Achieving extreme stiffness for beam-plate-shell-combined lattice metamaterial through a multilayer strategy and topology optimization

Abstract

Metamaterials composed of different geometrical primitives have different properties. Corresponding to the fundamental geometrical forms of line, plane, and surface, beam-, plate-, and shell-based cellular lattice metamaterials enjoy many advantages in many aspects, respectively. To fully exploit the advantages of each structural archetype, we propose a multilayer strategy and topology optimization technique to design cellular lattice metamaterial in this study. Under the frame of the multilayer strategy, the design space is enlarged, and the design freedom is increased. Topology optimization is applied to explore better designs in the larger design space. Beam-plate-shell-combined metamaterials automatically emerge from the optimization to achieve extreme stiffness. Benefiting from high stiffness, energy absorption performances of optimized results also demonstrate substantial improvements under large geometrical deformation. The multilayer strategy and topology optimization can also bring a series of tunable dimensions for cellular lattice design, which helps achieve desired mechanical properties, such as isotropic elasticity and functionally grading material property, and superior performances in acoustic tuning, electrostatic shielding, and fluid field tuning. We envision that a broad array of novel synthetic and composite metamaterials with unprecedented performance can be designed with the multilayer strategy and topology optimization.