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The background of the theory |
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The DVA has been used for preventing a destructive state occurred by wind, earthquake, or resonance and for securing a stability of the constructs have the high ductility and the low attenuation such as a high-rise building, a grand bridge, a long-span sleeve, and so on.
If applying the system which has the same vibration as the 1st and 2nd mode by using the mass of the additional spring when large amplitude of vibration is occurred by the rigid body motion in the 1st and 2nd mode, a small vibrator, the DVA, vibrates. The power of the spring is always same as the shifting power, and the power of the opposite directions are added to the main vibrator.
The construct of the DVA is very simple: therefore, it is the efficient method to control the vibration for securing the stability with an inexpensive expense.
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| [Theoretical DVA mode shape] |
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| The graph in the above shows the comparison of the vibration amount between the DVA and without the DVA in the time domain. For the case, which is with the DVA, the vibration amount is rapidly reduced at the resonance point. |
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