TMD for floor vibration control

Floor vibration in a building are considered harmful due to several reasons:

impair the operation of sensitive instruments

affect human psychology for acceleration level even greater than 0.005g

motion having peak amplitude greater than 1 mm is not desirable in active environments.

Traditional methods for improving the environment include

adding extra columns

adding extra thickness to the floors and

increasing structural stiffening

In a new application, TMDs are used bellow the floor of a building as shown in the figure.

Fig 17.4 : Houdaille Damper

The TMDs are tuned at a frequency of 6Hz which is the first resonating frequency of the floor. The change in floor vibration (acceleration response) after the application of the TMD is evident in the green curve in comparison to the blue curve showing under-damped response before the application of TMD.

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Figure 17.5: Vibration suppression by TMD

Congratulations! You have finished Lecture 17.