Finite Element Analysis on Application of Dynamic Vibration Absorbers on Floating Raft System

Abstract

The floating raft system is a widely‐used isolation set for vibration reduction; however it has a disadvantage in depressing low frequency and variable frequency vibration. Researches show that application of the dynamic vibration absorbers (DVAs) can significantly improve the low frequency and variable frequency isolation performance of the floating raft system. Aimed at predicting the effectiveness of vibration attenuation application of DVAs on the floating raft system, a numerical simulation based on the finite element analysis is proposed. Finite element (FE) model updating is an important tool to improve the accuracy of an initial FE model so that the predicted dynamic behaviour matches as closely as possible that observed during the experiment. A finite element model updating method was used, which is based on frequency response functions (FRF) of structure vibration and acoustic system by experiment and numerical computing respectively. The frequency response function (FRF) of a floating raft system with the DVAs is investigated numerically too and a performance index was defined to evaluate the vibration attenuation effect of the DVAs. A novel kind of adaptive tuned vibration absorber (ATVA) is used to fulfill the vibration attenuation experiment of the DVAs on a floating raft system. By comparing the experimental and numerical results, the availability of this simulation method is verified.