Modeling Three-Dimensional-Printed Polymer Lattice Metamaterial Recovery After Cyclic Large Deformation

Lattice structure metamaterials generally exhibit better stiffness and/or tunable properties than natural materials. They have important applications in mechatronics and tissue engineering areas. In this work, we demonstrate crystal structure-inspired body-centered cubic (BCC)-lattice architected structures using different acrylate-based polymer materials to study the mechanical response in large deformation. Rigid BCC lattice metamaterials manifest outstanding recovery properties after undergoing multi-cycle compression. With appropriate cell wall thickness, the lattices have the capacity to recover their original shape and maintain a degree of stiffness. In further exploration, we combined mechanical tests and digital image correlation to elaborate on the deformation mechanisms. The digital image correlation (DIC) proves that displacement discrepancy exists in local positions. We propose hourglass and twist models to describe the buckling-induced pattern transformation which occurs during cyclic compressive deformation using simulation.