Identification and Optimization of Vehicle Body Modes for Improved NVH Performance

The body structure of a vehicle serves as the foundation for its entire system and plays a crucial role in Noise, Vibration, and Harshness (NVH) performance. Optimizing the body's eigenmodes is crucial for achieving NVH characteristics. Traditional methods benchmark the global modes of competing vehicles to set design targets. While this approach has contributed to improved NVH performance, the relationship between these Body targets and actual vehicle performance remains unclear. Furthermore, the specific modes that most impact NVH are not clearly defined. This study identifies key body modes affecting NVH response and proposes strategies to optimize vehicle body structures for enhanced performance. First, we demonstrate how trimmed body eigenmodes affects the trimmed body response through mode participation factor analysis, identifying trimmed body modes responsible for critical peaks in response. Secondly, Modal Assurance Criterion (MAC) values are used to correlate trimmed body and Body-in-White (BIW) modes, pinpointing critical BIW modes. Optimizing the trimmed body response demonstrates how the critical BIW modes have changed, which are subsequently used to set BIW targets. And we validate the BIW optimization and apply the optimized results to the full vehicle, confirming improvements in response.