Directional long-frequency phase wave propagation characteristics, anisotropy, and effective yield surfaces of architected spinodal constructs

This work explores the directional long-frequency phase wave propagation characteristics, anisotropy, and multiaxial loading yield surface property of spinodal architectures, for the first time. Here, the theoretical model is developed for directional long-frequency wave propagation in three-dimensional (3D) anisotropic spinodal architecture and spinodal-reinforced interpenetrating phase composites (IPCs), and then verified by 3D finite element method (FEM) with a good agreement found. Based on the directional wave propagation profile, the anisotropic magnitude of spinodal architectures is captured and analyzed. Wherein, the effect of varying relative density, propagation plane, and matrix phase architecture property on directional wave propagation properties of the spinodal structure, IPCs, and anisotropy is explored. Furthermore, numerical homogenization is presented to compute the yield strength of spinodal topology, and verified by experiment in terms of effective stiffness and yield stress with an agreement found. Two well-established constitutive laws including extended Hill's model and D-F model are used to derive the macroscopic analytical function for multiaxial yield response of spinodal architectures. Our findings show that lower relative density leads to a lower phase wave velocity and a higher anisotropic magnitude of the spinodal topology. Interpenetrating soft phase materials in spinodal architecture can help reduce the wave velocity as well as the adversity wave energy generated by harmful sources such as impact, shock, sound, etc. The analytical functions based on considered constitutive laws exhibit an ability to fit the multiaxial yield stress data, but the function based on extended Hill's model demonstrates a better fit compared with that based on D-F model.