Collapse Surfaces Of The Octet-Truss Lattice At Different Lattice Angles

Abstract

Cellular materials are found extensively in nature such as wood, honeycomb, butterfly wings and foam-like structures like trabecular bone and sponge. This class of materials proves to be structurally-efficient by combining low weight with superior mechanical properties. Recent studies have shown there are coupling relations between the mechanical properties of cellular materials and their relative density. Due to its favorable stretching‐dominated behavior, continuum models of the octet‐truss were developed to describe its effective mechanical properties. However, previous studies were only performed for the cubic symmetry case where the lattice angle 𝜃�=45°. In this work, we study the impact of the lattice angle on the effective strength of the octet-truss. A graphical method is utilized to plot the collapse surfaces for plastic yielding and elastic buckling for different loading combinations at different lattice angles. Generally, the (𝜎�̅𝑥�𝑧�,𝜎�̅𝑧�𝑧�) loading space is preferable for lattice angles greater than 45°, while the (𝜎�̅𝑥�𝑥�,𝜎�̅𝑦�𝑦�) loading space is preferable for lattice angles lower than 45°.