Sound transmission loss and bending properties of sandwich structures based on triply periodic minimal surfaces

Abstract

Four types of triply periodic minimal surfaces sandwich structures (TPMS-SS), namely, G-SS, D-SS, D1-SS, and IWP-SS, have been proposed. The bending properties were evaluated by experiments and numerical simulations, and their sound insulation performance was investigated using theoretical, numerical and experimental methods. Firstly, the bending performance of four TPMS-SS was compared. Then, the acoustic vibration control equation of TPMS-SS was established and the theoretical solution for the sound transmission loss (STL) was derived based on Reissner's theory combined with the fluid-solid coupling condition. Next, experimental study was conducted on the STL performance of TPMS-SS using the impedance tube method, and the numerical model was verified using theoretical and experimental results. Finally, parametric studies were carried out to investigate the effects of parameters such as relative density (RD), panel thickness (hf), and sound incidence elevation angle (φ), as well as the type of structure, on the STL performance. The results show that TPMS-SSs can achieve >30 dB of STL in the frequency range of 1 Hz to 10 kHz. The STL value increases with relative density (RD), panel thickness (hf), and sound incident elevation angle (φ), while the location of the dips in the STL curves is affected by relative density and panel thickness. G-SS has the best bending performance, while D1-SS has the best acoustic performance. The results could be used for the optimization design of lightweight sandwich structures.