An Optimum Design Method for the Dual Dynamic Damper and its Effectiveness

In order to eliminate the drawbacks of a conventional dynamic absorber whose damping performance is very sensitive to the variation of parameters, use of a dual dynamic absorber is proposed in this paper. To reduce the transmissibility across a main vibration system at resonance, the optimum design procedure of the dual dynamic absorber is described, and optimum values for its tuning and damping parameters are specified in graphical forms and by formulas for the designing. Utilizing the design formulas, the effectiveness of the dual dynamic absorber in reducing the transmissibility at resonance is studied and shown to be considerably greater than that of the conventional dynamic absorber. Also, it is shown that by use of the dual absorber, it is possible to avoid a decrease of damping performance with the change of the natural frequency of the main vibration system and of damping in its absorbers.