JP2003161670A - Evaluation method for response and feature for auxiliary vibration table - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a response evaluation method for an auxiliary vibration table capable of modeling the table and easily evaluating a response from the table by using a numerical analysis, as well as a feature evaluation method for the table wherein any feature of the table hard to be found so far can surely be captured by an easier means even if every feature, etc., of the table components is unknown, to enable development of both a high-precision analysis model and an excitation testing. <P>SOLUTION: The method is to evaluate the response from the auxiliary vibration table equipped with an excitation means, characterized by that it substitutes a frequency-dependent complex spring for the excitation means to model the auxiliary vibration table, assumes a virtual excitation force signal proportional to an excitation target signal to calculate a relational expression for dynamic balance between the excitation force signal affecting the table and the table itself, and then obtains the response from the table based on the dynamic balance relational expression. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a response evaluation method and a characteristic evaluation method of a shaking table used in a vibration test for various test bodies.

[0002]

2. Description of the Related Art Generally, when designing various structures such as high-rise buildings and seismic isolation / vibration control structures, test specimens of the above structures are manufactured in advance and placed on a vibration table. , The seismic strength and safety of the structure are evaluated by vibrating until the test body is plastically deformed by a predetermined excitation target signal corresponding to the observed acceleration and displacement of seismic waves. .

By the way, in the case of conducting a vibration test of a test body using such a vibrating table, even if the predetermined vibrating target signal is inputted to the vibrating means of the vibrating table or its control device, the vibrating table itself is There is a problem that a desired vibration waveform cannot be reproduced due to the characteristics and the effect of interaction with the vibration table due to the plastic deformation of the test body. Therefore, in the past, the test vibration was previously mounted on the vibration table in advance, the response of the vibration table at this time was measured, and the transfer function of the response to the vibration target signal was evaluated. However, so-called input compensation has been performed in which the excitation target signal is corrected in advance using the inverse transfer function.

[0004]

However, in the above-mentioned conventional method by the input compensation, it is assumed that the characteristics of the test body are linear. Therefore, when the characteristics of the test body have non-linearity, , Even if the excitation target signal is corrected by input compensation at a certain excitation level, if the excitation level is increased and excitation is performed, the characteristics of the test object change, resulting in a difference between the excitation target signal and the vibration table response. There is a problem that the desired vibration test cannot be performed because of the deviation.

On the other hand, as another conventional vibration experiment method by input compensation, a test body is mounted on the vibrating table to conduct a vibrating experiment, and at the same time, the vibrating table is driven and controlled. A reaction force compensation method is known in which the reaction force from the test body, which is a disturbance at the time of measurement, is measured in real time and is fed back as a compensation signal.However, depending on this reaction force compensation method, the mechanism and control system are complicated. In addition, there is a problem that it is difficult to perform a vibration experiment in a wide frequency range because the effect of compensation differs depending on the frequency range.

Therefore, the vibration table is modeled in advance, and the response of the vibration table is evaluated by numerical analysis to set a vibration signal for obtaining a desired vibration waveform during the experiment.
A method is being sought for conducting a vibration test in which the above-mentioned test body is mounted. In this way, when the vibration table is modeled in advance and its response and characteristics are to be grasped, the vibrating means constituting the vibration table, for example, in a hydraulic vibration table, a hydraulic actuator, a servo valve, etc. It is desirable to faithfully model the characteristics of, and the characteristics of the feedback control system for the acceleration, velocity, and displacement of the vibration table.

Generally, in the above-mentioned shaking table system, in order to control the motion of the shaking table to achieve a target response, a control system mainly including displacement / velocity / acceleration feedback and minor pressure difference feedback is used. ing. FIG. 1 shows a block diagram of a uniaxial shaking table of an acceleration control system having a static pressure joint.
For example, shaking table mass: 1000 kg, maximum amplitude: ± 50 m
m, maximum acceleration: ± 3 G (supply hydraulic pressure: 140 kg / cm
^It is an electro-hydraulic vibrating table having the performance of ² ), and the above-mentioned hydrostatic joint is used to reduce the stroke between the vibrating shafts when applied to a biaxial or triaxial vibrating table.

In FIG. 1, Ap: pressure-receiving area of the vibrator piston, ba: viscous drag coefficient on the piston side, bt: Viscous table side viscosity resistance coefficient, i: Servo valve input current, c = V / 2κ (here, V: volume on one side of the cylinder, κ: bulk elastic modulus of hydraulic oil), D: damping coefficient of static pressure joint, K: static rigidity of static pressure joint, f: Excitation force, Ka: Acceleration feedback gain, Kv: velocity feedback gain, Ky: displacement feedback gain, ki: Servo valve flow gain, Ks: Servo amplifier gain, kp: Reduction rate of output flow rate due to internal leakage of servo valve, R: Leakage flow coefficient of cylinder and bypass circuit Pm: Cylinder differential pressure, Ma: Piston side flow rate, Mt: mass of vibration table side, ya: piston displacement, yt: shake table displacement, R (s): acceleration command signal.

From such a block diagram, the equation of motion of the vibrating table in the Laplace transform region can be described as the following equation (1).

[Formula 1]

In the above formula (1), the exciting force f can be expressed as the following formula (2).

[Formula 2]

Therefore, theoretically, the response of the uniaxial shaking table can be evaluated by the equations (1) and (2). However, in practice,
Even when the characteristics such as the characteristics of each component in the above-mentioned shaking table are obtained, in order to directly solve the above equations (1) and (2), the higher order differential equations should be solved sequentially. However, there is a problem in that it is difficult to grasp all of the above characteristics and the performance setting method of the feedback control system.

The present invention has been made in view of the above circumstances, and a vibrating table response evaluation method capable of easily evaluating the response of the vibrating table by modeling the vibrating table and performing a numerical analysis. Even if the various characteristics of the components of the shaking table are unknown, the characteristics of the shaking table, which were difficult to grasp up to now, can be reliably obtained by a simple method, so a vibration test with high accuracy can be performed. It is an object of the present invention to provide a vibrating table characteristic evaluation method that can be performed.

[0013]

A vibrating table response evaluation method according to the present invention according to claim 1 is a method for evaluating a response of a vibrating table provided with a vibrating means, wherein the vibrating means is used. The vibration force signal acting on the vibration table is modeled by replacing the vibration table with a complex spring having frequency dependence, and assuming a virtual vibration force signal proportional to the vibration target signal. And a dynamic balance relational expression between the vibration table and the vibrating table, and a response of the vibrating table is obtained based on the dynamic balance relational expression.

According to a second aspect of the present invention, in evaluating the response of the vibrating table provided with a plurality of vibrating means in the invention according to the first aspect, the plurality of vibrating means are connected to each other. It is characterized in that the vibrating table is modeled by replacing it with a complex spring as a compound effect acting on the center of gravity of the vibrating table.

Further, a vibrating table characteristic evaluation method according to a third aspect of the present invention is a method for evaluating the characteristic of a vibrating table provided with a vibrating means, wherein the vibrating means is frequency dependent. The shaking table is modeled by substituting a complex spring, and then, assuming a virtual exciting force signal proportional to the exciting target signal, dynamic fishing of the exciting force signal and the shaking table is performed. Then, a vibration relation experiment was performed for a plurality of different loads mounted on the vibration table, and based on the response of the vibration table and the dynamic balance relational expression obtained by these, the vibration table The above characteristic is obtained.

In this case, the invention according to claim 4 is characterized in that, when evaluating the characteristics of the vibrating table provided with a plurality of vibrating means in the invention according to claim 3, The invention is characterized in that the vibrating table is modeled by substituting a complex spring as a compound effect acting on the center of gravity of the vibrating table, and the invention according to claim 5 further comprises: Alternatively, the vibration test described in 4 is performed on two types of mounting loads, that is, no load and one mounting load. In the invention according to any one of claims 3 to 5, the response of the shaking table obtained by the vibration experiment means the displacement, speed, or acceleration of the shaking table obtained by the vibration experiment.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION In the vibrating table response evaluation method of the present embodiment, when the vibrating table is characterized in that the vibrating means is a hydraulic vibrating table, various configurations such as a hydraulic actuator and a servo valve are provided. It is considered that there is a dependency on the excitation frequency due to the characteristics of the elements and the characteristics of the feedback control system. Therefore, the vibrating table is modeled by replacing the vibrating means with a complex spring having frequency dependence. Hereinafter, if this is specifically shown as an embodiment, the equation (2) is substituted into the above equation (1), and K ′ (s) is obtained as shown in the following equations (3) and (4). And using G (s),
A dynamic balance relational expression of the vibrating table shown in Expression (5) is obtained.

[0018]

[Formula 3]

[Formula 4]

[0019]

[Formula 5] This equation (5) is a complex spring K ′ having frequency dependence.
Excitation force f = G (s) is applied to the vibrating table of mass Mt having (s).
It can be considered that R (s) is working. That is, the excitation target signal R (s) is multiplied by the transfer function G (s) of the equation (4) to obtain the excitation target signal R (s).
Virtual excitation force signal G (s) R (s) proportional to (s)
Assuming that this force has a mass M having a complex spring K ′ (s),
As a result of acting on the shaking table of t, the response of the shaking table can be evaluated.

Where K (s) and G (s) are
As shown in the equations (3) and (4), it is determined only by the characteristics obtained from the characteristics of each component of the vibrating table and the characteristics of the feedback control system. The response of the shaking table can be easily evaluated. Further, in the case where the vibrating table has a plurality of vibrating means, the plurality of vibrating means can be replaced by a complex spring as a compound effect that acts on the center of gravity of the vibrating table, thereby facilitating the same operation. It becomes possible to model the above-mentioned shaking table and evaluate the response.

Next, one embodiment of the vibration table characteristic evaluation method according to the present invention will be described with reference to FIGS. The present embodiment is a method that makes it possible to evaluate the characteristics of the vibrating table even when some characteristics of each component of the vibrating table or a part of the characteristics of the feedback control system cannot be grasped.

First, also in the present embodiment, the characteristics of the vibrating table 1 are such that, when the vibrating means is a hydraulic vibrating table, various characteristics of various constituent elements such as a hydraulic actuator and a servo valve and a feedback control system. 2 is considered to have a dependency on the excitation frequency, the excitation means (actuator) is driven by the complex springs K _v (iω) and K _H (having the frequency dependency) as shown in FIG. iω). Here, K _v (iω) is a vertical complex spring, and K _H (iω) is a horizontal complex spring.

Here, the vertical complex spring K _v (iω)
In the case where the vibration signal to be originally generated in the vibrating table 1 is the vibration target signal R _V (iω) during the vibration test on the test body,
It is proportional to the excitation target signal R _VI (iω), and the shaking table 1
Assume a virtual actuator excitation force signal (hereinafter, abbreviated as excitation force signal) F _V (iω) that is not affected by the movement of the actuator. Then, the relationship between the excitation target signal R _VI (iω) and the excitation force signal F _V (iω) under no load is
It is expressed as in equation (6). Where G ₀ (iω) is
It is a transfer function of the excitation target signal R _VI (iω) and the excitation force signal F _V (iω).

[Formula 6]

Then, according to the equation (6), dynamic response of the response of the vibrating table 1 at the position of the center of gravity of the vibrating table 1 at the time of no load during vertical vibration and the exciting force signal F _V (iω) The relational expression can be expressed as the following expression (7).

[Formula 7] Here, m _t is the weight of the vibrating table 1, and Z ₀ (iω) is the vertical response displacement at the center of gravity of the vibrating table 1.

Next, in the same manner as the equation (7), the weight of the weight M is
Vibration at the center of gravity of the vibrating table 1 when the weight 2 is installed
The response of the table 1 and the excitation force signal F_VDynamic fishing with (iω)
The relational expression is the vertical displacement at the center of gravity of the vibrating table 1.
Z_MIf (iω), it can be expressed as the following equation (8).
You can However, in this case, the excitation target signal R _VI
The magnitude of (iω) is multiplied by α as compared with that when there is no load.
In equation (8), α = 1, that is, the same excitation
Target signal R_VIIt also includes the case of (iω).

[Formula 8]

Then, according to the equations (7) and (8),
The complex spring K _v (iω) in the vertical direction of the vibrating table 1 can be evaluated by the following equation (9).

[Formula 9] The above equation (9) is obtained by the vertical displacements Z ₀ (iω) and Z _M (iω) of the vibrating table 1 when there is no load and when the weight 2 is mounted.
It is shown that the complex spring K _v (iω) in the vertical direction can be evaluated by experimentally measuring the frequency response of the above.

Next, the evaluation method for the complex spring K _H (iω) in the horizontal direction will be described. As in the case of the vertical direction, the vibration table 1 should be originally generated in the vibration table 1 during the vibration test. Excitation signal is excitation target signal R _HI
(Iω), this excitation target signal R _HI (iω)
It is assumed that a virtual excitation force signal F _H (iω) that is proportional to and is not affected by the motion of the vibrating table 1. As a result, the relationship between the excitation target signal R _HI (iω) and the excitation force signal F _H (iω) when there is no load is expressed by equation (10). Here, G ₁ (iω) is the excitation target signal R _HI (i
ω) and the excitation force signal F _H (iω).

[0028]

[Formula 10] Also, from the complex spring K _V (iω) in the vertical direction, the vibration table 1
The complex spring K _θ (iω) in the rotation direction with respect to the center of gravity of can be evaluated by the following equation (11).

[Formula 11] Here, L represents the horizontal distance from the center of gravity of the vibrating table 1 to the mounting position of the vertical actuator.

Complex spring K _{θ in} the rotation direction of the above equation (11)
(I [omega]) using the rotational inertia I _t of the center of gravity around the vibrating table 1, the horizontal displacement response of the center of gravity of the vibrating table 1 X ₀ (i
ω), the rotational direction response displacement of the center of gravity of the vibrating table 1 is Θ ₀ (i
ω), and the coefficient representing the deviation between the acting position of the horizontal excitation force and the center of gravity of the vibrating table 1 is β (β = 0 when there is no deviation),
The dynamic equilibrium relational expression between the response of the vibrating table 1 at the center of gravity of the vibrating table 1 at the time of no load during horizontal vibration and the exciting force signal F _H (iω) is as shown in the following formula (12). Can be expressed as

[Formula 12]

Next, the dynamic equilibrium relational expression between the response of the vibrating table 1 at the center of gravity of the vibrating table 1 when the weight 2 having the weight M is installed and the above-mentioned exciting force signal F _H (iω) is , X _M (iω) is the horizontal response displacement of the center of gravity of the vibrating table 1, and Θ _M (iω) is the rotational direction response displacement of the center of gravity of the vibrating table 1, then the following equation (13) can be similarly expressed. it can. However, in this case, the magnitude of the excitation target signal R _HI (iω) is multiplied by α as compared with that when there is no load. In the equation (13), α = 1, that is, the same excitation target signal R _HI (iω)
Including the case of

[Formula 13]

Here, I _H (iω) is a horizontal inertial force acting on the center of gravity of the vibrating table 1 from the weight 2, and I _θ (iω)
ω) is a rotational direction inertial force that acts on the center of gravity of the vibrating table 1 from the weight 2, and when the distance between the weight 2 and the vertical center of gravity of the vibrating table 1 is H, the following formulas (14) and (15) are given. )
It can be expressed as an expression.

[Formula 14]

[Formula 15]

Then, by substituting the equations (14) and (15) into the equation (13), the following equation (16) is obtained.

[Formula 16]

Then, this equation (16) and the above (12)
From the equations, the following equations (17) and (18) can be obtained, and these equations (17) and (18) allow horizontal displacement when the vibration table 1 is unloaded and when the weight 2 is mounted. By measuring X ₀ (iω), X _M (iω) and rotational direction response displacement Θ ₀ (iω) and Θ _M (iω) by an experiment, the horizontal complex spring K of the vibrating table 1 is measured.
It is possible to evaluate _H (iω) and the complex spring K _θ (iω) in the rotation direction with respect to the center of gravity of the vibrating table 1.

[Formula 17]

[Formula 18]

Then, in order to evaluate the complex springs K _V (iω) and K _H (iω) in the vertical and horizontal directions, vibration tests are carried out for two different loads on the vibrating table 1. By the way, in the present embodiment, a vibration test was carried out under no load (no load) and when a weight was mounted. The dimensions and specifications of the vibrating table 1 to be examined are as shown in FIG. 3 and Table 1. In addition, the vibration experiment in the present embodiment was carried out for two types of sine wave step vibration and random wave vibration in the horizontal direction and the vertical direction, respectively. These vertical and horizontal vibration conditions are
It is as shown in Table 2.

[0035]

[Table 1]

[0036]

[Table 2]

First, based on the results of the sinusoidal step excitation tests of Case 1 and Case 2, the vertical complex spring K _V (iω) was evaluated using the equation (9) for each frequency. By the way, the ratio of the vibration level when there is no load and when the weight is installed is
α = 250/300. Similarly, the frequency response was calculated by Fourier transform from the time history data of the vertical shaking table response displacement of the random wave excitation experiment results of Case 3 and Case 4, and the vertical complex spring K _V (iω) was evaluated. In this case, α = 1. FIG. 4 shows the result of the sine wave step excitation experiment, and FIG. 5 shows the result of the random wave excitation experiment.

Then, the excitation force signal F _V (iω) is calculated from the evaluation result of the complex spring K _V (iω) in the vertical direction obtained by the sinusoidal step excitation experiment and the equation (7). Thus, the transfer function G ₀ (iω) of the excitation force signal F _V (iω) with respect to the excitation target signal R _VI (iω) can be evaluated. The calculation evaluation of the excitation force signal F _V (iω) and the transfer function G ₀ (iω) can be similarly obtained from the result of the random wave excitation experiment. Figure 6
Shows the evaluation result of the transfer function G ₀ (iω) thus obtained in the form of amplitude, and FIG. 7 shows it in the form of phase.

Next, the horizontal complex spring K _H (iω) was evaluated using the equation (17) for each frequency from the results of sinusoidal step excitation tests of Case 5 and Case 6. By the way, the ratio of the vibration levels when there is no load and when the weight is mounted is α = 400/500. Similarly, Case
The frequency response was calculated by Fourier transform from the time history data of the horizontal shaking table response displacement of the random wave excitation experiment results of Case 7 and Case 8, and the horizontal direction complex spring K _H (iω) was evaluated. In this case, α = 1. FIG. 8 shows the result of the sinusoidal step excitation experiment.
Shows the result of the random wave excitation experiment.

Next, similarly, from the evaluation result of the complex spring K _H (iω) in the horizontal direction obtained by the above sinusoidal step excitation experiment and the equation (12), the excitation force signal F _H (i
By calculating ω), the excitation target signal R _HI (iω)
The transfer function G ₁ (iω) for can be evaluated. Similarly, the calculation evaluation of the excitation force signal F _H (iω) and the transfer function G ₁ (iω) can be similarly obtained from the result of the random wave excitation experiment. Figure 10
Is a transfer function G obtained by the above horizontal vibration experiment.
The evaluation result of ₁ (iω) is represented by the amplitude,
FIG. 11 shows a phase format.

As described above, according to the characteristic evaluation method of the vibrating table 1, the exciting means is the complex spring K having frequency dependence.
_The shaking table 1 is modeled by substituting _V (iω) and K _H (iω), and then the excitation target signal R _VI (i
ω), R _HI (iω), and a virtual excitation force signal F _V (iω), F that is not affected by the motion of the vibrating table 1.
Assuming _H (iω), the dynamic equilibrium relational expressions (7), (8), (12), and (13) with the vibrating table 1 are obtained, and two different loading loads on the vibrating table 1 are obtained. The vibration target signal R is calculated based on the response of the vibration table 1 and the relational expressions (9) and (17) obtained by these.
Excitation force signal F _V (i) for _VI (iω) and R _HI (iω)
ω), F _H (iω) transfer functions G ₀ (iω), G ₁ (i
ω) can be obtained.

At this time, according to the comparison between FIG. 4 and FIG. 5 and the comparison between FIG. 8 and FIG. 9, both the sine wave excitation and the random wave excitation are found although the results of the random wave excitation show some variations. The results of excitation correspond well, thus demonstrating the validity of the modeling method. Therefore, according to the characteristic evaluation method, it is possible to easily and surely obtain the characteristic of the vibration table, which has been difficult to grasp until now, by a simple method, and thus it is possible to perform the vibration experiment with high accuracy.

As shown in the above embodiment, when the test body is linear, the vibrating means of the vibrating table 1 is moved vertically and horizontally in the frequency domain to generate complex springs K _V (iω), K
_By modeling with _H (iω), evaluating the test body response for each frequency, and performing an inverse Fourier transform on this,
It is possible to obtain time-series data of the response of the test body, but when the test body is non-linear, it is necessary to perform time history response analysis. It is necessary to replace the complex spring with a physical model.

As such a method, a model capable of approximating a complex spring in a target frequency range, for example, a three-element model shown in FIG. 12 and a generalized Max in which a unit Maxwell model shown in FIG. 13 is arranged in parallel. A well model, a generalized Voigt model in which unit Voigt models as shown in FIG. 14 are connected in series can be used, and further, an integer differential rule, a fractional differential rule, etc. used to approximate the characteristics of the viscoelastic damper. Can also be used.

Further, in the above-mentioned embodiment, the vibration test of the vibrating table 1 is explained only when it is carried out for two kinds of mounting loads, that is, no load and one mounting load.
The present invention is not limited to this, and may be performed with two different loading loads, or with a large number of loading loads of three or more. By the way, if a vibration test is carried out with a large number of mounting loads in this way, the characteristics of the vibrating table 1 can be obtained with even higher accuracy.

[0046]

As described above, claim 1 or 2
According to the vibrating table response evaluation method according to the present invention described in
When evaluating the response of the shaking table equipped with the vibrating means, the vibrating table is modeled by replacing the vibrating means with a complex spring having frequency dependence, and a virtual table proportional to the vibration target signal is generated. Assuming a vibration force signal, a dynamic balance relational expression between the vibration force signal acting on the vibrating table and the vibration table is obtained, and based on the dynamic balance relational expression, I'm trying to get a response. As a result, from the conventional equation of motion of the shaking table in the Laplace transform domain, it is possible to avoid the difficulty of sequentially solving the higher-order differential equations to evaluate the response, and to improve the known specifications of each component of the shaking table and the feedback control system. Using the characteristic of, the response of the shaking table can be easily evaluated based on a simple analysis model.

Further, in particular, according to the characteristic evaluation method of the vibrating table according to any one of claims 3 to 5, the model is obtained by replacing the vibrating means of the vibrating table with a complex spring having frequency dependence. And then proportional to the excitation target signal,
In addition, assuming a virtual excitation force signal that is not affected by the shaking table, a dynamic equilibrium relational expression between the shaking force signal and the shaking table is obtained, and further, for a plurality of different mounted loads on the shaking table. In the case where the characteristics of the feedback control system described above are unknown because the characteristics of the vibration table are obtained based on the vibration table response and the dynamic equilibrium relational expressions obtained by conducting the vibration experiment. Also in the above, it is possible to easily and surely obtain the characteristics of the shaking table, which have been difficult to grasp until now, by a simple method, and thus it is possible to construct a highly accurate analysis model.

At this time, in particular, as in the invention described in claim 5, if the vibration test is carried out for two types of loading loads, that is, no load and one loading load, it is even easier. Therefore, the characteristics of the vibrating table can be obtained.

[Brief description of drawings]

FIG. 1 is a block diagram of an acceleration control system of a vibration table in an embodiment of a vibration table response evaluation method according to the present invention.

FIG. 2 is a diagram showing modeling of a vibrating table in an embodiment of a method of evaluating a characteristic of a vibrating table according to the present invention.

FIG. 3 is a diagram showing conditions of a vibration test with respect to a load mounted on a vibrating table.

FIG. 4 is a graph showing evaluation results of vertical complex springs by a sinusoidal step excitation test.

FIG. 5 is a graph showing evaluation results of vertical complex springs by a random wave excitation experiment.

FIG. 6 is a graph showing amplitudes of evaluation results of transfer functions in the vertical direction.

FIG. 7 is a graph showing the evaluation result of the transfer function in the vertical direction by phase.

FIG. 8 is a graph showing an evaluation result of a horizontal complex spring by a sinusoidal step excitation test.

FIG. 9 is a graph showing an evaluation result of a horizontal complex spring by a random wave excitation experiment.

FIG. 10 is a graph showing the evaluation result of the transfer function in the horizontal direction by amplitude.

FIG. 11 is a graph showing the evaluation result of the transfer function in the horizontal direction by phase.

FIG. 12 is a diagram showing a three-element model which is an example of a physical model of a complex spring.

FIG. 13 is a diagram showing a generalized Maxwell model which is an example of a physical model of a complex spring.

FIG. 14 is a diagram showing a generalized Voigt model which is an example of a physical model of a complex spring.

[Explanation of symbols]

1 shaking table 2 weights

Claims (5)

[Claims] 1. A method for evaluating the response of a shaking table provided with a vibrating means, wherein the vibrating table is modeled by replacing the vibrating means with a complex spring having frequency dependence, and vibrating. Assuming a virtual excitation force signal proportional to the target signal, a dynamic equilibrium relational expression between the excitation force signal acting on the vibrating table and the vibrating table is obtained, and the dynamic equilibrium relational expression Based on the above, a response evaluation method of the vibrating table is obtained. 2. When evaluating the response of the vibrating table having a plurality of the vibrating means, the plurality of vibrating means are replaced with complex springs as a compound effect acting on the center of gravity of the vibrating table. The vibration table response evaluation method according to claim 1, wherein the vibration table is modeled. 3. A method for evaluating the characteristics of a shaking table provided with a vibrating means, wherein the vibrating table is modeled by replacing the vibrating means with a complex spring having frequency dependence, and then a vibrating table is modeled. Assuming a virtual excitation force signal proportional to the vibration target signal, a dynamic equilibrium relational expression between the excitation force signal and the vibration table is obtained, and further, for a plurality of different mounted loads on the vibration table. A characteristic evaluation method for a vibrating table, characterized in that a vibrating table is obtained, and the characteristics of the vibrating table are obtained based on the response of the vibrating table and the dynamic equilibrium relational expression obtained thereby. 4. When evaluating the characteristics of the vibrating table having a plurality of the vibrating means, the plurality of vibrating means are replaced with complex springs as a compound effect acting on the center of gravity of the vibrating table. The vibration table characteristic evaluation method according to claim 3, wherein the vibration table is modeled. 5. The characteristic evaluation method for a vibrating table according to claim 3, wherein the vibration test is performed on two types of mounting loads, that is, no load and one mounting load.