Mechanical and sound absorption properties of AlSi10Mg metamaterials reinforced by hollow column and plate structures produced by selective laser melting

With the rapid development of rail transit, how to achieve structural light weighting while improving the energy absorption and acoustic absorption performance of structure, thereby providing better safety and comfort, has received widespread attention. This paper proposes a structure called built-up board lattice structure (BBLS), which combines the hollow column structure with the triply periodic minimal surface (TPMS) primitive structure and panel structure. Firstly, lattice metamaterials of AlSi10Mg were fabricated using the selective laser melting (SLM) process. In terms of mechanical performance, the BBLS with a relative density of 26.5% were 33.44% (compressive strength) and 42.19% (specific energy absorption) higher than TPMS-P. The yield strength, compressive strength, and energy absorption of the structures were compared at 26.5%, 33%, and 39.5% porosities. The Gibson-Ashby model was proposed, enabling the prediction of BBLS strength at varying densities. ABAQUS numerical simulations were used to verify the stress distribution of the metamaterials under compression. In terms of acoustic properties, a frequency range of 1000Hz–3500Hz was selected as the test frequency. A hollow column structure was introduced, which increased the peak sound absorption coefficient and the bandwidth where the sound absorption coefficient is greater than 0.5 by 61.8% and 44.8%, respectively, compared to TPMS-P. Numerical simulations using COMSOL demonstrated that the significant improvement in sound absorption performance is attributed to the substantial thermo-viscous losses generated on the inner walls of the hollow column structure. This study provides a new design concept for structures that combine mechanical and acoustic properties.