Metastructure with torsion-compression coupling behaviors: Additive-manufacturing, experimental and numerical investigations

A novel cylinder shell lattice structure with torsion-compression/tension coupling (TCC) effects composed of curved ligaments was designed, manufactured, and tested. The deformation mechanisms were investigated based on experiments and finite element simulation, and a systematic parametric investigation was conducted to study various factors influencing the torsional buckling behaviors and TCC effects. The TCC metastructures were fabricated with hybrid process including 3D printing and casting mould involving the application of polyurethane elastomer material. Compared with the design of compression-torsion coupling (CTC) structures, torsion was taken as the active loading mode in this article. The results show that different torsional behaviors can be obtained by altering microstructure parameters. And the main cause of TCC effects is stretching or bending of curved struts along the axial direction. This study is deemed to be helpful in the design of torsional metamaterials, which can be useful in flexible electronics, customized micromachine, and biomechanical devices.