JP2017009295A - Three-dimentional six degree-of-freedom vibration table device for centrifugal force loading device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a three-dimentional six degree-of-freedom vibration table device for a centrifugal force loading device, which can reproduce the behavior of an earthquake with excellent similarity and which can achieve reduction in size and saving of space.SOLUTION: A three-dimentional six degree-of-freedom vibration table device for a centrifugal force loading device replicates the behavior of the ground and a structure during an earthquake by using a miniature model, and is installed in the centrifugal force loading device. The vibration table device for a centrifugal force loading device, includes: a second base plate 12 (vibration table) on which a miniature model M is mounted; and six hydraulic cylinders 13a to 13f (actuators) which are provided on the lower side of the second base plate 12 and which vibrate the second base plate 12 at six degrees of freedom. The six actuators are provided in such a manner that their shaft cores are positioned on each side of a regular hexagon when viewed in a Z-axis direction. An air spring 21 capable of supporting the second base plate 12 is provided inside the six actuators and between a first base plate 11 and the second base plate 12.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a three-dimensional 6-degree-of-freedom shaking table device mounted on a centrifugal loading device.

  2. Description of the Related Art Conventionally, there is known a shaking table device for performing an experiment to reproduce the behavior of a ground or a structure during an earthquake. As an example of the shaking table device, a shaking table along the XY plane and an X-axis vibrator extending in parallel with the X-axis direction from the shaking table are provided, and a type (so-called horizontal) that vibrates the shaking table in the X-axis direction. There is a single-shaft type device.

  A vibration table extending along the XY plane; an X-axis vibrator extending parallel to the X-axis direction from the vibration table; and a Y-axis vibrator extending from the vibration table in the Y-axis direction. There is a device of a type that vibrates in the axial direction and the Y-axis direction (so-called horizontal biaxial type).

  Furthermore, the vibration table along the XY plane, the first XZ-axis vibrator extending from the vibration table in the X-axis direction and falling in the Z-axis direction, and the first XZ-axis vibrator of the vibration table are provided on the opposite side. And a second XZ-axis vibrator, and a device (so-called horizontal vertical two-axis type) device that vibrates the shaking table in the X-axis direction and the Z-axis direction.

  On the other hand, in an actual earthquake, an excitation force is generated in the X-axis direction, the Y-axis direction, and the Z-axis direction. Therefore, there has been a limit in reproducing the earthquake behavior with similarities in the conventional horizontal one-axis type, horizontal two-axis type, and horizontal vertical two-axis type devices.

  In view of this, a three-dimensional shaking table apparatus having vibration directions in three orthogonal directions (X-axis direction, Y-axis direction, and Z-axis direction) has been proposed (see, for example, Patent Document 1). The vibration table device of Patent Document 1 includes a vibration table (a vibration table along the XY plane), an X-axis vibrator extending from the vibration table in the X-axis direction, and a Y-axis vibrator extending from the vibration table in the Y-axis direction. A Z-axis vibrator extending from the vibration table in the Z-axis direction, and vibrating the vibration table in three orthogonal directions.

  Such a shaking table device may be used by being installed in a centrifugal loading device. The centrifugal force loading device includes a rotating body that rotates horizontally around a vertical rotating shaft, and a platform that is suspended from an end of the rotating body, and the vibration table device is installed on the platform.

  By rotating the rotating body of the centrifugal force loading device, it is possible to perform an excitation experiment using the shaking table device in a centrifugal acceleration field of several tens of G. If the magnitude of the centrifugal acceleration is nG, the specimen can be made a reduced model of 1 / n of the actual size, and the time for applying vibration can be reduced to 1 / n. As described above, by performing the vibration experiment using the shaking table device in the centrifugal acceleration field, the size of the reduced model can be reduced, and the time required for the experiment can be shortened.

JP 2002-22595 A (paragraph [0009] etc.)

  However, in the shaking table device of Patent Document 1, since the vibrators extend from the shaking table in three orthogonal directions, for example, when the shaking table device is placed, the width of the entire device in the X-axis direction and the Y-axis direction Therefore, it is impossible to realize compactness and space saving. For this reason, the platform of the centrifugal loading device on which the vibration table device is installed is inevitably enlarged.

  The present invention is a three-dimensional centrifugal loading device that can reproduce the behavior of ground and structures excited by an earthquake or the like with a reduced model, and can achieve compactness and space saving. An object is to provide a six-degree-of-freedom shaking table device.

  The first aspect of the present invention that solves the above problems is a three-dimensional 6-dimensional centrifugal load device mounted on a centrifugal load device for reproducing an earthquake behavior of the ground or a structure using a reduced model. A vibration table device having a degree of freedom, comprising: a vibration table on which the reduced model is placed; and an actuator that is disposed on a lower surface side of the vibration table and vibrates the vibration table with six degrees of freedom. There is a three-dimensional 6-degree-of-freedom shaking table device for a centrifugal loading device.

  According to the first aspect, since it is installed in the centrifugal acceleration field by the centrifugal force loading device, it is possible to use a reduced model smaller than the actual one and to measure the behavior due to shaking such as an earthquake in a short time. . An actuator for operating the vibration table is disposed on the lower surface side of the vibration table. Therefore, the size of the three-dimensional 6-degree-of-freedom shaking table device for centrifugal loading devices in the horizontal direction can be reduced.

  According to a second aspect of the present invention, in the three-dimensional six-degree-of-freedom vibration table device for centrifugal force loading device described in the first aspect, the centrifugal force loading device comprises an elastic body that supports the vibration table. It is in the three-dimensional 6-degree-of-freedom shaking table device.

  According to the second aspect, it is possible to avoid the weight of the shaking table and the reduced model from being applied to the actuator.

  According to a third aspect of the present invention, in the three-dimensional six-degree-of-freedom shaking table device for a centrifugal force loading device described in the second aspect, the six actuators are positioned on each side having a regular hexagon. And the elastic body is disposed inside the six actuators. The three-dimensional six-degree-of-freedom shaking table device for a centrifugal force loading device is provided.

  According to the 3rd aspect, the area | region inside an actuator can be used effectively as an installation place of an elastic body. Thereby, the horizontal size of the shaking table device can be reduced.

  A fourth aspect of the present invention predicts a Coriolis force generated in a centrifugal acceleration field in the three-dimensional six-degree-of-freedom shaking table device for a centrifugal force loading device described in any one of the first to third aspects. A three-dimensional centrifugal loading device comprising: a control device that calculates an influence excitation acceleration caused by the Coriolis force and operates the actuator with a target drive waveform that cancels the influence excitation speed It is in a 6-DOF shaking table device.

  According to the fourth aspect, it is possible to eliminate the influence of the Coriolis force generated when the reduced model is vibrated in the centrifugal acceleration field. As a result, a desired target excitation acceleration can be applied to the reduced model in the centrifugal acceleration field, and the behavior of the ground or structure during an earthquake can be more accurately reproduced.

  According to the three-dimensional six-degree-of-freedom shaking table device for centrifugal loading device of the present invention, it is possible to reproduce the behavior of earthquakes with similarities, and to realize compactness and space saving.

It is a schematic block diagram of a centrifugal loading apparatus. It is a side view of the platform of a centrifugal loading device. FIG. 3 is a diagram illustrating a configuration example and a usage example of the shaking table device according to the first embodiment. FIG. 3 is a diagram illustrating a configuration example and a usage example of the shaking table device according to the first embodiment. FIG. 3 is a diagram illustrating a configuration example and a usage example of the shaking table device according to the first embodiment. FIG. 3 is a schematic diagram illustrating a control example of the shaking table device according to the first embodiment. It is the schematic of the shaking table apparatus and centrifugal force loading apparatus which concern on Embodiment 2. FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The following description shows one embodiment of the present invention and can be arbitrarily changed within the scope of the present invention. In the drawings, the same reference numerals denote the same members, and descriptions thereof are omitted as appropriate.

(Embodiment 1)
(Centrifugal loading device)
A three-dimensional six-degree-of-freedom shaking table device (hereinafter referred to as a shaking table device) 10 for centrifugal loading device according to the present invention is a device for reproducing the behavior of the ground or a structure during an earthquake. Installed in the device. First, the centrifugal loading device will be described. FIG. 1 is a schematic configuration diagram of a centrifugal loading device, and FIG. 2 is a side view of a platform of the centrifugal loading device.

  As shown in FIGS. 1 and 2, the centrifugal loading device 1 includes a central axis 2, a horizontal arm 3 that rotates around the central axis 2, platforms 4 provided at both ends of the horizontal arm 3, a drive motor 5, a center It comprises a speed reducer 6 and a drive shaft 7 provided between the shaft 2 and the drive motor 5. The platform 4 (swinging base) is suspended from the horizontal arm 3 so as to be swingable.

  When performing centrifugal loading, the vibration table device 10 on which the reduced model M is placed is set on one platform 4 of the centrifugal loading device 1, and a weight is installed on the other platform 4. Then, the drive motor 5 is driven to rotate the central shaft 2 through the drive shaft 7 and the speed reducer 6. When the central shaft 2 rotates, the platform 4 swings up as the horizontal arm 3 rotates, and centrifugal acceleration acts on the vibration table device 10 and the reduced model M placed on the platform 4.

  The reduced model M is a model of the ground, structure, or the like to be subjected to an experiment on the behavior due to vibration. The scale of the reduced model M is determined according to the centrifugal acceleration that can be applied to the vibration table device 10 and the reduced model M on which the centrifugal force loading device 1 is placed on the platform 4. When the scale of the reduced model M is 1 / n, the centrifugal acceleration is n × G (gravity acceleration).

(Schematic configuration of shaking table device)
FIG. 3 is a perspective view illustrating a configuration example and a usage example of the shaking table device according to the present embodiment. 4 is a plan view of FIG. 3 viewed from above, and FIG. 5 is a side view of FIG. 3 viewed from the side. In each figure, the X axis, the Y axis, and the Z axis are orthogonal to each other. In the state where the centrifugal loading device 1 is not rotating and the vibration table device 10 is placed on the platform 4, the axes in FIGS. 1 and 2 coincide with the axes in FIGS. 3 to 5. To do. In a state where the centrifugal force loading device 1 is rotated and the platform 4 is swung outward, the Z-axis in FIGS.

  The vibration table device 10 includes a first substrate 11, a second substrate 12 (member corresponding to “vibration table” in the claims), six hydraulic cylinders 13 a to 13 f (six actuators), an air spring 21, It comprises.

  The first substrate 11 is along the XY plane. The first substrate 11 constitutes the lowermost surface of the vibration table device 10. The second substrate 12 is disposed above the first substrate 11 in the Z-axis direction. The reduced model M is placed on the upper surface of the second substrate 12. The 1st board | substrate 11 and the 2nd board | substrate 12 are comprised from the flat metal.

  The hydraulic cylinders 13 a to 13 f are disposed on the lower surface side of the second substrate 12 and include a piston rod 14 (shaft member) that drives in the axial direction L (direction corresponding to the “axis direction of the actuator” in the claims). Configured. Furthermore, the hydraulic cylinders 13 a to 13 f are configured to include a cap cover 15, a rod cover 16, and a cylinder body 17.

  A cap cover 15 is provided at the end of the cylinder body 17. One end of the first substrate side arm 18 is connected to the cap cover 15. The other end of the first substrate side arm 18 is connected to a first attachment portion 31 provided on the first substrate 11. The first attachment portion 31 is a convex portion provided on the surface of the first substrate 11 (surface on the second substrate 12 side). A slope is formed on one first attachment portion 31, and the cap cover 15 is attached to the slope. In the present embodiment, two inclined surfaces are formed on one first mounting portion 31, and two hydraulic cylinder cap covers 15 are attached to the two inclined surfaces, respectively.

  A rod cover 16 is provided at the opposite end of the cylinder body 17. A rod hole is formed in the rod cover 16. The piston rod 14 is slidably held in the rod hole. One end of the second substrate side arm 19 is connected to the end of the piston rod 14 on the rod cover 16 side. The other end of the second substrate side arm 19 is connected to a second mounting portion 32 provided on the second substrate 12. The second attachment portion 32 is a convex portion provided on the surface of the second substrate 12 (the surface on the first substrate 11 side). One second mounting portion 32 has a slope, and the rod cover 16 is attached to the slope. In the present embodiment, two slopes are formed on one second mounting portion 32, and rod covers 16 of two hydraulic cylinders are attached to the two slopes.

  The cap cover 15 and the rod cover 16 can adjust the orientation of the mounting surface to an arbitrary angle. Even if the angle of the attachment surface is adjusted, if they cannot be directly attached to the first substrate 11 and the second substrate 12, the cap cover 15 is attached via the first attachment portion 31 as in the present embodiment. It is preferable that the rod cover 16 is attached to the first substrate 11 and the rod cover 16 is attached to the second substrate 12 via the second attachment portion 32. On the other hand, when the angles of the attachment surfaces of the cap cover 15 and the rod cover 16 are adjusted and can be directly attached to the first substrate 11 and the second substrate 12, the first attachment portion 31 and the second attachment portion 32 are provided. It is not necessary to provide it.

  In this way, the hydraulic cylinders 13a to 13f are connected to the first mounting portion 31 of the first substrate 11 on the cap cover 15 side (fixed end side 15a) in the axial direction L, and on the rod cover 16 side in the axial direction L. It is connected to the second mounting portion 32 of the second substrate 12 at the (free end side 16a).

  The cap cover 15 and the rod cover 16 are provided with ports (not shown) communicating with the cylinder body 17. The piston rod 14 is driven in the axial direction L according to the pressure receiving area of the oil supplied through the port. Since the piston rod 14 is driven back and forth along the axial direction, the axial direction L is also the direction in which the piston rod 14 is driven back and forth.

(Hydraulic cylinder arrangement)
The hydraulic cylinders 13a to 13f are arranged such that the axis of the cylinder body 17 is positioned on each side of the regular hexagon when viewed in the Z-axis direction.

  Therefore, when viewed in the Z-axis direction, the axial direction L of the piston rod 14 of the adjacent hydraulic cylinder forms an angle of 120 degrees. When viewed in the Z-axis direction, the axial direction L of the piston rod 14 of the opposing hydraulic cylinder is parallel. When viewed in the Z-axis direction, the intersection when the axial direction L is extended is located at each vertex of the regular hexagon.

  The axial direction L of the piston rod 14 rises in the Z-axis direction at a predetermined angle from the fixed end side 15a to the free end side 16a with respect to the XY plane. In other words, the axial direction L of the piston rod 14 falls in the Z-axis direction at a predetermined angle from the free end side 16a to the fixed end side 15a with respect to the XY plane. When these angles are in the range of about 30 to about 40 degrees, the operation of the piston rod 14 is easily transmitted to the second substrate 12 efficiently.

  The hydraulic cylinders 13a to 13f are arranged so that the fixed end sides 15a or the free end sides 16a are paired with each other between adjacent hydraulic cylinders. The cap covers 15 of the adjacent hydraulic cylinders are close to each other, and the rod covers 16 of the adjacent hydraulic cylinders on the opposite side are close to each other. In other words, the hydraulic cylinders 13a to 13f are arranged so that the fixed end sides 15a are close to each other between the adjacent hydraulic cylinders, and between the adjacent hydraulic cylinders on the opposite side, the free end side. 16a is arranged so that they are close to each other.

  The arrangement of the hydraulic cylinders 13a to 13f is summarized as follows. For convenience, the hydraulic cylinders 13a to 13f are arranged in order along the circumferential direction in the order of the first hydraulic cylinder 13a, the second hydraulic cylinder 13b, the third hydraulic cylinder 13c, the fourth hydraulic cylinder 13d, the fifth hydraulic cylinder 13e, and the sixth hydraulic pressure. This is referred to as a cylinder 13f.

  The first hydraulic cylinder 13a is connected to the first mounting portion 31 of the first substrate 11 on the cap cover 15 side (fixed end side 15a), and the second of the second substrate 12 on the rod cover 16 side (free end side 16a). It is connected to the attachment portion 32. The axial direction L of the piston rod 14 rises in the Z-axis direction at a predetermined angle from the fixed end side 15a to the free end side 16a with respect to the XY plane. A second hydraulic cylinder 13b is disposed on the free end side 16a of the first hydraulic cylinder 13a.

  The second hydraulic cylinder 13b is disposed on the free end side 16a of the first hydraulic cylinder 13a. When the second hydraulic cylinder 13b is viewed in the Z-axis direction, the axial direction L of the piston rod 14 forms an angle of 120 degrees with the first hydraulic cylinder 13a. The second hydraulic cylinder 13b is arranged so that the free end sides 16a are paired with the first hydraulic cylinder 13a. The axial direction L of the piston rod 14 of the second hydraulic cylinder 13b falls in the Z-axis direction at a predetermined angle from the free end side 16a to the fixed end side 15a with respect to the XY plane. A third hydraulic cylinder 13c is disposed on the fixed end side 15a of the second hydraulic cylinder 13b.

  The third hydraulic cylinder 13c is disposed on the fixed end side 15a of the second hydraulic cylinder 13b. When the third hydraulic cylinder 13c is viewed in the Z-axis direction, the axial direction L of the piston rod 14 forms an angle of 120 degrees with the second hydraulic cylinder 13b. The third hydraulic cylinder 13c is arranged so that the fixed end sides 15a are paired with the second hydraulic cylinder 13b. The axial direction L of the piston rod 14 of the third hydraulic cylinder 13c falls in the Z-axis direction at a predetermined angle from the fixed end side 15a to the free end side 16a with respect to the XY plane. A fourth hydraulic cylinder 13d is disposed on the free end side 16a of the third hydraulic cylinder 13c.

  Hereinafter, based on the same purpose, the fourth hydraulic cylinder 13d, the fifth hydraulic cylinder 13e, and the sixth hydraulic cylinder 13f are arranged.

(Air spring)
As described above, the hydraulic cylinders 13a to 13f are arranged so that the axis of the piston rod 14 is positioned on each side of the regular hexagon when viewed in the Z-axis direction. Therefore, the region 20 is defined by the axial direction L of the six piston rods 14 when viewed in the Z-axis direction.

  The vibration table device 10 includes an air spring 21 (device corresponding to an “elastic body” in claims) capable of supporting the second substrate 12 inside the region 20. The air spring 21 is a spring device that uses the elasticity of compressed air. For this reason, it is easy to adjust the spring constant very small. Therefore, even if the air spring 21 extends in the Z-axis direction or the second substrate 12 descends in the Z-axis direction and the second substrate 12 is supported by the air spring 21, the vibration table device 10 can be added. There is no significant adverse effect on vibration performance.

  The number of air springs 21 is not limited to one, and a plurality of air springs 21 may be used. Further, the elastic body need not be the air spring 21. The structure is not particularly limited as long as it is a spring that does not significantly affect the vibration performance of the shaking table device 10 and can support the reduced model M.

(Control of shaking table device)
FIG. 6 is a schematic diagram for explaining a control example of the shaking table device 10.

  The shaking table device 10 includes a control device (not shown), and independently controls the operation of the hydraulic cylinders 13a to 13f by a control signal from the control device, and operates the second substrate 12 with six degrees of freedom. It can be controlled (so-called parallel motion method).

  The six-degree-of-freedom operation is an operation that vibrates the second substrate 12 along the X, Y, and Z axes, a pitch operation that rotates around the X axis, a yaw operation that rotates around the Y axis, and around the Z axis. It is a roll operation to rotate. The shaking table device 10 can apply a desired acceleration to the reduced model M placed on the second substrate 12 with six degrees of freedom by operating the hydraulic cylinders 13a to 13f. Hereinafter, the acceleration applied to the reduced model M by the operation of the second substrate 12 of the vibration table device 10 is referred to as excitation acceleration.

  When information indicating a shake due to an earthquake or the like to be reproduced is input, the shaking table device 10 (control device) obtains an excitation acceleration corresponding to the shake. The calculation for obtaining the excitation acceleration from the information indicating the shaking such as an earthquake can be performed by a known method. The excitation acceleration set in the shaking table device 10 in this way is referred to as target excitation acceleration. Since the target excitation acceleration is 6 degrees of freedom, the shaking table device 10 can add the target acceleration for each of the X axis, Y axis, Z axis, pitch angle (Pitch), yaw angle (Yaw), and roll angle (Roll). Each vibration acceleration is obtained.

  Then, a target drive waveform for obtaining the target excitation acceleration is created. The target drive waveform is a control signal given to the hydraulic cylinders 13a to 13f, and the hydraulic cylinders 13a to 13f perform operations such as expansion and contraction based on the target drive waveform. As shown in Table 1, a target drive waveform and a target excitation acceleration are created every 6 degrees of freedom. The target drive waveform can be created by a known method based on the target excitation acceleration.

  The shaking table device 10 gives the created target drive waveform to the hydraulic cylinders 13a to 13f. Thereby, the hydraulic cylinders 13a to 13f can be expanded or contracted individually or as a whole, and the second substrate 12 can be operated with six degrees of freedom. By performing such control, the shaking table device 10 can apply the shake due to the earthquake or the like to be reproduced to the reduced model M as an excitation acceleration of 6 degrees of freedom.

(Vibrating table device installed in centrifugal loading device)
The shaking table device 10 is placed on the platform 4 of the centrifugal loading device 1. By operating the centrifugal loading device 1, centrifugal acceleration is imparted to the vibration table device 10 placed on the platform 4 and the reduced model M placed on the vibration table device 10. Further, by operating the shaking table device 10, an excitation acceleration is applied to the reduced model M by the shaking table device 10 under centrifugal acceleration.

  Table 2 shows similarities that are established in an excitation experiment in which centrifugal acceleration is applied, that is, a so-called centrifugal dynamic field.

  In the centrifugal acceleration field where the centrifugal acceleration is n × G, the size of the reduced model M is 1 / n of the actual size, and the frequency, centrifugal acceleration, and excitation acceleration of the reduced model M are n times that of the actual size. The displacement is 1 / n of the actual product. In addition, the time for which the reduced model M is placed in the centrifugal acceleration field having the centrifugal acceleration of n × G corresponds to 1 / n of the time for placing the actual object in the gravity field of 1 × G.

  According to such a similarity law, when the centrifugal force loading device 1 applies a centrifugal acceleration of n × G (gravity acceleration) to the shaking table device 10 and the reduced model M, the reduced model M is 1 / n of the real thing. The size can be as follows. That is, the same stress state as that of the specimen having the actual size (n times the size of the reduced model M) can be reproduced by the reduced model M having a size of 1 / n.

  Further, not only the stress state but also the same vibration as the actual earthquake motion can be reproduced with the reduced model M having a magnitude of 1 / n.

  Specifically, when the actual seismic vibration frequency is f, the shaking table device 10 vibrates the reduced model M based on a waveform having a frequency of f × n. Thereby, the shaking table apparatus 10 can give the excitation acceleration which imitates shaking, such as an earthquake, with respect to the reduced model M in the same stress state as a real thing in a centrifugal acceleration field. The time for which the shaking table device 10 applies the excitation acceleration to the reduced model M can be shortened to 1 / n of the time for shaking due to an actual earthquake or the like.

  Incidentally, if the centrifugal loading device 1 is not used, that is, if the vibration table device 10 is used alone in a gravitational field and attempts to reproduce the behavior at the time of an earthquake, the scale of the reduced model M must be the actual size. In addition, the required time also takes the same time as the actual shaking time.

  According to the shaking table device 10 described above, since it is installed in the centrifugal loading device 1, it is possible to use a reduced model M smaller than the actual size, and in a shorter time than the time required for actual shaking, It is possible to measure the behavior due to shaking.

  In the shaking table device 10, hydraulic cylinders 13 a to 13 f that operate the second substrate 12 are arranged on the lower surface side of the second substrate 12. That is, the hydraulic cylinders 13 a to 13 f are not arranged around the second substrate 12. Therefore, the size that the shaking table device 10 occupies in the horizontal direction can be reduced, and the size in the horizontal direction of the platform 4 on which the shaking table device 10 is placed can also be reduced.

  As described above, according to the shaking table device 10 of the present invention, the ground and structure behaviors vibrated by an earthquake or the like can be reproduced with similarities by using the reduced model M, and the compactness and the saving can be achieved. Space can also be realized.

  In addition, the vibration table device 10 includes an air spring 21, and the air spring 21 supports the second substrate 12 on which the reduced model M is placed. Thereby, it is possible to avoid the weight of the second substrate 12 and the reduced model M from being applied to the hydraulic cylinders 13a to 13f. That is, excessive weight in the centrifugal acceleration field is not applied to the hydraulic cylinders 13a to 13f. As a result, as the hydraulic cylinders 13a to 13f, it is not necessary to use special cylinders that can withstand excessive weight, and hydraulic cylinders that can be used in a normal 1G gravity field can be used.

  Note that the vibration table device 10 does not necessarily include the air spring 21. In this case, hydraulic cylinders 13a to 13f having rigidity sufficient to support the weight of the reduced model M under the applied centrifugal acceleration are used.

  Furthermore, the vibration table device 10 is provided with an air spring 21 inside a region 20 formed by the axial direction L of the hydraulic cylinders 13a to 13f. The region 20 is determined by the configuration of the hydraulic cylinders 13a to 13f, but the region 20 can be used effectively as a place where the air spring 21 is installed. Thus, since the hydraulic cylinders 13a to 13f are installed in the region 20, the size of the vibration table device 10 in the horizontal direction can be reduced.

  An elastic body such as the air spring 21 may be disposed outside the hydraulic cylinders 13a to 13f. In this case, since the installation space for the air spring 21 is required outside the region 20, the size of the vibration table device 10 in the horizontal direction is increased. However, as described above, since the hydraulic cylinders 13a to 13f are arranged on the lower surface side of the second substrate 12, the vibration table device 10 is made smaller in the horizontal direction than the conventional vibration table device. Can do.

(Embodiment 2)
A shaking table device according to Embodiment 2 of the present invention will be described. The same parts as those of the first embodiment will be omitted as appropriate, and different parts will be mainly described.

(Outline configuration)
The shaking table device 10A according to the present embodiment basically has the same configuration as the shaking table device 10 of the first embodiment. The vibration table device 10A is different from that of the first embodiment in the control by the control device.

(Control of shaking table device)
The shaking table device 10A predicts the Coriolis force generated in the centrifugal acceleration field, and creates the target drive waveform in consideration of the influence excitation acceleration generated due to the predicted Coriolis force. The influence excitation acceleration refers to an acceleration that acts on the reduced model M due to the Coriolis force generated in the centrifugal acceleration field.

(Correction of drive waveform considering Coriolis force)
The reduced model M is vibrated by being excited with six degrees of freedom by the vibration table device 10 </ b> A and is rotated by the centrifugal force loading device 1. The reduced model M that moves in this way receives a Coriolis force acting in a direction orthogonal to both the vibration direction and the rotation axis direction. Assuming that the angular velocity of the rotational motion is ω, the mass of the reduced model M is m, and the velocity vector of the reduced model M is v, a Coriolis force according to 2 · m · ω × v acts on the mass point of the reduced model M.

  FIG. 7 is a schematic view of the shaking table device 10 </ b> A and the centrifugal force loading device 1 for explaining the Coriolis force. Each axis of the centrifugal loading device 1 is indicated by a solid line, and each axis of the vibration table device 10 is indicated by a dotted line.

  As shown in the drawing, in the state where the centrifugal loading device 1 is rotating, the Z-axis direction (see FIG. 3) of the vibration table device 10A is the direction toward the central axis 2 of the centrifugal loading device 1 (XY in FIG. 1). In a direction parallel to the plane and passing through the central axis 2).

  For example, the reduced model M vibrates in the X-axis direction (the dotted X axis and the solid Y axis) by the shaking table device 10A, and the reduced load model 1 causes the reduced model M to move in the Y axis (the dotted line in FIG. 7). When rotated at an angular velocity ωy around the Y axis and the solid Z axis, the Coriolis force Fz acts in the Z axis direction (the dotted Z axis and the solid X axis in FIG. 7).

  The direction of the Coriolis force Fz is reversed according to the vibration direction of the reduced model M. For example, when the reduced model M moves in the X-axis positive direction, Coriolis force acts in the Z-axis positive direction, and when the reduced model M moves in the X-axis negative direction, Coriolis force in the Z-axis negative direction. Works.

  On the other hand, when the reduced model M vibrates in the positive direction of the X axis, Coriolis force acts in the negative direction of the Z axis, and when the reduced model M vibrates in the negative direction of the X axis, There are cases where force acts.

  Which phenomenon occurs depends on the rotational direction (clockwise or counterclockwise) of the angular velocity ωy around the Y axis that has acted.

  The axes referred to hereinafter are the axes of the centrifugal loading device 1 shown by the solid line in FIG.

  Coriolis force is not generated when the reduced model M vibrates in the same direction as the rotation axis Z. That is, when the reduced model M is vibrated in the Z direction indicated by the solid line in FIG. 7 by the shaking table device 10A, the Coriolis force need not be considered. Therefore, the influence excitation acceleration generated due to the Coriolis force is only in the X-axis direction and the Y-axis direction.

  First, similarly to the first embodiment, when information indicating a shake due to an earthquake or the like to be reproduced is input to the shaking table device 10A (control device), target excitation for each of the six degrees of freedom corresponding to the shake is performed. Find the acceleration. Of the 6-degree-of-freedom target excitation acceleration, the X-axis and Y-axis are referred to as the X-axis target excitation acceleration and the Y-axis target excitation acceleration, respectively.

  Next, the X-axis influence excitation acceleration and the Y-axis influence excitation acceleration generated in the X axis and the Y axis due to the Coriolis force are calculated (first row in Table 3). These influence excitation accelerations can be obtained from the angular velocity of the reduced model M, the mass of the reduced model M, and the velocity vector of the reduced model M as described above.

  As shown in the second row of Table 3, the X-axis influence excitation acceleration affects the Y-axis target excitation acceleration, and the Y-axis influence excitation acceleration affects the X-axis influence excitation acceleration. For this reason, the excitation acceleration applied to the reduced model M does not become the desired target influence excitation acceleration, but includes an error only by the influence excitation acceleration.

  For this reason, as shown in the third row of Table 3, the X-axis target excitation acceleration is corrected so that the Y-axis influence excitation acceleration is offset. Specifically, a value obtained by inverting the sign of the Y-axis influence excitation acceleration is added to the X-axis target excitation acceleration. As a result, the Y-axis influence excitation acceleration caused by the Coriolis force is canceled out. Then, based on the corrected X-axis target excitation acceleration, an X-axis target drive waveform is created.

  Similarly, the Y-axis target excitation acceleration is corrected so as to cancel the X-axis influence excitation acceleration, and a Y-axis target drive waveform is created.

  Then, by giving the X-axis target drive waveform and the Y-axis target drive waveform obtained by performing such correction to the hydraulic cylinders 13a to 13f, the influence of the excitation acceleration caused by the Coriolis force is eliminated, and the desired The target excitation acceleration can be applied to the reduced model M.

  According to the vibration table device 10A described above, it is possible to eliminate the influence of the Coriolis force generated when the reduced model M is vibrated in the centrifugal acceleration field. Thereby, a desired target excitation acceleration can be given to the reduced model M in the centrifugal acceleration field, and the behavior of the ground or the structure during an earthquake can be reproduced more accurately.

(Other embodiments)
The embodiment of the present invention has been described above. However, the basic configuration of the present invention is not limited to the above embodiment.

  For example, the actuator is not limited to a hydraulic piston within the scope of the present invention. The actuator may be a piston having a drive system other than hydraulic pressure, and is not limited to a piston.

  The components shown in the drawings, that is, the thickness of the substrate, the size of the actuator, the relative positional relationship of each part, and the like may be exaggerated in explaining the present invention.

  In addition, the term “between” in this specification does not limit that the positional relationship between the components is “contact”. For example, the expression “providing an air spring between the first substrate and the second substrate” includes an element including another component between the air spring and the first substrate or between the second substrate and the air spring. Do not exclude.

  Similarly, the term “side” in this specification does not limit that the positional relationship between the components is “in contact”. For example, the expression “connected to the first substrate on the cap cover side (fixed end side) in the axial direction” does not exclude an element including another component between the cap cover and the first substrate. In addition, the expression “connected to the second substrate on the rod cover side (free end side) in the axial direction” does not exclude an element including another component between the rod cover and the second substrate.

DESCRIPTION OF SYMBOLS 1 Centrifugal loading apparatus, 10 Shaking table apparatus, 11 1st board | substrate, 12 2nd board | substrate (vibrating table), 13a-13f 1st-6th hydraulic cylinder (actuator), 14 Piston rod (shaft member), 15 Cap cover 15a fixed end side, 16 rod cover, 16a free end side, 17 cylinder body, 18 first board side arm, 19 second board side arm, 20 region, 21 air spring (elastic body)

Claims (4)

A three-dimensional 6-degree-of-freedom shaking table device for a centrifugal force loading device mounted on a centrifugal force loading device for reproducing an earthquake behavior of a ground or a structure using a reduced model,
A shaking table on which the reduced model is placed;
An actuator arranged on the lower surface side of the shaking table, and vibrates the shaking table with six degrees of freedom. A three-dimensional six-degree-of-freedom shaking table device for a centrifugal force loading device. In the three-dimensional 6-degree-of-freedom shaking table device for a centrifugal loading device according to claim 1,
An elastic body that supports the shaking table is provided. A three-dimensional six-degree-of-freedom shaking table device for a centrifugal loading device. In the three-dimensional 6-degree-of-freedom shaking table device for a centrifugal loading device according to claim 2,
The six actuators are arranged such that each axial direction is located on each side of a regular hexagon,
The elastic body is disposed inside the six actuators. A three-dimensional six-degree-of-freedom shaking table device for a centrifugal load device. In the three-dimensional 6-degree-of-freedom shaking table device for centrifugal loading devices according to any one of claims 1 to 3,
A controller that predicts a Coriolis force generated in a centrifugal acceleration field, calculates an influence excitation acceleration caused by the Coriolis force, and operates the actuator with a target drive waveform that cancels the influence excitation acceleration; A three-dimensional 6-degree-of-freedom shaking table device for a centrifugal loading device.