Beat phenomenon in combined structure-liquid damper systems

The classical bear phenomenon has been observed in most combined structure- liquid damper systems. The focus of this paper is to provide a better under standing of this phenomenon, which is caused by the coupling that is introd uced through the mass matrix of the combined system. However, beyond a cert ain level of damping in the secondary system (liquid damper), the beat phen omenon ceases to exist. This is due to coalescing of the modal frequencies of the combined system to a common frequency beyond a certain level of damp ing in the secondary system. Numerical and experimental results are present ed in this paper to elucidate the beat phenomenon in combined structure-liq uid damper systems. (C) 2001 Elsevier Science Ltd. All rights reserved.