Study On Vibration Reduction Of Floating Raft System Based On Blocking Mass Structure

The vibration isolation effect of floating raft isolation system is closely related to the parameters of the vibration isolator,the installation position,the underlying characteristics and the intermediate raft characteristics.It is very important to study the effect of these factors on floating raft isolation to improve the vibration isolation performance.In the flat plate floating raft system,the intermediate raft is a combination of the lower plate and the reinforcement bar,this stiffened plate structure can improve the rigidity of the raft greatly and provide a positive effect on the vibration isolation effect of the floating raft system.It is necessary to increase the width and height of the reinforcement,so that it has a strong resistance to vibration wave while the strength of the raft is strengthened and the design of the raft itself has better vibration isolation performance.In this paper,the basic theory of vibration isolation is analyzed,Based on the basic theory,the amplitude and frequency characteristics of single DOF vibration isolation system and the transmission rate of vibration isolation are analyzed.On the basis of this,paying more attention to analyze the vibration isolation characteristics of single layer,double layer and floating raft isolation system and study the effect of different parameters on vibration isolation system.This paper focuses on the suppression of vibration waves by reinforcing the blocking mass of reinforcement.The vibration isolation performance of the different cross-section parameters is investigated from the fluctuation theory based on the infinite long plate-resistive mass model;The modal difference between the laying resistance mass plate and the laying slab is analyzed from the modal angle of the structure of the finite length plate-resistive mass model,and the structure energy distribution is used to illustrate the inhibitory effect of the blocking mass on the vibration waves in the plate.On this basis,the effect of single-stage,multi-level,equal spacing,unequal spacing and spacing distance on the structure vibration is studied by using the finite element method.The results show that the blocking mass for the inhibitory effect of laying has good vibration wave plate,and with the increase of the series laying inhibitory effect is more obvious.Study on the basic theory of vibration isolation and the vibration resistance performance of blocking mass,three forms of raft structure and floating raft isolation system are designed.Separately on the raft body Vibration isolation performance,the floating raft system vibration isolation,the same raft foundation under the flexibility of the floating raft system overall vibration isolation effect and different incentives to the effect of floating raft isolation study.The results show that the floating raft of blocking mass structure at low frequency with the traditional raft form through raft isolation system is small,the isolation effect in high frequency is obviously superior to the traditional flat plate type floating raft system.Through the study of the blocking mass and floating raft isolation system,and introduces the vibration of blocking mass to float raft system vibration isolation design,when the floating raft system is excited at high frequency,the effect of the resonance of the elastic foundation effect is reduced,increases the system vibration isolation performance in full frequency,at the same time,for the design of raft body structure has a certain reference.