Treasuri2/FE: A Tool for the FE Simulation of Sound Package Parts Fully Integrated in Nastran 2009-01-2216

Porous materials are extensively used in the construction of automotive sound package parts, due to their intrinsic capability of dissipating energy through different mechanisms. The issue related to the optimization of sound package parts (in terms of weight, cost, performances) has led to the need of models suitable for the analysis of porous materials' dynamical behavior and for this, along the years, several analytical and numerical models were proposed, all based on the system of equations initially developed by Biot. In particular, since about 10 years, FE implementations of Biot's system of equations have been available in commercial software programs but their application to sound package parts has been limited to a few isolated cases. This is due, partially at least, to the difficulty of smoothly integrating this type of analyses into the virtual NVH vehicle development.

This paper presents a tool, called Treasuri2FE, that implements Biot's system of equations and is fully integrated inside Nastran. Treasuri2FE allows including in an efficient and flexible way sound package parts into Nastran vehicle FE models used for NVH analyses. All the steps that are necessary to obtain this, in particular the management of the incompatibility between the FE mesh of the sound package part and the FE mesh of the vehicle, are automatically carried out within Nastran.

Furthermore, the tool can be used in conjunction with Nastran ACMS and DMP, to improve computational efficiency.

In this way, the evaluation of the effect of a sound package part on the vibro-acoustic response of a vehicle can smoothly be introduced into virtual NVH vehicle development, making this important type of CAE analysis available to decision-makers.

The paper presents the tool and its functionalities, together with application examples on full-vehicle models up to 500Hz.