Multiunit impact damper—Re-examined

The multiunit impact damper with Coulomb friction has been studied theoretically and by simulation on the digital computer. It is found that the performance of a single damper is retained when it is replaced by a multi-unit damper with a moderate number of units having the same total mass, coefficients of Coulomb friction and restitution, and gap. However, the velocity discontinuity of the damped system is reduced significantly. In periodic motion with identical units, each unit exhibiting two equispaced impacts/cycle motion, impacts occur in clusters and are not uniformly distributed in time. The effect of the number of units and Coulomb friction on the amplitude reduction, velocity discontinuity at impact and temporal distribution of impacts is considered.