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This paper shows that the combination of a glass and passive acoustic treatment manufacturers can bring different benefits and considerably improve the interior acoustics of a vehicle. Glazing contributes to the design of the vehicle in addition to its primary role, good visibility and safety. From an acoustic point of view, this brings a challenge for the interior comfort. Indeed, glazing has no absorption and classically has an acoustic insulation weakness around its coincident frequency. In most of the cases, these different aspects make glazing one of the main contributors to the sound pressure level in the passenger compartment, and the trend is not one of change. However, there are possible countermeasures. One of which is the use of laminated glazing with acoustic PVB. This solution allows reducing the loss of insulation performance at the coincidence frequency. The other is the usage of passive interior acoustic trims.

To solve interior rolling noise issues after vehicle development has been finalized, a robust procedure is desired, which combines the strengths of both the experimental and the simulation world. This paper proposes a methodology that is focused on rolling noise issues in the frequency range from 100 to 600Hz and whose core is constituted by a source identification procedure. By means of an inverse method that makes use of the information coming from several microphones, each of the interior areas of the passenger compartment walls is identified as an equivalent source and one can then determine which one is the most contributing to the interior noise under operating condition. This allows a direct and optimized application of countermeasures aimed at the reduction of the interior rolling noise.

This paper describes a new approach for modeling a trimmed vehicle body by blending FEA models of the BIW, the passenger compartment and each individual trim component. The approach bases on the update of modal matrices, transforming the untrimmed body-cavity modal representation into an updated modal model including the effect of the trim configuration on the local and global NVH indicators. Results on simple and more realistic models are presented and show that the methodology fulfills the efficiency and accuracy criteria and is thus to guide the NVH development process.

Dampers (PDs) are passive devices employed in vibration and noise control applications. They consist of a cavity filled with particles that, when fixed to a vibrating structure, dissipate vibrational energy through friction and collisions among the particles. These devices have been extensively documented in the literature and find widespread use in reducing vibrations in structural machinery components subjected to significant dynamic loads during operation. However, their application in reducing vehicle interior sound has received, up to now, relatively little attention. Previous work by the authors has proven the effectiveness of particle dampers in mitigating vibrations in vehicle body panels, achieving a notable reduction in structure-borne noise within the vehicle cabin with an additional weight comparable to or even lower than that of bituminous damping treatments traditionally used for this purpose.