A novel membrane-coupled foldable metamaterial with low frequency sound absorption and vibration isolation performance

A novel membrane-coupled foldable metamaterial that incorporates mass blocks for resonant damping is presented in this paper. The sound absorption, compressive strength, and vibration control properties have been studied. The results showed that the foldable metamaterials can achieve low frequency sound absorption while possessing some structural capability. The sound absorption characteristics of the foldable metamaterials were seen to be adjustable by changing the size of the mass blocks on the membranes. Additionally, Finite Element simulations with fluid structural interaction were established to replicate the sound absorption experiments, highlighting the membrane's vibration as the primary source for sound absorption in the foldable metamaterials. The PLA-type foldable metamaterials were found to have better vibration control than an MPP-honeycomb structure while reducing the weight by 66.2 %. The modulus and strength of the CFRP-type foldable metamaterials could reach 233.02 MPa and 3.34 MPa, respectively, 98 % and 486 % higher than those of a conventional honeycomb structure.