Generally, heavier noise control treatments are favored over lighter treatments since heavier acoustic materials generally insulate (block) the noise source more effectively. For automotive applications, however, heavier materials cannot necessarily be adopted because of concerns about the total weight of the vehicle. Thus, it is desired to have lighter acoustic materials to mitigate the vehicle interior noise for the purpose of the weight minimization. Acoustical materials used in automobiles have both absorption and transmission characteristics, and there is necessarily a trade off between these two. Therefore, it is important to study the exchange between the absorption and transmission of acoustic materials particularly as it pertains to weight. The idea of trade offs between absorption and transmission performance of noise treatment was introduced in a previous study. Here, a method of weight minimization by adjusting the acoustic properties of a porous layer and a flexible microperforated panel surface treatment to balance the absorption and transmission characteristics to yield the same acoustic performance of conventional (heavier) materials at a lighter weight is demonstrated. This research proves that reducing the weight of noise treatments can be achieved while maintaining acoustic performance equivalent to that of heavier noise treatments by properly balancing the absorption and transmission performance.
Weight minimization, Acoustical treatment, Microperforates, Sound Transmission, Sound absorption
Acoustics and Noise Control
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