JPH07113721A - Vibration testing device, vibration testing method, and vibration testing jig for structure - Google Patents

Abstract

PURPOSE:To combine the vibration response calculation of a primary structure and the vibration test of the secondary structure together so as to accomplish an economical and highly precise vibration test. CONSTITUTION:On the basis of a vibration response calculation of a primary structure, an excitation signal for a vibrating table test of a secondary structure 4 is prepared, and a load from the secondary structure 4 is used for a vibration response calculation. For measuring the load, the secondary structure 4 is placed on a vibration testing jig, which is movable in the excitation direction. The vibration testing jig consists of a supporting member 14, which is movable in the excitation direction, a base plate 15, and the like.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration testing apparatus for structures, a vibration testing method and a vibration testing jig, and
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration test apparatus, a vibration test method, and a vibration test jig suitable for a structure in which the structure to be evaluated by vibration is large-scale and it is difficult to perform a vibration test on the entire structure.

[0002]

2. Description of the Related Art Conventionally, the evaluation of the vibration response when a structure is vibrated by an external force such as an earthquake has been conventionally carried out by mounting the structure on a vibrating table and vibrating it. However, when the structure is very large, it may be difficult to mount the real object on the vibrating table due to the limitation of the allowable load of the vibrating table. In such cases, the vibration response was evaluated by conducting a vibration test using a scale model that can be installed, by conducting a vibration test on only a part of the structure, or by applying both. .

Further, as shown in the schematic diagram of FIG. 11, a structure 1 whose vibration response is to be evaluated is connected to a foundation 2 like a building (hereinafter referred to as main structure 3), and installation Structures connected to the main structure 3 like equipment (hereinafter,
As a test apparatus applicable when it can be divided into secondary structures 4), Japanese Patent Laid-Open No. 4-278431 discloses "Testing apparatus for installation equipment and vibration calculation method for supporting structure".

FIG. 12 shows the structure of the secondary structure 4
Only the real thing is modeled, the main structure 3 is numerically modeled and input to the computer 5, and the vibration test by the vibrating table 6 and the numerical calculation by the computer 5 are simultaneously performed. For the numerical calculation, the load applied from the secondary structure 4 to the vibrating table is measured by the load measuring means 7. The experimental procedure is shown in FIG. That is, using the load measurement value qi and the seismic force Fi at a certain time ti (which is stored in the computer in advance), according to a numerical calculation algorithm previously input to the computer 5, the time after a certain time interval Δt ti
Calculate the vibration response of the +1 main structure.

[0005]

As in the prior art, in a scale model test using a vibrating table, non-linearity or the like is caused in a structure.
In some cases, the rules of similarity were complicated and did not hold. Further, in the partial model test, it was difficult to determine the correct excitation waveform when the partial model interacts with other parts. Further, in the test method in which the vibration test by the vibrating table and the numerical calculation are simultaneously performed, as shown in FIG. 13, the load applied to the vibrating table from the secondary structure, which is the actual model, is measured and used for the numerical calculation. It is necessary, but it is necessary to use Japanese Patent Laid-Open No. 4-278.
In Japanese Patent No. 431, the measuring means is not clearly shown and it is difficult to realize. In addition, since it is necessary to directly fix the secondary structure to be vibrated to the vibrating table, it is difficult to apply it when it is long. Furthermore, the vibration response of the real model can be evaluated by actually measuring the response, but it was difficult to evaluate the vibration response of the numerical model part.

In view of the above problems, it is an object of the present invention to calculate the load with high accuracy and calculate the vibration response of the main structure and the secondary structure, that is, the vibration of the structure with high accuracy. A test apparatus, a vibration test method, and a vibration test jig.

[0007]

In order to achieve the above object, the present invention provides one or a plurality of vibration exciters, a vibrating table driven by the vibrating machine, and a vibrating direction of the vibrating table. Installed between the base plate on which the test sample is mounted and the base plate and the vibrating table or a frame fixed to the vibrating table in the same vibration direction as the vibrating table. Load transmitting means for transmitting a load, load measuring means for measuring a load transmitted by the load transmitting means, load measured value transmitting means for transmitting a load measured value from the load measuring means, and the load measured value transmitting means And a computer for calculating the control signal of the vibration exciter based on the load measurement value transmitted by the computer and the data stored internally or the data input from the outside, and the control transmitting the control signal calculated by the computer. A signal transmitting means, is made of a control apparatus for controlling the vibration generator by a control signal transmitted by said control signal transmitting means.

An actual model of the secondary structure, which is connected only to the fixed main structure, is installed on the vibrating table via a support member movable in the vibration direction, and the actual model and It is a method of measuring the load transmitted to the vibrating table and using the measured load value to calculate the vibration response of the main structure.

Further, the above object is to provide a test member for a supporting member which is provided on the vibrating table and is movable in at least one direction, and a secondary structure which is supported by the supporting member and is coupled only to a main structure fixed thereto. It comprises a base plate on which a sample can be mounted, load transmitting means capable of transmitting a load between the base plate and the vibrating table in the movable direction of the supporting member, and a means for measuring the load transmitted by the load transmitting means. This is achieved by a jig for vibration testing of structures.

[0010]

According to the above structure, the load applied to the vibration table from the secondary structure is accurately measured, the vibration response of the main structure is sequentially calculated using the measurement result, and the vibration waveform is obtained. It is possible to obtain the vibration response of the main structure considering the influence of the vibration response of the secondary structure, and the vibration response at the installation point of the secondary structure of the main structure can be used as the excitation waveform. The vibration response of the substructure can be evaluated accurately.

By using a supporting member movable in one direction to support the base plate of the jig, the jig can be supported freely in the horizontal direction. Further, the base plate and the structure to be vibrated are shaken from the base plate and the object to be vibrated by vibrating by making the base plate coincide with the movable direction of the support member and the vibrating table exciting direction and fixing it to the vibrating table via the load transmitting means. All the applied load is transmitted by the load transmitting means. Accurate load measurement is possible by measuring this load.

Further, in the above case, the measured load includes the inertial force of the base plate portion. Therefore, when this inertial force occupies a large portion with respect to the measured load value, the load evaluation error is caused. As the cause, it is possible to evaluate the load without error by measuring the acceleration of the base plate, calculating the inertial force from its mass, and removing it from the load measurement value.

When it is possible to directly support the structure to be excited on the vibrating table in the same manner, the same action causes
Similar effects are obtained. In particular, if laminated rubber, hydrostatic bearings, rolling bearings, etc. are used as the support member that is movable in at least one direction, these can support a vertical load and are movable in the horizontal direction. Since the generated load is small, the error in the load measurement value can be reduced. In addition, the jig base plate, and
By opening an opening in the vibrating table and suspending the secondary structure to be vibrated, the structure can be applied to a long structure. Then, it is possible to evaluate the vibration response of the numerical model part by saving the calculation result in the computer and processing it after the test is completed or by outputting the calculation result successively.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Some embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a first embodiment of the present invention. That is, the secondary structure 4 that is the structure to be subjected to the vibration test.
Is mounted on the vibration test jig 18. The vibrating table test jig 18 includes a base plate 15, a support member 14 that supports the base plate and is movable in at least one direction, a load transmission unit 8 and a load transmission unit 8 in one of the directions in which the support member is movable. Measuring means for transmitted load 7
It is mounted on the vibrating table 6.

The vibration test jig 18 is mounted on the vibrating table 6 via the support member 14 so that the load transmitting direction of the load transmitting means 8 and the vibrating direction of the vibrating table 6 coincide with each other. One end 19 of the load transmitting means 8 is connected to the vibrating table 6 or a pedestal 9 fixed to the vibrating table 6. As a result, all the loads applied to the secondary structure in the vibration direction are transmitted through the load transmitting means 8, so that the load transmitted from the secondary structure 4 to the main structure 3 can be accurately measured. The vibrating table 6 is supported by bearings 20 and is driven by a vibration exciter 10 fixed to the foundation 2. The shaker 10 has its control device 1
Controlled by 1.

The measurement value signal from the load measuring means 7 is input to the computer 5 by the load measurement value transmitting means 12. In addition,
The load measuring means 7 is, for example, a combination of a strain gauge type load cell and a dynamic strain amplifier, the load measurement value transmitted is a voltage signal, and the load measurement value transmitting means 12 is, for example, a coaxial cable. Further, when the load measurement value is a voltage, the input to the computer 5 is performed by a D / A converter or the like. Therefore, in this case, the computer 5 needs to have a D / A converter.

An excitation signal is output from the computer 5. The excitation signal is output to the exciter control device 11 through the excitation signal transmission means 13. The vibration signal is, for example, a voltage signal output by an A / D converter included in the computer 5, and the vibration signal transmission unit 13 is, for example, a coaxial cable.

The output of the excitation signal is performed as follows. In the computer 5, according to an algorithm programmed in advance, a numerical model of the main structure 3, an external force such as seismic acceleration that has been input in advance or is input sequentially, and a load measurement value by the load measuring means 7,
The vibration response after a certain time interval is calculated from the measurement time of the load measurement value. Then, of the calculated values, a vibration signal is calculated such that the vibration response at the point where the secondary structure of the numerical model is connected is realized by the vibration table 6 after the fixed time interval. In calculating this excitation signal, the dynamic characteristics of the shaking table are taken into consideration. According to this vibration signal, the vibration exciter 10 fixed to the foundation 2 is driven and the vibration table 6 is vibrated. The vibration response algorithm is, for example, the central difference method, in which case the calculated vibration response is displacement.

FIG. 2 shows the processing and signal flow in the computer 5 in this embodiment. The calculation algorithm may be another method, and the vibration response may be another response, for example, acceleration. Further, the forms of the load measuring means 7 and various signals are not limited to the examples given above, but various forms are possible. The same applies to the load measurement value transmission means 12. in short,
Various configurations can be adopted without departing from the gist of the present invention.

According to this embodiment, the load applied from the secondary structure 4 to the main structure 3 can be accurately evaluated. Therefore, the vibration response of the main structure 3 can be accurately obtained in consideration of the influence of the vibration response of the secondary structure 4, and the secondary structure 4 can be vibrated by this. The vibration response of the structure 1 can be accurately evaluated only by the vibration test of No. 4.

Further, the support member 14 which is movable in at least one direction can have various configurations as follows. For example, laminated rubber can be used. Since the laminated rubber has a high rigidity in the vertical direction, the base plate 15 or the secondary structure 4 should be supported even if a vertical load is generated on the support member 14 due to the vibration of the secondary structure 4 to be excited. Is possible. Alternatively, a hydrostatic bearing can be used. Since the static pressure bearing has a very small frictional force, it is possible to reduce the error in the load measurement value. Also,
It is also possible to use rolling bearings. With the rolling bearing, the present embodiment can be constructed at low cost.

Next, a second embodiment of the present invention will be described with reference to FIG. In this embodiment, in addition to the first embodiment, an acceleration measuring means 16 having a measuring direction in which the vibration direction of the vibrating table is applied is installed on the vibration test jig, and the measured value signal is transmitted to the acceleration measured value transmitting means. It is transmitted by 17 and input to the computer 5. The acceleration measuring means 16 is, for example, a combination of a strain gauge type accelerometer and a dynamic strain amplifier, and the acceleration measuring value takes the form of a voltage signal, for example, and the acceleration measuring value transmitting means 16 is, for example, a coaxial cable.

In the computer 5, when the external force used for the vibration response calculation is determined from the input load measurement value, the mass of the vibration test jig 18 such as the base plate 15 and the acceleration measurement value input in advance in the computer are used. The inertial force by the vibration test jig 18 is calculated and subtracted from the load measurement value. As a result, the load applied from the secondary structure 4 to the main structure 3 can be measured more accurately. The signal and processing flow in this case are shown in FIG. The acceleration measuring means 16,
The transmission means 17, the form of the measured value, and the like are not limited to the above example, and other configurations may be used. That is, various configurations can be made without departing from the spirit of the present invention.

A third embodiment of the present invention will be described with reference to FIG. In this embodiment, the structure in which the secondary structure 4 is mounted on the vibration test jig 18 in the first embodiment is directly mounted on the vibrating table 6 via the supporting member 14 movable in at least one direction. It is installed. Also, the jig 18 for the vibration table
The load transmission means 8 that was connected to the secondary structure 4 is also directly connected to the secondary structure 4. In addition, the support member 1
The movable direction of No. 4 and the transmission direction of the load transmission means 12 are the same as in the above-described embodiments. The signals and processing flow in this embodiment are the same as those shown in FIG.

According to this embodiment, since the inertial force of the vibration test jig 18 is not added to the load measurement value, the load measurement can be performed with high accuracy, and the vibration response analysis and the experiment can be performed with high accuracy. . Needless to say, also in this embodiment, the support member 14 can have various configurations as in the above embodiments.

A fourth embodiment of the present invention will be described with reference to FIGS. 6 and 7. FIG. 6 shows an example of the vibration test jig according to the present invention. The opening 2 is formed in the base plate 15 of the vibration test jig 18 in the first to third embodiments.
This is an example in which 1 is provided. According to the present embodiment using such a jig, as shown in FIG. 7, when the secondary structure is long and the connection state with the main structure is hanging, the actual state is The same vibration condition as can be used.

Next, the signal and processing flow of the fifth embodiment of the present invention will be described with reference to FIG. In the present embodiment, in the configurations of the first to third embodiments, the result of the vibration response calculation of the computer 5 is used not only for generating the vibration signal of the vibrating table 6 but also output from the computer 6 during the vibration test, Alternatively, and / or, it is stored in the data storage means 24 in the computer 6 and can be used or processed after the test is completed. According to this embodiment, not only the vibration phenomenon of the secondary structure 4 to be tested but also the vibration response of the main structure 3 numerically modeled can be evaluated.

Further, as in the sixth embodiment shown in FIG.
If the vibration response is output as a signal to the outside of the computer at the time when the vibration occurs, the vibration response of the entire structure 1 can be recorded simultaneously with the output of the sensors 22 installed in the secondary structure 4 by, for example, the data recorder 23. It becomes possible to compare and examine.

This is the same as the seventh embodiment shown in FIG. 10, in which the output signal of the sensors 22 is input by the computer 5, and the vibration response calculation result and the data storage means 24 in the computer are received.
It can also be achieved by saving in.

In the embodiments shown so far, the vibration response amount realized by the vibrating table 6 is not particularly specified and described. If the equation of motion of the secondary structure 4 is modeled and described using, for example, the finite element method, it can be written as Equation 1.

[0031]

[Equation 1]

That is, the vibration response is determined by the acceleration realized by the vibrating table 6. Therefore, if the vibration response amount to be controlled is the acceleration, a more accurate vibration experiment can be performed. As long as the acceleration is controlled as a result, the vibration response to be controlled is not limited to the acceleration and may be displacement or velocity.

As described above, according to these embodiments,
The following effects can be obtained. Also in the partial model test, since the vibration waveform can be determined in consideration of the interaction between the partial model and other parts, it is possible to perform a test equivalent to the vibration of the whole. Since it is possible to accurately measure the load applied to the vibrating table from the secondary structure that is the object of vibration, accurate vibration response calculation, that is, accurate vibration test can be performed. For a long structure, by providing an opening in the jig, it is possible to realize vibration equivalent to the vibration conditions in an actual structure. By outputting or saving the vibration response calculation result of the numerical model, the vibration response of the numerical model part can be evaluated. If the vibration response amount to be controlled by the shaking table is acceleration,
More accurate vibration experiments can be performed.

[0034]

According to the present invention, since all the loads from the secondary structure are transmitted by the load transmitting means, the load can be accurately measured, and the vibration response calculation of the main structure and the secondary structure can be performed. That is, the vibration test of the structure can be carried out with high accuracy, high efficiency, and economically.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a first embodiment of the present invention.

FIG. 2 is an explanatory diagram of processing and signal flow in the computer according to the first embodiment of this invention.

FIG. 3 is a schematic diagram showing a second embodiment of the present invention.

FIG. 4 is an explanatory diagram of processing and signal flow in a computer according to the second embodiment of this invention.

FIG. 5 is a schematic diagram showing a third embodiment of the present invention.

FIG. 6 is a schematic diagram of a base plate according to a fourth embodiment of the present invention.

FIG. 7 is a schematic diagram showing a fourth embodiment of the present invention.

FIG. 8 is an explanatory diagram of signals and a flow of processing according to a fifth embodiment of the present invention.

FIG. 9 is an explanatory diagram of signals and a flow of processing according to the sixth embodiment of the present invention.

FIG. 10 is an explanatory diagram of signals and a flow of processing according to a seventh embodiment of the present invention.

FIG. 11 is a schematic view of a general structure.

FIG. 12 is a block diagram of a conventional experimental apparatus.

FIG. 13 is a diagram showing an experimental algorithm of a conventional experimental apparatus.

[Explanation of symbols]

 1 Vibration Response Evaluation Target Structure 2 Foundation 3 Main Structure 4 Secondary Structure 5 Computer 6 Shaking Table 7 Load Measuring Means 8 Load Transfer Means 9 Frame 10 Shaking Table Shaking Machine 11 Shaking Table Shaking Machine Control Unit 12 Load Measurement value transmission means 13 Excitation signal transmission means 14 Support member 15 Base plate 16 Acceleration measurement means 17 Acceleration measurement value transmission means 18 Vibration test jig 19 One end of load transmission means 20 Shaking table bearing 21 Opening 22 Sensors 23 Data Recorder 24 Data storage means

Claims (13)

[Claims] 1. One or a plurality of vibration exciters, a vibrating table driven by the vibrating machine, and a supporting member movable in a vibrating direction of the vibrating table, and a test sample is mounted on the vibrating table. A base plate, a load transmitting means installed between the base plate and the vibrating table or a frame fixed to the vibrating table, and transmitting a load in the same vibration direction as the vibrating table; and transmitting by the load transmitting means. Load measuring means for measuring the load, load measuring value transmitting means for transmitting the load measured value from the load measuring means, load measured value transmitted by the load measured value transmitting means, and data stored therein. Alternatively, a computer that calculates a control signal of the vibrator based on data input from the outside, a control signal transmission unit that transmits the control signal calculated by the computer, and a control signal transmission unit that transmits the control signal. And a control device for controlling the vibration exciter according to the control signal. 2. A test sample is mounted by being installed via one or a plurality of vibrators, a vibrating table driven by the vibrating machine, and a supporting member movable in a vibration direction of the vibrating table. A base plate, a load transmitting means installed between the base plate and the vibrating table or a frame fixed to the vibrating table, and transmitting a load in the same vibration direction as the vibrating table; and transmitting by the load transmitting means. A load measuring means for measuring a load, and a load measured value transmitting means for transmitting a load measured value from the load measuring means, and being installed on the base plate,
Acceleration measuring means for measuring acceleration in the vibration direction of the vibrating table, acceleration measurement value transmitting means for transmitting acceleration measurement values from the acceleration measuring means, the acceleration measurement values, the load measurement values, and internally stored By a computer for calculating a control signal of the vibrator, a control signal transmitting means for transmitting the control signal calculated by the computer, and the control signal transmitting means. A vibration testing device for a structure, comprising a control device for controlling the vibration exciter according to the transmitted control signal. 3. One or a plurality of vibration exciters, a vibrating table driven by the vibrating machine, a support member that is movable in a vibration direction of the vibrating table and supports a test sample, and the support member. The load transmitting means, which is installed between the supported test specimen and the vibrating table or the frame fixed to the vibrating table, transmits the load in the same vibration direction as the vibrating table, and the load transmitting means. Load measuring means for measuring the load to be transmitted, and load measuring value transmitting means for transmitting the load measured value from the load measuring means, the load measured value, and data stored internally or inputted from the outside. A computer for calculating a control signal of the vibration exciter based on the control signal, control signal transmitting means for transmitting the control signal calculated by the computer, and controlling the vibration exciter by the control signal transmitted by the control signal transmitting means. Do A vibration testing device for structures that consists of a control device. 4. An actual model of a secondary structure, which is connected only to a fixed main structure, is installed via a supporting member oscillatably provided on a vibrating table, and the actual model and the vibration are provided. A vibration test method for a structure, wherein a load transmitted to and from a table is measured, and a vibration response of the main structure is calculated using the measured load value. 5. Of the structures to be evaluated for vibration response, a main structure connected to a foundation is numerically modeled and input to a computer, and a secondary structure connected only to the main structure is a real model. And, a base plate is installed on a vibrating table driven by one or a plurality of vibration exciters via at least a supporting member movable in the vibration direction of the vibrating table, and the actual model of the secondary structure is mounted on the base plate. , Between the base plate and the vibrating table or a frame fixed to the vibrating table, the load transmitted in the vibrating table exciting direction is measured,
The measured value of the load is input to the computer at predetermined time intervals, and the measured value of the load and the data stored internally or input from the outside are input according to a program that is input in advance. Based on, calculate the vibration response of the numerical model after a fixed time from the load measurement time, in the vibration response of the numerical model, the vibration response of the point where the actual model of the secondary structure is coupled, A vibration testing method for a structure, wherein: a control signal of the vibration exciter that is realized by the vibrating table at the same time as the vibration response of the numerical model is repeatedly calculated based on the vibration response result. 6. Of the structures to be evaluated for vibration response, a main structure connected to a foundation is numerically modeled and input to a computer, and a secondary structure connected only to the main structure is a real model. And, a base plate is installed on a vibrating table driven by one or a plurality of vibration exciters through at least a supporting member movable in the vibration direction of the vibrating table, and the actual model of the secondary structure is mounted on the base plate. The load and acceleration transmitted in the vibration direction of the vibrating table are measured between the base plate and the vibrating table, and the measured values of the load and the acceleration are input to the computer at predetermined time intervals. According to the program that has been input in advance, the load and acceleration are measured and the load measurement time is based on the data stored internally or the data input from the outside. The vibration response of the numerical model after a fixed time is calculated, and in the vibration response of the numerical model, the vibration response at the point where the real model of the secondary structure is connected is the vibration response of the numerical model. A vibration test method for a structure, wherein calculation of a control signal of the vibration exciter realized by the vibration table at the same time is repeatedly performed based on the vibration response result. 7. The vibration test method for a structure according to claim 6, wherein, for the vibration response, an inertial force is calculated from a previously input mass of the base plate and the acceleration measurement value, and the inertial force is calculated. Vibration test method for a structure, which is based on a load value subtracted from the load measurement value 8. The vibration testing method for a structure according to claim 4, 5, 6 or 7, wherein the vibration response is acceleration. 9. A support member, which is provided on a vibration table and movable in at least one direction, and a test specimen of a secondary structure, which is supported by the support member and is coupled only to a main structure, can be mounted. Of a structure including a simple base plate, load transmitting means capable of transmitting load between the base plate and the vibrating table in the movable direction of the supporting member, and means for measuring the load transmitted by the load transmitting means. Test jig. 10. The jig for vibration test of a structure according to claim 9, wherein the base plate has an opening. 11. The jig for vibration test of a structure according to claim 9 or 10, wherein the support member is a laminated rubber. 12. The jig for vibration test of a structure according to claim 9 or 10, wherein the support member is a hydrostatic bearing. 13. The jig for vibration test of a structure according to claim 9, wherein the support member is a rolling bearing.