Investigation of mechanical and acoustic behavior of primitive type triply periodic minimal surface structures based sonic crystal in noise control applications

This study includes the mechanical and acoustic properties of primitive type (P-type) triply periodic minimal surface (TPMS) structures with five relative densities (RD_35, RD_40, RD_45, RD_50, and RD_55). The mechanical behavior is evaluated experimentally under uniaxial quasi-static compression test to determine the stress-strain response, young’s modulus, plateau stress, critical stress and energy absorption capacity of the structures. The results shows that increasing the relative density significantly enhances the mechanical properties, following a power-law relationship. Furthermore, the acoustic performance of these structures as scatterers of sonic crystals is analysed through numerical simulations and experimental measurements in the frequency range of 3 kHz - 16 kHz, focusing on frequency band gaps and insertion loss. These structures demonstrate significant sound attenuation and shifting of frequency band gap towards lower frequencies as the relative density increases. Additionally, results showed that increasing the number of scatterer rows (up to four) further enhanced insertion loss performance.