Multi-scale topology optimization considering fiber orientation for lattice structures

This paper presents a novel multi-scale topology optimization method that considers fiber orientation for designing lattice structures composed of multiple lattice microstructures, where dissimilar lattice microstructures are effectively connected by designable interface microstructures. Specifically, the topologies and base material fiber orientations of the lattice and interface microstructures, along with their distribution within the macrostructure are concurrently optimized. At the microscale, a density-based method is employed to characterize the material distribution within microstructures. Unlike previous studies that restrict the base material to the isotropic domain, this paper considers anisotropic fiber-reinforced composites and integrates fiber orientation optimization. The homogenization method is used to evaluate the effective material properties of lattice microstructures. At the macroscale, different lattice microstructures with distinct predefined volume fractions are treated as separate materials. The discrete material optimization method is applied to determine the optimal layout of the lattice microstructures within the macrostructure. Several numerical examples are provided to demonstrate the effectiveness of the proposed method.