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Fulfilling the current pass-by noise regulation is a challenge for the original equipment manufacturers and their suppliers. And it's not going to improve over time. Any possible ways to reduce the exterior noise can happen to be beneficial. In this context, simulations are natural alternatives to costly and long measurement campaigns to quantify the benefits of acoustic treatments. Nevertheless, modelling procedures to tackle this type of issues are far from being well-established, even though the literature is rich with studies describing the complex processes involved in the tyre–road contact. Very often, when it comes to full-vehicle modelling, tyre sources are replaced by simple sources as monopoles, thus introducing a physical simplification. This paper is concerned with the tyre noise modelling in finite element simulation in the perspective to assess the pass-by noise of a car. For that, the sound radiated by validated velocity maps from a tyre–road noise simulation model at different speeds and for different loads is compared with the noise radiated by monopoles in the close vicinity of the tyres. The aim is to define the limitation related to the use of the monopoles in order to correctly capture the relevant physics in the simulation.

Carbon fiber reinforced polymers (CFRP) are becoming a common solution to minimize the structural weight in aerospace and automotive applications. The dynamic response of such lightweight structures presents higher acceleration levels than equivalent metallic designs. Hence, damping techniques whose performance depends on accelerations like Particle Damping (PD) have a strong potential to damp them. This paper intends to demonstrate how vibrations on CFRP structures can be efficiently damped with PD, resulting in an added weight reduction compared to an equivalent viscoelastic treatment. First, it is analytically put in evidence how the usage of CFRP materials increases the performance of PD on a rectangular clamped plate. This is followed by a parametric study which permitted to improve the performance of the dampers by better understanding their characteristic behavior under vertical excitations. After optimizing the damper design, the paper finishes with an experimental comparison of PD and a viscoelastic constrained-layer treatment on steel and CFRP flat panels, which experimentally shows how the advantage of using PD increases when the CFRP sample is considered.

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