Lightweight design and sound insulation characteristic optimisation of railway floating floor structures

Abstract

Abstract The sound insulation performance of extruded panels used in railway vehicles is critical to control the interior noise, especially in the case of floor panels. To reduce the mass of floating floors and increase its sound insulation performance, a lightweight design instruction approach has been proposed based on the vibration response of each component of the floating floor structures. The total height, length, thickness of the top layer, thickness of the ribs, and thickness of the bottom layer in the typical cross section of the exterior floor are used as variables; the mass of the typical cross section and the averaged sound transmission loss (STL) results in 1/3 octave bands centred from 400 to 3150\u202fHz are used as the optimisation targets; the optimal result of the smallest mass and the largest averaged STL are achieved in commercial software VA One and Isight. The effect of this optimisation scheme on the sound insulation performance of the floating floor is analysed based on the verified STL prediction model. After this optimisation, the results indicate that the mass of the exterior floor structure is reduced by 15.2% compared with the original exterior floor structure, and the averaged STL in 1/3 octave bands centred from 400 to 3150\u202fHz and the weighted STL of the floating floor are increased by 0.8\u202fdB and 1\u202fdB, respectively.