Abstract
Aluminum hollow structure is adopted to railway carbodies to improve specific stiffness, but the acoustic transmission loss property of the hollow structure has not been examined in detail. We study the transmission loss with numerical analysis technique, and find out that the transmission loss is worse than the single plate with equivalent mass at the frequency, at which the 1st vibration mode of each plate element separated by rib is excited. This phenomenon occurs to arbitrary cross section structure with rib, therefore it is not easy to simultaneously improve the specific stiffness and the acoustic transmission loss property. We find that the numerical analysis result coincides with experiment data very well.
