ヘルムホルツレゾネータを内包した一重壁音響メタマテリアルの 音響透過損失の実験的評価

抄録

To improve the quietness of automobiles, the sound insulation performance of automobile windows is required. However,the design of an automobile window has many restrictions and it is difficult to improve the sound insulation performance. Yamamoto proposed an acoustic metamaterial in which a Helmholtz resonator is periodically encapsulated in a glass plate. Theoretical calculations and numerical analysis show that the proposed acoustic metamaterial plate (AMP) improves the sound transmission loss (STL) at 2.1 kHz resonance frequency of the resonator. In this study, the sound pressure level,acceleration level and STL inside the closed space of a flat plate and AMP are measured by means of vibration and sound insulation tests, and the effectiveness of the proposed AMP is verified. In the vibration test, an AMP was fixed to an experimental jig on an air mount, and the sound pressure level and acceleration level were evaluated by shaking the experimental jig. In the sound insulation test, STL was calculated by measuring the sound pressure inside the device with an intensity probe using a small sound insulation test rig.