Effective Mechanical Properties of 3D Structural Metamaterials

Recent advances in fabrication techniques have enabled the creation of novel materials with enhanced mechanical properties commonly known as metamaterials. They refer to materials consisting of a unit cell tessellated in three orthogonal directions with dimensions scaling down to the nanoscale. The objective of this research was to describe the effective properties of the octet-truss unit cell at different lattice angles and loading directions. The research is composed of three consecutive parts. The first part addressed the analytical derivation of the continuum-based model while including the lattice angle. The second part demonstrated the impact of the lattice angle on its effective properties, namely relative density, effective stiffness, and effective strength. Finally, potential in lattice structure optimization is demonstrated through an experimental study. This work addressed optimizing the structural configuration of the octet-truss, which when combined with favorable size effects, would unlock the full potential of mechanical metamaterials as load-bearing structures.