Abstract: The trend of high speed and light weight of the modern machines brings about some tremendously serious vibration and noise, so vibration isolation and noise reduction of flexible systems in high frequency range is a very important issue that must be considered in mechanical designs. The flexibility of vibrating systems being sufficiently taken into account, a generalized dynamics model and its mathematical description of fully flexible isolation systems with flexible machine and flexible base (FMFB), which are subjected to multi-excitations and supported by multi-mounts, is presented, by the sub-structural mobility synthesis and the transfer matrix approach. This model not only can readily degenerate to rigid machine and rigid base (RMRB), rigid machine and flexible base (RMFB), and flexible machine and rigid base (FMRB) isolation systems, etc., but also it can be used to analyze the passive and active isolation. In accordance with the combination of subsystems, the formulation of transmissibility and power flow of different systems is performed. The couple and transmission characteristics of various isolation systems are investigated, and some valuable results are obtained to give some important guidance for isolation designs.

Key words: Flexible system, Power flow, Transmissibility, Vibration isolation