대한기계학회:학술대회논문집 (Proceedings of the KSME Conference)
- 대한기계학회 2000년도 춘계학술대회논문집A
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- Pages.591-595
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- 2000
탄성다공성 재질에서 유한진폭 입사음파의 흡음 특성
Sound Absorption Characteristics of Finite-Amplitude Acoustic Waves in Poroelastic Materials
- 발행 : 2000.04.20
초록
Sound absorbing characteristics of poroelastic materials is known to be greatly affected by high intensity acoustic waves. However, this effect has not been considered yet. In this study, the extended semilinear model based on Biot's theory for the porous materials and the characteristics of nonlinear waves in poroelastic sound absorbing materials were introduced. The expressions for the finite-amplitude acoustic plane waves were presented. By combining each nonlinear wave with appropriate matching conditions, we could investigate the effects of finite-amplitude acoustic waves on absorption characteristics of poroelastic materials. In the most ideal case considered in this paper, the absorption coefficient was found to become larger than that of linear incident waves. It was shown that the absorption coefficient became greater especially as frequency goes higher and as distance from the source goes larger. These phenomena may be inferred to result from 'dissipation effects due to nonlinearity'. This finding may have important implications for high intensity noise control.
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