Multiscale concurrent topology optimization for large-scale assembled structures

Abstract

Although additive manufacturing has advantages in the fabrication of complicated structures and has been applied in many fields, large-scale structures often need to be partitioned into smaller components to comply with the size limitations of the printer, which compromises their overall structural performance. This paper presents a two-scale concurrent topology optimization method for multiple assembled structures, which can be fabricated with an additive manufacturing machine under maximum size limitations and further assembled via conventional joining processes. At the macroscale, the topology design of the macroscale structure and the partitioning of the overall structure into multiple components are realized by incorporating component size constraints into the Solid Isotropic Material with Penalization (SIMP) topology optimization framework. At the microscale, the topology of the self-connected microstructure unit located in the macroscale components and the bolted joint positions of the assembled microstructure unit located in the macroscale joints between different components are optimized based on the homogenization method. The smooth connection between the self-connected microstructure and the assembled microstructure is ensured by a geometric constraint. Finally, several numerical examples and a printing example are provided to illustrate the effectiveness of the proposed method, and the effects of some design parameters on the optimization results are analyzed.