Acoustic Cavity Modal Analysis for NVH Development of Road Machinery Cabins

Abstract

Noise and vibration comfort is a critical design criterion for road machinery. An acoustic modal analysis provides useful insights to understanding interior acoustic characteristics and to developing noise mitigation strategies, to improve operator comfort. In this study, an acoustic cavity modal analysis of a compactor cabin is done by utilizing analytical solution, FEA and experimental measurements. While the analytical method and FEA calculate the normal modes of a rigid-walled acoustic cavity, the physical test measures the acoustic modes in-situ that account for the vibro-acoustic coupling effect between the interior cavity and flexible panels. The discrepancies of resultant modal parameters extracted by testing and simulation are discussed. In addition, the impacts of the seat and steering column assembly on the acoustic cavity modes are also investigated. Last but not least, a local vibro-acoustic behavior of the cab and its relation to the interior booming noise is deeply investigated. From the NVH development standpoint for a practical cabin, the findings of this investigation not only help troubleshooting cabin noise issues but also lead to improvement in virtual acoustical modal predictions and guide the design to achieve a robust NVH performance.