JPH05107146A - Two-dimensional vibration testing machine - Google Patents

Abstract

PURPOSE:To obtain a two-dimensional vibration testing machine for response control elements, allows horizontal and vertical motions but does not allow rotational motions, and can highly accurately vibrates the specimen to a high frequency. CONSTITUTION:While the rotational motions of the upper and lower end sections 1a and 1b of a specimen caused by a moment which increases following the deformation of the specimen 1 in the shearing direction is restricted by means of the static bearings 3a and 3b and 4a and 4b of a horizontal and vertical guides 3 and 4, the shearing and axial loads applied to the specimen 1 are detected by means of a two-component gauge 8 fitted to a vertical guide shaft 5 and the detected loads are fed back to a control circuit to vibrate the specimen.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a two-dimensional vibration tester for testing and evaluating the characteristics and reliability of seismic isolation elements for protecting reactor containment vessels and building structures from earthquakes.

[0002]

2. Description of the Related Art A conventional device is, for example, Mitsubishi Heavy Industries Technical Report 2
As described in Vol. 3, No. 3 (1987-5), a pressure platen that applies axial and shear loads to the test body is supported by a horizontally movable rhombus parallelogram ring, and Allowing deformation and deformation in the shear direction at the same time,
In addition, it has a mechanism to keep the end face of the test piece horizontal. Further, Proceedings of the Japan Society of Mechanical Engineers (C edition), Vol. 54, No. 507 (Sho 63-11), p. The one described in 2618 applies two test bodies at the same time, and has a mechanism capable of simultaneously loading the axial direction and the shearing direction while keeping the end surface of the test body horizontal by a link-type jig.

A device related to this kind of device is, for example, Japanese Patent Publication No. 54-44461.

[0004]

In all of the above-mentioned prior arts, the link mechanism holds the end surface of the test piece horizontal and applies force in the axial direction and the shearing direction. However, there is a problem that the end face cannot be kept horizontal due to the bending moments at the upper and lower ends of the test piece when the amount of deformation in the shearing direction of the test piece becomes large, which lowers the accuracy of the loading test. Further, when the test body is dynamically vibrated, there is a problem that the error of the force applied to the test body becomes large due to the influence of the inertial force due to the mass of the movable portion of the vibration exciter.

The object of the present invention is to restrain the rotational movement of the end face due to the bending moment of the upper and lower end portions of the test body, which occurs when the deformation amount of the test body in the shearing direction becomes large, and to allow only horizontal movement and vertical movement. It is to provide a two-dimensional vibration tester that does not generate rotational movement.

[0006]

[Means for Solving the Problems] The above object is to guide a vibrating table on which a test body is mounted in a horizontal direction by static pressure bearings to restrain rotational movement and to maintain a vertical guide shaft for applying a vertical force to the test body. This is achieved by guiding the bearing in the vertical direction and restraining the rotational movement by a pressure bearing. Further, in the hydrostatic bearing, the bearing and the shaft are joined via an oil film having a gap of 20 to 50 μm, and if the force in that case is 100,000 kg, a very high rigidity of 2.00 × 10 ⁷ kg / cm can be obtained. ..

[0007]

According to the above technical means, the upper part of the test body is fixed to the vertical guide shaft, and the lower part is fixed to the vibration table. The vertical shaker applies an axial load to the test body via the vertical guide shaft. In this state, the horizontal shaker
Move the vibration table horizontally and apply a shear load to the test piece. The rotational movement of the end faces due to the bending moments of the upper and lower ends of the test body caused by the large amount of deformation in the shear direction of the test body guides the static pressure bearing that guides the vibration table in the horizontal direction and the vertical guide in the vertical direction. Restrain with hydrostatic bearings.

[0008]

Embodiments of the present invention will be described below with reference to FIGS. 1 to 6.

First, FIG. 1 is an overall structural view of a loading test apparatus according to an embodiment of the present invention. FIG. 2 is a diagram showing a mounting relationship between the two-component force meter and the test body, and FIG. 3 is a diagram showing an equalization model thereof.

In FIG. 1, reference numeral 1 is a seismic isolation element which is a test body. The lower end face is fixed to the vibration table 2 and the upper end is fixed to the vertical guide shaft 5. The vibration table 2 is connected via a swivel joint 4a to a horizontal vibrator 4 that applies a shear load to the test body 1, and the static pressure bearings 3a and 3b of the horizontal guide 3 are connected.
Supported by. The horizontal shaker 4 is a swivel joint 4
It is fixed to the reaction force wall 9a via b. Vertical guide shaft 5
Is connected to a vertical vibrator 7 that applies an axial load to the test body 1 via a swivel joint 7a, and is supported by static pressure bearings 6a and 6b of a vertical guide 6. The vertical shaker 7 is fixed to the reaction force frame 9b. 4c and 7c are servo valves for controlling the flow rate and direction of the pressure oil to the vibrators 4 and 7, respectively.
10 is the hydraulic pressure source. Reference numerals 11 and 12 denote hydraulic pressure sources that supply pressure oil to the static pressure bearings 3a and 3b of the horizontal guide 3 and the static pressure bearings 6a and 6b of the vertical guide 6 via the throttles 13 and 14, respectively. Slide bar 3c of the horizontal guide 3,
3d is a hydrostatic bearing 3a, 3b which is floated and supported by a small oil film. Similarly, the vertical guide shaft 5 is levitationally supported by the static pressure bearings 6a and 6b of the vertical guide 6 by a small oil film.
Further, 8 in FIG. 2 is a two-component force meter that simultaneously detects a horizontal force (= shear load) and a vertical force (= axial load) applied to the test body 1, the lower surface of the test body 1 and the upper surface of the test body 1. It is fixed to the vertical guide shaft 5.

Next, the operation will be described.

First, in FIG. 1, when a force is applied to the pushing side of the vertical vibration exciter 7, an axial load in the compression direction is applied to the test body 1 via the swivel joint 7a and the vertical guide shaft 5. Next, when a force is applied to the side where the horizontal shaker 4 pushes out, the vibration table 2 is pushed out through the swivel joint 4a, and a shear load is applied to the test body 1. At this time, the deformed state of the test body 1 is represented as shown in FIG. 4, and in order to keep the upper end face 1a and the lower end face 1b of the seismic isolation element 1 which is the test body parallel, It is necessary to hold the indicated moment M.

[0013]

[Equation 1]

Here, Fx: Shear load Fz: Axial load H: Height of test piece X ₁ : Horizontal deformation amount Z ₁ : Vertical deformation amount Moment M shown in equation 1 is the slide bar of the horizontal guide 3. Hydrostatic bearings 3a and 3b supporting 3c and 3d and a hydrostatic bearing 6 of a vertical guide 6 supporting a vertical guide shaft 5.
The end surfaces 1a and 1b of the test body 1 are held horizontal while allowing the deformation in the guiding directions.

FIG. 2 shows the mass of the movable part of each exciter when the test body 1 is dynamically excited (in the case of a horizontal exciter, the mass of the exciter piston + the mass of the swivel joint 4a + the vibration). The mass of the table 2, and in the case of the vertical shaker, the mass of the vertical shaker piston + the mass of the swivel joint 7a + the mass of the vertical guide shaft 5). A two-component force meter 8 is attached to and the shear load Fx and the axial load Fz are directly detected. FIG. 3 shows an equivalent vibration model in this case. In this figure, the equation of motion, the relational expression of coordinates, the reaction force Fs of the seismic isolation element, which is the test body, and the measurement force Fm of the two-component force meter are shown by the following equations.

[0016]

[Equation 2]

FIG. 6 shows the results calculated in step 1. FIG. 6 shows the test piece shown in FIG. 2 in which the seismic isolation element 1 (k = 1.54 × 10 ⁶ N / m) and the bicomponent force meter 8 are installed in reverse. The calculation result is shown. This result shows that the spring rigidity of the bicomponent force meter is sufficiently higher than the spring rigidity of the seismic isolation element 1, so that by attaching the bicomponent force meter 8 to the vertical guide shaft 5 side, accurate measurement up to high frequencies is possible. It shows that there is. Therefore, the two-component force meter 8 is attached to the vertical guide shaft 5, and the shear load and the axial load applied to the test body 1 are detected and fed back to the control circuit, so that inertia caused by the mass of the movable part of the vibration exciter including the vibration table 2 can be obtained. Excludes the influence of force and can vibrate up to high frequencies.

According to the two-dimensional vibration tester of the present embodiment, the rotational movement of the upper and lower ends of the test body due to the moment increasing with the deformation of the test body in the shearing direction is restrained by the guide device of the hydrostatic bearing system. As a result, it is possible to carry out an accurate loading test without allowing the horizontal movement and the vertical movement to generate the rotational movement, and the effect is great.

A two-component force meter fixed to the vertical guide shaft directly detects the shear load and the axial load acting on the test body and feeds it back to the control circuit, so that the inertial force due to the mass of the movable part of the vibration exciter is detected. The influence is extremely small and it is possible to excite up to a high frequency.

Therefore, by using both in combination, the effect can be further enhanced.

[0021]

According to the present invention, an axial deformation and a shearing direction deformation which a test body receives in a test in which loads are applied to the test body in the axial direction and the shearing direction are allowed at the same time,
In addition, it is possible to hold the horizontal movement of the upper and lower ends of the test body by restraining the rotational movement, and further reduce the influence of the inertial force due to the mass of the moving part of the shaker including the vibration table to the test body up to a high frequency band. Since the applied axial load and shear load can be detected, a highly accurate vibration test can be performed.

[Brief description of drawings]

FIG. 1 is a system diagram showing an overall configuration of a two-dimensional vibration testing machine according to an embodiment of the present invention.

FIG. 2 is a side view showing a mounting relationship between a two-component force meter and a test body.

3 is a vibration model diagram of FIG.

FIG. 4 is an explanatory diagram of a force applied to a test body and a deformed state.

5 is a characteristic diagram of the vibration model shown in FIG.

FIG. 6 is a characteristic diagram of the vibration model shown in FIG.

[Explanation of symbols]

1 ... Test body, 2 ... Vibration table, 3 ... Horizontal guide, 4 ...
Horizontal shaker, 5 ... Vertical guide shaft, 6 ... Vertical guide, 7 ...
Vertical shaker, 8 ... Bisection force meter.

Claims (1)

[Claims] 1. A two-dimensional vibration tester for performing horizontal and vertical motions independently or horizontal-vertical motion coupled vibrations. A vibration table on which a test body is mounted and the vibration table are subjected to a small frictional force. A hydrostatic bearing that guides in a horizontal direction to restrain rotational movement, a horizontal shaker that vibrates the vibration table via a joint, a vertical guide shaft that applies a force in the vertical direction to a test body mounted on the vibration table, It consists of a hydrostatic bearing that guides the vertical guide shaft in the vertical direction with a small frictional force and restrains the rotational movement, and a vertical exciter that vibrates the vertical guide shaft through a joint, and is horizontal to the test body alone. A two-dimensional vibration tester characterized by applying an exciting force to the upper and lower sides alone or to the horizontal-upper and lower side simultaneously.