MULTI DEGREES OF FREEDOM, MULTI PLATFORMED SHAKING SIMULATOR

The technical field of the invention The invention is related to earthquake simulators and shaking tables.

Known status of the technique

The earthquake simulators and shaking tables are made to determine the effects of the earthquake in advance so as to establish the necessary precautions by simulating surface motion at the time of the earthquake. They are also used to perform vibration tests of different objects.

Nowadays, earthquake simulators or shaking tables have mostly one or two degrees of freedom (1) (2). There are a few simulators with six axes (3) worldwide. These six-axis simulators (3) can simulate all possible movements in space by making all translations and rotations in and about X, Y, Z axes.

Technical problems to be solved by the invention

It is well known that the structures and objects under devastating effects during the earthquake take place right over the principal fault line or cracks of earth. Existing simulators (1) (2) (3) cannot simulate enough earthquake or vibration effects on the structures and objects right over the principal fault line or cracks of earth.

With the invention, since using only one simulator or shaking table is not enough, simultaneous usage of multiple simulators or multiple shaking tables make possible to determine earthquake or vibration effects on the structures and objects right over the principal fault line or cracks of earth more realistically. Explanations of Figures

Figure 1 : Top view of an earthquake simulator or a shaking table having only one degree of freedom.

Figure 2: Top view of an earthquake simulator or a shaking table having two degrees of freedom.

Figure 3 : Perspective view of an earthquake simulator or a shaking table having six degrees of freedom (with the base of a Stewart Platform).

Figure 4: Top view of a system consisting of multiple earthquake simulators or multiple shaking tables having any degree of freedom (1, 2, 3 or more).

Figure 5: Top view of an earthquake simulator or a shaking table having 6 + 6 degrees of freedom.

Figure 6: Top view of the upper panel having non-uniformly divided and separately moving parts.

Figure 7: Front view of an experimental set up of an earthquake simulator or a shaking table having 6 + 6 degrees of freedom carrying a small scale housing model. Figure 8: Front imaginative view of the result of the experiment utilized by an earthquake simulator or a shaking table having 6 + 6 degrees of freedom carrying a small scale housing model.

Figure 9. Top view of an earthquake simulator or a shaking table having one fixed and one freely moving platforms.

Definitions of reference numbers on figures;

All parts in Figures are numbered and described as follows.

1) An earthquake simulator or a shaking table having only one degree of freedom.

2) An earthquake simulator or a shaking table having two degrees of freedom.

3) An earthquake simulator or a shaking table having six degrees of freedom.

4) An earthquake simulator or a shaking table having any degree of freedom (1, 2, 3 or more).

5) The crack region between adjacent platforms representing the principal fault line or cracks of earth.

6) A platform with sides representing the non-uniform principal fault line or cracks of earth. 7) The Crack region between adjacent platforms representing the non-uniform principal fault line or cracks of earth.

8) A small scale housing model for the earthquake experiment.

9) The crack region of the small scale housing model determined by the earthquake experiment.

10) A fixed panel or panel-like object.

Explanation of invention:

The invention is based on simultaneous usage of multiple conventional single simulators or multiple conventional shaking tables (1) (2) (3). Since each platform or panel of multiple simulating platforms or shaking tables can have any number of degrees of freedom (4) individually, these platforms or panels together can simulate the principal fault line and cracks of earth (5) by making similar motions of two sides of the principal fault lines or cracks with different axes and orientation angles. When necessary, panels with non-uniform sides representing possible crack shapes can be attached to the moving top divisions (6) so as to simulate the principal fault lines and cracks of earth (7) geometrically as well. Before constructing a building, skyscraper, etc. in an earthquake zone, their small scale models (8) can be tested with the invented simulator or shaking tables to determine all possible crack paths (9) in case buildings take place on the principal fault lines and cracks of earth. Since at least one platform or panel of multiple platforms or multiple shaking tables move with any number of degrees of freedom (4), it is also possible to simulate cracks (5) similar to the principal fault lines by replacing other moving platforms or panels with fixed or mounted objects (10) i.e. zero motion objects. Since all system does not depend on any control unit, it can be used as conventional earthquake simulators or shaking tables (1) (2) (3).

Industrial application of the invention

The invented earthquake simulator or shaking tables with multiple platforms or panels having multi degrees of freedom will make possible to simulate earthquakes more realistically than conventional earthquake simulators or shaking tables (1) (2) (3) and speed up research studies to build safer structures against earthquakes and vibrations of any kind.

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Before constructing a building, skyscraper, etc. in an earthquake zone, their small scale models (8) can be tested with the invented simulator or shaking tables to determine both weak spots of buildings and all possible crack paths (9) in case buildings take place on the principal fault lines and cracks of earth. Thus, it will be possible to strengthen determined weak parts of the building before earthquakes happen. Furthermore, the invented simulator can utilize vibration and fatigue tests of various structures.