Curved-crease origami foldcore sandwich structure with combined sound absorption and load-bearing capabilities

This paper proposed an ultra-lightweight and multifunctional sandwich structure with a micro-perforated plate and curved-crease origami foldcore. It not only exhibits excellent sound absorption capability in the medium-low frequency ranges but also possesses a notable load-bearing property. The volume equivalent method was proposed to compute the sound absorption coefficient of the structure. A theoretical method was introduced to calculate the different strengths of the foldcore. Simultaneously, FEA was implemented on the structure to calculate its acoustic and mechanical properties. Subsequently, a specimen was manufactured and tested to validate the theoretical models and FEA. Good agreement was obtained between experimental, theoretical, and FEA results. Finally, the influence of geometric parameters on acoustic and mechanical performance of the proposed structure was investigated. The results demonstrate that optimized geometric parameters enable the proposed structure to achieve effective sound absorption within 500–1400 Hz range and a peak sound absorption coefficient of 0.999 at a specific frequency, coupled with a significant enhancement in unit mass bearing stress from 11.35 MPa/g to 37.95 MPa/g. An Ashby diagram further highlights the superior mechanical performance of the structure under lightweight conditions compared to other designs. Consequently, the proposed sandwich structure, which combines acoustic and mechanical capabilities, demonstrates significant potential for engineering applications.