Predicting vibroacoustic performance of thin-walled lightweight structures during conceptual design

Abstract To predict the vibroacoustic performance of complex thin-walled structures, an analysis using a finite element model considering structure–acoustic interaction is often required. The acoustic response of such models can be time-consuming to compute and sensitive to minor design changes. These models can be too computationally intense since fast design optimizations must be performed. Moreover, knowledge of the final design is limited in the conceptual design phase, which implies that detailed modeling and analysis is of less value. It is therefore of interest for engineers to evaluate an efficient conceptual model using a prediction metric that has an acceptable correlation to the acoustic response of the structure. In this paper, we investigate different vibroacoustic prediction metrics for their adequacy to be used in the conceptual design of a thin-walled lightweight structure. As a reference model, we use a finite element model considering structure–acoustic interaction to compute the vibroacoustic performance of an automotive vehicle. We evaluate the adequacy of different prediction metrics for a conceptual model in terms of their correlation to the acoustic response inside the vehicle computed using the detailed reference model. Two measures were determined to have poor performance as prediction metrics: frequencies of the fundamental modes and global stiffness, respectively. However, a significant correlation was demonstrated for a prediction metric based on transfer mobilities.