Dampers or isolators stabilize against violent motion caused by harmonic motion . It balances the vibration of a system with comparatively lightweight component so that the worst-case vibrations are less intense.

Acceleration is decreased because the base isolation or damping system lengthens a building's period of vibration, the time it takes for a building to rock back and forth and then back again. And in general, structures with longer periods of vibration tend to reduce acceleration, while those with shorter periods tend to increase or amplify acceleration. The building's displacement in the direction opposite the ground motion is actually due to inertia. The inertia forces acting on a building are the most important of all those generated during an earthquake.

When building begins to oscillate it excites the Tuned Mass Damper (TMD) into motion. The TMD inertia forces produced by this motion are approximately anti-phase to the dynamic forces driving the building .Building motion thus greatly reduced with the dynamic forces primarily driving the TMD instead of building. The energy of this motion is dissipated by the internal damping mechanism associated with TMD.

When the ground shakes, the rollers freely roll, but the building above does not move. Thus, no force is transferred to the building due to the shaking of the ground; simply, the building does not experience the earthquake. You may notice that displacement of building reduces by using base isolators.

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