Development of a Suspended Floor Structure for a Railway Vehicle

The interior noise of a passenger cabin mainly comprises the transmitted noise and structure-borne noise. To reduce the level of the interior noise, new countermeasures against the structure-borne noise from the floor panel are required. In this study, we verified the vibration characteristics of a car body and clarified that the vertical vibration of the side structure is less than that of the floor structure, which supports the floor panel. On the basis of this result, we devised a new floor structure, wherein the floor panels are suspended from the side panel. Moreover, we evaluated the effectiveness of the design by numerical analysis and excitation tests using a test vehicle. Here we outline the suspended floor structure, predict the noise reduction effect by numerical analysis, test the vibration reduction effect, and compare the results with those for a conventional fixed floor structure in a Shinkansen-type test vehicle.