高減衰系を対象とした入力-応答点間の距離減衰のモデル化

抄録

In the experimental modal analysis, uniform modal characteristics determined from material properties are assumed and the parameters are identified. When the object is a high-damping system, the measured data from the response point close to the excitation point differs from that from the response point far from the excitation point, and the latter has larger damping characteristics. This phenomenon cannot be explained by conventional damping characteristics called viscous damping or structural damping, and it is necessary to introduce damping characteristics (damping in distance) that depend on the distance of the response point from the excitation point. In this study, we proposed a new damping characteristic that expresses the damping in distance of a high-damping system. We took up the continuum systems as an object and verified its validity by numerical analysis. As a result, it was confirmed that in the frequency response function (FRF) considering structural damping and damping in distance, the height of the resonance peak becomes lower because of damping in distance when the response point is far from the input point. From this results, by introducing the model of damping in distance, the damping that depends on the distance between the input and the response point was acted and it became possible to appropriately express the vibration phenomenon in a high-damping system.