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NVH simulations for an automotive component industry represent a convenient mean to compare different solutions and make decisions on design choices based on the predictions of the component vibro-acoustic behavior. This paper presents the vibro-acoustic characterization and comparison of two fuel rail assemblies (FRAs) by mean of simulations in Ansys Workbench & LMS Virtual.Lab. These simulations required a preliminary finite element (FE) modal analysis on the FRAs. To verify the reliability of the FE models, an experimental modal analysis was performed on one of the two fuel rails in free-free condition. The correlation between FE and test models highlighted some differences: a sensitivity study proved that the differences depend on the modeling of some brazed joints. The results of the following NVH simulations were checked by performing an acoustic impact test on the two FRAs in free-free condition inside an anechoic chamber.

Hand-transmitted vibration may be a cause of discomfort for two-wheeled vehicles. While there are international standards for the assessment of comfort in whole-body vibration exposure, there are not equivalent guidelines for hand transmitted vibrations. The present study analyzes accelerometer data acquired in road testing with various approaches in order to compare different criteria that could be adopted for comfort assessment in two wheeled vehicles. The ISO standard 5349-1986(E), which is specific for health risks, uses the maximum acceleration of the surface in contact with the hand, suitably weighted. But many researchers suggest particular weight functions and also energetic approaches (transmitted and/or absorbed energy). The effects of the grip force and of the speed of the vehicle have also been considered.