Abstract: The transmission characteristics of the power flow and the optimum design of vibration isolation & absorption synthetic control system of machines on upstairs or on aboard, are studied. In view of practical vibration control in engineering, an asymmetric flexible system with multiple excitation forces is modeled, in which isolation & absorption technique and substructure mobility synthetic technique are synthetically used and universal power flow equation of the synthetic control system is introduced. In addition, an approach to the optimum design of multi – DVA is proposed, in which the power flow is made the control object, Furthermore, using two parallel ends – clamped beams as flexible foundation, various power flows are calculated and analyzed to reveal the control mechanism of structure – borne noise of the system. By a few small – mass DNA, optimum control of the system in wide frequency is successfully achieved.

Key words: Optimum design, Power flow, Vibration absorption, Vibration isolation