The Integral Boundary Method for the analysis of mid-frequency NVH problems

In the NVH analysis of car structures, there are manifold applications dealing with fluid-structure coupling and vibro-acoustic responses affected from uncertainties especially in the mid- and high frequency range. In this paper a probabilistic formulation based on BEM, able to account for the uncertainties in the geometric description of structures, is presented. The starting point is the classical integral boundary formulation, introducing a probabilistic description of the boundaries, which is solved in terms of expected values. The method, named SIF, can be applied to both acoustic domains and structures. In this paper some application of this method to 2D systems are reported. When dealing with systems made of components which exhibit different vibro-acoustic behaviour as a function of frequency, the probabilistic formulation can be coupled with deterministic methods, like FEM and BEM, to obtain a consistent formulation. The results obtained coupling the SIF with BEM or FEM, and solving some mid-frequency problems are reported in this paper. Those results prove that the application of the boundary element method to NVH problem, affected from uncertainties, leads to relevant results.