Development of the estimation method of energy flow path inside the 3-dimensional structure using surface velocity data and finite element method

结构强度测量有助于了解振动能量在物体中的传递路径，目前已有大量的研究报道。然而，由于很难测量厚结构的内部振动分布，大多数工作只针对薄体，如梁或板。在本研究中，我们提出了一种新的适用于厚物体的SI测量方法。在已知被研究物体的密度、声速、尺寸以及激励和吸收位置的情况下，利用有限元动力分析方法对结构的局部表面振动数据进行动力分析，得到结构的整体振动分布。可以使用结果来估计整个SI分布。基于这种方法，我们成功地对厚振动体进行了多次SI测量。这种方法的优点是：(1)只需要结构的表面振动数据就可以估计整个SI分布。(2)如果先验满足上述条件，则适用于任意三维结构。在研究中，还考察了测量误差和所需测量数据量的影响。

Many studies about structural intensity (SI) measurement, which is useful to know transmission paths of the vibration energy in a body, have been reported until now. Most of the works, however, have been done only for thin bodies, such as beams or plates because of the difficulty in measuring interior vibration distribution in thick structures. In this research, we propose a new SI measurement method applicable to thick bodies. The entire vibration distribution in the structure is calculated by dynamic analysis of finite element method (FEM) from the partial surface vibration data if the density, the sound velocity, sizes of a body under study and the locations of excitation and absorption are given apriori. The entire SI distribution can be estimated using the results. Based on this method, we have successfully carried several SI measurements for thick vibrating bodies. The merits of this method are as follows: (1) Only surface vibration data of the structure is needed to estimate the entire SI distribution. (2) It is applicable for arbitrary 3-D structures if the conditions mentioned above are satisfied apriori. In the research, the influence of the measurement error and the required number of the measurement data are also investigated.