Page 37 - MSAM-4-1

Materials Science in Additive Manufacturing TPMS for perfect sound absorption

A B

C D

E

Figure 9. Acoustic band structure of: (A) Gyroid-6 mm, (B) Gyroid-12 mm, (C) Gyroid-18 mm, (D) Gyroid-24 mm, and (E) Gyroid-30 mm
Abbreviation: k”: Bloch wave vector, imaginary part

Table 7. Sound absorption characteristics of primitive and frequency of the primitive structure with the same thickness
multicavity‑primitive is higher than that of the gyroid structure, except for the
structure with a 12 mm thickness. The sound absorption
Specimen Thickness, Frequency Absorption λ peak /T
T (mm) at first at first peak, coefficient of the resonance peak α of Primitive-12 mm,
1
peak, α 1 Primitive-18 mm, Primitive-24 mm, and Primitive-30 mm
f 1 (Hz) are 0.465, 0.505, 0.524, and 0.55, respectively. The α of
1
Primitive-6 mm 6 - - - Primitive-18 mm, Primitive-24 mm, and Primitive-30 mm
Primitive-12 mm 12 5440 0.465 5.32 is 5.6%, 19.5%, and 15.9% lower than that of Gyroid-18 mm,
Gyroid-24 mm, and Gyroid-30 mm, respectively. The
Primitive-18 mm 18 4050 0.505 4.76
Primitive-24 mm 24 2850 0.524 5.08 uniform primitive structures also present a subwavelength
absorption peak, as the λ
/T is >4. The experimental first
peak
Primitive-30 mm 30 2190 0.550 5.29 absorption peak frequency of the Primitive-24 mm structure
Multicavity-primitive 30 2090 0.913 5.54 is 2850 Hz, which is 764 Hz lower than the QWRF.

Volume 4 Issue 1 (2025) 10 doi: 10.36922/msam.5737