Layered fiber orientation optimization for continuous fiber reinforced polymer additive manufacturing using multi-material topology optimization

With increasing demand for lightweight components in many industries, components must be optimized to save as much weight as possible. One of the main optimization tools employed by designers is topology optimization as it identifies the critical load paths within components. An even more powerful tool is multi-material topology optimization (MMTO) due to it also optimizing material selection in a component. By incorporating material selection into the optimization, new material options can be included to further improve upon the objective. The major drawback of MMTO is that the designs produced are often not manufacturable. Traditionally, these results would be interpreted by designers and modified to produce a manufacturable design. To reduce the amount of changes to the optimal design and simplify the design process, constraints can be made to tailor the optimization result to a chosen manufacturing method. This paper focuses on continuous fiber reinforced polymer additive manufacturing (CFRPAM). Being an additive manufacturing process, CFRPAM is able to realize the complex geometry often seen in topology optimization with little intervention while the continuous fiber reinforcement allows the process to produce high strength components. The research presented in this paper adapts a material model of the continuous fiber reinforced polymer and constrains the optimizer to solutions readily manufacturable with CFRPAM. The resulting methodology achieves simultaneous layered fiber orientation optimization and topology optimization. The method is shown to reduce compliance by up to 22.1% compared to the current industry standard.