FEM aided structural intensity measurement method for thick body

Abstract

Many studies about structural intensity(SI) measurement, which is useful to know transmission paths of the vibration energy in a body, have been reported. 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 paper, a new SI measurement method applicable to thick bodies is proposed. The entire vibration distribution in the structure is calculated by dynamic analysis of the finite element method (FEM) from the partial surface vibration data if the elastic parameters, the sound velocity, sizes of a body under study, and the locations of excitation and absorption are given a priori. The entire SI distribution can be estimated using the results. Based on this method, several SI measurements for thick vibrating bodies have been successfully carried. 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 a priori. The principle and the experimental results are described in the report.