Tuned Mass Damper

Excitation forces are compensated by mass forces so that parts of the structure (main construction) remain almost at rest in a specific frequency range. In vibration damping, an additional oscillator consisting of mass and stiffness (undamped absorber) or of mass, stiffness, and damping (damped absorber) is attached to the main structure for calming.

The undamped absorber is usually used for stationary harmonic oscillation problems, where the absorber natural frequency f_T is tuned to the excitation frequency. Theoretically, the vibration amplitudes of the main system can be reduced to zero if no damping is present.

For stationary broadband excitation, which is essential in the range of a natural system frequency, the use of an optimally damped absorber is useful. The natural frequency  wT, opt and the damping ratio D_opt of the optimally damped absorber can be designed according to the formula of the Den Hartog formula: