Abstract
The design optimisation of lattice metamaterial unit cells for enhanced properties has
been a central theme in current studies. This study contributes to this cause through
the development of modified re-entrant structure geometries. Through geometric
tailoring and hybridisation of the conventional re-entrant lattice structure, three
novel geometries have been developed, and their respective mechanical properties
and deformation behaviour under in-plane compressive loading have been investigated
using numerical modelling through the finite element analysis technique. Model
3, which comprised a centrally placed auxetic star shape fused onto the re-entrant
structure, demonstrated higher stiffness and greater energy absorption properties.
Model 1, which comprised a cellular arranged star with double arrow-head auxetic
structures around the walls of the re-entrant geometry, demonstrated a lower stiffness
with unique elasticity. Model 2, which consisted of an integrated rib comprising
different auxetic geometries, demonstrated functionally graded deformation behaviour
suitable for tailored mechanical properties. Models 1 and 3 displayed unique
properties as a result of the resulting load paths and deformation models associated
with each geometric configuration. The findings offer valuable insights for guiding
future research aimed at optimising re-entrant lattice structures for tailored mechanical
properties. The demonstrated improvements provide a strong foundation for
exploring additional design variations.