구조-음향 연성 시스템의 진동모드에 의한 소음 예측

Abstract

An acoustic domain combined with a flexible structure induces a unique sound field due to the interaction between a fluid and the structure at acoustic-structure boundaries. In this study, the characteristics of the acoustic modes induced by a structural vibration mode were examined, and the acoustic noise from the vibration mode was predicted using a numerical analysis. For this, a reverberation chamber with a shell at one side was constructed as a finite-element model, and the modal parameters of the vibration and acoustic modes were evaluated using an eigenvalue analysis. In addition, the structural vibration and sound pressure caused by a impulse load impacting the shell were analyzed with a time-domain acoustic-structure coupling analysis, and an acoustic mode was analyzed from a specific vibration mode by identifying the vibration and acoustic modal response from the measured responses. The framework for predicting the acoustic mode presented in this study can enhance the understanding of sound pressure induced by vibration. Further, it is expected that this framework could be applied to predict the heavy weight floor impact sound from the vibration of a slab in an apartment.