Analyzing Effects of Cell to Chassis Technology on Sound Transmission Loss of Skateboard- Sharing Vehicles

Limited published research has critically examined the impact of Cell-to-Chassis (CTC) structures on the Noise, Vibration, and Harshness (NVH) performance of electric vehicles (EVs), with most studies focusing on conventional Cell-to-Pack (CTP) systems. A concern is that vehicles employing CTC architectures may exhibit compromised NVH performance due to the absence of a dedicated floor panel. To investigate the NVH performance implications of the CTC structure, this study adopts a comprehensive methodology encompassing: (1) theoretical Sound Transmission Loss (STL) analysis utilizing mass law and double-panel principles, (2) finite element (FE) modeling of STL, (3) in-vehicle Acoustic Transfer Function (ATF) testing, and (4) interior noise measurements conducted at a constant 60 km/h on a smooth asphalt road. Simulation results demonstrate that, compared to a conventional CTP floor system, the studied CTC structure achieves a 5–40 dB increase in STL across the 200–2000 Hz frequency range. This finding is consistent with theoretical calculations. Furthermore, experimental results from in-vehicle ATF and interior noise tests reveal no significant acoustic difference in the 400–1400 Hz frequency range, which is primarily associated with tire noise, between a configuration with complete floor insulation (including carpeting) and one with insulation (including carpeting) removed from the CTC area. This research validates an effective simulation method for floor system STL and demonstrates that the acoustic insulation performance of the CTC structure enables potential cost and weight reductions by minimizing the requirement for traditional carpeting and sound insulation pads. This approach also suggests a pathway to reducing Volatile Organic Compound (VOC) emissions from these ancillary materials.