Enhancing compressive mechanical properties of anisotropic shell-based architected materials

Anisotropic architected materials offer significant advantages in expanding the design space of mechanical properties. However, anisotropic design for tailored compressive mechanical properties has remained limited due to the lack of comprehensive studies on large compressive deformation of anisotropic architected materials. In this paper, we designed and fabricated shell-based spinodoid architectures with highly tunable anisotropic mechanical properties and explored the mechanisms by which anisotropy affects the scaling laws for compressive mechanical properties. The results show that anisotropy can regulate the material arrangement within the architectures respect to load direction, enabling a wide range of scaling law exponents from 1.03 to 1.77. Further deformation analysis reveals that architectures with high anisotropy undergo global buckling, while direction-independent architectures exhibit localized deformation during compression. Architectures with specific anisotropic properties exhibit a broad design space at a fixed relative density and demonstrate superior effective modulus across a wide range of relative densities compared to traditional direction-independent lattice and shell-based architectures. Finally, by quantifying the geometrical anisotropy using the Mean Intercept Length (MIL) method, a generalized scaling law is derived to predict the compressive mechanical properties of anisotropic architected materials. This work offers innovative solutions for expanding the design space and enabling direction-dependent applications.