A novel hybrid intersecting spherical shell mechanical metamaterial

A novel curved mechanical metamaterial was designed by intersecting spherical shells and integrating them with plate lattices. Unlike most existing designs, which feature straight or flat members, the proposed design utilises curved surfaces—a largely underexplored approach. Precisely modulating the degree of spherical shell intersection allowed for tuning the lattice’s mechanical characteristics. Numerical homogenisation revealed that the designed lattice outperforms traditional octet lattices, exhibiting near-elastic isotropy at a relative density of 0.3. The lattices were fabricated using selective laser sintering with polyamide 12 and tested under uniaxial compression. Experimental and numerical investigations demonstrated that increasing the relative density monotonically enhances mechanical performance, shifting the deformation mode from unstable buckling to a more stable regime. Full-field 3D digital image correlation captured and analysed the detailed deformation mechanism, with results validated against numerical simulations. A comparative analysis with existing lattice designs in the literature highlighted the advantages of the hybrid intersecting spherical shell lattice, showcasing its superior mechanical properties and potential for engineering applications.