Stiffness-based optimization framework for the topology and fiber paths of continuous fiber composites

Recent advancements of additive manufacturing technology have enabled the fabrication of complex geometries and fiber placement along customized paths. The proposed approach introduces a novel framework for the optimized topology and the fiber paths in order to create variable stiffness designs. The optimized distribution of the material is achieved by two different methods: a density-based method and a level-set method for orthotropic materials. The fiber orientation of each element or the fiber path is considered as the design variable. The optimized orientation is obtained using an energy-based method and a level-set based method. In addition to a fiber angle filtering scheme, three new approaches for the design of fiber infill pattern are introduced to enforce the fiber path continuity across the domain, ensure manufacturability, and achieve reduced compliance. The effects of fiber infill pattern techniques on the compliance is demonstrated in three benchmark case studies.