Keywords: vehicle dash, sound transmission loss, STL, structure–sound interaction, sound contribution, sound treatment, structural optimisation, vehicle noise, acoustic response, acoustic performance
Sound treatment and structural optimisation for acoustic performance of front dash with sound contribution
Dash of the vehicle poses an important role in attenuating the sound radiated from the engine cabin. The acoustical performance of a vehicle dash system is determined by the sound transmission loss (STL). Computational modelling of such system poses challenge due to the complexity of the material properties as well as geometry. In the analysis, a numerical method with structure–sound interaction is adopted to calculate STL of the dash. The whole dash has divergence of STL performance between different sections due to a lot of factors including the construction of structure and modal shape. With the critical regions and frequency ranges for STL performance pinpointed by sound contribution method, the way of improving the acoustic performance has been investigated through sound treatment and structural optimisation, which leads to the discovery that either approach has the distinct enhancement to the STL of the system and inevitable deterioration exists.