Developing Mechanical Metamaterials Under an Adaptable Topology Optimization Design Framework

Developing mechanical metamaterials through topology optimization attracts high attention in both computational design and engineering applications. However, most of the studies in the literature are of quite limited applicability and poor extensibility. Hence, this work originally established an adaptable metamaterial topology optimization framework through integrating a commercial finite element analysis (FEA) platform. Particularly, the sensitivity analysis was derived and simplified to avoid the complex extraction of internal FEA information according to the strain-energy-based homogenization method. A series of two- and three-dimensional metamaterials with different properties, i.e., bulk and shear moduli, negative Poisson's ratio, were subsequently devised. These optimized metamaterials were fabricated and experimentally tested based on the additive manufacturing, firmly demonstrating the effectiveness of the developed design framework. This well-structured design framework can be conveniently extended to the systematic design of metamaterials with various other exclusive performances, fulfilling the urgent need for metamaterial design methods.