抄録
This paper presents new techniques for vibration transmission analysis on the finite element (FE) model using Transfer Path Analysis (TPA). The techniques are 1) a contribution calculation technique for structure with manifold and continuous transfer paths, and 2) a visualization technique of contributions for efficient derivation of measures to reduce vibration. Taking advantage of the characteristics of the numerical model, the cross section whose contributions are calculated is changed sequentially between input point and output point. This contribution of each node and each DOF is converted to influence degree, which is a new indicator and expresses vibration characteristics effectively. The magnitude of the influence degree is visually expressed by deformation of the FE model to support understanding of vibration transmission characteristics. First, the authors applied the proposed techniques to the simple vehicle body FE model for the purpose of reducing vibration at the position on the panel. The parts that are responsible for vibration at the target position were shown as characteristic diagrams. On the basis of these diagrams, the authors modified the structure of the body. As a result, the panel vibration in the focused-on frequency was reduced, and the relationship was obtained by which the measures based on influence degree change the mode shape of vibration to reduce the vibration response. Next, the authors applied this approach to the W/B FE model that represents the actual vehicle body, which is complicated in the same way. As a result, the vibration at the target position was reduced. From this result, the effectiveness and usefulness of the proposed approach was demonstrated.
