acceleration estimation. The vibration analysis algorithm used in the test apparatus of the present invention can be stably executed.

Further, with the test apparatus of the present invention, the vibration test can be performed only when the above conditions are satisfied, and the test can be performed without causing damage to the test body due to the divergence of the vibration analysis.

[Brief description of drawings]

FIG. 1 is a block diagram of a test apparatus according to an embodiment of the present invention.

FIG. 2 is a block diagram of a conventional test apparatus for installed equipment.

FIG. 3 is an explanatory view of an installation device installed in the support structure.

FIG. 4 is an explanatory diagram showing an example of a computer algorithm.

FIG. 5 is an explanatory diagram showing another embodiment of a computer algorithm.

FIG. 6 is an explanatory diagram of a one-degree-of-freedom system model.

[Explanation of symbols]

1 ... Installation equipment, 2 ... Vibration table, 3 ... Actuator, 4 ...
Control circuit, 5 ... Digital computer, 6 ... Digital / analog converter, 7 ... Load detector, 8 ... Analog / digital converter, 9 ... Acceleration detector, 10 ... Support structure, 1
4 ... Vibration calculation algorithm, 15 ... Excitation control calculation algorithm.

Claims (10)

[Claims] 1. A part of a structure is modeled by using a real thing or a model, and the other part is modeled numerically, and one or a plurality of actuators attached to a boundary part of the real model with the numerical model part, and An actuator control device, a device for measuring a reaction force generated from an actual model in the actuator, a digital computer for calculating a vibration response of the numerical model, a means for inputting the reaction force measurement value to the digital computer, And a means for outputting a value calculated from the vibration response calculation value of the digital computer to the control device of the actuator as an excitation signal, the digital computer inputs the reaction force measurement value generated in the actuator at regular time intervals. Then, using the reaction force measurement value and the known external force value, the boundary portion between the numerical model and the actual model The vibration response including the acceleration at the reaction force measurement time is calculated so that the acceleration realized by the actuator after a certain time from the reaction force measurement time becomes the value calculated from the past acceleration calculation value including the reaction force measurement time. In addition, the structure testing device is provided with a function of outputting a vibration signal to the actuator control device. 2. The structure testing apparatus according to claim 1, wherein the acceleration realized by the actuator after a certain period of time is an acceleration calculation value at a reaction force measurement time. 3. The acceleration realized by the actuator after a certain period of time according to claim 1, is a value estimated by using an acceleration calculation value at a reaction force measurement time and an acceleration calculation value at a previous time step. Testing equipment for structures. 4. The acceleration realized by the actuator after a certain period of time is an acceleration calculation value at a reaction force measurement time, an acceleration calculation value at a previous time step, and
Further, the structure testing apparatus, which is a value estimated by using the acceleration calculation value in the previous time step. 5. The digital computer according to claim 1, wherein the number n of acceleration calculation values used for acceleration estimation before a vibration test can be input to the digital computer, and the acceleration realized by the actuator after a predetermined time is a reaction force. A structure testing apparatus that is a value estimated using n acceleration calculation values including the acceleration calculation value at the measurement time. 6. The mass according to claim 2, from the mass of the real model to be tested and the numerical model, A method for testing a structure, characterized in that the value ρ _i obtained in 1 is set to be smaller than 1 for all eigenmodes of the numerical model. 7. The mass ρ _i obtained by the mathematical formula 1 from the mass of the real model to be tested and the numerical model according to claim 3.
To 1/3 for all eigenmodes of the numerical model
Test method for structures set smaller. 8. The mass ρ _i obtained by the mathematical formula 1 from the mass of the real model to be tested and the numerical model according to claim 4.
To 1/7 for all eigenmodes of the numerical model
Test method for structures set smaller. 9. The value ρ obtained by the mathematical expression 1 from the mass of a real model to be tested and a numerical model when the number of calculated values used for acceleration estimation is n.
_{Let i be the following} for all eigenmodes of the numerical model: A test method for structures that is set smaller than ρ _cr specified in. 10. The structure according to claim 1, 2, 3, 4 or 5, wherein said actuator has a load detector, said digital computer fetches its output value and uses the output value as a test object. Of the numerical value, and the value ρ _i obtained from the numerical model from the numerical model is calculated from the numerical value n based on the number n of calculated values used for acceleration estimation for any eigenmode of the numerical model. A test device for installed equipment that has the function of generating an alarm and disabling the test when it is larger than ρ _cr defined in.