A study on the improvement of sound insulation performance of aluminum chassis

In recent years, the automobile industry has rapidly shifted towards electric vehicles, with an increasing number of vehicles using aluminum instead of steel for a significant portion or the entire or part of the vehicle body. Aluminum body panels reduce sound insulation performance compared to steel panels because they depend on surface density. This situation causes uncomfortable sound environment for vehicle passengers. To address the sound insulation issues associated with lightweight panels, it is necessary to research how to optimize the thickness and weight of interior and exterior car components in order to enhance sound insulation performance. In this study, the acoustic characteristics were initially confirmed by measuring indoor noise while driving a vehicle constructed from two different materials: steel and aluminum, under the same conditions as other parts. In addition, to select a sound absorbing material suitable for the characteristics of the vehicle body material, steel and aluminum panels were installed between the reverberation chamber and the anechoic chamber, respectively, and sound transmission loss was evaluated by combining the various thickness and weight. Based on these results, we decided on a proposed specification (aluminum panel with weight/thickness added) above the basic specification (steel panel with existing sound insulation parts).