Vibro-acoustic analysis of a coach platform under random excitation

• Analytical model is developed to predict structural-borne noise inside a cabin.
• Effects of operational speed on the time and frequency responses are studied.
• Track irregularity has a significant effect on the acoustic pressure inside cabin.
• A critical speed is introduced in which maximum pressure level is predicated.
• Spatial distribution of the sound pressure and critical regions are addressed.

Vibro-acoustic analysis of a rail vehicle cabin is presented in this paper. Vehicle is modeled by an air cavity coupled to a flexible floor panel. Analytical procedure is employed to predict the structural-borne noise in the vehicle model generated by random excitation of the panel. In this study, natural frequencies of the coupled system are obtained and then the sound pressure field inside the cavity is analytically determined. In order to find dynamic responses of the coupled system in the time domain, Durbin's numerical Laplace transform inversion algorithm is employed. Convergence of the algorithm is verified and eventually a parametric study is carried out to investigate the effects of rail irregularity and vehicle speed on the time and frequency responses.