Impact of parametric variation to achieve extreme mechanical metamaterials through topology optimization

Abstract

Metamaterials are manufactured structures having extreme properties which do not exist in nature. Topology optimization (TO) provides an excellent alternative to the intuition-based homogenization approach used in commercial packages for automating the design of metamaterials. However, multiple topological parameters must be decided to get the tailored effective properties. This research aims to study the optimum parameters to be used in TO for developing incompressible material. To achieve this, we design microstructures to maximize the bulk modulus. A number of parametric studies are performed by varying topological control parameters such as volume fraction, penalization power, filter radius, mesh size and initial design. In addition to this, the combinations of these parameters are also investigated. These studies will be helpful for the design of incompressible metamaterials. The bulk modulus for topologically optimized designs approaches the Hashin–Shtrikman upper bound (HSUB). The results show that appropriate parameter selection can significantly improve the microstructure’s incompressibility. Such materials can have potential applications in designing aerospace and energy-absorbing components.