Vibration propagation analysis in plates using the irrotational intensity field

International audienceStructural intensity is a technique that is used to indicate the magnitude and the direction of vibration energy flow within a structure. In this work, the structural intensity of flat plates subjected to harmonic excitation is conducted using the finite element method. The intensity field provides information on the energy transmission path including the position of the sources and the sinks. However, a rotational component appears that is masking the vibration energy flow and makes its understanding difficult. Thus, a methodology is proposed to filter out the rotational component of the structural intensity field. The approach is based on the decomposition of the structural intensity field into rotational, irrotational and harmonic components. Only the irrotational component is needed to describe the path of vibration energy. The proposed methodology combines a dynamic response computation and a diffusion equation solving. Its efficiency is illustrated on plates, providing a deep understanding of the energy transmission paths at medium and high frequencies