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Mechanism of Light Weight Sound Insulation Material Using Thin-film Cells

Article of Honda R&D Technical Review Vol.32 No.1


Weight reduction of the sound insulation material used to enhance cabin quietness is being advanced for the purpose of reducing vehicle weight. Sound insulation material with a structure of double walls with an intermediate layer of porous material between them is frequently used. There are reports from previous research that the use of thin-film cells instead of porous material can maintain similar sound insulation performance while enabling weight reduction. However, since the mechanism of sound insulation by thin-film cells is not clearly understood, in the present research, the question of why thin-film cells possess the same sound insulation performance as porous material was examined, with a focus on the propagation speed of sound waves transmitted through thin-film cells (apparent sound speed). The relationship between sound insulation performance and apparent sound speed was also formulated as an equation in order to obtain adequate sound insulation performance, and a method of deriving the apparent sound speed from the internal structure of the thin-film cells was devised. By means of the above examination of the mechanism, findings were obtained to enable performance design of lightweight sound insulation material using thin-film cells.


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Author (organization or company)

Ikumi KURIHARA(Innovative Research Excellence)、Takashi KONDO(Innovative Research Excellence)、Takao YAMAGUCHI(Gunma University)

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