Abstract
The propagation paths of the vibration that generates in the mechanical structure are searched using the vibration intensity defined as "the vibration energy that passes through the unit cross section and the unit width in the unit time". Excitation sources are also identified. Propagation paths of different type such as the straight type, the meander type and the vortex type are found in a thin rectangular plate. In order to make clear the generating mechanism of the propagation paths, phase relation in natural mode between the excitation point and the damping point is investigated.
