Abstract: A general transmission matrix method for multiple degrees-of-freedom vibration analysis of isolation system with multiple elastic mounts is developed, in which the distributed and flexible nature of the mounts and the structural interactions due to multiple mounting system are taken into consideration. A set of matrix formulations relating the kinematic and dynamitic parameters of input and output terminals of isolator system are derived, which made the synthesis of complex system easier and made the investigation of multi-dimensional wave effects in the mount on power flow spectrum possible. It is found that the first two resonant flexural modes of foundation plate have notable effects on the power input to the system and transmitted to the foundation at higher frequencies. In particular, the power transmission excited by the moment induces more flexural waves power in the supporting structure than that excited by the axial force. It is also found that the standing longitudinal waves of the mount induced by the moment and/or axial force excitation have obvious effects on the power transmission, and the increase of the thickness of foundation plate produces an increase in the peak values of resonance.

Key words: Power flow, Standing waves, Transmission matrix, Vibration isolation