2020 年 86 巻 883 号 p. 19-00311
In this paper, sound absorption properties of poroelastic lattice structure are investigated through numerical simulation and measurement. The lattice structures discussed in this paper are composed of slender beams only (BCC) and beams and shells (BCC-S), and can be fabricated by using the selective laser metal melting machine. In our numerical investigation, the homogenization method is used to calculate a macroscopic elastic tensor for a solid phase, an equivalent density and a bulk modulus for a fluid phase. Also, the sound absorption coefficient for normal incidence can be calculated by using these macroscopic parameters. The obtained numerical result of the sound absorption coefficient agrees qualitatively with the experimental result. In particular, it is found that the dense BCC-S structure attains sufficient sound absorption capacity in comparison with other conventional sound absorption materials.
