Influence of Sound Insulation Evolution on Interior Noise for Subway Rail Vehicle’s Carbody

As the operational service lifespan of subway rail vehicles increased, the sound insulation of the carbody inevitably deteriorated, leading to heightened noise levels inside the vehicles and significantly compromising passenger comfort. Therefore, the impact of the subway carbody’s sound insulation performance on interior noise throughout its service life was studied. The research of this paper was carried out by combining experimental and simulation methods. Through experimental testing, it examined the sound insulation levels of different vehicle components, including the door, side wall and underframe. The carbody sound insulation with different operational lifetimes was obtained. Subsequently, an acoustic simulation model for interior noise in subway vehicles was established via the statistical energy method, and measured data was used to ensure reliability. Finally, based on the simulation model, the interior noise values under different operational service lifespans were obtained. The influence patterns of varying sound insulation performance across different carbody components on interior noise levels were analyzed. The influence of the change in sound insulation over the operational lifespan on the interior noise was obtained. The findings of this paper hold practical engineering significance for developing noise control strategies and maintenance plans for subway rail vehicles.