Investigating the mechanical behavior of the infinity structure inspired by the silkworm cocoon and comparing it with the rod structure for use in architectural cellular structures

Open cell structures are architectural cell structures with a determined periodic geometry that can be designed parametrically based on mathematical models or simulations of nature. The silkworm cocoon can be used as a natural structure to design open structure cells. The silk cocoon consists of a hierarchical structure with multiple functions, which have evolved over millions of years to create optimal conditions for metamorphosis and preserving the life of the insect against Predators. In this article, inspired by the infinite loop structure used by silkworms in making cocoons, open cell structures were designed to investigate mechanical properties. For this purpose, based on Maxwell's formula in the design of rod open cell structures, different samples consisting of straight rods or infinity ring structures with different parameters were made using FDM 3D printing method. After manufacturing the parts, the axial tensile stress test was performed on the samples. The obtained results showed that the cell structures designed based on the rings used in the silkworm cocoon are non-isotropic single layers. Although the infinite cell structures have a lower tensile modulus and strength, the larger elastic strain and the gradual process of failure, and as a result, the conversion of the tensile modulus to bending in this structure, is considered one of their important advantages, which are used in various applications such as building sandwich panels that bear the duty They don't have the burden, they can be noticed.