Topology morphing in lattice structures through tensile buckling

Incorporating, by design, tensile buckling into the macroscopic response of lattice structures offers a novel approach for adaptive (meta-)material/structure development. In this study, we explore the potential of utilizing the simultaneous tensile buckling of adjacent cells to induce a transformation in lattice topology. Unit cells are passively transformed from rectangle-like to triangle/pentagon-like unit cells, with an associated change in the effective macroscopic properties. This approach provides a new route to elastically tailor the non-linear response of (meta-) materials/structures. The paper explores the behavior of such a system through finite element analysis. The results identify: i) that the initial lattice internal topology (rectangular) is dominated by membrane effects, ii) a negative region of stiffness is associated with the transformation phase, and iii) once formed, the new topology (triangular/pentagonal) exhibits positive stiffness in both compression and tension.