広帯域の振動低減を実現する動吸振要素のメカニズム検討

抄録

Broadband dynamic absorber is proposed by authors, which is a beam, or a plate added on to a main structure and enable its vibration reduction. Vibration reduction in broadband frequency is demonstrated in previous study but its detailed mechanism is not explained yet. In this study, clarifying mechanism of broadband dynamic absorber is targeted to design an appropriate absorber for an arbitrary system. As an example, vibration reduction of a uniform beam with a simple beam shaped broadband dynamic absorber is demonstrated through numerical simulation. To clarify the difference and common points of broadband dynamic absorber and conventional dynamic absorber, pseudo modal model, diminished simplified model, of broadband dynamic absorber is modelled. By comparing the vibration reduction effect of the broadband dynamic absorber with the vibration reduction with conventional dynamic absorber, the mechanism of broadband dynamic absorber is investigated that each translational and rotational mode performs as dynamic absorber respectively, so vibration reduction in broadband frequency is achieved. Further, it is suggested that pseudo modal model is similar to multiple dynamic absorber, so the design procedure of multiple dynamic absorber can also be applied on the optimization design of broadband dynamic absorber. Even so, it is difficult to handle all modes especially in higher frequency range. In those cases, vibration energy propagation analysis are still effective tool.