FEM Aided Structural Intensity Measurement for a Thick Body

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. In the method, the entire vibration distribution in the structure is estimated form limited number of the measured partial surface vibration data with the aid of dynamic analysis of finite element method (FEM). The entire SI distribution is calculated using the estimated vibration and stress distributions. Several SI measurements for thick vibrating bodies have been successfully carried out by the proposed method.