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Materials Science in Additive Manufacturing                             TPMS for perfect sound absorption




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                                        E















            Figure 15. Acoustic band structure of: (A) Diamond-6 mm, (B) Diamond-12 mm, (C) Diamond-18 mm, (D) Diamond-24 mm, and (E) Diamond-30 mm
            Abbreviation: k”: Bloch wave vector, imaginary part

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            Figure 16. Sound absorption curves of graded primitive (GP) and multicavity GP structures: (A) Type I, and (B) Type II

            wider than that of GP-24 mm-Ⅰ. This result indicates that   3.7. Comparison of sound absorption characteristics
            the sound waves incident from one side of a large unit cell   of TPMS structures
            size can increase the bandgap’s width, which is related to the   The NRC of all of the TPMS structures is displayed in
            impedance-matching mechanism of acoustic metamaterials.  Figure 18. The curves of thickness and NRC of uniform

            Volume 4 Issue 1 (2025)                         15                             doi: 10.36922/msam.5737
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