Floating Raft Isolation System Admittance Power Flow

Floating raft vibration isolation system is a good approach of controlling vibration, and this system has been successfully used in navigation. Compared with engineering application, the theory research apparently is very slowly. So, it is very useful that to study the theory of the floating raft vibration system, because it can reduce the vibration of the ship machine, can advance the battle effectiveness of naval vessel, and approve .the life condition of sailor.Mobility power flow approach is originally defined as the time average of instantaneous power, is an effective method for vibration analysis and control of complex structure.It is great significance to understand the mechanism of floating raft for reducing the vibration in building and ship structure, for this purpose, a theoretical research model-raft system, consisting of many machines, is set up. From sub-structure analysis, this thesis deduces the power input to the system and power transmitted to the mid-structure or base structure. Both the forces and the velocities at the installation positions in mid-structure and base structure of raft system are solved. Based on the limited nonsymmetrical distributed system, a vibration model that including mid-structure and base structure dynamical characteristics has been built up. And the vibration transfer characteristics of floating raft vibration isolation system with this model have been studied. The vibration response and vibration power flow equation has been concluded under stable random effect, and the effect of vibration power transfer has been analyzed since raft's parameter has been changed.