An Efficient Modeling Approach for Mid-frequency Trim Effects

In traditional FE based structure-borne noise analysis, interior trims are normally modeled as lump masses in the FE structure model and acoustic specific impedance of the trim is assigned to the FE acoustics model when necessary. This simplification has proven to be effective and sufficient for low frequency analysis. However, as the frequency goes into the mid-frequency range, the elastic behavior of the trim may impose some effects on the structural and acoustic responses. The approach described in this paper is based on the structural FE and acoustic SEA coupling analysis developed by ESI, aiming to improve the modeling efficiency for a possible quick turnaround in virtual assessments. The idea is to reassemble the FE-SEA hybrid analysis results for the trimmed condition by combining radiated sound power from untrimmed body structure with trim component absorption, insertion loss data and other necessary information which can be extracted easily and quickly from an untrimmed FE model, and/or SEA model.