CAE Analysis of Dynamic Stiffness and NTF of Exhaust Attachment Point for NVH Improvement

Dynamic stiffness at vehicle attachment points like powertrain, suspension or exhaust significantly affect excitations being transferred from respective sources to vehicle structure, which in turn affect the NVH performance. Simulation tools can be used to predict and improve attachment location dynamic stiffness and Noise Transfer Function (NTF).

In this paper a case study on the influence of improvement in dynamic stiffness of exhaust attachment point to improve NTF is presented. Correlation of predicted results with test results and design solution through simulation has been developed to improve NTF performance. This was corroborated by experimental results too. The results show that higher dynamic stiffness will generally lead to better NTF, which is a measure of sensitivity to excitation at any attachment location and resulting in cab noise. So for vehicle NVH development, it is prudent to maintain adequate dynamic stiffness at all the attachment locations at the design stage itself.