Search Results

Finite element (FE) based simulations for fully trimmed bodies are a key tool in the automotive industry to predict and understand the Noise, Vibration and Harshness (NVH) behavior of a complete car. While structural and acoustic transfer functions are nowadays straight-forward to obtain from such models, the comprehensive understanding of the intrinsic behavior of the complete car is more complex to achieve, in particular when it comes to the contribution of each sub-part to the global response. This paper proposes a complete target cascading process, which first assesses which sub-part of the car is the most contributing to the interior noise, then decomposes the total structure-borne acoustic transfer function into several intermediate transfer functions, allowing to better understand the effect of local design changes.

In the automotive industry, acoustic trim components are playing an essential role in vehicle Noise, Vibration and Harshness (NVH). They act in three different ways: reducing the structure vibration, absorbing incident acoustic waves and reducing both the structure-borne and air-borne noise transmission. Mastering acoustic trims is key for interior acoustic comfort, a major differentiator in terms of customer appreciation. An elegant and efficient way to solve trimmed vehicle models numerically is the well documented and widely used Reduced Impedance Matrix (RIM) method. It solves the structure and cavity in modal coordinates, while the acoustic trim components are solved in physical coordinates where their complex damping behavior can be fully captured. This method is very accurate to compute structure and cavity results but couldn’t initially recover data such as pressure or displacement inside the acoustic trim parts.