Single unit impact damper in free and forced vibration

The single unit impact damper under free and forced vibrations is studied. The effects of mass ratio, coefficient of restitution, and gap size on the free vibrations are determined by simulating motion on the digital computer. Agreement of theoretical results with the present and previous experimental results in the free vibration state is good. In the study of forced motion, charts are developed, by using the closed form solution, showing optimum gaps and corresponding displacement amplitude reduction within the resonant frequency range. The optimum gap at resonance is not necessarily optimal at other frequencies.