Low-frequency sound absorption performance of TPMS-based micro-perforated panel sandwich structures

TPMS-based structures have captured significant attention due to their excellent mechanical properties and potential for sound absorption. However, existing research has primarily focused on their high-frequency acoustic performance, while the low-frequency domain remains underexplored. To address this research gap, the present study selected three TPMS configurations—D-type, G-type, and F-RD-type—and fabricated six variants with diameters of 100 mm by adjusting the relative density control parameter ( C = 0.2 and C = 0.4) using selective laser melting. These samples were subsequently combined with micro-perforated panels to form a novel sandwich structure, aiming to overcome the challenge of low-frequency sound absorption of TPMS structures. Theoretical and numerical models were developed to describe the sound absorption performances of the proposed MPP-TPMS sandwich structures, and the validities were confirmed through experiments. A systematic analysis was implemented to study the influence of configuration type, relative density, and micro-perforated plate thickness on the acoustic absorption behaviors. The results indicate that the predicted sound absorption from the simulation model exhibits strong consistency with the experimental measurements. All three configurations are found to exhibit a typical single-peak resonant sound absorption characteristic within the low-frequency regime. Under identical geometric parameters, the D-type configuration attains a peak sound absorption coefficient of up to 0.93, while the F-RD type configuration possesses the widest sound absorption bandwidth of 190 Hz. As the relative density control parameter is elevated from 0.2 to 0.4, the peak absorption frequency undergoes a shift toward the high-frequency range, with both the peak absorption coefficient and the absorption bandwidth demonstrating a monotonic increasing trend. An increase in the thickness of the micro-perforated plate leads to a downward shift of the peak absorption frequency and an enhancement of the peak absorption coefficient, accompanied by a diminishment of the absorption bandwidth. The results of this study presented a valuable theoretical basis for the engineering application and parameter optimization of TPMS sandwich structures in low-frequency sound absorption.